The existence of microorganisms in nature has been under speculation since
ancient times, and they were exploited for beer and vinegar production long before
anything was known about their existence. The scientific study of microorganisms
began with their observation under the microscope in the 1670s by Antony van
Leeuwenhoek. Louis Pasteur, in 1860, reported the first synthetic medium for
microorganisms and introduced the biological concept of alcohol fermentation. The
next phase started with the use of modern industrial fermentation, aiming for largescale aerobic fermentation facilities. Selected strains of yeast, Saccharomyces
cerevisiae, are commonly used for the fermentation of commercial alcohols, namely
wine, beer, and distilled liquor. Vinegar is prepared by allowing a wine to go sour with
the aid of a specific microbe under controlled conditions. Cider vinegar is made from
alcohol in fermented apple cider, whereas wine vinegar comes from grapes. Genetic
alteration of microorganisms has been an important practice in many industries,
including agriculture, the beverage industry, the pharmaceutical industry, etc. The
prerequisites to a practical industrial microbiological process are the organisms,
medium, and product upon which the whole gamut of production depends. The
discovery of penicillin by Alexander Fleming in 1929 triggered an intensive search for
antibiotics during the Second World War, and several other antibiotics were
discovered. The wonderful activities of the microbial community are now exploited by
industrial microbiologists to find suitable microorganisms for desired products such as
antibiotics, amino acids, food products, enzymes, amino acids, vaccines, organic
solvents, and other value-added products. The benefits of microbial activities are also
widened commercially in other fields, like the agriculture sector, through biofertilizer
and biopesticide preparations. Carrier based bio-inoculants are agriculturally useful in
terms of nitrogen fixation, phosphorus solubilization, or nutrient mobilization, to
increase the productivity of soil and crop. Most commercial biopesticides are of
microbial origin and are primarily based on the Bacillus thuringiensis (Bt)
microorganism. Potential microorganisms are exploited in many other sectors, from
petroleum, mining, textiles, polymers, cosmetics, waste treatment, health care, and so
on. Industrial production of citric acid is also accomplished by microbial fermentation
using the fungus. Many microorganisms are capable of synthesizing bioactive L-optical isomers of amino acids from inorganic nitrogen compounds. Commercially useful
enzymes are manufactured from microorganisms using 'immobilized enzyme
technology'. Among the commercially available enzymes, proteases and amylases are
produced in maximum quantities. Insulin is another very important pharmaceutical
product, produced commercially by a genetically engineered bacteria. Recombinant (r-)
DNA technology has been exploited in order to provide selective improvements in
various specialties that include crop agriculture, pharmaceutics, gene therapy, vaccine
design, and bioremediation. The technology has now become the mainstay of the
pharmaceutical industry. Natural genetic engineering uses ‘forced evolution’ and
‘adaptive mutation’. Such ‘environmentally directed mutation’ can produce microbes
with new biosynthetic capabilities. Extremozymes from extremophiles are becoming
increasingly attractive as biocatalysts for industrial applications, particularly at high
temperatures. However, a vast microbial world is yet to be examined for its efficacy
towards new industrial products. So, research on industrially useful microorganisms
has tremendous potential and a long way to go.
Keywords: Antibiotic, Amino acid, Alcohol, Biofertilizer, Enzyme, Fermentation industry, Microorganisms, Recombinant (r-) DNA technology, Yeast.
