Biology > Microbes in Human Welfare > Industrial Uses of Microbes
Microbes are omnipresent i.e. they exist everywhere: in soil, air, water and also in the human body and the bodies of plants and other animals! They also exist in places where no other life-form exists. Bacteria, fungi, protozoa, viroids are examples of microorganisms. The general presumption is that the microbes are harmful to us because some of them cause diseases to both plants and animals including humans. However, there are many microorganisms, who are useful to us in many ways. In this article, we shall study the use of Industrial uses of microbes.
The process of anaerobic respiration in which the complex molecules incompletely brakes into simple ones by the microbial action is called fermentation. There are many types of fermentation that are distinguished by the end products formed from pyruvate or its derivatives. The two fermentations most commonly used by humans to produce commercial foods are ethanol fermentation (used in beer and bread) and lactic acid fermentation (used to flavor and preserve dairy and vegetables).
Production of Alcoholic Beverages:
Beverages like wine, beer, whisky, Brandy, Rum are produced from malted cereals and fruit juices. Wine and beer produced without distillation. While whisky, brandy, rum produced after distillation. Yeasts are the main fermenter and alcohol producer in the production of wine, beer, and other alcoholic drinks. Vinegar is a food product made by acetic acid bacteria that can ferment the alcohol in alcoholic liquids to acetic acid.
Wine Making:
Harvesting is the first step in the winemaking process and an important part of ensuring delicious wine. Grapes are the only fruit those have the necessary acids, esters, and tannins to consistently make natural and stable wine. Then mechanical presses are used to stomp or trod the grapes into what is called must. Must is simply freshly pressed grape juice that contains the skins, seeds, and solids. After crushing and pressing, fermentation is carried out by allowing the must to ferment naturally for 6-12 hours. When aided with wild yeasts in the air. Microbes used for making wine is Saccharomyces cerevisiae var. ellipsodeus. ( brewer’s yeast) Different flavours can be obtained by using different flavours. When fermentation is complete, clarification of process begins, in which solids such as dead yeast cells, tannins, and proteins are removed. Then the wine is transferred or “racked” into a different vessel such as an oak barrel or a stainless steel tank. Wine can be distributed immediately for use but aging the wine in oak barrels will produce a smoother, rounder, and more vanilla flavored wine. It also increases wine’s exposure to oxygen while it ages, which decreases tannin and helps the wine reach its optimal fruitiness.
Beer Making:
Beer is made from the fermentation of grains, particularly barley. Barley grains are cleaned and soaked in water for about 2 days. Then excess water is drained away and the barley is incubated for 4-5 days to allow germination. The process is called malting. Then the germinated seeds are then killed by slow heating at 80°. This process is called kilning. The temperature should be monitored because, if the kilning temperature is higher, the beer produced will be darker. The dried barley grains are then crushed between rollers to produce coarse powder called grist. Grist is mixed with warm water and the resulting materials are maintained at 65°C for about 1 hour. The process is called mashing. Then the filtrate is then boiled with stirring for 2-3 hours. Then the process of fermentation is carried out. Microbes used for making beer is Saccharomyces cerevisiae. The fermenting solution is allowed to stand for a few days. Then it is clarified, carboxylated and bottled.
Whisky Making:
Whisky is obtained from fermenting mixed grains of corn, wheat, barley, etc. The product of fermentation is distilled. Distillation is just further processing of fermented beverage to purify and remove any diluting components like water. This increases the proportion of their alcohol content and that’s why they are also commonly known as ‘Hard Liquor’, to distinguish distilled beverages from undistilled ones.
Production of Organic Acids:
Various of organic acids are obtained by fermentation using microbes. Organic acids are commercially prepared using fungi. Examples of acids that are derived and manufactured on a large scale using fungi are acetic acid, citric acid, gluconic acid, fumaric acid, and lactic acid.
Some organic acids obtained from the microbial source are as follows. The citric acid (Aspergillus niger), Gluconic acid (Aspergillus niger), Fumaric acid (Rhizopus arrhizus), Acetic acid or vinegar (Acetobacter aceti), Butyric Acid (Clostridium butylicum), Lactic acid. (Lactobacillus).
Production of Vitamins:
Vitamins are complex organic compounds required in very small quantities for normal growth and development of a body. There are two types of vitamins a) water-soluble (vitamins B and C) and b) fat-soluble (vitamins A, D, E, and K). All vitamins are not produced in the body, hence they are obtained through food and supplements, tablets.
Some important vitamins (microbial source) are as follows. Vitamin B2 (Neurospora gossypii and Eremothecium ashbyi), Vitamin B12 (Pseudomonas denitrificans) and vitamin C (Aspergillus niger).
Production of Antibiotics :
Some secondary metabolites, products of fermentation have therapeutic use. Bacteria and viruses are isolated and their antigens and enzymes are extracted. These antigens help in the development of antibiotics and antivirals. Penicillin produced by Alexander Fleming from Penicillium notatum while working with Staphylococcus aureus. Earnest Chain and Howard Plorey awarded Nobel Prize in 1945 for establishing Penicillin as an effective antibiotic. Penicillin is used to treat diseases like plague, whooping cough, diphtheria, leprosy.
Some important antibiotics(microbial source) are as follows. Chloromycetin (Streptomyces venezuelae), Erythromycin (Streptomyces erythreus), Penicillin (Penicillium chrysogenum), Streptomycin (Streptomyces griseus).
Production of Chemicals :
Lipases used in detergents to remove oil strains from Laundry. Pectinases and Proteases to clarify bottled juices.
Streptokinase (from Streptococcus) act as clot buster in the treatment of myocardial infraction (heart attack). An immuno-suppressant Cyclosporin A (Trichoderma polysporum) is used in organ transplant patients. Statins produced by yeast (Monascus purpureus) used as blood, cholesterol-lowering agent. Some bacterial and fungal species are used in the preparation of steroids that are then injected into the human body for different purposes.
Production of Gibberellin:
Gibberellins are a group of growth hormones produced by higher plants and fungi to promote growth by stem elongation.
The first gibberellin was obtained by Japanese scientists Yabuta and Sumiki in 1938 from rice seedlings infected with the fungus Gibberella fujikuroi. About 15 types of gibberellins are obtained from Gibberella fujikuroi. Gibberellins are used to induce parthenocarpy in apple, pear, etc. They are also used for breaking dormancy and inducing flowering.
Production of Enzymes:
Enzymes are biocatalyst which are required for initiation or acceleration of the biological process in a living organism. These enzymes convert complex substances like starch, proteins, and fats into simple absorbable substances. Now enzymes are produced to give desirable flavours to cheese and butter, sweetness to confectionaries, animal feed, soybean milk, etc.
Some important enzymes (microbial source) are as follows. Invertase (Saccharomyces cerevisiae), Pectinase (Scerotiana libertine), Lipase (Rhisopus spp), Cellulase (Trichoderma konigi).
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