VOL 82 (2017)

COMMUNICATIONS IN AGRICULTURAL AND APPLIED BIOLOGICAL SCIENCES

Formerly known as

MEDEDELINGEN FACULTEIT LANDBOUWKUNDIGE EN TOEGEPASTE BIOLOGISCHE WETENSCHAPPEN

Publishers

PROF. GUY SMAGGHE PROF. STEVEN SLEUTEL

DR. JAN BAETENS PROF. EVELINE VOLCKE

Editorial address

Coupure links 653 9000 Gent (Belgium)

ISSN 1379-1176

The results published in this book of abstracts are under the full responsibility of the authors. The organizing committee cannot be held responsible for any errors in this publication and potential consequences thereof.

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PROCEEDINGS

22ND NATIONAL SYMPOSIUM ON

APPLIED BIOLOGICAL SCIENCES

FACULTY OF BIOSCIENCE ENGINEERING

KU LEUVEN FEBRUARY 7TH, 2017

Website

www. nsabs2017.be

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ORGANIZING COMMITTEE KU Leuven – host institute 2017: Barbara De Coninck, Bram Van den Bergh, Eline Vanuytrecht, Liesbeth François, Mariya Petrova and all the volunteers of the (FR)ACTIE association Universiteit Antwerpen: Dieter Vandenheuvel, Jelle Hofman Universiteit Gent: Jan Baetens, Chris Callewaert, Caroline Van der Heyden Vrije Universiteit Brussel Julien Cousin Saint Remi, Kris Pauwels, Wim De Malsche Université Catholique de Louvain Valentin Couvreur, Xavier Draye, Gauthier Lequeue Université de Liège: Hélène Soyeurt, Jérôme Bindelle Université Libre de Bruxelles: Christian Hermans REVIEWER COMMITTEE KU Leuven: Barbara De Coninck, Bram Van den Bergh, Eline Vanuytrecht, Liesbeth François, Mariya Petrova, Trees De Baerdemaeker, Niels De Brier Universiteit Antwerpen: Ingmar Claes, Jelle Hofman, Tom Tytgat, Dieter Vandenheuvel, Erik Van Eynde, Sammy Verbruggen, Karen Wuyts Universiteit Gent: Jan Baetens, Chris Callewaert, Caroline Van der Heyden, Aisling Daly, Michiel Stock, Steffie Van Nieuland Université Catholique de Louvain: Valentin Couvreur, Sixtine Passot, Gauthier Lequeue Université de Liège: Hélène Soyeurt, Jérôme Bindelle, Angélique Léonard, Jean-Micel Romuee, Benoit Mercatoris, Magali Deleu, Georges C. Lognay, Université Libre de Bruxelles: Vrije Universiteit Brussel Julien Cousin Saint Remi, Kris Pauwels, Wim De Malsche, Damya Laoui, Yann Sterckx Diagenode Geoffrey Berguet

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ACADEMIC SUPPORT The National Symposium on Applied Biological Sciences (NSABS2017) is jointly organized by the following institutes:

- Faculty of Bioscience Engineering, KU Leuven - Department of Bioscience Engineering, University of Antwerp - Faculty of Bioscience Engineering, Gent University - Faculty of Bioscience Engineering, Université Catholique de Louvain - Earth and Life Institute, Université Catholique de Louvain - Université Libre de Bruxelles - Université de Liège - Faculty of Scince and Bioscience Egineering, Vrije Universiteit Brussel

WEBSITE www.nsabs2017.be ACADEMIC AND GOVERNMENTAL FINANCIAL SUPPORT The organizing committee of NSABS2017 is grateful for the financial and logistic support by the following institutes and their doctoral schools:

- KU Leuven - UAntwerp - VUB - UGent - ULB - UCL - ULg - UGent Doctoral Schools (Bioscience) Engineering - YouReCa - FNRS Graduate School on Environmental Sciences, Technologies and Management

(ENVITAM) - FNRS Graduate School on Agricultural Sciences and Biological Engineering (EDT-SCAIB) - FNRS Graduate School in Plant Sciences - Vlaamse overheid - Vlaanderen in Actie - Richting Morgen (Vlaamse overheid)

ENVITAM

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INDUSTRIAL SPONSORS

The NSABS2017 organizing committee is extremely grateful for the financial support received from VWR:

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PROGRAM

22nd NATIONAL SYMPOSIUM ON APPLIED BIOLOGICAL SCIENCES

08.30-09.10

Registration

09.10 – 09.20

Welcome

(Aula BMW1- ON2 04.223)

09.20 – 10.05

First keynote talk – Prof. Kevin Verstrepen, KU Leuven & VIB

“Generating superior industrial yeasts”

(Aula BMW1- ON2 04.223)

10.05 – 10.50

Second keynote talk – Dr. An Michiels, Global Head of Research Bayer CropScience Vegetables

“Innovitation”

(Aula BMW1- ON2 04.223)

10.50 – 11.15

Coffee break

(Foyer)

11.15 – 12.55

Thematic parallel oral presentations

(Aula BMW1, Aula BMW3, Aula BMW4)

12.55 – 14.15

Poster session and lunch break

(Foyer)

14.15 – 16.15

Thematic parallel oral presentations

(Aula BMW1, Aula BMW3, Aula BMW4)

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16.15 – 17.15

Poster seesion and coffee break

(Foyer)

17.15 – 17.30

Closing remarks and awards

(Aula BMW1- ON2 04.223)

17.30 – … Network reception

(Foyer)

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THEMATIC PARALLEL ORAL PRESENTATIONS

Session 1.1: Food technology and Industrial Microbiology p. 1

Chair: Abram Aertsen (Aula BMW1 - ON2 04.223)

11.15-11.35 Impact of storage factors on colour changes of pasteurised strawberry juice: a kinetic study. Carolien Buvé (KU Leuven)

11.35-11.55 Screening of rheological properties of various microalgae species towards their application in food products Tom Bernaerts (KU Leuven)

11.55-12.15 The role of acetic acid bacteria in lambic beer production processes is underestimated Jonas De Roos (VUB)

12.15-12.35 Exploring Dunaliella salina as single cell protein (SCP): the influence of light/dark regime on the growth and protein synthesis Yixing Sui (UAntwerp)

12.35-12.55 Evolution of the metabolite profiles of coffee beans under various post-harvest processing methods Sophia Jiyuan Zhang (VUB)

Session 1.2: Environment and Agriculture p. 10

Chair: Xavier Draye (Aula BMW3 - ON2 04.216)

11.15-11.35 Is soil pore structure control on substrate decomposition manifested through N availability? Peter Maenhout (UGent)

11.35-11.55 Partitioning selection and complementarity effects to understand overyielding in tree diversity experiments Thomas Van de Peer (KU Leuven)

11.55-12.15 Iron coated sand/glauconite filters for phosphorus removal from artificially drained agricultural fields Stany Vandermoere (UGent)

12.15-12.35 Tunisian dairy farmers’ perceptions of climate change impacts and options for adaptation Hajer Amamou (ULg)

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12.35-12.55 Extraction and connection of artificial drainage networks in agricultural areas using LiDAR data Jennifer Roelens (KU Leuven)

Session 1.3: Chemistry and Engineering p. 16 Chair: Wim De Malsche (Aula BMW4 - ON2 04.212)

11.15-11.35 Cu-Ni pyrazolate frameworks as heterogeneous catalysts for the synthesis of neuroactive molecules Francisco García Cirujano (KU Leuven)

11.35-11.55 A study of the ZIF-8 zeolitic imidazolate framework as adsorbent for volatile organic compounds detection and removal Thomas Virdis (VUB)

11.55-12.15 Spatio-temporal modelling of filter cake formation in filtration processes Bram De Jaegher (UGent)

12.15-12.35 Peak deconvolution to correctly and completely sssess the true band broadening of chromatographic columns Yoachim Vanderheyden (VUB)

12.35-12.55 Design and evaluation of a miniaturized microfluidic platform for ion-exchange chromatography Sam Wouters (VUB)

Session 2.1: Food technology and Industrial Microbiology p. 24

Chair: Jéroeme Bindelle (Aula BMW1 - ON2 04.223)

14.15-14.35 Viscoelastic properties of high pressure homogenised citrus fibre fractions obtained after sequential pectin extraction Katleen Willemsen (KU Leuven)

14.35-14.55 Role of degree and pattern of methylesterification on Fe2+ adsorption capacity of citrus pectin Miete Celus (KU Leuven)

14.55-15.15 Exploring the microbiota associated with green coffee bean production Florac De Bruyn (VUB)

15.15-15.35 Influence of oil type on in vitro lipid digestion and carotenoid bioaccessibility: a kinetic study Sarah Verkempinck (KU Leuven)

viii

15.35-15.55 The influence of citrate in type II sourdough fermentations initiated with a citrate-positive lactic acid bacterial starter culture Andrea Comasio (VUB)

15.55-16.15 Towards upgrading of wastewater resources to microbial protein: Volatile fatty acids impacting growth kinetics and yield of purple bacteria Abbas Alloul (UAntwerp)

Session 2.2: Environment and Agriculture p. 31

Chair: Bram Van De Poel (Aula BMW3 - ON2 04.216)

14.15-14.35 Flemish policy tackling agricultural ammonia emissions: still room for improvement David De Pue (UGent)

14.35-14.55 Does replacing grass silage by maize silage in Flemish dairy cattle diets lead to methane reduction? Dorien Van Wesemael (UGent)

14.55-15.15 Ecological water quality and threshold responses of macroinvertebrate communities to stream velocity in the Guayas River basin (Ecuador) Thi Hanh Tien Nguyen (UGent)

15.15-15.35 Development and validation of an UHPLC-ESI-MS/MS method to quantify estrogenic compounds as pyridine-3-sulfonyl derivatives in aqueous matrices Alex Glineur (ULg)

15.35-15.55 Emerging threats to Ugandan honeybees, pilot study reveals presence of pesticides and honeybee pathogens Deborah Ruth Amulen (UGent)

15.55-16.15 Contrasting vulnerability and resilience to drought-induced defoliation in mixed versus pure stands. Ana Rita Silva (KU Leuven)

Session 2.3: Human health and Genomics and biotechnology p. 38 Chair: Mariya Petrova (Aula BMW4 - ON2 04.212)

14.15-14.35 Functional and structural elucidation of a ssDNA-binding protein encoded by the N4-like, Pseudomonas phage LUZ7 Maarten Boon (KU Leuven)

14.35-14.55 Intrinsically disordered proteins – extraordinary protein functions and novel method for their detection Nevena Hristozova (VUB)

14.55-15.15 HokB, a pore-forming toxin, induces persistence after dimerization Dorien Wilmaerts (KU Leuven)

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15.15-15.35 Nanobody-based depletion of protumoral tumor-associated macrophages as novel cancer therapy Evangelia Bolli (VUB)

15.35-15.55 Akkermansia muciniphila colonization of an in vitro distal colon is largely mucin and pH dependent Florence Van Herreweghen (UGent)

15.55-16.15 Revealing the role of TBC1D24 mutations in epilepsy Jone Paesmans (VUB)

1

Lecture session 1.1

FOOD TECHNOLOGY AND INDUSTRIAL MICROBIOLOGY

2

IMPACT OF STORAGE FACTORS ON COLOUR CHANGES OF PASTEURISED STRAWBERRY JUICE: A KINETIC STUDY

Carolien Buvé*, Biniam Kebede*, Cédric De Batselier*, Celia Carrillo Pérez**, Huong Pham*,

Marc Hendrickx*, Tara Grauwet* and Ann Van Loey*

*KU Leuven, Belgium; ** University of Burgos, Spain

An attractive colour is one of the most important food quality attributes determining

consumers’ acceptance and purchase behaviour of food products. Unfortunately, processing and

mainly storage negatively affect colour and thereby product acceptability. Literature data show that

colour loss results from the simultaneous degradation of natural pigments (e.g. anthocyanins) and

formation of brown compounds through different pathways (e.g. ascorbic acid (AA) degradation). For

fruit-based shelf-stable products, browning is a quality handicap determining the shelf-life of these

products. Nevertheless, insight into the effect of storage on colour changes in fruit-based products is

still limited.

In the present work, the effect of three relevant storage factors (storage time and

temperature, and oxygen availability) on changes in colour related-attributes (CIELAB values,

anthocyanin and AA content) of pasteurised strawberry juice was studied quantitatively. For this

purpose, an accelerated shelf-life test (ASLT), in which pasteurised strawberry juice was stored at

ambient and abuse temperatures (20 42°C) in two types of bottles with different oxygen

permeability, was performed. The redness, the anthocyanin and AA content decreased, while the

total colour difference increased significantly during storage. The change in all attributes was

accelerated at higher temperatures, as quantified through the activation energy. A higher oxygen

availability also resulted in a faster change of the attributes during storage. Different pathways seem

to contribute to the browning of strawberry juices during storage and interactions between

compounds or pathways should not be overlooked when explaining colour changes in juices.

Furthermore, this work shows the potential of ASLT in combination with kinetics to study, predict and

evaluate quality changes during storage and to optimize storage conditions of strawberry juices to

guarantee food quality and minimise food waste.

3

SCREENING OF RHEOLOGICAL PROPERTIES OF VARIOUS MICROALGAE SPECIES TOWARDS THEIR APPLICATION IN FOOD PRODUCTS

Tom Bernaerts*, Agnese Panozzo*, Veerle Doumen*, Imogen Foubert**, Lore Gheysen**,

Koen Goiris***, Paula Moldenaers*, Marc Hendrickx* and Ann Van Loey*

*KU Leuven, Belgium; ** KU Leuven, KULAK, Belgium;

*** KU Leuven Technology Campus Ghent, Belgium

Microalgae are considered as an interesting source of several health beneficial components

and nutrients, including omega-3 long chain polyunsaturated fatty acids, proteins and antioxidants.

To date, intensive research is carried out towards extraction of individual components from

microalgae. However, using the complete microalgal biomass in food products might be an

innovative strategy to utilize other functional components from microalgae. Microalgal cell wall

polysaccharides could for instance play a structuring role in food products, allowing microalgal

biomass to be used as a multifunctional ingredient.

To date, structuring properties of microalgae are only very limitedly described in literature.

Therefore, this study comprises a screening of the rheological characteristics of different microalgae

species (Chlorella, Nannochloropsis, Odontella, Phaeodactylum, Porphyridium, Schizochytrium and

Spirulina). Aqueous model systems were prepared at both pH 4 and 6, simulating fruit and vegetable

based products respectively. Mechanical and thermal processing were applied, treatments that are

commonly used in food processing. The effect of processing was investigated on both rheological

properties and microstructure of the microalgal suspensions.

The obtained results showed substantial differences in rheological properties between the

different microalgae species. The impact of mechanical processing was largely depending on the type

of microalga, while thermal processing mostly resulted in structure build-up. Changes in flow

behavior after processing could be related to both particle characteristics and serum viscosity. The

results of this study show the great potential of microalgal biomass towards food applications.

Whereas some microalgae species can be used to introduce health beneficial components without

disturbing the structure of the food matrix, other species displayed interesting thickening properties

for use as a multifunctional ingredient in food products.

4

THE ROLE OF ACETIC ACID BACTERIA IN LAMBIC BEER PRODUCTION PROCESSES IS UNDERESTIMATED

Jonas De Roos,* Stefan Weckx*, Peter Vandamme* and Luc De Vuyst*

* Vrije Universiteit Brussel, Belgium

Lambic beers are spontaneously fermented and matured (wooden casks) for 3 years. Earlier

studies reported a transient occurrence and limited role of acetic acid bacteria (AAB). Moreover, the

techniques that were used in these studies are outdated and have a low throughput compared to

nowadays’ techniques. Aseptic sampling at different heights, improved cultivation and matrix-

assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) identification

of 2000 isolates, and metabolomic analysis allowed investigation of the spatial distribution of

microbiota and metabolites. Two casks filled with the same wort were studied. This multiphasic

temporal approach enabled mapping of the microbial community dynamics and metabolite kinetics.

The temporal microbial and metabolite composition of both casks was complex, yet strikingly similar

over time. Four distinctive phases could be distinguished: an Enterobacteriaceae and AAB phase

(dominated by Klebsiella spp. and Acetobacter orientalis), a main yeast fermentation phase

(dominated by Saccharomyces cerevisiae), an acidification phase due to lactic acid bacteria

(dominated by Pediococcus damnosus) and AAB growth (dominated by Acetobacter pasteurianus),

and a maturation phase (dominated by Brettanomyces bruxellensis and P. damnosus). It was

interesting to notice that different AAB species were present during the first and third phase of the

production process. They contributed to the production of acetic acid (both phases) and acetoin and

ethyl acetate (third phase). The different spatial sampling points in the casks revealed small but

unmistakable differences in microbial and metabolite composition. In particular, higher AAB counts

and higher concentrations of acetic acid were present at the air/liquid interface at certain time

points. These data indicate that the occurrence and functional role of AAB during the lambic beer

production process were underestimated in the past.

5

EXPLORING DUNALIELLA SALINA AS SINGLE CELL PROTEIN: THE INFLUENCE OF LIGHT/DARK REGIME ON THE GROWTH AND PROTEIN SYNTHESIS

Yixing Sui* and Siegfried Vlaeminck*

* Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience

Engineering, University of Antwerp, Belgium

INTRODUCTION

Single cell protein (SCP), or originally named microbial protein, is the edible microbial biomass

derived from e.g. microalgae, bacteria and fungi, which can be used as protein sources replacing

conventional protein sources for animal feed or human food such as fishmeal and soybean

(Anupama & Ravindra 2000). SCP presents great potential as protein supplement to alleviate the

problem of food scarcity in the future (Nasseri et al. 2011). In general, microalgae as SCP contains

above 50% protein over dry weight and specifically for the marine microalgae Dunaliella salina the

amount stays around 57% (Becker 2007). Commercially the most common system for Dunaliella sp.

production is the outdoor open pond, thus the microalgal cells are subjected to a natural light/dark

cycle (Hosseini Tafreshi & Shariati 2009). Being photo-autotrophic microorganisms, the lack of light

energy sources is a risk leading to night biomass loss (Ogbonna & Tanaka 1996). On the other hand,

for some microalgae species cell division occurs primarily during the night suggesting its night

protein synthesis (Cuhel et al. 1984). As a consequence, day and night metabolisms of microalgae

introduced by light/dark cycles potentially will have big impacts on the biomass development, both

in growth and biochemical composition. In this study, the effect of the light/dark cycle on the growth

and protein synthesis of Dunaliella salina was explored in comparison with continuous light

cultivation.

MATERIAL AND METHODS

Microalgal strain and cultivation conditions

Green microalgae Dunaliella salina (184.80) was obtained from SAG, Culture Collection of

Algae at Göttingen University, Germany. Modified Johnson's medium (Borowitzka 1988) was used for

cultivation, replacing NaCl with table salt (Everyday, Colruyt Belgium) at 117g/L. Erlenmeyer flasks of

500mL containing 400mL microalgal suspension were used for cultivation at a constant temperature

of 20 °C, pH of 7.5 and light intensity of ±55 µmol/m2/s respectively. Mixing was achieved by placing

the flasks on a multipoint magnetic stirrer (Thermal Fisher Scientific, Cimarec™ Poly15) at 200 rpm

and carbon was supplied by sparging air with an air pump (TetraTech®, APS100) at 4.12 vvm into the

individual flasks through a serological pipet (VWR International).

Growth under 24h continuous light and 12h/12h light/dark cycle

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In total 6 Erlenmeyer flasks were used for cultivation, of which 3 under 24h continuous light

and 3 under 12h/12h light/dark cycle as triplicates. For all flasks, the initial concentration of

Dunaliella salina suspension was equally at 0.027 OD unit at 680nm (OD680). Samples were taken

twice per day for analyses and then stored at -20 °C. Data of algal growth were presented in both

OD680 and cell number which were calculated in their common logarithm: 𝑙𝑜𝑔$%(𝑋/𝑋%) where X

and X0 are the OD680 or cell number of time X and time initial respectively. Based on the obtained

growth curve, the specific growth rate (µ) was calculated by carefully selecting two time points (T1

and T2) with their corresponding OD unit (X1 and X2) at exponential phase and following equation:

µ(𝑑-$) = (𝐿𝑛𝑋1 − 𝐿𝑛𝑋$)/(𝑇1 − 𝑇$).

Analytical methods

OD680 was measured with a UV-VIS Spectrophotometer (UV-2501PC, Shimadzu). The biomass

ash free dry weight (AFDW) was evaluated with a pre-defined correlation with OD680 following

equation: 𝐴𝐹𝐷𝑊(𝑔 𝐿⁄ ) = 𝑂𝐷:;% ∗ 0.5069 − 0.0131. Total cell numbers were determined with a

Multisizer 3 Coulter Counter (Beckman Coulter). To determine the total crude protein content the

Markwell method (Markwell et al. 1978) was used.

RESULTS AND DISCUSSION

Growth of Dunaliella salina under continuous light and 12h/12h light/dark cycle

To investigate the effect of light/dark cycle on the growth of Dunaliella salina, cultures were

exposed to two different illumination strategies, both continuous light and 12h/12h light/dark cycle.

The corresponding curves are shown in Figure 1. Cultures under two different illumination strategies

showed clearly different growth curves over 700-hour cultivation but both presented clear growth

stages of lag phase (data not shown), exponential phase, decelerating phase, stationary phase and

declining phase. Cultures under continuous light had a growth rate of 0.456 d-1 reaching a final

biomass concentration of 1.364 gAFDW/L while cultures under 12h/12h light/dark cycle showed a

20% slower growth rate of 0.364 d-1 reaching 40% less biomass concentration of 0.813 gAFDW/L.

Being obligate photoautotrophic microalgae, Dunaliella salina evidently requires light to support the

growth (Borowitzka L.J. and Borowitzka M.A. 1989) and without light source both growth rate and

biomass concentration will reduce correspondingly. When comparing the growth pattern followed by

OD680 and cell number, it is interesting to see that OD680 and cell number overlaps each other well

before late exponential phase, however diverges fairly afterwards. The difference is mainly because

the biomass at late growth stage contains both living cells and residual cell debris. This implies a

difference between cell number and biomass when demonstrating results. Thus wisely and correctly

choosing parameters to demonstrate experimental results is highly important.

7

Figure 1 Growth of D. salina under continuous light (CL) and 12h/12h light/dark (LD) cycle followed by both OD680 and cell number. The cultivation was at temperature 20°C and light intensity ~55 µmol/m2/s with continuous mixing at 200 rpm. Figures are shown in means ± standard deviation.

Protein synthesis of Dunaliella salina under continuous light and 12h/12h light/dark cycle

Protein synthesis of microalgae is one of the most vital mechanisms in their growth. Samples

from different growth stages of both continuous light and 12h/12h light/dark cycle were collected for

crude protein analysis as shown in

Figure 2. In general, protein built-up and decline pattern of Dunaliella salina biomass varies

from its growth pattern. Evident increase of protein content up to 80% of its AFDW appeared at the

end of exponential phase. Nevertheless the biomass concentration at this stage was merely around

0.4 gAFDW/L. Protein content declined eventually to 62% of its AFDW despite the continuing

biomass growth. In photosynthetic microalgae, high protein and low carbohydrate content are

generally the main characteristics of rapidly growing cells (Zhu et al. 1997). However, when growth

limiting factors occur such as nutrient and/or light, lower protein and higher carbohydrate content

will be realised, typically in the stationary phase of their growth (Zhu et al. 1997; Fidalgo et al. 1998).

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On the other hand, in spite of the varied growth rate under both continuous light and 12h/12h

light/dark cycle, their protein content of biomass synchronized each other. Clearly light/dark cycle

has few influence on the protein synthesis while growth stages play a more important role.

Figure 2. Growth of D. salina under continuous light (CL) and 12h/12h light/dark (LD) cycle followed by cell number and protein content. The cultivation was at temperature 20°C and light intensity ~55 µmol/m2/s with continuous mixing at 200 rpm. Figures are shown in means ± standard deviation.

CONCLUSION

Dunaliella salina proves to be a strong candidate for single cell protein production with the

highest protein content reaching 80% AFDW at the exponential phase. Despite the lower growth rate

under 12h/12h light/dark cycle, the protein content remained comparable with under continuous

light. This implies that biomass cultivation in expensive closed bioreactors with full artificial light

regime has no advantage over low-cost open outdoor cultivation under natural light regime in terms

of biomass protein content.

ACKNOWLEDGEMENTS

This research is supported by China Scholarship Council and project Microbial Nutrients on

Demand (MicroNOD).

REFERENCES

Anupama & Ravindra, P., 2000. Value-added food: Single cell protein. Biotechnology Advances, 18(6), pp.459–479. Becker, E.W., 2007. Micro-algae as a source of protein. Biotechnology Advances, 25(2), pp.207–210. Borowitzka, M.A., 1988. Algal Growth Media and Sources. In Micro-algal Biotechnology. pp. 456–465. Borowitzka L.J. and Borowitzka M.A., 1989. ß-Carotene (Provitamin A) production with algae. In Biotechnology of vitamins, pigments and

growth factors. pp. 15–26. Cuhel, R.L., Ortner, P.B. & Lean, D.R.S., 1984. Night synthesis of protein by algae. Limnology and Oceanography, 29(4), pp.731–744. Fidalgo, J.P. et al., 1998. Effects of nitrogen source and growth phase on proximate biochemical composition, lipid classes and fatty acid

profile of the marine microalga Isochrysis galbana. Aquaculture, 166(1–2), pp.105–116. Hosseini Tafreshi, A. & Shariati, M., 2009. Dunaliella biotechnology: Methods and applications. Journal of Applied Microbiology, 107(1),

pp.14–35. Markwell, M.A.K. et al., 1978. A modification of the Lowry procedure to simplify protein determination in membrane and lipoprotein

samples. Analytical Biochemistry, 87(1), pp.206–210. Nasseri, a. T. et al., 2011. Single Cell Protein: Production and Process. American Journal of Food Technology, 6, pp.103–116. Ogbonna, J.C. & Tanaka, H., 1996. Night biomass loss and changes in biochemical composition of cells during light/dark cyclic culture of

Chlorella pyrenoidosa. Journal of Fermentation and Bioengineering, 82(6), pp.558–564. Zhu, C.J., Lee, Y.K. & Chao, T.M., 1997. Effects of temperature and growth phase on lipid and biochemical composition of Isochrysis

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galbana TK1. Journal of Applied Phycology, 9(5), pp.451–457.

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10

EVOLUTION OF THE METABOLITE PROFILES OF COFFEE BEANS UNDER VARIOUS POST-HARVEST PROCESSING METHODS

Sophia Jiyuan Zhang*, Florac de Bruyn*, Vasileios Pothakos*, Julio Torrres**, Charles Lambot**, Alice Moroni**, Cyril Moccand**, Wilbert Sybesma**, Stefan Weckx* and Luc De

Vuyst*

* Vrije Universiteit Brussel, Belgium; ** Nestlé R&D Centre Tours

The journey of coffee production starts at the fresh coffee cherries. The matured coffee

cherries are harvested and undergo post-harvest processing to produce green coffee beans, which

are suitable for roasting. The processing methods, mainly wet and dry processing, are crucial for the

green coffee bean quality as well as the final coffee sensory attributes. In both cases, microorganisms

naturally present in these ecosystems and endogenous bean metabolism are active and interlinked

throughout the process. Their dynamics can be affected by the different processing methods

employed. However, little is known about the evolution of the metabolite profiles of coffee beans or

how they are impacted by different processing methods.

Aiming to follow the entire post-harvest processing chain, freshly harvested Arabica coffee

cherries were processed by four variations of wet and dry methods on an Ecuadorian farm. While

coffee samples were taken at each processing step, other parts of the cherries (e.g., mucilage from

wet-processed beans and drying outer layers from dry-processed beans) were also collected. Various

chromatographic techniques were applied to measure the targeted chemical compounds, including

UPLC-MS/MS, GC-FID, and HPAEC-PAD.

It was found that the microbial activities mainly occurred in the mucilage and drying outer

layers in the wet- and dry-processed coffee beans, respectively. The microbial metabolites were

produced and accumulated on the beans. Concurrently, the changes in the profiles of simple

carbohydrates and phenolics indicated an active endogenous bean metabolism due to abiotic

stresses. Consequently, the chemical compositions of the final green coffee beans from various

processing practices were distinct, indicating potential differences in the final coffee cup quality. To

conclude, the results of this study contributed to a better understanding of coffee bean processing,

which shed light on a potential quality enhancement of green coffee beans.

11

Lecture session 1.2

ENVIRONMENT AND AGRICULTURE

12

IS SOIL PORE STRUCTURE CONTROL ON SUBSTRATE DECOMPOSITION MANIFESTED THROUGH N AVAILABILITY?

Peter Maenhout*, Steven Sleutel,* Luc Van Hoorebeke*, Veerle Cnudde*, Jan Van den Bulcke* and Stefaan De Neve*

* Ghent University, Belgium

Soil pore structure determines the location of OM particles, the distribution of O2, water,

micro-organisms and nutrients. Mineral N availability plays a crucial role in microbial degradation of

N-poor substrates. To study these complex relationships we set up microcosm soil incubations

combined with pore network quantification. We hypothesized that C-mineralization would be

stimulated by increased N diffusion in soils with a more compact structure and higher water content.

Second, we hypothesized that fungi would dominate C-mineralization in soils with limited N

diffusion. We expect this innovative combination of methodologies to reveal new insights in the

small scale carbon dynamics.

We created soil cores with a reconstructed soil texture, namely a silt and clay (S+C) content of

50% or 20%, and a sand content of 50 and 80%, respectively. Two levels of water filled pore space

(WFPS of 25% and 50%) and amendment with OM high in nitrogen (grass) or low in nitrogen

(sawdust) were applied. During the incubations CO2 was measured frequently via GC-TCD. X-ray CT

was used to quantify the soil 3D architecture and the microbial community composition was

assessed using PLFA fingerprinting. For the first time, CT-based characteristics of the local porosity

surrounding the OM particles will be correlated with C-mineralization and microbial community

structure.

C-mineralization in the sawdust treatments was higher in the 50%_S+C soils than in the

20%_S+C soils at 25%WFPS, while such effect was not observed at 50% WFPS or for grass at both

water contents. This interactive effect of soil structure and substrate type suggests that soil structural

control on C-mineralization would be induced by differences in N diffusion. PLFA, however, did not

reveal promotion of fungal over bacterial biomarkers in treatments with likely N-limited substrate

decomposition. CT-based local porosity quantification confirms existence of localized elevated

porosity surrounding substrate particles

13

PARTITIONING SELECTION AND COMPLEMENTARITY EFFECTS TO UNDERSTAND OVERYIELDING IN TREE DIVERSITY EXPERIMENTS

Thomas Van de Peer*, Kris Verheyen**, Quentin Ponette***, Nuri Nurlaila Setiawan** and Bart Muys*

* KU Leuven, Belgium;

** Ghent University, Belgium; *** Université Catholique de Louvain, Belgium

It is generally accepted that positive effects of biodiversity on primary productivity are driven

by selection and complementarity. However, only few attempts have been made to understand these

mechanisms in forests, as trees are large and long-living, and forests therefore hard to manipulate in

comparison to e.g. grasslands or aquatic microcosms.

The present study meets these shortcomings by examining diversity-productivity relationships

(DPR) in large-scale tree-based experiments. Aboveground biomass was measured in three

plantations (GE, ZE and HE) in Belgium. These has been established in contrasting environments, but

they all have an identical design and span a diversity gradient from one to four tree species. We

applied two-way and three-way additive partitioning methodologies to measure net diversity effects

and to a posteriori distinguish between key operators.

Six years after establishment, net diversity effects were significantly positive. In the least

productive site GE, complementarity and selection were both positive and equally important.

Selection originated from competitive dominance of high-biomass species (Larix x eurolepis and

Pseudotsuga menziesii), which increased productivity at the expense of low-biomass species

(Quercus petraea and Acer pseudoplatanus). In the post-agricultural site ZE, complementarity was

positive and selection was negative. Negative selection means that low-biomass species (Fagus

sylvatica and Tilia cordata) benefited disproportionally from interspecific interactions. Their improved

performances did not fully diminish productivity of high-biomass species. Thus, part of the selection

effect was not attributable to competitive dominance but to trait-dependent complementarity.

Mixture productivity in the juvenile plantations was higher than expected from monocultures of

component species. Besides complementarity, selection is an important but complex driver of DPR,

most relevant for forest management.

14

IRON COATED SAND/GLAUCONITE FILTERS FOR PHOSPHORUS REMOVAL FROM ARTIFICIALLY DRAINED AGRICULTURAL FIELDS

Stany Vandermoere* and Stefaan De Neve*

* Ghent University, Belgium

In Flanders (Belgium) reactive phosphorus concentrations in streams and lakes are three to four

times higher than the 0.1 ppm P limit set by the Water Framework Directive. Much of the excessive P

input in surface waters is derived from agriculture and more particularly from direct P input from

artificially drained fields (short-circuiting the buffering capacity of the subsoil). Here we report on the

development and performance of filters reducing P losses via drains at lab and field scale. After a

preliminary screening experiment based on material availability, P sorption capacity and speed of P

sorption, iron coated sand and acid pre-treated glauconite were selected as starting materials for

filter development. These materials, both rich in Fe, were mixed in ratios of 100/0, 90/10, 80/20,

70/30 and 60/40 (iron coated sand/glauconite ratio, based on weight basis) and filled in plastic tubes

for saturated hydraulic conductivity (Ksat) testing. This lead to the determination of a clear

relationship between Ksat of the filter materials and filter material particle size and bulk density.

Based on this, two different filter types were developed and tested at lab scale for several days with

a 0.01 M CaCl2 solution containing 0.5 ppm P. Results showed that all types of iron coated

sand/glauconite mixtures in both filter systems reduced P outflow concentrations with 50 to almost

100%, whereby pure mixtures of iron coated sand performed the best. However only the mixtures

with 100% and 90% iron coated sand could maintain an appropriate hydraulic conductivity of 1 to 2

dm/min. Therefor only these filter mixtures were tested at field scale at two sites. During the period

of one month both filters showed a P removal efficiency of 50 to 70%, whereby the pure mixture of

iron coated sand performed the best. Moreover this pure mixture could process larger volumes than

the mixture containing glauconite.

15

TUNISIAN DAIRY FARMERS’ PERCEPTIONS OF CLIMATE CHANGE IMPACTS AND OPTIONS FOR ADAPTATION

Hajer Amamou*, Hedi Hammami*, Mokhtar Mahouachi** and Yves Beckers*

* Gembloux Agro-Bio Tech, Université de Liège; Belgium

** Ecole Supérieure d'Agriculture du Kef

Climate change strongly affects the profitability of farm animals, where a warmer thermal

environment is the major factor that can negatively affect the production efficiency in dairy cows.

Scenarios predict that climate change will increase the annual average temperature by 1.1°C by 2030

and decrease the annual precipitation in Tunisia. Due to these increasing hazards tied to climate

change, Tunisian dairy farmers are looking for effective adaptation strategies in order to secure milk

production.

This study aimed to explore the adjustments and adaptations strategies used by Tunisian

breeders in the context of climate change (CC) and the knowledge held by breeders about the effects

of CC on their dairy systems. Qualitative and quantitative variables were collected from a survey

provided to owners of 566 dairy farms among the different regions of the country. Tunisian dairy

cattle breeders used numerous strategies to limit the negative effects of CC, being classified into four

main axes: feeding strategies, management practices, environmental management and genetics. The

most frequently used strategies for adapting to CC by Tunisian dairy farmers were giving animals

access to shady areas, storage of forage, purchasing fodder, irrigating, and providing drinking water

to animals ad libitum. Almost all dairy farmers in Tunisia recognize that the major negative impacts of

CC concerned wider animal performances and its well-being and forage production.

16

EXTRACTION AND CONNECTION OF ARTIFICIAL DRAINAGE NETWORKS IN AGRICULTURAL AREAS USING LIDAR DATA

Jennifer Roelens*, Jos Van Orshoven*, Stefaan Dondeyne* and Jan Diels*

* KU Leuven, Belgium

Low-lying agricultural areas are frequently drained by ditch networks to improve production

and manage water supplies. These man-made alterations to the natural flow network impact

substantially the hydrology and water quality of the network causing them to play a key role in flood

control and surface water pollution. Localizing ditches and their connectivity to the hydrological

network helps to inform spatially-targeted water resource management decisions and future

modeling efforts.

Ditch networks can be defined from local morphologies using large area Digital Elevation

Models (DEM) with a high spatial resolution. A preliminary network is detected in an automated way

by thresholding the residual relief of the area. Noise in the preliminary network is removed by

thresholding the length of the detected segments.

Hydrological connectivity is not accounted in these methods as it does not follow a classical

flow algorithm approach. Therefore, disconnections in the preliminary ditch network are then

evaluated by a probability for connectivity. Probability maps are created using auxiliary datasets and

hydrological properties of the preliminary network.

The results are expected to facilitate input data acquirement for spatially explicit hydrological

models by avoiding field surveys that require significant human resources and funding. These results

can then improve the accuracy of spatially explicit hydrological models and the catchments

hydrologic response.

17

Lecture session 1.3

CHEMISTRY AND ENGINEERING

18

Cu-Ni PYRAZOLATE FRAMEWORKS AS HETEROGENEOUS CATALYSTS FOR THE SYNTHESIS OF NEUROACTIVE MOLECULES

Francisco García Cirujano*, Elena López Maya**, Jorge Rodriguez Navarro**, Dirk De Vos*

* Centre for Surface Chemistry and Catalysis (COK), KU Leuven, Belgium; ** Departamento de Química Inorgánica, Universidad de Granada, Spain

Tryptamine and GABA analogs are widely used for the treatment of pain, psychiatric disorders and

neurodegenerative diseases.1 In order to produce such pharmacologically active compounds in an

efficient manner, enol-type addition reactions have been applied in the presence of homogeneous

catalysts. However, due to the drawbacks of the soluble bases commercially used, we have design a

new family of solid metal-organic frameworks (MOFs) with catalytic activity in CC forming reactions.2

The NiBDP@Cu MOF used as heterogeneous catalyst is able to carry on tandem multi-steps

reactions in one-pot, obtaining the pharmaceutically active compounds in high yields after a simple

filtration of the reusable catalyst.

References:

1. Leyva-Perez et al., Angew. Chemie Int. Ed. 2014, 53 (33), 8687–8690

2. N. M. Padial et al., Angew. Chemie Int. Ed. 2013, 52 (32), 8290–8294

NiBDP@K NiBDP@Cu

K+

Cu2+

19

A STUDY OF THE ZIF-8 ZEOLITIC IMIDAZOLATE FRAMEWORK AS ADSORBENT FOR VOLATILE ORGANIC COMPOUNDS DETECTION AND REMOVAL

Thomas Virdis*

* Vrije Universiteit Brussel, Belgium

The unavoidable increase of volatile organic compounds (VOCs) in the environment has lately

attracted the attention of scientific community, as an adequate solution needs to be found to

prevent the excessive spreading of these substances in the surroundings. Among known VOCs

removal systems, gas phase adsorption provides one of the most interesting outcomes in terms of

efficiency and applicability. Physisorption of volatile compounds is a reversible spontaneous process

and allows separating target organics from the air stream. Many VOCs adsorption processes based

on activated carbons and zeolites have been reported in literature. However, the adsorption of VOC

mixtures at low concentration has been barely studied. As materials design and development has

progressed, a more recent class of adsorbents known as metal-organic frameworks (MOFs) has

emerged. MOFs consist of a crystal structure composed of organic linkers coordinated with transition

metal ions. Among the various framework types a MOF can adopt, Zeolitic Imidazolate Frameworks

(ZIFs) are surely of great interest for their topological isomorphism with zeolites. In this work, we

have investigated the adsorption of a number of representative VCs on ZIF-8. As water concentration

in the atmosphere exceeds that of the VOCs, the effect of relative humidity on VOC uptake was

studied in detail. Adsorption isotherms were measured by means of vapour phase breakthrough

experiments and gravimetric analysis at 30°C, while the single component affinity was assessed via

pulse gas chromatography (100 – 200°C). The different adsorption behaviour is analysed in terms of

the physicochemical properties of the compounds. Moreover, breakthrough profiles show

development of intermediate plateaus in specific concentration ranges, both for mixtures and pure

compounds.

20

SPATIO-TEMPORAL MODELLING OF FILTER CAKE FORMATION IN FILTRATION PROCESSES

Bram De Jaegher*,**, Wouter Naessens*,**, Jan Baetens** and Ingmar Nopens*

*BIOMATH, Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, Belgium (email: Bram.DeJaegher@UGent.be, Ingmar.Nopens@UGent.be).

**KERMIT, Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, Belgium (email: Jan.Baetens@UGent.be).

Abstract

The operation of membrane filtration units, used in many industrial, medical and

environmental applications, is mainly hampered by the operational cost due to membrane fouling.

Mathematical modelling can provide knowledge build-up, better process control and decision

support tools to improve the operation of these processes. However, the knowledge concerning the

underlying mechanisms of filter cake formation is still quite limited. As a result, the majority of

fouling models is still very empirical and does not provide an adequate framework for a generic

membrane fouling model. In order to further elucidate the underlying mechanisms of membrane

fouling, a mechanistic Euler-Lagrangian model was developed with a detailed description of all the

relevant subprocesses (Figure 1).

The Eulerian model layer is based on computational fluid dynamics and computes the Navier-

Stokes equations to obtain a velocity/pressure profile in the simulated domain. The movement of the

dispersed particles is modelled through the Lagrangian model layer where each particle and its

modelled quantities (velocity, forces, etc. ) are individually tracked by a moving frame of reference.

The velocity of these particles is determined by a force balance. The formation of filter cake is

modelled by means of a collision detection algorithm that tracks the collision of free moving particles

with the wall and the existing filter cake. If a collision occurs, particles can attach to the wall and the

cake layer, contributing to the growth of this layer.

Figure 1: Schematic representation of the model layers.

This modelling approach, enables the in-silico evaluation of the operational parameters (crossflow

velocity, transmembrane flux, particle size distribution, etc.) on the filter cake formation. As a

21

qualitative validation of the model, several virtual experiments were performed to replicate the

spatial segregation of particles due to the Segré-Silberberg effect. The relation between the particle

diameter and the crossflow velocity on the radial migration of dispersed particles, as described by

the Segré-Silberberg effect, was investigated. These experiments revealed an important impact of

wall repulsion effects and different lift forces on the transport of particles in tubular membranes.

Furthermore, the simulation results indicated that the membrane-directed migration of free moving

particles increased with particle size and crossflow velocity (Figure 2), which is in agreement with the

Segré-Silberberg effect.

Figure 2: Effect of the crossflow velocity on the radial migration of particles with a different entry height in a microchannel.

The presence of an equilibrium position of dispersed particles between the central axis and the

membrane in laminar flow conditions and the dubious role of the crossflow velocity raises questions

about the current turbulent operation of membrane units. The possibility to exploit this effect to

reduce membrane fouling could be very powerful and should be further investigated.

An important, but often neglected part, of mathematical modelling is the validation of the model.

One has to assess the predictive capabilities of the model by comparing the simulation results to

experimental results. To perform a controlled and reliable validation of both model layers and to

mimic the modelling assumptions as much as possible, an experimental filtration unit was designed

based on computational fluid dynamics simulations to obtain a well-characterised and laminar flow

profile in the experimental setup. This unit enables the profilometric analysis of the formed filter

cake during the experiments and the direct observation of the fouling with a high speed camera.

Bibliographic references

1. Naessens, W., Maere, T., and Nopens, I. (2012). Critical review of membrane bioreactor models – Part 1: Biokinetic and filtration models. Bioresource Technology, 122:95–106.

22

2. Owen, G., Bandi, M., and Howell, J. A. (1995). Economic assessment of membrane processes for water and waste water treatment. Journal of Membrane Science, 102:77–91.

3. Judd, S. (2008). The status of membrane bioreactor technology. Trends in Biotechnology, 26(2):109– 116.

4. Segré, G. and Silberberg, A. (1962). Behaviour of macroscopic rigid spheres in Poiseuille flow Part 1. Determination of local concentration by statistical analysis of particle passages through crossed light beams. Journal of Fluid Mechanics, 14(01):115

5. Segré, G. and Silberberg, A. (1961). Radial Particle Displacements in Poiseuille Flow of Suspensions. Nature, 189(4760):209–210.

6. Zeng, L., Balachandar, S., and Fischer, P. (2005). Wall-induced forces on a rigid sphere at finite Reynolds number. Journal of Fluid Mechanics, 536:1–25.

23

PEAK DECONVOLUTION TO CORRECTLY AND COMPLETELY ASSESS THE TRUE BAND BROADENING OF CHROMATOGRAPHIC COLUMNS

Yoachim Vanderheyden*, Ken Broeckhoven* and Gert Desmet*

* Vrije Universiteit Brussel, Belgium

The recent advances in chromatography have brought us columns that can produce such

sharp and narrow peaks that the extra-column volumes of the current generation of instruments

inevitably causes an efficiency loss. This also puts a serious strain on the ability to measure the

"column-only" efficiency of these columns, especially when using weakly retained components,

which are most sensitive to the hydrodynamic quality of the packing.

In column performance studies, the effect of extra-column band broadening (ECBB) is

traditionally eliminated using the variance subtraction method, owing its popularity to the fact that it

is based on a simple subtraction. However, by focusing only on its variance, information describing

the shape and the asymmetry of the peak is discarded. Since the variance subtraction method can

only be correctly applied when the variance is calculated via the 2nd order moment integral, the

observed “column-only” variance and its associated plate height may gravely overestimate the band

broadening compared to the parameters that are more relevant for the practical reality such as the

plate heights based on the half height width or on the 4��-, 5�- or even 6�-width.

The peak deconvolution method on the other hand can filter out the extra-column contributions

while preserving all the shape features of the peak. The present study provides evidence for the fact

that the peak deconvolution method can be applied to the current generation of high speed and high

efficiency columns and instruments and indeed allows to eliminate all ECBB while retaining all the

peak asymmetry information of the “column-only” dispersion. This has been shown by testing the

same column on 3 different systems, with different extra-column volumes and detector, and showing

that, after deconvolution, the resulting "column-only" peaks remain (slightly) asymmetric but

coincide perfectly, at least within the variability on the flow and injection reproducibility of the

instrument.

24

DESIGN AND EVALUATION OF A MINIATURIZED MICROFLUIDIC PLATFORM FOR ION-EXCHANGE CHROMATOGRAPHY

Sam Wouters* and Sebastiaan Eeltink*

* Vrije Universiteit Brussel, Belgium

Ion-exchange chromatography is the prevalent technique for the analysis of inorganic anions,

and can be used for analysis of organic acids and ionizable biomolecules. Neutralization of the ionic

mobile phase is required prior to conductivity detection. Therefore, the columns are hyphenated

with suppressors, converting the eluent to a weak acid or water, while enhancing the conductivity of

the analyte. Currently however, modular IC systems are characterized by significant extra-column

dispersion, affecting the attainable separation efficiency. This aspect can be addressed by integration

of multiple system components on a chip platform.

This contribution discusses the development of a novel chip-based platform for at-line ion-

exchange separations. The study aims at better understanding of design requirements to maximize

separation efficiency, while establishing improved detection limits when analyzing minute sample

amounts. The device encompasses three key features: separation, suppression, and detection.

Pressure resistant separation chips featuring on-chip injection have been developed. The dimensions

of the suppressor module and its operating conditions were optimized to yield a device capable of

suppressing up to 0.35 µEq/min, making the device compatible with typical gradient conditions

applied in capillary-scale separations. Detector cell geometry was systematically varied using a flow-

through ring-electrode design, resulting in a device allowing to establish limits of detection in the

sub-ppb level from common anions. A fivefold increase in signal-to-noise ratio was achieved

compared to a commercial capillary conductivity detector. The current contribution also

demonstrates the integration of conductivity detection on a microfluidic membrane suppressor. The

device was used to analyze minute samples taken from an ice core drilled in Antarctica, allowing to

detect traces of volcanic and biological activity.

25

Lecture session 2.1

FOOD TECHNOLOGY AND INDUSTRIAL MICROBIOLOGY

26

VISCOELASTIC PROPERTIES OF HIGH PRESSURE HOMOGENISED CITRUS FIBRE FRACTIONS OBTAINED AFTER SEQUENTIAL PECTIN EXTRACTION

Katleen Willemsen*, Agnese Panozzo* and Marc Hendrickx*

* KU Leuven, Belgium

The primary cell wall (CW) of fruit and vegetables is constituted of a load-bearing network of

cellulose and hemicellulose, embedded in a pectin matrix. The latter is believed to act as a glue

holding the CW fibres together. As a consequence, fruit and vegetables CW fibres are organised in a

tightly dense network, that impairs their structuring potential upon dispersion. In this regard, the

present study aimed at understanding the effect of pectin removal and high pressure

homogenisation on the microstructure and viscoelastic properties of citrus fibres. Selective

solubilisation and removal of pectin from citrus peels was achieved by sequential pectin extraction.

Thereafter, the obtained fibre insoluble residues and filtrates were characterised for their pectin

composition (neutral sugar and galacturonic acid content, degree of methoxylation, and molar mass

distribution). Moreover, microstructure, particle size distribution, and viscoelastic characteristics of

the diverse insoluble residue suspensions were investigated by microscopy, laser diffraction, and

rheological analyses.

Due to different extraction conditions, the CW insoluble residues and filtrates showed various

pectin composition, in terms of both amount as type of pectin. In particular, highly methoxylated

branched pectin was removed under mild water conditions, low methoxylated linear pectin using a

chelator while cellulose bound pectin was solubilised under alkaline conditions. According to the

present results, the extent rather than the type of pectin removal seemed crucial to obtain

viscoelastic enhancement of the residual citrus fibre suspensions. Increase in intermicrofibrillar void

volume, created between the cellulose-hemicellulose network by extensive pectin extraction,

resulted in increased particle size and viscoelastic properties upon high pressure homogenisation.

Contrarily, homogenisation of non-depleted CW material resulted in the disruption of the stiff

microfibrillar CW structure.

27

ROLE OF DEGREE AND PATTERN OF METHYLESTERIFICATION ON Fe2+ ADSORPTION CAPACITY OF CITRUS PECTIN

Miete Celus*, Katrien Roggen*, Zahra Jamsazzadeh Kermani*, Clare Kyomugasho*, Tara Grauwet*, Ann Van Loey* and Marc Hendrickx*

*KU Leuven, Belgium;

Pectin, a cell wall polysaccharide present in fruits and vegetables possesses several

functionalities in both food and non-food related industries, with its polyvalent ion binding capacity

being of particular interest. This pectin property is greatly attributed to its degree of

methylesterification (DM) and blockiness (DBabs), which are a measure for the percentage and

distribution of non-methylesterified galacturonic acid units, respectively. Although pectin is

hypothesised to bind several cations including Fe2+, only its Ca2+ binding capacity has been greatly

explored in the food industry. This study is therefore aimed at investigating the role of pectin

structural properties (DM and DBabs) on its ability to bind Fe2+. The obtained insights could

contribute in this way to clean label products, where use of pectin as a natural food ingredient

compared to synthetic ingredients in Fe2+ chelating applications is more appealing to consumers.

Pectins with different DMs and DBabs were tailored by controlled demethylesterification of

high DM citrus pectin. This was achieved using carrot pectin methylesterase or saponification with

NaOH resulting in pectin with a blockwise (high DBabs) or random (low DBabs) distribution of

methylesters, respectively. Subsequently, Fe2+ adsorption isotherms of the derived pectins were

obtained through equilibrium dialysis studies and the experimental data were fitted according to the

Langmuir adsorption isotherm model in order to quantify the maximum adsorption capacities.

Results of this study showed that both DM and DBabs influence the Fe2+ binding capacity of

pectin. The lower the DM or higher the DBabs of pectin, the greater its Fe2+ binding capacity.

However, the DBabs of pectin showed a higher impact on the maximum Fe2+ adsorption capacity

compared to DM. Consequently, targeted modification of pectin structural properties is useful in

optimising its chelating capacity and therefore the associated functional properties.

28

EXPLORING THE MICROBIOTA ASSOCIATED WITH GREEN COFFEE BEAN PRODUCTION

Florac De Bruyn*, Sophia Zhang*, Vasileios Pothakos*, Charles Lambot**, Julio Torres**, Alice Moroni**, Cyril Moccand**, Wilbert Sybesma**, Stefan Weckx* and Luc De Vuyst*

* Vrije Universiteit Brussel, Belgium;

** Nestlé R&D Centre Tours

Coffee is the most consumed beverage in the world. It is brewed from the roasted and ground

seeds of the coffee tree. However, there is a long way to go from the harvesting of fresh coffee to the

brewing of a cup of coffee. Indeed, harvested coffee needs to undergo processing before it can be

roasted. This on-farm post-harvest processing will yield green coffee beans, which is the raw material

for roasting. In essence, it is a fermentation that is performed by a complex microbial community.

However, this community can affect coffee quality in beneficial or detrimental ways. Little is known

about the ecology of the microbiota associated with coffee processing. Moreover, a vast array of

different processing methods exists globally and each one has its own specificities. Therefore, this

study aimed at elucidating differences in the community composition associated with coffee

different processing methods. Two wet and two dry processing experiments were set up in parallel

on an Ecuadorian farm. This allowed to assess how the communities were shaped not only by the

processing method, but also by technological practices employed locally. Lactic acid bacteria (mainly

leuconostocs) and Pichia yeasts were present in all experiments, regardless of processing type or

technological practices. Some microbial groups were influenced by the type of processing, for

instance, acetic acid bacteria and non-Pichia yeasts were more prevalent in dry processing. Others

were impacted by the practice employed, as showed by shifts towards acid-tolerant lactobacilli with

increasing fermentation time. This study contributes to the characterization of the microbiota

associated with different types of post-harvest coffee processing. Assessing who is there is the first

step to knowing what they are capable of. Ultimately, the answers to these questions will help

improve coffee quality and make its production more sustainable for all stakeholders of the coffee

value chain.

29

INFLUENCE OF OIL TYPE ON IN VITRO LIPID DIGESTION AND CAROTENOID BIOACCESSIBILITY: A KINETIC STUDY

Sarah Verkempinck*, Laura Salvia Trujillo*, Lucie Moens*, Marc Hendrickx* and Tara

Grauwet*

*KU Leuven, Belgium

Carotenoid absorption is linked to lipid digestion due to the hydrophobic nature of these

micronutrients. In order to exhibit biological activity, carotenoids must be successively released from

the food matrix, transferred into a lipid phase, incorporated into mixed micelles and absorbed into

the intestinal mucosa. Lipid digestibility and subsequent carotenoid bioaccessibility, which is the

micellarized fraction, may be determined by the oil type used in emulsion formulation. Therefore, we

investigated the specific influence of oils unsaturation degree in emulsions on both lipid digestion

and carotenoid bioaccessibility through a kinetic study. Emulsions were prepared with different

carrot enriched oils (5% w/v), being olive; soybean and linseed oils and were stabilized with sucrose

ester (0.5% w/v). All emulsions were subjected to in vitro digestion consisting of a gastric and small

intestinal phase. Clear emulsion destabilization was observed during the gastric phase with visible

flocculation and coalescence with regions of free and emulsified oil, as shown by particle size values

and microstructure. Consequently, incomplete lipid digestion occurred in the intestinal phase for all

emulsion regardless the oil type. Despite this incomplete digestion, differences in terms of

carotenoid incorporation into micelles were still observed between all oil types. Olive oil emulsions

led to faster carotenoid micellarization and a higher final carotenoid bioaccessibility compared to

soybean and linseed oil emulsions. This suggests that monounsaturated fatty acids from olive oil,

which might be slightly more hydrophobic in comparison to polyunsaturated fatty acids from

soybean or linseed oil, may lead to the formation of mixed micelles with greater capacity of

solubilizing hydrophobic compounds, like carotenoids. The results observed in this work evidence the

relevance of the lipid composition in achieving optimal carotenoid bioaccessibility in the

gastrointestinal tract.

30

THE INFLUENCE OF CITRATE IN TYPE II SOURDOUGH FERMENTATIONS INITIATED WITH A CITRATE-POSITIVE LACTIC ACID BACTERIAL STARTER CULTURE

Andrea Comasio*, Henning Harth*, Simon Van Kerrebroeck* and Luc De Vuyst*

* Vrije Universiteit Brussel; Belgium

Currently, certain strains of lactic acid bacteria and yeasts are applied as starter cultures for

the industrial production of sourdoughs, which are mainly used as flavour ingredients in (industrial)

bakeries. The starter cultures are responsible for acidification (lactic acid bacteria), aroma generation

(lactic acid bacteria and yeasts) and leavening (yeasts and heterofermentative lactic acid bacteria),

which are desirable properties for sourdough products. Unfortunately, the aroma and taste profiles

of the manufactured bakery products do not always completely fulfil the expectations of the

consumers and producers and, hence, both parties are continuously searching for innovative

products with unique aroma and taste profiles. This can be achieved through the addition of extra

ingredients such as yoghurt, fruits, and seeds. This study aimed at examining the influence of added

citrate on the competitiveness of a citrate-consuming lactic acid bacterial starter culture strain,

namely Lactobacillus crustorum LMG 23699, used to initiate a wheat sourdough fermentation

process, on its metabolite production kinetics, and on the organoleptic properties of the resulting

sourdoughs and baked products. Whereas there were no differences in counts between

fermentations performed with or without citrate, the data indicated that sourdough fermentations

carried out with the addition of citrate increased the production of lactic acid. Also, the sourdoughs

obtained with the use of citrate produced acetoin. This typical and desired compound (butter aroma)

gave a more complex aroma to the baked products. In conclusion, citrate can be an interesting

sourdough ingredient to accentuate the aroma of baked products.

31

TOWARDS UPGRADING OF WASTEWATER RESOURCES TO MICROBIAL PROTEIN: VOLATILE FATTY ACIDS IMPACTING GROWTH KINETICS AND YIELD OF PURPLE BACTERIA

Abbas Alloul* and Siegfried Vlaeminck*

* Antwerp University; Belgium

The conventional fertilizer–food chain is a cascade of inefficiencies. Upgrading nutrients from

wastewater to microbial biomass could improve the efficiency, with this protein-rich product used as

feed. It is a challenge to a produce a controllable biomass on wastewater, given its complexity in

organics composition. Fermentation might render a solution, through its generation of simple

Volatile Fatty Acids (VFA). Purple-non sulfur bacteria (PNSB) cultivated in a photoheterotrophic mode

provide an excellent target group, as they have a perfect carbon assimilation efficiency and a high

growth rate compared to other phototrophs. The objective of this study was to map the effects of

VFA on PNSB growth kinetics, carbon yield and protein production.

Batch cultivations were performed with three different VFAs (acetate, propionate, butyrate)

and with a mix of these compounds (1/1/1 on C-basis). The microorganisms used for the

experiments were Rhodopseudomonas palustris, Rhodospirillum rubrum and Rhodobacter

sphaeroides along with a synthetic community (mixture of the three strains) and a PNSB enriched

community. All tests were performed under photo-anaerobic (30W/m²) conditions at 28°C.

Results showed that the growth rate of the pure cultures and the enriched community was

elevated between 1.3-2.5 times for the VFA mix compared to the single VFA. The carbon yield for all

experiments was around 1 gCOD-biomass/gCOD-fed and there was no difference between different

PNSB and the source of organic. Overall, the enriched community performed best, with superior

growth rates (1.8–2.2/d) and protein productivity (1.3 kg dry weight/m3/d).

This study demonstrated that the VFA-profile resulting from fermentation from wastewater

will strongly effect the PNSB production and product characteristics. Best results were obtained with

a VFA mix and with an enrichment community, conditions that prevail in wastewater applications,

strengthening the potential for PNSB production on fermentate.

32

Lecture session 2.2

ENVIRONMENT AND AGRICULTURE

33

FLEMISH POLICY TACKLING AGRICULTURAL AMMONIA EMISSIONS: STILL ROOM FOR IMPROVEMENT

David De Pue * and Jeroen Buysse*

* University of Gent; Belgium

Ammonia (NH3) emissions from livestock farms cause eutrophication in nearby nature

reserves. This process of atmospheric deposition threatens the biodiversity and conservation goals in

protected nature areas. In Flanders, the control of this problem is mediated through the licencing

policy. For each new environmental permit application involving ammonia emissions, a Significance

Score is calculated. This score is a measure of the impact on the location where the damage caused

by the new project is presumed to be the highest. Projects were the Significance Score exceeds a

certain limit cannot get a permit, while projects with a moderately high Significance Score can only

get a permit if they can guarantee that there is no increase in the emission when compared to the

previous situation. Projects with a low Significance Score are exempt from additional emission

restrictions. To evaluate the efficiency and effectiveness of this policy, we designed a linear

programming (LP) model, applied to a dataset consisting of all industrial pig- and poultry farms in

Flanders. For all these farms, we calculated the Significance Score and the Total Impact Score, an

alternative that is a better reflection of the total damage caused by the emission. The LP model

maximizes the societal profit, which is the sum of the individual farms minus the external health cost

related to the formation of secondary particulate matter. The farms all have an individual permit

constraint, while in the reference scenario, they also have an individual constraint related to their

significance score. If we rephrase the model, so that it minimizes the total impact while imposing the

constraint that the societal benefit should be at least as big as for the reference scenario, the total

impact is 23.7% less than in the reference scenario. This indicates that there is still room for

improvement in terms of environmental effectiveness of the policy, without reducing the total

societal benefit.

34

DOES REPLACING GRASS SILAGE BY MAIZE SILAGE IN FLEMISH DAIRY CATTLE DIETS LEAD TO METHANE REDUCTION?

Dorien Van Wesemael*, Leen Vandaele*, Nico Peiren*, Veerle Fievez** and Sam De

Campeneere*

* ILVO (Instituut voor Landbouw- en Visserijonderzoek); Belgium ** Laboratory for Animal Nutrition and Animal Production Quality, Ghent University

It is often stated that replacing grass silage (GS) by maize silage (MS) in dairy rations is a

promising nutritional strategy to reduce methane (CH4) emissions (Van Middelaer et al., 2013; Mills

et al., 2001), as MS is rich in starch. In practice, however it is not feasible to simply replace one

forage by another without affecting the performance of cows (i.e. the milk production and/or

composition). In order to have a sufficiently high starch supply in the total diet (±20%, Grant, 2010),

diets rich in GS are accompanied by high starch concentrates (HSC). In this trial we compared a

GS/MS diet (65/35 ratio on DM (dry matter) base) with a MS/GS diet (65/35 ratio), to investigate the

effect on CH4 emissions. We used 12 high-producing (31±3 kg milk/day) Holstein Friesian cows,

divided in two uniform groups (control and treatment). At the end of a control period of six weeks, in

which all cows received the GS/MS diet with HSC, the CH4 emissions of all cows were measured in

open-circuit chambers (OCC). After these measurements, the treatment group switched to the

MS/GS diet for a six week period. The control group remained on the GS/MS diet with HSC for that

period. In the last week CH4 emissions of all cows were measured again in the OCC. Replacing GS by

MS did not change the absolute CH4 emissions of the cows (on average 423 and 425 g CH4/day

respectively), nor the CH4 emissions expressed per kg DM intake (DMI) or per kg of produced milk

(MP) (20g CH4/kg DMI, 16g CH4/kg MP, respectively). Based on these results we can conclude that in

practice the replacement of GS by MS in typical Flemish dairy diets does not lead to CH4 reduction,

because it is more than only the exchange of two forages.

35

ECOLOGICAL WATER QUALITY AND THRESHOLD RESPONSES OF MACROINVERTEBRATE COMMUNITIES TO STREAM VELOCITY IN THE GUAYAS RIVER BASIN (ECUADOR)

Thi Hanh Tien Nguyen*, Pieter Boets**, Koen Lock*, Minar Naomi Damanik Ambarita*, Marie Anne Eurie Forio*, Peace Liz Sasha Musonge*, Natalija Suhareva*, Elina Bennetsen*,

Gert Everaert*, Luis Elvin Dominguez Granda***, Thu Huong Thi Hoang**** and Peter Goethals*

* Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology, Belgium;

** Provincial Centre of Environmental Research, Ghent Belgium *** Escuela Superior Politécnica del Litoral, Ecuador

**** Hanoi University of Science and Technology, Vietnam

The Guayas River basin is one of the most important water resources in Ecuador, but the

expansion of human activities has led to a degraded water quality. Unfortunately, detailed

information on the water quality and the ecological status of the Guayas River basin is not available

for decision making and water management. The purposes of this study were: (1) to explore the

ecological water quality and the importance of physical-chemical variables in structuring the

macroinvertebrate communities and (2) to determine if the thresholds in stream velocity related to

macroinvertebrate community composition could be identified in the Guayas River basin.

Macroinvertebrates and physical-chemical water quality variables were sampled at 120 locations

during the dry season of 2013 in the Guayas River basin. The Biological Monitoring Working Party –

Colombia (BMWP-Colombia) values were calculated to assess the ecological water quality. Canonical

Correspondence Analysis (CCA) was performed to identify relevant physical-chemical characteristics

of the river influencing the distribution of the macroinvertebrate communities. The BMWP-Colombia

scores indicated that water quality of the sampling sites within the Guayas River basin ranged from

good to very bad. According to the CCA, the most important environmental factors influencing the

distribution of macroinvertebrate communities are stream velocity, chlorophyll, conductivity,

temperature and elevation. Threshold Indicator Taxa ANalysis (TITAN) was able to discriminate

between the macroinvertebrate communities related to stagnant water (Daule-Peripa reservoir) and

the macroinvertebrate community related to running waters. The results provide essential

information to further support water management plans of the Guayas River basin. Information

obtained will be useful for management of similar rivers in South-America, as well as the rest of the

world.

36

DEVELOPMENT AND VALIDATION OF AN UHPLC-ESI-MS/MS METHOD TO QUANTIFY ESTROGENIC COMPOUNDS AS PYRIDINE-3-SULFONYL DERIVATIVES IN AQUEOUS

MATRICES

Alex Glineur*, Sébastien Ronkart**, Katherine Nott**, Georges Lognay* and Eva Tyteca*

* Gembloux Agro-Bio Tech, Université de Liège; Belgium ** Société Wallonne des eaux

Natural estrogens (estrone:E1, 17-β-estradiol : E2, estriol : E3) and synthetic estrogen (17-α-

ethinylestradiol: EE2) are powerful endocrine disruptors. They may have deleterious effects on

aquatic wildlife and also humans even at extremely low concentrations. For this reason, these

molecules have been included in a watch list from the European Commission regarding emerging

aquatic pollutants. The maximum detection limits are set at 0.035 and 0.4 ng/L for EE2 and E1, E2

respectively. Reaching such low levels of concentration of estrogenic compounds is a challenge, even

using state-of-the-art analytical methods. In this study, we developed a UHPLC-ESI-MS/MS (ultra-high

performance liquid chromatography-electrospray ionization-tandem mass spectrometry) method

allowing the quantification of E1, E2, E3 and EE2 residues in aqueous matrices. Studies commonly

used ESI in negative mode, albeit the poor ionization efficiency of native estrogenic compounds in

this mode. In this study, the molecules were derivatized using a sulfonyl chloride reagent: pyridine-3-

sulfonyl (P-3-S). The resulting response in the positive mode was significantly enhanced. Similarly to

other dansyl derivatives, the product ion spectra of the P-3-S derivatives indicate ions originating

from the derivatization reagent moiety (Zhang et al. 2004). Moreover, several other ions were

included in the product ion spectra of the P-3-S. Their specificity was assessed by a qualitative

approach implying the analysis of different types of water samples (groundwater, surface water).

Some product ions were found to be noticeably better for quantification and confirmation of the

analytes. The developed analytical method was validated according to the NF T90-210 norm which is

suitable to assess the performances of a method in the water quality field. The limits of detection

were 0.012, 0.015, 0.030 and 0.006 ng/L in groundwater and 0.267, 0.237, 1.33 and 0.087 ng/L in

surface water for E1, E2, E3 and EE2 respectively.

37

EMERGING THREATS TO UGANDAN HONEYBEES, PILOT STUDY REVEALS PRESENCE OF PESTICIDES AND HONEYBEE PATHOGENS

Deborah Ruth Amulen*, Paul Cross**, Lina De Smet*, Niels Piot*, Marijke D’haese*, Dirk C.

de Graaf*, Pieter Spanoghe* and Guy Smagghe*

* Ghent University; Belgium ** Bangor University, United Kingdom

Demand for honey in the global market outstrips supply. In an effort to avert this, many

development organizations and governments are encouraging African farmers to embrace

beekeeping, a process that requires healthy honeybees and safe products. However, information on

the health status of these honeybees especially in Uganda is generally limited, including knowledge

of hive product contamination. Our study set out to address the above knowledge gaps through

molecular pathogen and multi-residue screening of agricultural pesticides commonly used. A total of

286 honeybee colonies from 143 apiaries across three ecological zones and 93 hive products (honey,

honeybees, and beeswax) were collected for analysis. Out of the 10 virus pathogens screened, four

were detected i.e. Deformed wing virus, Black Queen Cell Virus, Acute Bee Paralysis and Sac Brood

virus. Other pathogens present and some of which were first time detection in Ugandan colonies

included Phorid fly, Spiroplasma spp, Trypanasomatid spp and Apicytis bombi. Additionally, out of 36

compounds screened we detected 20 pesticides in beeswax with higher frequencies near citrus and

tobacco farms linking contamination to agricultural activity. Although, presence of pesticides and

honeybees are known to cause devastating effects to bees, at the moment the detected

concentrations in Ugandan colonies may not be much of risk, since all levels were below the lethal

dose for honeybees and maximum residue limits for EU. We still recommend routine monitoring to

ensure the potential pathogen and pesticide effects to honeybees are regulated.

38

CONTRASTING VULNERABILITY AND RESILIENCE TO DROUGHT-INDUCED DEFOLIATION IN MIXED VERSUS PURE STANDS.

Ana Rita Silva*, Koenraad Van Meerbeeck*, Thomas Van de Peer*, Geert Sioen**, Christian

Laurent***, Quentin Ponette****, Kris Verheyen* and Bart Muys*

* Ghent University, Belgium; ** Research Institute for Nature and Forest (INBO), Belgium *** Département de la Nature et des Forêts (SPW), Belgium;

**** Université catholique de Louvain, Belgium

Drought is one of the most important climate-related events through which rapid ecosystem

changes can occur as it affects the survival and function of existing forests. The impacts of these

changes become evident during regular monitoring efforts of tree health, such as those commonly

undertaken in the ICP Forests monitoring plots.

In this study, we revisited the trends in defoliation of Belgian monitoring plots, and

hypothesized that the effects of climate-related vitality loss are tempered in mixed stands in

comparison to monocultures. Three main European species were considered: European beech,

sessile oak and pedunculate oak, growing in pure and mixed stands, which allowed us to test for

species identity and diversity effects in terms of forest defoliation response to drought, from 1988 to

2015. Within the covered period, the most extreme drought episodes were always followed by

defoliation peaks. Our results also indicate that sessile oak is more tolerant to drought than beech;

but mixed beech has the quickest recovery and was significantly more resilient than in pure stands.

Finally, the higher resistance and resilience to episodic drought stress of sessile oak, both in

pure and mixed stands, provide additional arguments for a preferential choice of this species as a

climate change adaptation strategy.

39

Lecture session 2.3

HUMAN HEALTH AND GENOMICS AND BIOTECHNOLOGY

40

FUNCTIONAL AND STRUCTURAL ELUCIDATION OF A SSDNA-BINDING PROTEIN ENCODED BY THE N4-LIKE, PSEUDOMONAS PHAGE LUZ7

Maarten Boon*, Jeroen De Smet*, Elke De Zitter*, Marc De Maeyer*, Luc Van Meervelt*

and Rob Lavigne*

* KU Leuven, Belgium

Bacteriophages are the natural enemy of bacteria, which makes them ideal for investigating

potential antibacterial applications. Through millions of years of coevolution they have become

excellent at setting crucial host processes to their hand. A significant amount of this host

reorganization is directed through protein-protein interactions of phage ‘early’ proteins with host

target proteins [1]. Hence, they could provide new insights on possible antibacterial targets.

However, the function of these phage proteins is largely unknown. Moreover, most of them have

little to no sequence homology with known proteins, making functional predictions difficult.

The early phage protein studied here is gp14 from a Pseudomonas aeruginosa phage, LUZ7.

This protein was previously shown to be toxic when expressed in P. aeruginosa, leading to

filamentous growth of the cell [2]. Based on in silico predictions, we tested this protein for DNA

binding activity in various Electrophoretic Mobility Shift Assays (EMSAs). The results show sequence

independent binding to both dsDNA and ssDNA and RNA, with a much higher affinity for ssDNA.

Using X-ray data, a model of gp14 was built. The model reveals that the protein occurs as a

homodimer with features of a PC4-fold. This is a fold commonly found in ssDNA binding proteins and

supports the ssDNA binding character of the protein.

Comparison of Pseudomonas phage LUZ7 to the related coliphage N4 indicates that this ssDNA

binding phage protein might be a functional analogue of N4 gp2, a protein recently elucidated in E.

coli. Interestingly, both proteins have no sequence similarity whatsoever, but their biological role in

shifting transcription from early to middle phase might be conserved.

REFERENCES

[1] Roucourt, B., Lavigne, R. (2009). Environ Microbiol 11: 2789-2805

[2] Wagemans, J., et al. (2014). Cellular Micrbiol. 16: 1822-1835

41

INTRINSICALLY DISORDERED PROTEINS – EXTRAORDINARY PROTEIN FUNCTIONS AND NOVEL METHOD FOR THEIR DETECTION

Nevena Hristozova*, Denes Kovacs* and Peter Tompa*

* VUB – VIB, Belgium

The importance of protein multi-functionality remains underestimated. We know very little of

the ability of certain proteins to perform conceptually different functions with the same ultimate

goal of protecting the cell they are active in. Plants accumulate Late Embryogenesis Proteins to a

large extent under abiotic stress conditions alongside other protective molecules. We are able to

show now that some of these LEA proteins can function as promiscuous chaperones, while others

showed them being able to bind ions, water or membranes. The lack of conventional chaperone

structural domains in LEA proteins might be the evolutionary tradeoff of specificity and binding

strength for the ability to protect various partners directly via transient weak interactions, and

indirectly by sequestering ions and/or binding water. Investigating the ability of some proteins to

double as chaperones during adverse conditions would provide insights into the ability of organisms

to repurpose already synthesized proteins in conditions when producing new, more specific/suitable

proteins might not be an option. In a rapidly changing environment, every bit of knowledge of the

mechanisms plants employ to survive stress is of unprecedented importance for our efforts to

develop sustainable and resilient crop varieties, in order to ensure food security.

We developed a method we to test putative chaperones which we believe is a significant

improvement of the state of the art. The use of it may lead to a considerable increase in the number

of experimentally verified proteins with such functions, and may also allow the dissection of their

molecular mechanism. Additionally, we test the fitness of our method to assess the proteostatic

functions of complex protein mixtures. In our case we tested a full bacterial protein extract, but we

believe it being adaptable for measuring blood serum or cerebral fluids, where increase of

chaperones often indicates inflammation or disease.

42

HokB, A PORE-FORMING TOXIN, INDUCES PERSISTENCE AFTER DIMERIZATION

Dorien Wilmaerts*, Jan Michiels* and Natalie Verstraeten*

* KU Leuven, Belgium

Infectious diseases are among the leading causes of death worldwide. In addition to the well-

known and widely studied problem of resistance, bacterial populations are known to harbor a small

number of so-called persister cells that transiently show tolerance to very high doses of antibiotics.

Among the known effectors of persisters are toxin-antitoxin modules that can induce dormancy or

growth arrest when the toxin concentration reaches a certain threshold. Recently, we showed that

the conserved GTPase Obg mediates bacterial persistence by upregulating expression of the toxin

hokB. This gene encodes a membrane protein which after insertion causes the membrane potential

to collapse, thereby inducing persistence. In the current project we further elucidated the mode of

action of HokB. We discovered that formation of disulfide bridges in the periplasmic part of the

peptide is crucial for induction of persistence. The formation of these dimers is effectuated by an

oxidoreductase in the periplasm. Interestingly, a specific balance between monomers and dimers of

HokB seems to be important for the induction of persistence. The biological consequences of this

dimerization are currently under investigation as we hypothesize that the monomer/dimer ratio has

an influence not only on the induction of persistence but also on the resuscitation of HokB-induced

persister cells. Furthermore, in vitro experiments showed that HokB is a pore-forming toxin, and that

the pore size is too big to be selective. Identifying the nature of molecules that are transported

through HokB pores is the subject of ongoing investigation. Combined, our findings provide new

insights in the regulation of persistence at the single-cell level and we anticipate that these results

will contribute to a better understanding of the molecular mechanisms underlying persistence.

43

NANOBODY-BASED DEPLETION OF PROTUMORAL TUMOR-ASSOCIATED MACROPHAGES AS NOVEL CANCER THERAPY

Evangelia Bolli*, Matthias D'Huyvetter**, Kiavash Movahedi*, Nick Devoogdt**, Tony

Lahoutte** and Jo Ginderachter*

* CMIM, Vrije Universiteit Brussel, Belgium ** ICMI, Vrije Universiteit Brussel, Belgium

Tumors are considered as organoid structures, which contain not only cancer cells but also

non-transformed types of cells, the stromal cells. A bidirectional interplay exists between

transformed and non-transformed cells, which results in tumor progression and metastasis. Tumor-

associated macrophages (TAMs) are one of the dominant cell types present in murine and human

tumors. Clinical and experimental studies have delineated the highly pro-tumorigenic role of TAMs

through a variety of mechanisms. For this reason, the depletion of pro-tumorigenic TAMs forms an

attractive perspective in the treatment of cancer.

We have previously shown that the Macrophage Mannose Receptor (MMR, CD206) is highly

expressed on the surface of pro-tumorigenic TAMs, rendering it an important molecule for targeted

TAM depletion. Hence, we intend to deplete the pro-tumorigenic MMRhigh TAMs by using anti-MMR

Nanobody (Nb)-conjugates, whereby Nbs are the antigen-recognition domains of camelid heavy

chain-only antibodies. For this purpose, we have generated both anti-mouse and cross-reactive anti-

human/mouse MMR Nbs and have selected the lead compounds, cross-reactive Nb3.49 and anti-

mouse Nb1, based on their optimal in vivo pharmacokinetic properties. [99mTc]-labeled Nb1 exhibits

high tumor penetrance, upon blocking of extra-tumoral binding sites with an excess of unlabeled

bivalent Nb1, as visualized via SPECT/microCT imaging. The same behavior has been observed in the

case of [18F]-labeled Nb3.49 via PET imaging. We have currently conjugated the lead anti-MMR Nb1

to the therapeutic radionuclide 177Lu for radioimmunotherapy. Co-administration of the therapeutic

radiolabeled MMRNb1 with an excess of unlabeled bivalent MMRNb1 to TS/A breast tumor-bearing

mice, leaded to remarkable retardation of tumor growth compared to non-treated animals.

44

AKKERMANSIA MUCINIPHILA COLONIZATION OF AN IN VITRO DISTAL COLON IS LARGELY MUCIN AND Ph DEPENDENT

Florence Van Herreweghen*, Pieter Van den Abbeele**, Thijs De Mulder***, Rosemarie De

Weirdt*, Annelies Geirnaert*, Emma Hernandez Sanabria*, Ramiro Vilchez-Vargas*, Ruy Jauregui****, Dietmar Pieper****, Willem De Vos*****, Clara Belzer***** and Tom Van de

Wiele*

* Ghent University, Belgium ** ProDigest, Belgium

*** ILVO, Belgium *** Helmholtz Centre for Infection Research, Germany

***** Wageningen University, The Nederlands

Introduction and objectives: Akkermansia muciniphila is an abundant human colon microbe

that feeds on mucin as its sole carbon, nitrogen and energy source, thereby producing acetate and

propionate. A. muciniphila has been correlated with human health in various studies but a

mechanistic understanding of its colonization is still lacking. Materials and methods: In this study, we

used the dynamic SHIME model to uncover the ecological behavior of A. muciniphila in the colon, i.e.

its main site of colonization and its response to environmental parameters that are associated with a

healthy gut such as a low colon pH, the consumption of fibres (inulin) and mucin. Results and

discussion: A. muciniphila was found to colonize the distal colon (pH 6.6-6.9) more abundantly (+4

log copies/mL) than the proximal colon (pH 5.6-5.9) and this colonization pattern is due to the

preference of A. muciniphila for pH 6.15-6.9. The addition of mucin upon ten days of mucin

deprivation caused a dramatic increase of A. muciniphila (±4,5 log increase over two days), far

exceeding the response of any other bacteria present. The inulin treatment did not affect A.

muciniphila in this in vitro model, despite the observed effect of inulin on A. muciniphila in vivo (Van

den Abbeele et al., 2011). Together, our findings indicated the preference of A. muciniphila for the

distal colon environment due to its preference for more neutral pH and uncovered the quick and

stable response of A. muciniphila to mucin supplementation. The results of this study are indicative

of a high sensitivity of A. muciniphila to environmental changes. This high sensitivity could explain

why its abundance in vivo changes drastically when the conditions in the colon change, for example

due to certain disease states (Everard et al., 2011; Png et al., 2010; Wang et al., 2011; Zhang et al.,

2009). This could clarify why A. muciniphila is so often correlated with diseases and might be an

indicator species for gut health.

45

REVEALING THE ROLE OF TBC1D24 MUTATIONS IN EPILEPSY

Jone Paesmans*$, Baptiste Fischer*$, Kevin Lüthy**$, Jone Paesmans*, Charlotte De Koninck*, Ine Maes**, Jef Swerts**, Sabine Kuenen**, Valerie Uytterhoeven**, Wim

Versées*, Patrik Verstreken**

* Vrije Universiteit Brussel, Belgium ** KU Leuven

$ Equal contribution

Epilepsy can be defined as a group of neurological diseases, which are characterized by

recurrent and unprovoked seizures. Genetic forms of epilepsy have been mainly ascribed to

mutations in genes encoding ion channels and neurotransmitter receptors. However, nowadays also

mutations encoding proteins involved in other pathways are being identified as genetic causes of

epilepsy. One of these newly discovered epilepsy genes is TBC1D24 coding for the TBC1D24 protein.

Several studies have linked mutations in this gene to different devastating forms of epilepsy and also

to other neurological diseases such as DOORS syndrome and non-syndromic hearing loss. However,

the molecular mechanisms underlying these pathologies are still unresolved.

Via a genetic screen for alterations in synaptic transmission, an ortholog of TBC1D24 was

identified in Drosophila, called Skywalker. We were able to solve the crystal structure of one of the

domains of Skywalker, namely the TBC domain, revealing an unexpected cationic pocket conserved

among TBC1D24 homologs. Cocrystallization and biochemistry showed that this pocket binds

phosphoinositides phosphorylated at the 4 and 5 position. This binding is disrupted by some patient

mutations present in this pocket. Further, we showed that membrane binding via this pocket restricts

Skywalker diffusion in presynaptic terminals. In addition, the pathogenic mutations cause severe

neurological defects in flies such as impaired synaptic-vesicle trafficking and seizures. These defects

are reversed by genetically increasing synaptic PI(4,5)P2 concentrations through Synaptojanin

mutations.

Hence, we discovered that a TBC domain affected by clinical mutations directly binds

phosphoinositides through a cationic pocket and that phosphoinositides binding is critical for

presynaptic function.

46

POSTER SESSIONS

47

Poster session A: Food technology and Industrial Microbiology (noon session) A.1 Integrating clean label ingredients and non-thermal processing to retain fresh quality of cloudy fruit

juice during refrigerated storage. Junjie Yi, Biniam Kebede, Kristiani Kristiani, Tara Grauwet, Ann Van Loey and Marc Hendrickx A.2 The effect of heat shock on browning-related enzyme activity in lettuce. Celine Vanden Abeele, Katleen Raes and Imca Sampers A.3 Dissection of novel resistance mechanisms in Cupriavidus metallidurans. Md Muntasir Ali, Kristel Mijnendonckx, Natalie Leys, Pieter Monsieurs, Daniel Charlier and Rob Van

Houdt A.4 Yeast in a dynamic environment: Understanding robust growth Henning Lindhorst and Steffen Waldherr A.5 Synergistic gelation of protein and polysaccharide at low pH as a potential gel-based delivery system Wahyu Wijaya, Ashok Patel and Paul Van der Meeren A.6 Pocket Power! – increasing the potential of anaerobic digestion at farm-scale Tine Vergote, Anke De Dobbelaere, Bart Ryckaert, Jeroen Buysse, Eveline Volcke and Erik Meers A.7 Effect of cinnamon (Cinnamomum burmanii Blume) essential oils on the textural, rheological, melting

profile and antioxidant activity of white chocolate Dimas Rahadian Aji Muhammad, Valérie Lemarcq, Elien Alderweireldt, Pauline Vanoverberghe and

Koen Dewettinck A.8 Metabolism, absorption and bioactivity of Aronia polyphenols incombined microbial in vitro

digestion/cell culture models Ting Wu, Charlotte Grootaert, Stefan Voorspoels, Griet Jacobs, Judit Pitart, Ilse Scheirlinck, Senem

Kamiloglu, Sam Possemiers, Marina Heinonen, Nevena Kardum, Maria Glibetic, Guy Smagghe, Katleen Raes and John Van Camp

A.9 Investigating the emulsion stabilizing capacity of pectin and protein-rich broccoli serum Jihan Santanina Santiago, Laura Salvia Trujillo, Alex Palomo, Anuj Niroula, Ann Van Loey and Marc

Hendrickx A.10 A discrete element approach for simulating the processing of biomass Mathias Leman, Tom Leblicq, Simon Vanmaercke, Herman Ramon and Wouter Saeys A.11 Germination in psychrotrophic Clostridium botulinum: mechanism and inhibition by natural

antimicrobial compounds Aurélie De Jong, Charlien Clauwers and Chris Michiels A.12 Characterization of phenotypic and genotypic diversity of Sinorhizobium meliloti strains Vincent Greffe and Jan Michiels A.13 Controlling the flow behaviour of dark chocolate formulated with coconut sugar produced by

combination of ball mill and liquefier device Arifin Dwi Saputro, Davy Van de Walle, Maria Paulina González and Koen Dewettinck

48

A.14 Surface behavior of soluble protein fractions from Spirulina platensis Barka Abakoura and Christophe Blecker A.15 Press and Solvent oil extracted from Safou (Dacryodes edulis) pulp: comparison between their

chemical and physical properties. Yamoneka Wasso Juste, Paul Malumba, Sabine Danthine and Christoph Blecker A.16 Interfacial properties of milk fat globule membrane- A langmuir film balance study Priyanka Malik, Sabine Danthine and Christope Blecker A.17 Regression analysis of different sources of dormancy duration value for the potato varieties Margot Visse, Hervé Vanderschuren, Hélène Soyeurt and Brice Dupuis

49

Poster session B: Environment and Agriculture (noon session) B.1 Vulnerability to climate change among maize-based smallholders in three districts of Woliata Zone,

Ethiopia Sisay Belay Bedeke and Natarajan Kolandavel B.2 The contribution of pollinators in the pollination of pome fruits Jolien Smessaert, Olivier Honnay and Wannes Keulemans B.3 Adaptation to climate change among maize-based smallholders in three districts of Ethiopia Sisay Belay Bedeke, Kolandavel Natrajan, Wouter Vanhove and Patrick Van Damme B.4 Suitability of multipurpose trees, shrubs and grasses to rehabilitate gullies in sub-humid tropics Ayalew Legass, Poesen Jean, Muys Bart, Padro Roc, Hirko Dibaba and Diels Jan B.5 Acidogenic fermentation of potato wastes to produce carboxylate platform chemicals: influence of

cations used for pH control on metabolic profile Florent Awedem Wobiwo, Ebenezer Djiazet, Thomas Happi Emaga, Maurice Boda, Elie Fokou, Magali

Deleu and Patrick A. Gerin B.6 A decision support system for maximizing ecosystem services provided by urban green based on

species choice Annelies Calmeyn B.7 Overall situation and influence factors of rural population employment in China: based on 1095

samples from 22 Provinces in 2016 Tian Tian B.8 Comparison of two laboratory-scale ensiling methods to assess effect of reducing sugars Sophie Herremans, Virginie Decruyenaere, Yves Beckers and Eric Froidmont B.9 Adoption of alternative biofuel trees in Karnataka, India: a choice experimental study Floris Dalemans, Bart Muys, Miet Maertens and Anne Verwimp B.10 Particulate matter deposition on urban green: an indicator of habitat quality in cities Ana Castanheiro, Karolien De Wael and Roeland Samson B.11 Biomonitoring of urban air quality: the potential of hyperspectral measurements Jolien Verhelst, Dimitri Dauwe and Roeland Samson B.12 Ecological intensification of fish production : Fertilization strategies in Africa fish farms Mafwila Kinkela Patrick, Kambashi Mutiaka Bienvenu, Rollin Xavier and Bindelle Jerome B.13 Is faecal neopterin a good biomarker for intestinal health in chicken? Mohammad Kamely and Theo Niewold B.14 Parameters related to water balance improve the relationship between the milk urea concentration

and urinary N excretion. Pieter Deckers, Dorien Van Wesemael, Nico Peiren, Veerle Fievez and Leen Vandaele B.15 Relationships between methane emissions from dairy cows and farm technico-economic results.

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Pauline Delhez, Benoît Wyzen, Anne-Catherine Dalcq, rédéric Dehareng, Nicolas Gengler and Hélène Soyeurt

B.16 Controlling aphids on wheat by sowing wildflower strips within field: it’s possible! Séverin Hatt, Thomas Lopes, Qinxuan Xu, Fanny Boeraeve, Julian Chen and Frédéric Francis B.17 Green walls for sustainable buildings and cities: aerodynamic characterisation of vegetation Kyra Koch, Roeland Samson and Siegfried Denys B.18 Assessment of the combined effect of temperature and relative humidity on fungal growth Liselotte De Ligne, Guillermo Vidal Diez de Ulzurrun Jan Baetens, Jan Van den Bulcke and Bernard De

Baets B.19 Identification of a Linuron mineralizing bacterial genus in a BPS material through stable isotope

probing Harry Lerner, Basak Ozturk, Anja Dohrmann, Christoph Tebbe, Kathleen Marchal, Rene de Mot and

Dirk Springael B.20 Differences between the leaf and stem essentials oils of domestic Mentha spicata var. spicata (L.

1753) plants Gabriel Olive and Gilles Olive B.21 Physicochemical characteristics and fatty acid profile of longissimus dorsi muscle of Bni-Guil sheep

breeding in eastern Morocco Kamal Belhaj, Ahmed Elamrani, Mohamed Boukharta and Marianne Sindic B.22 An NFO-LP-model to optimise water allocation in dammed river systems. Jaime Veintimilla, Stefaan Dondeyne, Dirk Cattrysse and Jos Van Orshoven B.23 Physical chemical treatment of landfill leachate: Monitoring and characterization of DOM using

spectral and chemometric techniques. Violet Oloibiri, Sam Deconinck, Michael Chys, Kristof Demeestere and Stijn Van Hulle B.24 Forest policies for sustainable forest management in the Congo Basin. Maximilien Tiogang Djomo B.25 Benthic macroinvertebrate functional feeding groups patterns in Albertine rift rivers relative to

physical variables land-use and physical variables in Southwestern Uganda Peace Liz Sasha Musonge B.26 Simulation of maize crop production by EPICSM model under different irrigation systems in Egypt Hani Mansour B.27 A combined respirometric-titrimetric setup for the development, calibration and validation of a model

describing the microalgal growth rate Dave Manhaeghe, Bjorge Decostere, Diederik Rousseau and Stijn Van Hulle

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Poster session C: Chemistry and Engineering (afternoon session) C.1 A novel surface complexity measure based on the chemical pattern of protein interfaces Tamas Lazar, Mainak Guharoy, Eva Schad, Shoshana Wodak and Peter Tompa C.2 Production of bio-degradable plastics Sofie Winderickx C.3 Characterization of new calpain inhibitors based on an intrinsically disordered protein, calpastatin Hung Nguyen, Mihaly Varadi, Peter Tompa and Kris Pauwels C.4 Improved UV light efficiency using a photocatalytic spiraled reactor design with a plasmonic TiO2

coating Natan Blommaerts, Ramesh Asapu, Silvia Lenaerts and Sammy Verbruggen C.5 Harvesting energy from air pollution with an Un-biased gas phase photo-electrochemical cell Myrthe Van Hal, Tom Bosserez, Jan Rongé, Johan Martens, Silvia Lenaerts and Sammy Verbruggen C.6 An EPR study on the nature of radicals in the B-class dye-decolorizing peroxidase from K. pneumonia Kevin Nys, Vera Pfanzagl, Christian Obinger and Sabine Van Doorslaer C.7 Bioavailability of pomegranate-derived polyphenols in an in vitro model combining luminal digestion

with epithelial Caco-2 cell transport Hanne Vissenaekens, Charlotte Grootaert, Francisco Tomas-Barberan, Judit Pitart, Ilse Scheirlinck,

Rocio Garcia-Villalba, Sam Possemiers, Matthijs Verhille, John Van Camp and Carlos Espín C.8 Confined catalytic Janus swimmers in a crowded channel: geometry-driven rectification transients and

directional locking Vyacheslav Misko C.9 Characterization of a protein family related to Parkinson’s disease Margaux Leemans C.10 Stability of Difference Schemes for Reaction-Diffusion Models of Chemical-Reaction Networks Nathan Muyinda, Bernard De Baets and Shodhan Rao C.11 Nanobody discovery platform: From a llama immune response to tailor-made biological agents. Tomasz Uchanski and Jan Steyaert C.12 Volatile organic compounds in the interaction between Banana plants (Musa sp.) and Panama Disease

Fusarium oxysporum f.sp. cubense Tropical Race 4 (FocTR4) Chadi Berhal, Caroline De Clerck, Carolina Levicek, Francois Verheggen, Marie-Laure Fauconnier and

Sébastien Massart C.13 Injectable peptide hydrogels for controlled drug release Edith Oyen, Charlotte Martin, James Gardiner, Bruno Van Mele, Annemieke Madder, Richard

Hoogenboom, Mariana Spetea and Steven Ballet

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Poster session D: Human health and Genomics and Biotechnology (afternoon session) D.1 Protein intrinsic disorder: a double-edged sword? Mauricio Macossay Castillo, Giulio Marvelli, Mainak Guharoy, Peter Tompa and Shoshana J. Wodak D.2 Role of aquaporins in membrane diffusion of hydrogen peroxide in plant cells upon salt and water

stress Ahmed Ismail and FranÇois Chaumont D.3 Chemical inhibitors of the SOG1 transcription factor to promote aluminium tolerance in maize and

barley Manon Demulder D.4 Using protein interactions to develop new antibiotic production lines Thomas Lathouwers, Birgit Uytterhoeven, Chris Michiels and Rob Lavigne D.5 Elevated CO2 mitigates drought stress in Arabidopsis thaliana: Role of glucosinolates metabolism. Hamada Abdelgawad, Gaurav Zinta, Marios Nektarios Markakis, Gerrit T.S. Beemster and Han Asard D.6 Roles of ERD14 in plant stress responses Phuong Nguyen Nhu, Tran Thanh Thu, Maria Tossounian, Stefanie Clemens, Denes Kovacs and Peter

Tompa D.7 An innovative method to identify interaction partners of the persister protein Obg Pauline Herpels, Jan Michiels, Natalie Verstraeten, Josep Rayo Company and Anastassios Economou D.8 Antibiotic-tolerant persisters contribute to the evolution of genetic resistance Etthel Windels, Joran Michiels, Bram Van den Bergh, Tom Wenseleers, Maarten Fauvart and Jan

Michiels D.9 Development of tools for haploid breeding in Chrysanthemum Chunlian Jin and Danny Geelen D.10 Dermal exposure of Belgian florists to insecticide residues Khaoula Toumi, Laure Joly, Christiane Vleminckx and Bruno Schiffers D.11 Transcriptomic biomarkers in elderly women: Toward understanding age-related hearing impairment Amal Bouzid, Ibtihel Smeti, Amine Chakroun, Abdelmonem Ghorbel, Joel Lachuer, Tim De Meyer and

Saber Masmoudi D.12 Functional display of fusion proteins using the curli biogenesis pathway Imke Van den Broeck, Han Remaut and Nani Van Gerven D.13 Comparative genomics study of Pseudomonas aeruginosa nosocomial strains Cédric Lood D.14 Phylogenetic history and synteny of AT-Hook proteins in monocarpic and polycarpic plant species Rashmi Hazarika and Vera van Noort D.15 Genome-wide transcriptional changes in a polyphagous arthropod pest upon exposure to insecticide

synergists.

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Simon Snoeck, Wannes Dermauw, Richard Clark, Luc Tirry and Thomas Van Leeuwen D.16 Fluorescent probiotic strains for studying microbe-microbe and microbe-host interactions Irina Spacova, Elke Lievens, Tine Verhoeven, Hans Steenackers, Jozef Vanderleyden, Sarah Lebeer and

Mariya Petrova D.17 Exploring the role of suspected pathogens of chronic middle ear pathology and their interaction with

potentially beneficial microbes Jennifer Jörissen, Marianne van den Broek, Sander Wuyts, Ilke De Boeck, Paul Van de Heyning, Vincent

Van Rompaey, Olivier Vanderveken, An Boudewyns and Sarah Lebeer D.18 Targeting Neuropilin-1 through single-domain antibodies: a novel strategy to tackle tumor-associated

macrophages Stefano Bonelli, Damya Laoui, Jiri Keirsse and Jo Van Ginderachter D.19 Molecular characterization of a GntR-like transcription factor involved in heat stress response in

Sulfolobus acidocaldarius Liesbeth Lemmens, Ezra De Koning and Eveline Peeters D.20 Unraveling the metabolic phenotype of tumor-associated macrophages and the impact of metabolic

reprogramming on their functionality. Xenia Geeraerts, Jo A D.21 Fluorescent microscopy combined with Raman-data acquisition and analysis Dmitry Khalenkow D.22 Ly6Clo monocytes promote hepatoregeneration during drug induced liver failure Chloé Abels, Alison Redmond, Mohamed Musrati, Sofie De Groef, Jo Van Ginderachter and Alain Beschin D.23 Improving apple fruit biological control by microbiota using omics tools Abdoul Razack Sare, Haissam Mohamed Jijakli and Sebaastien Massart D.24 16S amplicon sequencing: methods, limitations and a case study Stijn Wittouck, Ilke De Boeck, Sander Wuyts, Eline Oerlemans, Olivier Vanderveken and Sarah Lebeer D.25 BrewPro: Multi-stage microbial technology for the cost-effective production of high-quality animal feed

on brewery effluents. Gustavo Gomes de Sousa and Siegfried Vlaeminck

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