Useful Microorganis

ms By: Riya Sharma, S3H

Some bacteria have useful properties – they can, for instance, be used to

make yoghurt and cheese from milk. Yeast can be useful to us too. Yeast

cells can be used to make alcoholic drinks (such as beer and wine) from

plant sugars.

Some bacteria are useful to us. For example, they can be used to make:

•yoghurt

•cheese

•vinegar

•compost

•silage (fermented plant material used to feed cattle and sheep in winter)

Cheese Yogurt Vinegar Compost

Making yoghurt

The bacteria used in making yoghurt are Lactobacillus bacteria. Milk contains a sugar called lactose. The bacteria are able to break this down to form lactic acid. The lactic acid both lowers the pH of the yoghurt, which helps to preserve it, and denatures milk proteins, which gives the yoghurt its sharp taste.

Fermentation

Fermentation is the production of ethanol. It occurs

when yeast breaks down sugars in the absence of oxygen.

Fermentation is used to make alcoholic drinks, such as beer

and wine. Carbon dioxide gas is also produced during

fermentation:

glucose (sugar) → ethanol (alcohol) + carbon dioxide

Fermentation is an example of anaerobic respiration in yeast.

C6H12O6 → 2C2H5OH + 2CO2

Yeast can undergo aerobic respiration or anaerobic respiration. In bread-making, the yeast starts off respiring aerobically, producing water and also carbon dioxide to make the dough rise.

When the air runs out, the yeast begins to respire anaerobically. Any alcohol produced boils away during baking. When making alcoholic drinks, yeast establishes an oxygen-free environment provided no air is allowed to enter the fermentation container.

Useful Microorganisms At A Glance1) Microorganisms help us in making alcohol. E.g. Yeast, Zymomonas mobilis, Schizosaccharomyces.

2) Microorganisms help us in bakery. E.g. Yeast.

3) Microorganisms is used in making medicines. E.g. In Antibiotics- Penicilium Notatum.

4) Microorganisms is used in making curd/Yoghurt. E.g. Streptococcus Thermophilus  or  Lactobacillus.

5) Microorganisms fix atmospheric nitrogen (NO2) to the soil. E.g. Rhizobium orFrankia.

6) Microorganisms help us in researching on diseases, such as in vaccination.

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7) Microorganisms replenish the soil. Microorganisms play critical roles in decomposition.

8) Microorganisms are essential tools in biotechnology, biochemistry, genetics and molecular biology. E.g. Yeasts

9) Microorganisms are used in energy production. Scientists are researching the use of algae to produce liquid fuels and bacteria to convert various forms of agricultural and urban waste into usable fuels (Biofuel).

10) Microorganisms are used in Water Treatment/Sewage Treatment

Decomposition

Algae

WWTP