Phosphate solubilizing microorganisms: Effect of carbon, nitrogen, and phosphorus sources

Abstract

Although most soils contain large amounts of total phosphorus, they are deficient in phosphates available to plants. However significant populations of soil microorganisms present the ability to dissolve poorly soluble mineral phosphates. Most of these microorganisms are heterotrophs and depend on carbon and energy sources that can be found in the rhizosphere or by recycling crop residues. Besides, nitrogen and phosphorus sources may be considered as control factors in soil, because as carbon sources, they influence microorganisms growth and consequently their solubilization capacity. The principal mechanism for mineral phosphate solubilization is the production of organic acids. Some studies indicate that the phys- iology and biochemistry of C, N, and P play a role in the phosphate solubilization process. Is was suggested that increased numbers of phosphate solubilizing microorganisms in soil may be significant in relation to the phosphorus economy of the plant.