Effects of Inorganic Soluble Phosphate on Phosphate Solubilization and Acid Phosphatase Activity of the Bacterial Strain Pantoea agglomerans, Isolated from Soil

Abstract

The present study assessed the effect of application of inorganic soluble phosphate (P) on phosphatase enzyme activity of phosphate solubilizing bacterial strain identified as Pantoea agglomerans. The strain was employed in phosphatase enzyme induction studies using N B R 1 P medium which contained Ca3(P04)2 as a source of inorganic insoluble P. The medium was amended with four levels of inorganic soluble P (0, 0.5, 1.0 and 1.5 g/1 K H 2 P O 4 viz., Po, Pi, P2 and P 3 ). As revealed by the results, phosphatase activity and phosphate solubilization were decreased by inorganic soluble P ( K H 2 P O 4 ) in the N B R I P medium inoculated with phosphate solubilizing bacterial strain. The highest phosphatase activity (118.85 U/ml) and phosphate solubilization (642 pg/ml) were recorded when medium contained only inorganic insoluble P and the lowest phosphatase activity (95.3 U/ml) and phosphate solubilization (210 pg/ml) were recorded at the highest level of inorganic soluble P (1.5 g/1). Therefore it can be concluded that presence of soluble P represses the P solubilization activity of P. agglomerans under in vitro conditions