SAHELI ALI, ANUPAM GHOSH, SAMIR KUMAR MUKHERJEE AND ANILAVA KAVIRAJ1
Abstract
Twenty seven bacterial isolates which could produce extracellular phytase were obtained out of the total bacterial population from the rumen of goat (Capra aegagrus hircus). Among these, three strains exhibiting comparatively higher phytase activity were selected for further study, and representative isolates were designated as KUAKSP1, KUAKSP2 and KUAKSP3. Based on the analysis of the respective 16S rDNA sequence data using BLAST algorithm in the NCBI database, the isolate KUAKSP1 was identified as the strain of Stenotrophomonas maltophilia, KUAKSP2 and KUAKSP3 as the strains of Escherichia coli. All the three strains showed better phytase activity in neutral to slightly alkaline pH at 37°C. At higher temperature (47°C) phytase activity of these strains was significantly reduced, except that of the KUAKSP1 at pH 7.5. There was no significant difference in phytase activity of the isolated bacterial strains in between 27°C and 37°C except of KUAKSP3, which showed higher phytase activity at 27°C at alkaline pH (8.0 to 8.5). It seems from this study that these three bacterial strains from the rumen of goat could potentially be used as effective candidates for hydrolysis of phytate in industries involved in fish feed formulations.