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How LABs are useful to us? Explain.OR Give a brief account on importance of Lactobacillus bacteria in household products.

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LAB is lactic acid bacteria.
They grow in milk and convert it to curd.
During growth, the LAB produces acids that coagulate and partially digest the milk proteins.
A small amount of a curd added to the fresh milk as inoculum or starter contain millions of LAB, which at suitable temperature multiply, thus converting milk to curd.
LAB improves milk quality by increasing vitamin B12.
In our stomach too, the LAB play very beneficial role in checking disease causing microbes.

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Explain in short : Microbes are omnipresent.

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Protozoa, Bacteria, Fungi, Microscopic plant virus, Viroids, and prions etc. are microorganisms.
Microorganisms are found in soil, water, inside our body and that of other animals and plants.
They are present even at sites where no other life-form could possibly exist.
Microbes are found at deep inside the geysers thermal vents where temperature may be as high as 100°C.
Microbes are also found deep in the soil, under the layers of snow several metres thick, and in highly acidic environments.

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Microbes are useful in household products. Explain this with suitable examples. OR What are the uses of bacteria and fungi in our daily life? OR Write uses of miceo-Orgunisms in house-hold pruducts. (JUNE 2025) OR Microbes produce gases during metabolism. Explain with suitable examples.

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We useful microbes for various purposes. Some products are derived from them everyday. Such as -

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Explain the role of different micro organisms in the production of cheese.

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Cheese is an edible substance. Microbes are used at different stages of cheese making.
Different varieties of cheese are known by their characteristic texture, flavour and taste which is given by specific microbes used in the cheese production.
The large holes in “Swiss cheese” are due to production of a large amount of carbon dioxide by a bacterium named Propionibacterium sharmanii.
The “Roquefort cheese” are ripened by growing a specific fungi (Penicillium Roquefortii) on them, which gives them a particular flavour.

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Why Saccharomyces cerevisiae is known as baker's and brewer's yeast? Explain.

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Saccharomyces cerevisiae is a fungi (yeast).
The dough, which is used for making bread, is fermented using Saccharomyces cerevisiae, called baker’s yeast.
This yeast is also, used for production of ethanol from the fermentation of cereals and fruit juices, so it is called brewer’s yeast.

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Give the name of some traditional Indian recipes which are made from wheat, rice and chickpeas and the name of microbes used in.

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Recipe :
(1) Wheat: bread, cake etc
(2) Rice: Dosa, Idli etc.
(3) Chickpeas: dhokla, khandavi, gatta etc.
Microbes:

(1) Bacteria: Lactobacillus

(2) Yeast-fungi: Saccharomyces cerevisiae

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What are fermentors? Describe alcoholic beverages.

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Many useful products for mankind are produced or synthesized by using microbes at industrial level
Beverages and antibiotics are examples of this.
For industrial production, useful microbes are grown into a big vessel which is called fermentors.
Microbes have been used from time immemorial for the production of beverages like wine, beer, whiskey brandy, rum.
Saccharomyces cerevisiae (brewer’s) yeast is used to produce ethanol from cereals and fruit juices.
Yeast produces ethanol by an anaerobic respiration pathway.
Depending on the type of the raw material used for fermentation and the type of processing (with or without distillation) different types of alcoholic drinks are obtained.
Wine and beer are produced without distillation.
Whisky, brandy and rum are produced by distillation.

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Write about the microbes which play significant role in controlling of pathogenic bacteria?

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Some microbes are used to prepare drugs.
Antibiotics which is produced by the use of microbes, inhibits the growth of pathogens or kill them.
These drugs commonly derived from fungi and bacteria. e.g.
(1) Penicillium notatum (fungus) secrete penicillin antibiotic which inhibits or slow down the growth of Staphylococci bacterium.
Antibiotics weaken the cell wall of bacteria. Such weak bacteria are destroyed by immune cells WBC.
(2) Streptomysin, tetracyclin, penicillin etc. are common antibiotics.

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Microbes are used for industrial production of certrain useful products / substances on a large scale. Explain with examples.

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Many products which are useful for mankind are produced by microbes on industrial level. For example: vinegar, beverages, antibiotics, chemicals, enzymes and other biochemical molecules.
Saccharomyces cerevisiae– Yeast is used to prepare vinegar, wine, beer, whiskey, brandy or rum like beverages and also, used for bread making.
Saccharomyces cerevisiae (brewer’s) yeast is used to produce ethanol from cereals and fruit juices.
Antibiotics are chemical substances which are produced by microbes. They kill pathogenic microbes or slow down their growth. For example: Penicillin
We cannot imagine a world without antibiotics.
Microbes are also used for commercial and industrial production of certain chemicals like organic acids, alcohols and enzymes.
Examples :

Microbes

Product

1.

Aspergillus niger

Citric acid

2.

Acetobacter aceti

Acetic acid

3.

Clostridium butyricum

Butyric acid
Q.10.Describe the role of microbes in the production of bioactive molecules.
OR
State the sources and uses of statins and cyclosporin A.
OR
Find out the name of the microbes from which cyclosporin A (an immunosuppressive drug) and statins (Blood cholesterol lowering agents) are obtained.
Ans. (1) Cyclosporin A :
It is derived from Trichoderma polysporum fungi.
This bioactive molecule is used as immunosuppressive drug in organ transplant patients.
(2) Statins :
It is derived from Monascus purpureus, a yeast.
This drug is used as blood cholesterol lowering agent.

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What are antibiotics? Antibiotic production is the most significant discoveries of the 20th century. Explain with examples. OR How was first antibiotic discovered? Explain. OR Explain Antibiotics.Or Discovery of antibiotics is a chance discovery.

– Explain.

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Antibiotics are chemical substances which are produced by microbes. It kills pathogenic microbes or slow down their growth.
These chemicals are called antibiotics.

(anti = opposite, bio = life)

e.g. Penicillin is the first discovered antibiotic.

Discovery :

  • Alexander Fleming while working on Staphylococci bacteria , once observed a mould growing in one of his unwashed culture plates around which Staphylococci could not grow.
  • He found that it was due to a chemical produced by the mould and he named it penicillin after the mould Penicillium notatum.
  • However, its full potential as an effective antibiotic was established much later by Ernest Chain and Howard Florey.
  • This antibiotic was extensively used to treat American soldiers wounded in world war II
  • Fleming, Ernest Chain and Howard Florey were awarded the Nobel prize in 1945, for this discovery.

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Explain the role of microbes in the production of chemicals, enzymes and other bioactive molecules.

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Microbes are also used for commercial and industrial production of certain chemicals like organic acids, alcohols and enzymes.