Choosing Microorganisms for Industrial Microbiology

Lab.1.
Practical Industrial Microbiology
Choosing Microorganisms for Industrial Microbiology
The M.Os employed by industry have been isolated from nature (environment), and many cases,
were modified using classic mutation-selection procedures. Selection and use of M.Os in
industrial microbiology and biotechnology are challenging tasks that require a solid
understanding of M.Os growth and manipulation, as well as microbial interactions with other
organisms.
It is necessary first to identify a suitable M.Os that carries out the desired process in the most
efficient manner. This M.Os then is used, either in a controlled environment such as a fermenter
or in complex systems such as in soils or waters to achieve specific goals. The major sources of
microbial cultures for use in industrial microbiology were natural materials such as soil samples,
waters and spoiled bread and fruits…..etc.
Microbes possess a wealth of metabolic equipment that brings about diverse chemical
transformations. These characteristics of microbes could be exploited in obtaining some valuable
products of daily use. The cheap raw materials available in nature as a waste may be converted in
to useful commercial products by activity of microbes.
Microbes thus serve a dual purpose. Firstly, they are good agents of disposal of these wastes and
secondly the resultant end products of their breakdown are useful commercial products.
Characteristics of using M.O. in industrial microbiology
1. They possess a broad variety of enzymes making an array of chemical conversions
possible.
2. They have relatively high metabolic activity which allow conversions to take place rapidly.
3. They possess a large surface area for quick absorption of nutrients and release of end
products.
4. They have a high rate of multiplication.

5. They should be easily cultivated and maintained.
6. They should have genetic stability with infrequent mutation.
Medium and conditions for microbial growth
After selecting the suitable microbes for the purpose, it is necessary to develop a fermentation
process that optimizes conditions for desired microbial activity and that should yield maximum
amount of the product with highest economic profit. The organic and inorganic composition of
the medium, pH, temperature and O2 concentration are the main factors that are varied to
maximize the efficiency of production process. Essential nutrients in the medium for microbial
growth include C, N, P and growth factors and the choice can be made on economic and
biological grounds.
Nutrient
Raw material (sources)
Carbon & energy Molasses, whey, corn sugar, starch, cellulose, vegetable oil, agricultural
source
wastes (corn cobs), petroleum fractions.
Nitrogen sources Soybean meal, corn-steep liquor (from corn milling), stick liquor (slaughter
house products), nitrate salts, pure ammonia or ammonium salts, air (for N2
fixers).
Phosphorus Phosphate salts
source
Vitamin Crude preparations of plant and animal products.
Iron, trace salts
Crude inorganic chemicals.