Microbes in Industrial Products

• Microbes are used to synthesise many products valuable to human beings, including beverages, organic acids, vitamins, growth hormones, enzymes, antibiotics, and other useful compounds.
• These products are secondary metabolites produced during the idio phase and are not required for the growth of microorganisms.
• The type of substrate and the type of microorganism determine the type of secondary metabolite produced.

• Industrial-scale production requires growing microbes in very large vessels called fermenters or fermentors.
• The main function of a fermenter is to provide a controlled environment for the growth of a microorganism, or a defined mixture of microorganisms, in order to obtain the desired product.
• A fermentor is described as a closed vessel with arrangements for aeration, agitation, temperature control, pH control, and removal of waste biomass along with products.

Zymology is the applied science that deals with the biochemical processes of fermentation and their practical uses.

Oenology is the science and study of wine and wine-making.

Alcoholic Beverages

• Alcoholic beverages are products of alcoholic fermentation of specific substrates.
• Microbes, especially yeasts, have been used since ancient times for the production of wine, beer, whisky, brandy, and rum.
• Saccharomyces cerevisiae, commonly called brewer’s yeast, is used for fermenting malted cereals and fruit juices to produce ethanol.
• Saccharomyces cerevisiae var. ellipsoideus is also mentioned as brewer’s yeast for the production of alcohol from malted cereals and fruit juices.

Distilled and Non-distilled Beverages:

Additional Beverage Details:

• Beer may be produced by Saccharomyces carlsbergensis or Saccharomyces cerevisiae.
• Wine is produced by the fermentation of grape juice by yeast.
• Red wine is prepared from black grapes, including skins and sometimes stems, while white wine is prepared only from the juice without skins and stems.
• Rum is made from fermented sugarcane, molasses, or sugarcane juice by Saccharomyces cerevisiae.
• Whisky is a distilled alcoholic beverage made from fermented grain mash by Saccharomyces cerevisiae.

Traditional Fermented Drinks:

• A traditional drink prepared by fermenting sugar sap from palm plants and the coconut palm is described.
• Pathaneer is obtained from fermenting the sap of palms and coconut trees.
• When pathaneer is left undisturbed for a few hours, it ferments with the help of naturally occurring yeast and forms toddy.
• Toddy contains about 4 percent alcohol.
• After 24 hours, toddy becomes unpalatable and is used for vinegar production.
• Fenny is made by fermenting the fleshy pedicels of cashew fruits.

Alcohol Content:

• Beer contains 3 to 5 percent alcohol.
• Wine contains 9 to 14 percent alcohol.
• Wine coolers contain about 4 to 6 percent alcohol.
• Distilled spirits such as whisky, gin, scotch, and vodka usually contain 35 to 50 percent alcohol.

Ethanol:

• Saccharomyces cerevisiae is the major producer of ethanol.
• Ethanol is used for industrial, laboratory, fuel, and beverage purposes.
• Ethanol is also referred to as industrial alcohol.
• Bacteria such as Zymomonas mobilis and Sarcina ventriculi are also involved in ethanol production.
• Principal substrates for commercial ethanol production include molasses, corn, potatoes, and wood wastes.

Production of Organic Acids

• Microbes are used for the commercial and industrial production of certain organic acids.
• These compounds may be produced directly from glucose or formed as end products from pyruvate or ethanol.
• Certain microbes convert carbohydrates into organic acids.

Organic Acids and Microbes

Uses:

• Citric acid is used in confectionery.
• Fumaric acid is used in resins as a wetting agent.
• Gluconic acid is used in medicine for the solubility of calcium.

Production of Vitamins

• Vitamins are complex organic nitrogenous compounds required in small amounts and capable of performing many life-sustaining functions in the body.
• These compounds are not synthesised in humans except for vitamin D, so they must be supplied in the diet.
• Microbes can synthesise vitamins and are used in commercial production.

Vitamins:

• Thiamine
• Riboflavin
• Pyridoxine
• Folic acid
• Pantothenic acid
• Biotin
• Vitamin B12
• Ascorbic acid
• Beta-carotene
• Ergosterol

Vitamins and Microbial Sources:

Antibiotics are chemical substances produced by some microbes that can kill or retard the growth of other disease-causing microbes.

• Antibiotics are regarded as one of the most significant discoveries of the twentieth century.
• Most antibiotics are secondary metabolites.
• Antibiotic means “against life”.
• Antibiosis is the property of antibiotics to kill microorganisms.

Importance:

Antibiotics have greatly improved the ability to treat deadly diseases such as plague, whooping cough, diphtheria, leprosy, meningitis, syphilis, and tuberculosis.

Discovery of Penicillin:

• Penicillin was the first antibiotic discovered.
• Alexander Fleming observed a mould growing in an unwashed culture plate of Staphylococci around which the bacteria could not grow.
• The mould was identified as Penicillium notatum.
• The chemical produced by the mould was named penicillin.
• Its full potential as an effective antibiotic was established later by Ernst Chain and Howard Florey.
• Penicillin was extensively used to treat wounded soldiers during World War II.
• Fleming, Chain, and Florey were awarded the Nobel Prize in 1945.
• Penicillin is produced by Penicillium notatum and Penicillium chrysogenum.
• Penicillin inhibits synthesis of the bacterial cell wall.

Broad-spectrum and Narrow-spectrum Antibiotics

• Broad-spectrum antibiotics act against a wide range of disease-causing bacteria.
• Narrow-spectrum antibiotics are active against a selected group of bacterial types.
• Narrow-spectrum antibiotics are preferred because they target specific pathogenic organisms and are less likely to cause resistance.

Antibiotic Resistance

• Antibiotic resistance occurs when bacteria develop the ability to defeat the drug designed to kill or inhibit their growth.
• It is accelerated by misuse and overuse of antibiotics and poor infection prevention control.
• “Superbug” refers to strains of bacteria resistant to the majority of antibiotics commonly used today.

Antibiotics and Microbial Sources

Note:

• Streptomycin was first isolated by Waksman and associates in 1944 from Streptomyces griseus.
• Erythromycin was derived by Selman Waksman in 1952 from Streptomyces erythreus.
• Selman Waksman discovered streptomycin and first used the term antibiotic in 1943.

• Enzymes are proteins known as bio-catalysts.
• They promote reactions more quickly and efficiently.
• In living beings, enzymes play a key role in metabolic reactions and are essential for survival.
• Many microbes synthesise and excrete large quantities of enzymes into the surrounding medium.
• This property makes microbes useful for commercial enzyme production.

Enzymes:

• Amylase
• Cellulase
• Protease
• Lipase
• Pectinase
• Streptokinase
• Invertase
• Glucose isomerase
• Glucose oxidase
• Rennin

Enzymes and Microbial Sources:

Uses of Enzymes

• Enzymes improve the quality of fabrics in the textile industry.
• They are used in biomechanical pulping and bleaching in the pulp and paper industry.
• They are used in fermentation processes for production of bread, wine, and beer.
• They are used in extraction of carotenoids and olive oil.
• Lipases are used in detergent industry and help remove oily stains from laundry.
• Lipases are also used in cosmetics, animal feed, and agricultural industries.
• Pectinases and proteases are used for clarification of bottled fruit juices.
• Cellulase is also mentioned with juice clarification.
• Glucose oxidase is used to remove oxygen from soft drinks and salad dressings.
• Amylases are used in sizing agents in textile and paper industry, bread production, chocolate and corn syrups, and removal of spots in laundry.
• Rennet is used to separate milk into solid curds for cheese making.
• Microbial enzymes are also used for synthesis of alkene oxides in plastics production.

Streptokinase

• Streptokinase is produced by Streptococcus.
• It is modified by genetic engineering in one linked treatment.
• It has fibrinolytic effect.
• It is used as a clot buster to remove blood clots from blood vessels in patients who have undergone myocardial infarction.

Gibberellin Production

• Gibberellin is a group of growth hormones mainly produced by higher plants and fungi.
• It promotes growth by stem elongation.
• The first gibberellin was isolated by Yabuta and Sumiki in 1938 from rice seedlings infected with Gibberella fujikuroi.
• About 15 different types of gibberellins have been isolated.

Uses of Gibberellins

• They are used to induce parthenocarpy in apple and pear.
• They are used in breaking seed dormancy.
• They are used in inducing flowering in long day plants.
• They are used to enlarge grape fruits.

Bioactive Molecules and Medical Uses:

• Microbes are also used for the production of bioactive molecules.
• These molecules have important medical uses.

• Cyclosporin A is also mentioned for anti-inflammatory, antifungal, and anti-parasitic properties in one linked treatment.
• Statins act by competitively inhibiting the enzyme responsible for synthesis of cholesterol.

• Industrial fermentation uses large, controlled vessels to cultivate microbes for the large-scale production of valuable secondary metabolites.
• Yeast (Saccharomyces cerevisiae) ferments sugars in cereals and fruit juices to produce non-distilled (wine, beer) and distilled (whisky, rum) alcoholic beverages.
• Specific microbes convert carbohydrates into commercial organic acids, such as Aspergillus niger for citric acid and Lactobacillus for lactic acid.
• Microbes are utilized to commercially synthesize essential vitamins, like Vitamin B12 and Riboflavin, which humans cannot produce naturally.
• Certain microbes produce antibiotics, like Penicillin, which are chemical substances that kill or inhibit the growth of disease-causing pathogens.
• Microbial enzymes act as commercial bio-catalysts, functioning in detergents (lipases), juice clarification (pectinases), and medicine (streptokinase).
• Microbes produce critical bioactive molecules for medicine, including immunosuppressive agents (Cyclosporin A) and cholesterol-lowering drugs (Statins).
• Fungi (Gibberella fujikuroi) synthesize gibberellins, which are agricultural hormones used to promote plant stem elongation and break seed dormancy.