Role of Nitrogen , Phosphorus & Sulphur in Microbial Nutrition :

Role of Nitrogen , Phosphorus & Sulphur in Microbial Nutrition : 

1.Nitrogen : Nitrogen is required for synthesis of amino acids , purines , pyramidines , few carbohydrates and lipids , enzymes co-factor and other substances.

Most of phototrophs & many nonphotosynthetic organism reduces nitrate to ammonia and incorporate the ammonia in assimilatory nitrate reduction.

A variety of bacteria e.g.Cyanobacteria & Rhizobium can reduce and assimilate atmospheric nitrogen using nitrogenase system.

               Fixation & Role Of Nitrogen 

2.Role of Phosphorus in Microbial Nutritions :

Phosphorus deficiency suppresses the growth and development of microorganisms, while their excess has a negative effect on regulation of phosphate metabolism. The intracellular content of Pi is strictly regulated.

Phosphorus present in nucleic acids , phospholipids , ATP , several co-factors and some proteins and other cell components.

All micro-organisms use inorganic phosphate (Pi)

as their phospho source & incorpoare directly.

E.coli can use the both organic andn inorganic phosphate (Pi).

Organo-phosphates such hexose 6 phosphate can taken up directly by transport proteins.

Other organophosphates are often hydrolyzed in the periplasm by Alkaline Phosphatase to produce inorganic Phosphate (Pi) which is transported across plasma membrane.

When inorganic phosphate is outside of the cell it crosses outer membrane by uae of porins protein channels.

3.Role of Sulphur for Microbail Nutritions :

These microbes use inorganic sulfur compounds as electron acceptors to sustain several activities such as respiration, conserving energy and growth, in absence of oxygen.

Required for  Sulfur-reducing bacteria are microorganisms able to reduce elemental sulfur (S) to hydrogen sulfide (H2S).

Sulphur is needed for synthesis of substances like amino acids cyateine and methionine , some carbohydrates biotin and thiamine.

Most of them uses sulphate as source of sulphur and reduce it by assmilatory sulphate reduction few requires a reduced form of sulphur such as cysteine.