Define fermentation according to Biochemists and Industrial Microbiologists

• According to the biochemist, Fermentation is the process of energy production in a cell under anaerobic conditions (absence of oxygen).
• In the absence of oxygen yeast ferment ethanol anaerobically for their cellular.
• On the other hand, in industrial fermentation, fermentation occur aerobically by breaking down and re-assembling of biochemical compounds.

The first industrial process for the production of a microbial metabolite was carried out by the yeast through working on  malt or fruit extracts has been carried out on a large scale for ethanol production following a long years.

As a result the term fermentation was described by the industrial microbiologists in a way that is a process for the production of product by the mass culture of a microorganism.

Industrial fermentation

There are many important role of fermentation in industrial sector. Although the word fermentation has very compact definitions,. For example if when we talk about industrial fermentation it demonstrates very little about the decomposition and re-assembly of organic compounds.

Somewhat in industrial context, fermenter culture in industrial capacity frequently describes to highly oxygenated conditions, whereas in the biochemical perspective it is completely an anaerobic process.

Commercially important fermentation can be classified into five major groups

• First group that produce microbial cells also called biomass as the product
• Second group that produce microbial enzymes
• Third one that produce microbial metabolites
• Next group which produce recombinant products
• This group modify a particular compound which is added to the fermentation in  the transformation process.

Microbial Biomass

Microbial biomass, specially considered as the bacteria fungi, express the measure of the total quantity of living beings that exists in organic soil. The microbial biomass plays an important role by breaking down the organic waste materials, dead bodies of plant and animal and release carbon dioxide and plant available nutrients which is essential nutrient for soil and green plants.

There are two major groups of the commercial production of microbial biomass. They are-

• In baking industry use of yeast production
• For human or animal food the production of microbial cell such as single cell protein is most familiar.

Microbial enzymes

• Enzyme has enormous importance in industrial sector. It has been produced commercially from plant, animal and microbial sources.
• To develop new fermentation technique the microbial enzymes have the greater significance to produce large quantities product by established fermentation techniques.
• The advancement of recombinant DNA technology enabled the activity of enzymes  in greater quantity that come from animal origin. Example is the production of insulin.

Microbial Metabolites

There are two types of microbial metabolites

Primary metabolites

By using fermentation process, many significant primary metabolites can be produced and it has considerable economic importance. Such as ethanol, citric acid, vitamins etc.

Secondary Metabolites

Secondary metabolites have numerous functions. Such as antimicrobial activity, some are specific enzyme inhibitors, some others are used as promoters and large amount of secondary metabolites have pharmacological characteristics. For example, antibiotics.

Written by:

Md. Rayhan Mahmud

Masters student, Department of Ecology and Population Genetics

University of Oulu, Finland

M.Sc. in Microbiology, Jagannath University, Bangladesh