Friendly Microorganisms
Microorganisms are used for various purposes. They are used in the preparation of curd, bread and cake.
Curd contains several microorganisms. Of these, the bacterium, Lactobacillus promotes the formation of curd. It multiplies in milk and converts it into curd. Bacteria are also involved in the making of cheese, pickles and many other food items. An important ingredient of rava (sooji ) idlis and bhaturas is curd. Bacteria and yeast are also helpful for fermentation of rice idlis and dosa batter.
They are also used in cleaning up of the environment. For example, the organic wastes (vegetable peels, remains of animals, faeces, etc.) are broken down into harmless and usable substances by bacteria. Bacteria are also used in the preparation of medicines. In agriculture they are used to increase soil fertility by fixing nitrogen.