MICROBES IN HUMAN WELFARE

 

MICROBES IN HUMAN WELFARE

• Microbes are diverse – protozoa, bacteria, fungi and microscopic plants viruses, viroids and also prions (proteinocious infectious agents)
• Microbes like bacteria and fungi can be grown in nutrient media to form colonies and can be seen in naked eyes.
• Some microbes’ causes diseases and some are useful for human being.

MICROBES IN HOUSEHOLD PRODUCTS:

        Lactic acid Bacteria:

• Lactic acid Bacteria (LAB) grow in milk and convert it to curd.
• LAB produces acids that coagulate and partially digest milk proteins.
• A small amount of curd added to fresh milk as inoculums or starter.
• LAB improves nutritional quality of milk by increasing vitamin B₁₂
• LAB plays very important role in checking disease causing microbes.
• Dough, used to make dosa and idli is also fermented by bacteria.
• The puffed-up appearance of dough is due to the production of CO₂.
• Baker’s yeast (Saccharomyces cervisiae) is used to making bread.
• ‘Toddy’ a traditional drink is made by fermentation of sap from palms.
• Large holes in ‘Swiss cheese’ are due to production of large amount of CO₂ by a bacterium named Propionibacterium sharmanii.
• The ‘Roquefort cheese’ is ripened by specific fungi, which gives specific flavor.

MICROBES IN INDUSTRIAL PRODUCTS:

• Microbes are used in industry to synthesize a number of products
• Beverages and antibiotics are some examples.
• Microbes are grown in very large vessels called fomenters.

Fermented Beverages:

• Yeasts are used for production of beverages like wine, beer, whisky, brandy or rum.
• Saccharomyces cervisiae commonly called ‘brewer’s yeast used for fermenting malted cereals and fruit juices to produce ethanol.
• The type of raw material used for fermentation and the processing, different types of alcoholic drinks are produced.
• Wine and beer are produced without distillation.
• Whisky, brandy and rum are produced by distillation of the fermented brooth.

Antibiotics:

• Antibiotics are the chemical substances which are produced by some microbes and can kill or retard the growth of other microbes.
• The first antibiotic discovered is the penicillin, from a mould (fungus) Penicillium notatum.
• Antibiotics have greatly improved our capacity to treat deadly diseases such as plague, whooping cough. Diphtheria and leprosy.

Chemicals, Enzymes and other Bioactive Molecules:

• Aspegillus niger (a fungus) produces citric acid.
• Acetobacter aceti (a bacterium) produce acetic acid.
• Clostridium butylicum (a bacterium) produce butyric acid.
• Lactobacillus(a bacterium) produces lactic acid.
• Saccharomyces cerevisiae (yeast) used for production of ethanol.
• Lipases are used in detergent produced by microbes.
• Pectinase, proteases and cellulase, make bottled fruit juices clearer.
• Streptokinase produced by Streptococcus used as a ‘clot buster’, for removing clots from the blood vessels.
• Cyclosporin-A produced by a fungus called Trichoderma polysporum used as immunosuppressive agent in organ transplantation.
• Statins produced by Monascus purpureus used as blood cholesterol lowering agents. It acts as competitive inhibitor for the enzyme responsible for synthesis of cholesterol.

MICROBES IN SEWAGE TREATMENT:

• The waste water generated in cities and town containing human excreta. This municipal water-water is called sewage.
• Before disposal to the natural body sewage is treated in sewage treatment plants (STPs) to make it less polluting.
• Treatment is done by heterotrophic microbes naturally present in sewage.

Primary treatment:

• Involves the physical removal of particles – large and small from sewage through filtration and sedimentation.
• Initially floating debris is removed by sequential filtration.
• The grit (soil and small pebbles) are removed by sedimentation.
• All solids that settle form the primary sludge, and the supernatant forms the effluents.
• The effluents are from the primary settling tank taken for secondary treatment.

 

CBSE Biology (Chapter Wise) Class XII ( By Mr. Hare Krushna Giri )
Email Id : [email protected]