A Study of Phosphate Solubilizing Capacity by Penicillium Aurantiogriseum under Different Carbon and Nitrogen Resources

Phosphate-solubilizing fungi have been successfully applied to the release of phosphorus from insoluble tricalcium phosphate. A phosphate-solubilizing fungi Penicillium aurantiogriseum was isolated and investigated the phosphorus solubilizing capacity under different carbon and nitrogen resources. The highest released phosphorus content reached 1000 mg/L in ammonium and sucrose conditions. Carbon resources did not limit the release of phosphorus by Penicillium aurantiogriseum. However, nitrate and urea significantly reduced the phosphorus release, which had a low phosphorus content (~780 mg/L). Glucose and ammonium were more efficient for fungal growth and organic acid secretion. Oxalic acid secreted by Penicillium aurantiogriseum dominated the release of phosphorus. The formed calcium oxalate promoted the dissolution of tricalcium phosphate. This study indicated that the effective utilization of Penicillium aurantiogriseum to dissolve tricalcium phosphate need to support more ammonium nitrogen.