PinkMonkey Online Study Guide-Biology
10.1 Fermentation
Fermentation is a process very much similar to anaerobic respiration. It is a metabolic process in many micro-organisms and involves oxido-reduction reactions resulting in the breakdown of complex organic molecules into various end products with the release of energy. Fermentation is mostly extracellular and is brought about with the help of enzymes released by the micro-organisms. The end products or the various intermediate products (primary and secondary metabolites) of the fermentation activities of many micro-organisms are highly useful. Hence, micro-organisms have been commercially exploited by the fermentation industry. Thus, with reference to industrial microbiology, fermentation may be defined as "a process for the production of useful products through mass culture of micro-organisms."
Micro-organisms involved in the fermentation industry : More
than a million different micro-organisms are known to exist in nature.
However, only a few hundred species are of commercial importance. Some
of these species are listed below.
Algae |
Chlorella sp., Spirulina sp:,etc.
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Bacteria |
Acetobacter lacti, Bacillus subtilis, Pseudomonas denitrificans, etc.
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Actinomycetes |
Streptomyces aureofaciens, S.griseus, Nocardia sp ;,etc.
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Fungi |
Aspergillus niger, Penicillium notatum,
P. chrysogenum, Sacchromyces sp;,Gibberella fujikuroi, Fusarium
moniliforme, etc.
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Fermenter : A fermenter is a vessel designed to
carry out fermentation process, (i.e. the microbiological reactions under
the controlled conditions). Hence, a fermenter is also called a bio-reactor.
The fermenter allows long term operation in aseptic conditions. It has
the necessary arrangements for adequate aeration, agitation, pH control,
temperature control, sampling, harvesting, etc. Thus, it is very convenient
for operation in the fermentation industry.
Uses of fermentation
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Useful intermediate products : The various intermediate
compounds produced during fermentation activity are classified as
primary and secondary metabolites. Some of the commercially important
metabolites are (a) Primary metabolites, such as amino acids,
proteins, carbohydrates, vitamins, acetone, ethanol, organic acids
etc. and (b) Secondary metabolites such as antibiotics, toxins,
alkaloids, gibberellins, etc.
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Enzymes : Enzymes produced by the micro-organisms
during fermentation include amylases, cellulases, invertase, esterase,
lipase, protase, lactase, etc.
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Microbial biomass: After the process of industrial
fermentation is over, the exhausted cells of the micro-organisms (in
the fermenter) serve as microbial biomass. It is also known
as microbial protein or single cell protein (SCP). It is an
important source of proteins.
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Table of Contents
10.0 - Introduction
10.1 Fermentation 10.2
Manufacture of Alcohol 10.3
Antibiotics 10.4
Vitamins
Chapter 11
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