Prospectus of phosphate solubilizing microorganisms and phosphorus availability in agricultural soils: A review

Abstract

Phosphate solubilizing microorganisms (PSMs) offer an ecologically acceptable mean for converting insoluble phosphate to soluble forms making them available for plants to absorb. Several bacterial strains (Pseudomonas, Bacillus, Rhizobium and Enterobacter) and fungal strains (Aspergillus and Penicillium) have so far been recognized as powerful phosphate solubilizers. Insoluble phosphates are converted into available forms by phosphate solubilizing microorganisms via the process of acidification, chelation, exchange reactions and production of organic acid. Though phosphorus is found to be a limiting factor in many soils, application of PSMs as biofertilizers or bioconverters for solubilizing fixed phosphorus has not yet been successfully practiced. In this context, isolation, identification and characterization of soil PSMs are considered to be effective in broadening the spectrum of phosphate solubilizers available for field application