Find out role of microbes in following and discuss it with your teacher.
(i) Single cell protein (SCP), (ii) Soil

(i) Single Cell Protein (SCP) is protein rich microbial biomass which can be used as food and feed. SCP has all the essential amino acids. Fat content is low. Both autotrophs and heterotrophs are used as SCP. Amongst autotrophs. Spirulina has become an important food supplement which is used in various forms including tablets. It has 60% protein, all minerals, vitamins and unsaturated fats. Amongst heterotrphs, yeast and mushrooms are being raised as SCP. There is an increasing use of low cost organic matter (saw dust, paddy husk and other organic wastes) for raising SCP like Fusarium graminearum and common mushrooms.
(ii) Soil. Microbes take part in formation and maintenance of soil. (a) They add organic matter to freshly formed soil.The process is called humification. (b) They act as scavengers and remove orgainc remains. (c) Microbes take part in biogeochemical circulation. (d) Some microbes act as biofertilizers and biopesticides.