Role of microbes in phosphorus cycle
a. Conversion of organic phosphate into insoluble inorganic phosphates: in the presence of microbes Cunningham Ella spp., Arthrobacter spp., Streptomyces spp., Rhizopus spp. & Bacillus secrete phosphatase enzyme which decompose different organic phosphorus compounds (Nucleoproteins & Lysithins, Glycerol, Fatty acids, Phosphates & Cholin) in the soil. In this decomposition, organic phosphorus is converted into phosphoric acids which combine with soil bases like-calcium & magnesium oxides & iron oxides to produce salts of Ca, Mg & Iron. These salts are less soluble & thus less available to the plants.
Nucleoproteins→Nuclein→nucleic acid→ Phosphoric acid (CH3PO4) → combines with soil base (CaO, MgO) →Calcium triphosphate & Magnesium diphosphate (less soluble & less available to the plants).
So, these salts undergo mineralization & solubilization in the presence of microbes to produce calcium hydrogen phosphate highly soluble & more available to the plants.
b. Conversion of insoluble inorganic phosphates into soluble inorganic phosphates: certain bacteria like Penicillium, Mycobacterium, Pseudomonas, Micrococcus, Sclerosium, Aspergillus etc. produce H2SO4, HNO3, citric acid, glumatic acid, succinic acid, lactic acid, malic acid, fumaric acid, tartaric acid & α-ketoglutaric acid which help in mineralization or solubilization. Conversion of insoluble phosphate into soluble phosphate is called solubilization.