Microorganisms and Their Applications

Fermentation

• Fermentation is the breakdown of substances by fungi and bacteria.
• Fermentation often produces carbon dioxide and alcohol/acid.
• Alcohol is made by fermenting sugar using yeast.
• Wine is made by fermenting sugar in grapes using yeast.
• Beer is made by fermenting sugars in rice and barley.

Commercial Uses of Microorganisms

• Yeast is used in bakeries to make bread rise, which makes the bread light and fluffy.
• Yeast is also used to make dhokla light and fluffy.
• Idli and dosa are made by fermenting a mixture of rice and pulses.

Retting of Fibres

• Linen fibres are obtained from the flax plant.
• Jute fibres are obtained from jute plants.
• Retting occurs when bacteria break down the stems of plants, loosening the fibres.
• These fibres are used to make threads.

Production of Leather

• Bacteria are traditionally used in the leather-making industry.
• During the processing of hide, bacteria make the hide soft and pliable.

Food Industry

• Some bacteria break down lactose in milk to form lactic acid.
• This is used to make curd.
• Curd is made when lactic acid acts on casein (a milk protein).

The Making of Cheese

• Cheese is made similar to curd.
• Bacteria convert lactose to lactic acid in milk.
• An enzyme then sets the curd, separating the semi-solid curdled material from the liquid.
• Cheese is made from this curdled material.
• Bacteria and fungi create the distinctive flavour and smell of cheese.

Making of Vinegar

• Yeast cells break down the sugar found in fruits and convert it into alcohol.
• Bacteria then convert this alcohol into vinegar.

Algae

• Algae are used to make agar (vegetarian gelatine).
• Sodium compounds from algae keep ice cream smooth and free of crystals.
• Algae products are used as food stabilisers and thickeners in salad dressings.
• Algae are a potential source of food.
• Seaweed is consumed as food in China and Japan.
• Chlorella is a single-celled alga used in research on photosynthesis and as a space food source.

Making of Antibiotics

• Antibiotics kill microorganisms or stop their growth.
• Fungi produce antibiotics like penicillin and cephalosporin.
• Bacteria produce antibiotics like streptomycin, chloramphenicol, and tetracycline.
• Antibiotics kill disease-causing microorganisms without harming the body.
• They are used to cure illnesses from minor to life-threatening.
• Antibiotics are used to cure plant and animal diseases.
• They are mixed with food to cure livestock infections.

Immunity and Making of Vaccines

• An antigen is a foreign substance or a disease-causing microbe that enters the body.
• Antibodies are proteins the body produces to fight antigens.
• Antibodies are specific to each antigen.
• Immunity is the body's ability to resist infection.
• Some immunity is inherited.
• Some immunity is acquired after recovering from a disease.
• Antibodies remain in the body after recovery from a disease.
• Immunity can be induced by introducing dead or weakened microbes (vaccines).
• This is called vaccination or immunisation.

Explore the diverse roles of microorganisms in fermentation, food production, and the textile industry. This quiz covers how fungi and bacteria contribute to making bread, beer, wine, and leather. Test your knowledge on the commercial uses and biological processes involving these tiny organisms.