Phosphate-solubilizing capacity of two fungal strains under different culture conditions.

[Objective]The present experiment was aimed to study the effects of different inorganic solid and liquid media and phosphorus sources on phosphate-solubilizing capacity of two fungal strains to find out the best culture conditions for obtaining high potential of phosphate-solubilizing capacity. [Method]The molybdenum blue colorimetry was used to determine the phosphate-solubilizing capacity of two fungal strains (FC and H3) in various culture media (inorganic or organic phosphorus liquid medium, SP, NBRIY, NBRIP and NBRIYP). Different types of phosphorus sources (tricalcium phosphate, iron phosphate, aluminum phosphate, dicalcium phosphate and organic phosphorus), and different concentrations of tricalcium phosphate (0.3, 0.5, 0.7, 0.9 and 1.1%) were used. [Result]Both the strains were found suitable for culturing 5 days in the PDA medium. After culturing for 7 days in different media, FC strains showed the strongest phosphate-solubilizing capacity in NBRIY, followed by inorganic phosphorus medium, NBRIP, organic phosphorus medium and NBRIYP, while H3 strain had the highest phosphate-solubilizing capacity in inorganic phosphorus medium, followed by NBRIP, SP, NBRIY, organic phosphorus medium and NBRIYP. Out of different phosphorus sources, both the FC and H3 strain were found to have strongest phosphate-solubilizing capacity with dicalcium phosphate. Both the strains were found to grow and show phosphate-solubilizing capacity in liquid medium with different concentrations of tricalcium phosphate, which was the highest with 0.5% tricalcium phosphate. [Conclusion]The best culture medium for FC and H3 were identified as NBRIY and inorganic phosphate medium, respectively. Both the 2 strains were able to solublize the insoluble phosphate, however, the strain H3 had higher phosphate-solubilizing capacity.