How do microorganisms help us in digestion of food ??

Micro-organisms such as bacteria and fungi are decomposers and can obtain nutrients by breaking down the remains of dead plants and animals. They help in the breakdown of organic matter or biomass from the body of dead plants and animals into simple inorganic raw materials, such as CO₂, H₂O, and some nutrients which are used by plants.  
          If they are completely removed from the surface of earth then the remains of dead plant and animals will accumulate.  Thus it will result in accumulation of wastes and also unavailability of raw materials. This will effect all the bio-geochemical cycles and overall life on earth. Thus, microorganisms help in cleaning our environment.

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