Isolation and identification of a phosphate solubilising fungus from soil of a phosphate mine in Chaluse, Iran

Microbial solubilisation of phosphorus from insoluble phosphates is an environmental friendly and cost effective approach in sustainable soil management. Introducing the indigenous microorganisms to soil requires shorter adaptation period and causes fewer ecological distortions than exogenous microorganisms. This study was conducted to isolate and identify the indigenous fungi for phosphate solubilisation in Mazandaran, Iran. A potent phosphate solubilising fungus was isolated from an Iranian phosphate mine and selected for solubilisation of rock phosphate (RP). The identified fungus was characterised by calmodulin-based polymerase chain reaction method as Aspergillus tubingensis SANRU (Sari Agricultural Sciences and Natural Resources University). The phosphate solubilisation ability of the fungal strain was carried out in shake-flask leaching experiments containing various concentrations of RP (1%, 2%, 4%, or 8% w/v). The maximum P solubilisation rate of 347 mg/l was achieved at 1% of RP concentration on day 9. The regression analysis indicated that the P solubilised mainly through acidification. This study shows the possibility of using A. tubingensis SANRU for application in the management of P fertilisation