Give a detailed account of industrial application of microbes.

Explanation

At present a number of biologically important products are being manufactured on a commercial scale with the help of microbes. For this microbes are grown in large vessels called fermentors supplied with nutrients, optimum temperature, pH and aeration etc.
Some of the industrial products obtained using microbes are:
(i) Antibiotics These are the chemical substances, produced by some microbes that can kill or retard the growth of other disease causing microbes.
Several antibiotics have been producing using industrial fermentation against diseases capable of causing epidemics.
(ii) Alcoholic beverages Several ethanol containing beverages are developed by fermentation of different substrates, i.e. sugarbeet, potatoes, corn, sugarcane, etc. Yeasts like S. cerevisiae, C. brassicae, bacteria like Zymomonas mobilis are used in production of ethanol at industrial scale.
The type of alcoholic drink depends upon the raw material used for its production such as beer is obtained by the fermentation of barley grains while wine is produced by grapes.
(iii) Organic acids These are produced as the results of metabolic actions of microbes, e.g.
Acetic acid The production of acetic acid or vinegar occurs in two steps. i.e. preliminary fermentation and secondary fermentation. Former involves production of ethyl alcohol while latter involves the prooduction of acetic acid under aerobic conditions.
Citric acid It is produced by the fermentation of beet molasses, sucrose, commercial glucose, starch hydrates, etc. Many fungi, bacteria and yeasts are used for the same.
(iv) Enzymes Microbial growth in culture medium, releases various substances including enzymes. The quantity and quality of enzymes depend upon the microbial strain and cultural conditions.
Some enzymes and their application have been discussed below
Lipase produced by Rhizopus sp., used in detergent formulations and helps in removing oily stains from the laundry due to its digestive application.
Pectinase produced by Aspergillus sp., used for clarifying bottled fruit juices.
Proteases They are produced by Aspergillus niger and Bacillus subtilis. They are used as clarifying agents for beer, meat tenderiser, etc.