(1) They are utilised in the making of curd, bread and cake.
(2) They are used in the production of alcohol, wine, acetic acid.
(3) They are used in the preparation of medicines called antibiotics.
(4) They are used in agriculture to increase the fertility of soil.
(5) They clean up the environment by decomposing the organic matter of dead plants, dead animals and animal waste into harmless and simple substances.