Hydrolysis of Organic Phosphate Forms by Phosphatases and Phytase Producing Fungi of Arid and Semi Arid Soils of India

Abstract

Abstract: Phytase and phosphatase producing fungi were isolated from the soil’s of arid and semi arid regions of India and tested for their ability to hydrolyze two important organic P compounds: phytin and glycerophosphate. The identified organisms belong to the four genera: Aspergillus, Penicillium, Pseudeurotium and Trichoderma. A significant negative correlation (r =-0.386, n = 28, p<0.05) was observed between the development of fungal mats and the pH of the media. The extracellular phosphatases (E) released by different fungi were less than that released intracellularly (I), but the trend was reversed in case of phytase production. The E:I ratio of different fungi ranged from 0.45-0.61 for acid phosphatase, 0.41-0.54 for alkaline phosphatase and 44.9-71.9 for phytase. The efficiency of hydrolysis of different organic P compounds by different fungi varied from 0.98-3.54 µg min g for phytin to 1.82-5.89 µg min g for glycerophosphate. The-1-1-1-1 trend of efficiency was as follows: Trichoderma sp.>Aspergillus sp.>Pseudeurotium sp.>Penicillium sp. T. harzianum was found to be most efficient organic P mobilizer as compared to other fungi tested. In this paper, we investigate the relative abilities of intra-and extracellular fungal acid and alkaline phosphatase respectively and of phytase to hydrolyze different organic P compounds normally present in soil. Key words: Trichoderma Aspergillus Penicillium Organic P INTRODUCTION hydrolysis of organic P is predominantly mediated by the