Efficiency of some phosphatase producing soil-fungi

Seven efficient phosphatase producing fungi (PPF) were isolated and identified as Aspergillus rugulosus, A. fumigatus, A. terreus, A. niger, A. parasiticus, Pseudeurotium zonatum and Trichoderma harzianum. Their efficiency to hydrolyze different compounds of organic phosphorus (mono- and hexa-) was examined. The fungi reduced the pH of the medium, which was maximum with A. niger. A significant negative correlation of pH with development of fungal mats was observed (r = -0.39, n = 28, p < 0.05). The maximum secretion of acid phosphatase by PPF was at 21 d and alkaline phosphatase at 14 d. Acid phosphatase produced by PPF was three times higher than alkaline phosphatase. The intracellular phosphatase activity was significantly higher than extracellular activity. The efficiency to hydrolyse mono-phosphate by phosphatases released from the PPF was 4-times higher than hexa phosphate. T. harzianum was found to be most efficient organic P mobilizer as compared to the other fungi, tested. The efficiency per unit of enzyme produced by different fungi was different and that indicated the isoenzymes being of different types.