Effect of Different Carbon Sources on Phosphate-Solubilizing Fungi Isolated from Phosphate Mines

Aspergillus niger isolated from phosphate mine which is capable of superior leaching phosphorus, was identified by the internal transcribed spacer analysis. we studied the effects of different C sources on the leaching of low grade phosphate, and explored the mechanism of rock phosphates dissolved by A. niger with the application of HPLC and ICP-AES. The results suggest that phosphorus leaching rate is the highest by A. niger under the condition of soluble starch compared to the other C sources, which may be relative to oxalic acid, malic acid and its total content. At the sometime, there is negative correlation between phosphate leaching capacity and pH of culture mediums in different C sources.