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Citation: Nitin KS, Vivek KT, Santosh KM. The Production of Xylanase Enzyme (E.C. Number = 3.2.1.8) Using Solid Substrate

Fermentation. Biotechnol Ind J. 2017;13(4):145.

© 2017 Trade Science Inc.

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The Production of Xylanase Enzyme (E.C. Number=3.2.1.8) Using Solid

Substrate Fermentation

Nitin Kumar Singh*, Vivek Kumar Tiwari and Santosh Kumar Mishra

IMS Engineering College , Ghaziabad, India

*Corresponding author: Nitin Kumar Singh, IMS Engineering College , Ghaziabad, India, Tel: 01332 285 311; E-mail:

[email protected]

Received: June 04, 2017; Accepted: July 21, 2017; Published: July 24, 2017

Introduction

The Global market for industrially useful enzymes was estimated to be about $4.2 billion in year 2014 and is expected to

develop at a compound annual growth rate (CAGR) of approximately 7% over the period from 2015 to 2020 to reach nearly

$6.2 billion in the year 2015 at Industrial Enzyme Market [1-9]. Within the grain-processing proteins sector alone which

accounts for the widest sector where enzymes are used the growth is significant. Presently the technical industries, dominated

by the detergent, textile, starch and fuel alcohol industries, account for the bulk of the overall enzymes used in the industrial

sector, with the feed and food enzymes along totaling solely regarding thirty fifth of total. Enzymes are a group of protein

which increases the rate of the biological reaction. Xylanase is the class of enzymes which convert the polysaccharide beta-

Abstract

The production of Xylanase enzyme (E.C. number=3.2.1.8) was studied using solid substrate fermentation. Various solid substrates

were selected as a solid substrate for Xylanase production using SSF. Optimum xylanase activity was observed when Pea peel has

been used as solid substrate. The production of the xylanase is carried out some other solid agricultural waste because. Agro

industrial waste are a good source of nutrition for the growth of the microorganisms as they are rich in carbon source and agro-

industrial wastes such as wheat bran, sugarcane bagasse, corn cob, rice bran and wheat straw are abundantly available and

cheapest natural carbon sources. The present study is an attempt for process optimization for xylanase production using agro

industrial waste as a sole carbon source. The production of the enzyme xylanase has industrial use and it can be used for many

commercial purposes including chlorine free bleaching of the wood pulp prior to papermaking. Xylanases can also be used as food

additives in poultry, in wheat flour for improving the handling of dough and increasing the quality of baked products, it is also used

for the extraction of coffee, extraction of plant oils and starch. Different physical and chemical parameters which affects the

production of xylanase has been optimized by batch experiment as well as using statistical tool i.e., Design-Expert. Experimental

outcomes showed that agro-industrial residue having excellent potential for the production of industrial important enzyme i.e.,

Xylnase.

Keywords: Agro-industrial; Plant oils; Xylanase enzyme; Fermentation

www.tsijournals.com | July-2017

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1,4-xylan into xylose, it breaks hemicellulose, which is the major components of plant cell walls. It plays a major role for the

degradation of plant cells hemicelluloses into the usable nutrients. Xylan is found in massive quantities in softwoods from the

gymnosperms i.e., 7% to 10% and hardwoods from the angiosperms i.e., 15% to 30% of the plasma membrane content and

similarly as in annual plants about 30%. It is mainly present in the secondary cell wall of plants, but it is also found in

primary cell wall, mainly in monocots. The ecological niches of those micro-organisms which having capability to produce

xylanase are numerous and widespread and generally embrace environments wherever stuff accumulate and deteriorate,

similarly as within the tum of ruminants [10-14]. Xylanases are produced by bacteria, fungi, snails, marine algae, protozoans,

yeast, seeds, insect, crustaceans, etc., (mammals do not produce xylanases). The main source for industrially important

xylanases is the filamentous fungi. Solid state fermentation (SSF) process is the preferable biochemical process for the

production of xylanases using various agro industrial waste although various methods use submerged fermentation for the

enzyme. The process of the SSF is more economical and it is easy to isolate the enzyme in a SSF. Use of SSF provide various

advantages to the system the low wetness content of the substrates eliminates the borderline contamination, lowering the

operational value of the reactors, it is also economical [15-21]. For SSF the product separation is simple and fewer

cumbersome. One of the major advantages of using SSF is that there is low waste water output and also no issues of foaming.

Xylanases can be of fungal origin or the bacterial origin and based on the climatic conditions where the enzyme is originated

it can be Extremophilic xylanases, Thermophilic xylanase, Psychrophilic xylanase or alkaliphililic and acidophilic xylanase.

Xylanase is an industrially important enzyme which is used in many industrial processes. The major current application of

xylanases is within the pulp and paper industries for economical biobleaching. Xylanases would even be needed for detergent

applications, xylanase would be helpful in animal feeds if accessorial to the feeds, they'd be most fitted to use within the

baking business as dough preparation. The use of Xylanase can be seen in production, cut back haze within the final product,

to extend wort filterability. In occasional extraction and within the preparation of soluble occasional. It is also used in the

production of pharmacologically active polysaccharides to be used as, within the proto-plastation of plant cells, antimicrobial

agents or antioxidants, and within the laundry of exactitude devices and semiconductors, within the production of alkyl

radical glycosides to be used as surfactants. Further, this study can be useful in reducing the cost of enzyme. The future

prospects of this enzyme lie in its use as Biofuel and replacement of chlorine from the industries which is used in beaching

purposes. The objective of the research work was to isolate and screen the microorganism producing xylanase and its process

optimization using a statistical tool i.e., Response Surface Methodology. The study was done using the agricultural waste

products.

Materials and Methods

Inoculum preparation

Culturing and sub culturing of microorganisms- Source microorganism culture was provided by IMSEC culture bank. This

culture was grown on Potato Dextrose Broth. Culture was revived after two or three weeks regularly. Maintenance of culture

and inoculum preparation- Once the reviewed strain was inoculated in the Petri plates containing PDA media. Culture plates

are covered with parafilm and incubated at 28°C in BOD incubator [22-25]. YEPD broth was prepared by using yeast,

peptone, dextrose and distilled water. This broth was incubated at 30°C for 4 days for the growth and kept in refrigerator for

the maintenance of culture [26-32]. For inoculum development prepare a broth of Aspergillus nidulens and inoculate 500 µl

from it to all the autoclaved flask keep it in incubator at 30°C for 5 days to observe growth Screening and selection of agro

waste for the Xylanase production- Various agro industrial waste were taken, used and screened for their ability to produce


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Xylanase. After the grinding the substrate was autoclaved and then seeded with the microorganism, after 72hrs of incubation

the growth of fungus was optimum and further enzyme was extracted and assayed. Out of the various solid Substrates used

this has been observed that growth of the microorganism was maximum in Pea peels, therefore pea peels were selected for

the further research work for Xylanse production.

Enzyme assay

The amylase assay was performed according to the protocol. One unit of enzyme activity is defined as the quantity of enzyme

that caused 0.01% reduction of color intensity of xylan solution at 50 1C in 1 min per ml.

Optimization of process parameters

Optimization of various process parameters were carried out based on the growth of the micro-organism and how that

particular parameter is affecting the activity of the enzyme. Various previous studies done for the production of the enzyme

estimated that the growth of the enzyme is optimal at the temperature of around 30°C to 35°C, experiments were set

accordingly keeping in mind the optimal temperature range and since the presence of the moisture content provides a better

environment for the growth of the fungus, this parameter needs to be optimized to get the maximum enzyme activity [33-35].

Since carbon source is required to meet the energy requirements of the cell, so an additional carbon source other than the raw

substrate is provided in order to meet the requirements of the microorganism during the growth phase. Nitrogen is also an

important macronutrient which is used by the microorganism for DNA synthesis and other work such as synthesis of the

amino acids. So, on providing an optimal amount of the carbon and nitrogen source the growth of the microorganism can be

optimized.

Optimization by response surface methodology: Response surface methodology i.e., RSM is a collection of statistical and

mathematical techniques for empirical model building. By careful design of experiments, the objective is to optimize a

response which is influenced by several independent variables (input variables). An experiment is a series of tests, called

runs, in which changes are made in the input variables in order to identify the reasons for changes in the output response [36-

39]. This was done using Design Expert tool by which we can use the RSM effectively. Different sets of experimental runs

were provided by this tool by using different variables which were used to set up the experiment. The variables taken here are

the temperature, moisture content, carbon source and nitrogen source. Different runs of the experiment were done and the

results were analysed for the different runs of the experiment.

Result and Discussion

During the present research work, this has been observed that different solid agro industrial substrate can be used for the

production of xylanse and product formation is directly associated with the growth of fungi. Further on the basis of initial

screening that Pea Peals having excellent potential for the production of xylanase as solid substrate the Xylanase production

process was optimized. The results indicate that Pea peels when used as solid substrate the maximum absorbance was

observed at 540 nm wavelength with 100% initial moisture content used. It has been also found that initial moisture content

plays significant role in the growth of microorganism and subsequently in the production of Xylanase [40-45]. Temperature

also play another critical role in the growth of fungi and product formation Result of experiment showed that the growth of

the microorganism was maximum at 30°C. Experimental outcome indicates that additional Carbon and Nitrogen sources


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enhance the growth of A. nidulans and resulting in the enhanced production of xylanase. It was observed that during the

experiments Dextrose was preferred carbon source which promotes the growth of fungus. On the other hand 0.1M urea when

used as supplementary nitrogen source in the solid substrate enhances the maximum growth of the microorganisms After the

initial results of individual experiment the effect of all the four factors we have used DESIGN EXPERT tool to see the

combined effects of the factors on the growth of the microorganism. Eight different experiments were performed in different

flasks according to runs provided by RSM tool of Design expert and the further enzyme activity has been recorded.

The effect of different physical and chemical parameters on the Xylanase production were observed. During this research

work the major parameters that affects the growth of the filamentous fungi and production of xylanase were moisture content,

temperature, Carbon source and nitrogen source. Experimental outcome of the various physical and chemical parameters has

been given below:

Moisture content

For optimization of the moisture content three flasks with solid substrate including desired moisture content and other

supplementary nutrients were incubated at 30°C for 72 hrs. The crude enzyme was extracted and enzyme activity was

observed. Results reveals that when moisture content was used 100% w/v the enzyme production was maximum further this

has also been observed that when moisture content is increased it decreases the porosity of the solid substrate that

prevents the growth of the filamentous fungi. However, lower moisture content i.e. , 80% seems to unavailability of

desired water content for the growth of filamentous fungus resulting in the decrease of enzyme activity. Similar type of

study was performed by Ajay Pal [13] by using soybean cake with variable moisture content as solid substrate the

optimum growth of microorganism was observed with 70% moisture content. Result of moisture content showed that

moisture content is a critical factor that affects the growth of microorganism. The variable moisture content is needed

by different solid substrate due to variable properties of solid substrate i.e. , porosity, particle size and surface area etc

(FIG. 1).

FIG. 1. Effect of moisture content on enzyme activity.


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Temperature

For optimizing the temperature for the growth of the microorganisms on the solid substrate, the solid substrate was

three different flasks and the 100% moisture content was provided, the flasks were incubated at three different

temperatures i.e., 25°C, 35°C and 30°C. After inoculating the flasks with A. nidulens maximum enzyme activity was

observed at 30°C when pea peels were taken as solid substrate. Sanghi et al. [3] performed similar type study in which

effect of temperature on xylanase production was optimized using wheat bran as asolid substrate and maximum enzyme

activity was at 30°C when pea peels were taken as solid substrate (FIG. 2)

FIG. 2. Effect of temperature on enzyme activity.

Carbon source

Xylanase research suggests that supplementary carbon source promotes the growth of microorganism when used in

desired concentration. For the optimization of the role of additional carbon content, initially four carbon sources i.e. ,

Xylose, Dextrose, Maltose and Fructose were used in solid substrate. Experiments were set up in four different flasks in

which the substrates were provided with these additional carbon sources. Result of these experiment showed that when

Dextrose were used in 1.5% w/v 5 ml in each flask was used there is maximum growth of fungi. Jatinder et al. [12]

investigated the effect of carbon source and it was found that using RSM the most suitable additional carbon source

was Dextrose, in our study we found that with Dextrose as additional carbon source the enzyme activity was maximum

(FIG. 3).


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FIG. 3. Effect of additional carbon source on enzyme activity.

Nitrogen content

For the optimization of the additional Nitrogen source which is to be provided to the substrate in order to support the

growth of the microorganisms, four different flasks with different nitrogen sources and their different concentrations

were incubated at 30°C. A similar study for the optimization of the additional nitrogen source was done by Yang et al .

in the year 2005. In our study, it was found that 0.1 M urea was best suited for the growth of the microorganism and the

enzyme activity was maximum at 0.1 M urea concentration (FIG. 4).

FIG. 4. Effect of additional nitrogen source on enzyme activity.


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Result of optimization of process parameters using design expert: Design Expert tool is the statistical way to know

the effect of one variable on the other variable. After studying the effect of various parameters individually, there was a

need to study that how the presence of one variable affects the other variable when both the parameters are used

simultaneously in the growth media. The experimental design using Response Surface Methodology was used to

estimate the coefficients in a mathematical model, to predict the response and to check the applicability of the model.

These four independent variables were studied at different levels and their minimum and maximum values are listed.

As evident from table below, run orders with different combinations of Temperature, Moisture, Nitrogen and Carbon

source levels enhanced Xylanase activity. Similar result was also obtained by Liu et al. [44] where Plackett–Burman

design with response surface methodology was proved better for optimization for the production of the enzyme.

Cotarlet and Bahrim [35] also mentioned the importance of statistical designs over “one-variable-at-a-time”

conventional approach for optimization. Relevance of statistical approach over conventional methods was also

mentioned in literature reports. Significance of statistical designs for production of enzymes was also in agreement with

the results of Kammoun et al. [23] were the yield of the enzyme was increased. For the analysis by using the statistical

tool eight different experiments were set according to the runs provided by Design Expert using RSM, these

experiments were set and the enzyme assay was done. The table below shows the runs and the results of the assays. The

contour plots were obtained which shows the dependency of one variable on the other variable.

Different graph patterns were obtained which show the dependency of one variable on the other variable, like the

dependency of Enzyme activity on Moisture and Temperature, Moisture and additional Carbon source, additional Nitrogen

source and Temperature on Enzyme activity, additional Carbon source and Temperature on Enzyme activity (TABLE 1). The

graph plots show how the presence of one variable affects the utilization of the other variable for the growth of the

microorganism (FIG. 5-8).

TABLE 1. Runs of experiments by design expert.

Run Temp Moisture Nitrogen Carbon Response

1 30 80 0.1 1 37.33

2 25 120 0.15 1.5 21.54

3 25 100 0.15 0.5 23.93

4 35 120 0.1 1 32.55

5 35 100 0.05 1.5 31.1

6 30 120 0.05 0.5 35.9

7 35 80 0.05 1.5 27.76

8 30 100 0.1 1 37.81


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FIG. 5. Combined effect of moisture and temperature on enzyme activity.

FIG. 6. Combined effect of moisture and additional carbon source on enzyme activity.

Design-Expert® SoftwareFactor Coding: ActualR1

Design points above predicted value37.81

21.54

X1 = A: TemperatureX2 = B: Moisture

Actual FactorsC: Nitrogen source = 0.1D: Carbon source content = 1

80

90

100

110

120

25 27

29 31

33 35

20

25

30

35

40

R1

A: Temperature (C)B: Moisture (%)


37.81

21.54

X1 = B: MoistureX2 = D: Carbon source content

Actual FactorsA: Temperature = 30C: Nitrogen source = 0.1

0.5

0.7

0.9

1.1

1.3

1.580

90

100

110

120

20

25

30

35

40

45

50

R1

B: Moisture (%)

D: Carbon source content (%)


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FIG. 7. Combined effect of additional nitrogen source and temperature on enzyme activity.

FIG. 8. Combined effect of additional carbon source and temperature on enzyme activity.


37.81

21.54

X1 = A: TemperatureX2 = C: Nitrogen source

Actual FactorsB: Moisture = 100D: Carbon source content = 1

0.05

0.07

0.09

0.11

0.13

0.15

25

27

29

31

33

35

10

20

30

40

50

60

70

R1

A: Temperature (C)

C: Nitrogen source (M)


37.81

21.54

X1 = A: TemperatureX2 = D: Carbon source content

Actual FactorsB: Moisture = 100C: Nitrogen source = 0.1

0.5

0.7

0.9

1.1

1.3

1.5

25

27

29

31

33

35

10

20

30

40

50

60

70

R1

A: Temperature (C)

D: Carbon source content (%)


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Conclusion

During the present research work it has been observed that Aspergillus niger have excellent potential for the production

of enzyme Xylanase when Pea peels were used as solid substrate. Simultaneously this has been found that Orange

peels, Bagasse, Pineapple peels, Mousseme peels also have good potential as a solid substrate for Xylanase production.

Good potential to utilize agricultural waste for the production of Xylanase, traditionally many agro waste have been

used for the production of this enzyme. It has been found that Pea peels are a good substrate for Xylanase production.

Moisture content also plays a major role in enzyme activity. Apart from Moisture content other factors like

temperature, additional carbon and nitrogen content were also optimized.

REFERENCES

1. Prasad CS, Mandal AB, Gowda NKS, et al. Enhancing phosphorus utilization for better animal production and

environment sustainability. Current Science. 2015;108(7):1315.

2. Adhyaru DN, Bhatt NS, Modi HA. Optimization of upstream and downstream process parameters for cellulase-

poor-thermo-solvent-stable xylanase production and extraction by Aspergillus tubingensis FDHN1. Bioresources

and bioprocessing. 2015;2(1):3.

3. Sanghi A, Garg N, Sharma J, et al. Optimization of xylanase production using inexpensive agro-residues by

alkalophilic Bacillus subtilis ASH in solid-state fermentation. World J Microbiol Biotechnol. 2008;24(5):633-640.

4. Avcioglu B, Eyupoglu B, Bakir U. Production and characterization of xylanases of a Bacillus strain isolated from

soil. 2005;21:65-68.

5. Beg Q, Kapoor M, Mahajan L, et al. Microbial xylanases and their industrial applications: A review. Applied

microbiology and biotechnology. 2001;56(3-4):326-338.

6. Biely P. Microbial xylanolytic systems. Trends Biotechnol. 1985;3(11):286-290.

7. Chandel AK, Da Silva SS, Carvalho W, et al. Sugarcane bagasse and leaves: foreseeable biomass of biofuel and bio‐

products. Journal of chemical technology and biotechnology. 2012;87(1):11-20.

8. Ko CH, Lin ZP, Tu J, et al. Xylanase production by Paenibacillus campinasensis BL11 and its pretreatment of

hardwood kraft pulp bleaching. International Biodeterioration & Biodegradation. 2010;64(1):13-19.

9. Hoyoux A, Blaise V, Collins T, et al. Extreme catalysts from low-temperature environments. J Biosci Bioeng.

2004;98(5):317-330.

10. Chapla D, Divecha J, Madamwar D, et al. Utilization of agro-industrial waste for xylanase production by

Aspergillus foetidus MTCC 4898 under solid state fermentation and its application in saccharification. Biochemical

Engineering Journal. 2010;49(3):361-369.

11. Ding CH, Jiang ZQ, Li XT, et al. High activity xylanase production by Streptomyces olivaceoviridis E-86. World

Journal of Microbiology and Biotechnology. 2004;20(1):7-10

12. Elegir G. Szakács G, Jeffries TW. Purification, characterization, and substrate specificities of multiple xylanases

from Streptomyces sp. strain B-12-2. Appl a Environ Microbiol. 1994;60(7):2609-2615.

13. Farhath Khanum, Ajay pal. The effects of solid substrates, moistening medium, initial moisture content, incubation

time and temperature on the production of xylanase by Aspergillus niger DFR-5. 2010;101:7563-7569.

14. Filho EXF. Purification and characterization of a β-glucosidase from solid-state cultures of Humicola grisea var.

thermoidea. Canadian J Microbiol. 1996;42(1):1-5.

http://www.sciencedirect.com/science/article/pii/S0960852410007157


11

15. Sanghi A, Garg N, Gupta VK, et al. One-step purification and characterization of cellulase-free xylanase produced

by alkalophilic Bacillus subtilis ash. Brazilian J Microbiol. 2010;41(2):467-476.

16. Ghanem NB, Yusef HH, Mahrouse HK. Production of Aspergillus terreus xylanase in solid-state cultures:

application of the Plackett–Burman experimental design to evaluate nutritional requirements. Biores

Technol. 2000;73(2):113-121.

17. Dhillon GS, Oberoi HS, Kaur S, et al. Value-addition of agricultural wastes for augmented cellulase and xylanase

production through solid-state tray fermentation employing mixed-culture of fungi. Industrial Crops and Products.

2011;34(1):1160-1167.

18. Jayapal N, Samanta AK, Kolte AP, et al. Value addition to sugarcane bagasse: Xylan extraction and its process

optimization for xylooligosaccharides production. Industrial Crops and Products. 2013;42:14-24.

19. Jiang ZQ, Deng W, Li LT, et al. A novel, ultra-large xylanolytic complex (xylanosome) secreted by Streptomyces

olivaceoviridis. Biotechnol Lett. 2004;26(5):431-436.

20. Ferris JJ, Joshi S. Prospects for ethanol and biodiesel, 2008 to 2017 and impacts on agriculture and food.

In Handbook of bioenergy economics and policy. Springer New York; 2010; p91-111.

21. Agrawal DC, Banerjee AK, Kolala RR, et al. In vitro induction of multiple shoots and plant regeneration in cotton

(Gossypium hirsutum L.). Plant Cell Reports. 1997;16(9):647-652.

22. Lynd LR, Weimer PJ, Zyl WH, et al. Microbial cellulose utilization: Fundamentals and biotechnology. Microbiol

Mol Biol Rev. 2002;66:506-77.

23. Mahalakshmi N, Jayalakshmi S. Amylase, cellulase and xylanase production from a novel bacterial isolate

Achromobacter xylosoxidans isolated from marine environment. Int J Adv Res Biol Sci. 2016;3(1):230-233.

24. Prasad CS, Mandal AB, Gowda NKS, et al. Enhancing phosphorus utilization for better animal production and

environment sustainability. Current Science. 2015;108(7):1315.

25. Masui DC, Zimbardi ALRL, Souza FHM, et al. Production of a xylose-stimulated β-glucosidase and a cellulase-

free thermostable xylanase by the thermophilic fungus Humicola brevis var. thermoidea under solid state

fermentation. World J Microbiol Biotechnol. 2012;28:2689-2701.

26. Nair SG, Shashidhar S. Fungal xylanase production under solid state and submerged fermentation

conditions. African Journal of Microbiology Research. 2008;2(4):82-86.

27. Oberoi HS, Chavan Y, Bansal S, et al. Production of cellulases through solid state fermentation using kinnow

pulp as a major substrate. Food Bioprocess Technol. 2010;3:528-536.

28. Peralta RM, Terenzi HF, Jorge JA. β-D-Glycosidase activities of Humicola grisea: Biochemical and kinetic

characterization of a multifunctional enzyme. Biochim Biophys Acta Gen Subj. 1990;1033:243-249.

29. Polizeli ML, Rizzatti ACS, Monti R, et al. Xylanases from fungi: Properties and industrial applications. Appl

Microbiol Biotechnol. 2005;67:577-591.

30. Polizeli ML, Rizzatti ACS, Monti R, et al. Regulation of xylanase in Aspergillus phoenicis: A physiological and

molecular approach. 2008;35:237-244.

31. Poutanen K Enzymes: An important tool in the improvement of the quality of cereal foods. Trends in Food Science

& Technology. 1997;8(9):300-306.

32. Murthy PS, Naidu MM. Production and application of xylanase from Penicillium sp. utilizing coffee by-

products. Food and Bioprocess Technology. 2012;5(2):657-664.


12

33. Saha SP, Ghosh S. Optimization of xylanase production by Penicillium citrinum xym2 and application in

saccharification of agro-residues. Biocatalysis and Agricultural Biotechnology. 2014;3(4):188-196.

34. Sánchez C. Lignocellulosic residues: biodegradation and bioconversion by fungi. Biotechnol Adv. 2009;27(2):185-

194.

35. Shah A, Datta M. Xylanase production under solid-state fermentation and its characterization by an isolated strain

of Aspergillus foetidus in India. World J Microbiol Biotechnol. 2005;21:233-243.

36. Singhania RR, Sukumaran RK, Patel AK, et al. Advancement and comparative profiles in the production

technologies using solid-state and submerged fermentation for microbial cellulases. Enzyme Microb Technol.

2010;46:541-549.

37. Souza DT, Bispo ASR, Bon EPS, et al. Production of thermophilic Endo-β-1,4-xylanases by Aspergillus

fumigatus FBSPE-05 using agro-industrial by-products. Appl Microbiol Biotechnol. 2012;166:1575-1585.

38. Gaur R, Tiwari S, Rai P, et al. Isolation, production, and characterization of thermotolerant xylanase from solvent

tolerant Bacillus vallismortis RSPP-15. Int J of Poly Sci. 2015.

39. Nagar S, Gupta VK, Kumar D, et al. Production and optimization of cellulase-free, alkali-stable xylanase by

Bacillus pumilus SV-85S in submerged fermentation. J Indus Microbiol Biotechnol. 2010;37(1):71-83.

40. Ncube T. Development of a fungal cellulolytic enzyme combination for use in bioethanol production using

Hyparrhenia spp as a source of fermentable sugars (Doctoral dissertation, University of Limpopo (Turfloop

Campus)); 2013.

41. Yang CY, Sheih IC, Fang TJ. Fermentation of rice hull by Aspergillus japonicus under ultrasonic

pretreatment. Ultrasonics sonochemistry. 2012;19(3):687-691.

42. Cotta W. Identification of a broad-specificity xylosidase/arabinosidase important for xylooligosaccharide

fermentation by the ruminal anaerobe Selenomonas ruminantium GA192. 2001;43:293-298.

43. Jiang Z, Li X, Yang S, et al. Improvement of the breadmaking quality of wheat flour by the hyperthermophilic

xylanase B from Thermotoga maritima. Food Research International. 2005;38(1):37-43.

44. Su Y, Li X, Liu Q, et al. Improved poly-γ-glutamic acid production by chromosomal integration of the Vitreoscilla

hemoglobin gene (vgb) in Bacillus subtilis. Bioresource technology. 2010;101(12):4733-4736.

45. Zanoelo FF, Polizeli MLM, Terenzi HF, et al. β-Glucosidase activity from the thermophilic fungus Scytalidium

thermophilum is stimulated by glucose and xylose. FEMS Microbiol Lett. 2004;240:137-143.

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