Inorganic Phosphate Solubilization by Fungi Isolated from Agriculture Soil

Abstract

Phosphorus is one of the major nutrients, second only to nitrogen in requirement for plants. Microorganisms are involved in a range of process that effect the transformation of soil phosphorus ­­(P) and thus are integral component of the soil ‘P’ cycle. In the present study fungal strains isolated from agriculture soil, having potential to solubilize insoluble inorganic phosphates were characterized. Two fungal isolates were tested for their phosphate solubilization efficiency in both solid and liquid medium. Isolates were identified as Aspergillus sp. and Penicillium sp. depending upon their colony morphology and microscopic studies. Phosphate solubilization was related to pH decrease caused by growth of fungus in medium containing glucose as carbon source. The rock phosphate was solubilized upto 61.6% gm biomass in 10 days at 30â—¦c. Decrease in pH indicates that absence of soluble P in media induces the acid production. Phosphate solubilizing microorganisms convert insoluble phosphates into soluble forms generally through the process of acidification, chelation and exchange reactions. Thus such microorganisms may not only compensate for higher cost of manufacturing fertilizers in industry but also mobilizes the fertilizers added to soil.