fermentation dr. tijani a. s. - bowen university
TRANSCRIPT
FERMENTATION
DR. TIJANI A. S.
Learning Objectives:
After this topic, student will be able to:
Describe fermentation
Explain fermentation techniques
Describe types of fermentation
Know applications of fermentation
Fermentation
Fermentation is characterized by the metabolic processes that are used to transfer electrons
released from nutrients to molecules obtained from the breakdown of those same nutrients.
Fermentation utilizes numerous organic compounds, such as sugars, as endogenous electron
acceptors to promote the electron transfer that occurs.
Fermentation includes the processes by which energy is extracted from the oxidation of organic
compounds. The oxidation of organic compounds occurs by utilizing an endogenous electron
acceptor to transfer electrons released from nutrients to molecules obtained from the breakdown
of these same nutrients.
Fermentation
The international use of fermentation technology for large scale production of
microbial biomass or metabolites is called Industrial fermentation.
Fermented products have immense use in food, medicine and other industries.
Modern industrial fermentation units use genetically engineered microbes for the
production of desired metabolites
Types of Fermentation
Batch fermentation
Continuous fermentation
Fed-batch fermentation
Types of Fermentation
Batch fermentation
Product of growth can be biomass or metabolites
The nutrient environment in the fermenter is continuously changed
Change in the environment in the fermenter enforce change in the metabolism of the
cells
Results in cessation of cell multiplication
Microbes in the batch culture show the following pattern of growth with distinct
phases
Lag phase: microbe adapt to the environment
No apparent growth.
Exponential phase: microbial growth proceeds at the maximum rate
Stationary phase: no overall growth most of the secondary metabolites are
produced
Death phase: no growth at all, cells start to die and their population decreases,
fermentation stops before the death phase
Types of Fermentation
Continuous fermentation
Substrate is added continuously to the fermenter, and biomass or products are
continuously removed at the same time
Under this condition the cells remain in logarithm phase of growth
Used for production of some primary metabolites (e.g, ethanol and organic acids), in
waste water treatment, and fermented foods and for the production of monoclonal
antibodies and recombinant proteins by animal cell cultures.
Types of Fermentation
Fed-batch fermentation
Is a modified version of the batch fermentation
The culture is fed with fresh nutrient medium without removing the growing
microbial culture
Allows one to supplement the medium with such nutrients that are depleted or that
may be needed for the terminal stages of the culture.
this periodical addition of the nutrients prolong the log and stationary phases of the
microbes in the fermenter and
Results in the rapid increase of biomass and subsequent increased production of
metabolites in the stationary phase
The range of fermentation
There are five major groups of commercially important fermentations:
Those that produce microbial cells (biomass production) e.g Yeast
Those that produce microbial enzymes e.g glucose isomerase
Those that produce microbial metabolites e.g. antibiotics (penicillin), vitamins
Those that produce recombinant products e.g insulin, human therapeutics, amino acids
Those that modify a compound which is added to the fermentation in the transformation
process
Applications
Fermentation process is used:
Applications
Other applications include:
8. To produce antibiotics and other related products
9. To produce ethyl alcohol used as gasohol
10. To produce alcoholic beverages like beer and wine
11. Yoghurt is produced from milk
12. Cheese is also produced by fermentation of milk
References
Pharmaceutical Biotechnology First edition by P. R Kavi Kishor, Maruthi Rao and I.
Sampath Kumar.
Advances in Applied Biotechnology Edited by Marian Petre