Production of L-glutaminase by Pseudomonas VJ-6

Abstract

Of the fifteen bacterial isolates screened for glutaminase production, four were positive for glutaminase production. Among them only one isolate Pseudomonas-VJ6 was selected based on plate assay. Glutaminase production was 51.5 U/ml by submerged fermentation. Enzyme activity of was assayed in various ranges of incubation period, temperature and pH. The enzyme activity was optimal at 72 hrs (53.3 U/ml), temperature, 30°C (56.0 U/ml) and pH of 6.0 (57.6 U/ml). Nutritional parameters, carbon and nitrogen sources also played an efficient role in enhancing the yield. Among the different carbon sources, glucose with concentration (10 g/l) showed maximum activity of 58.4 U/ml and among different nitrogen sources yeast extract (2 g/l) showed maximum activity of 58.9 U/ml. L-glutaminase was partially purified from cell free extracts of Pseudomonas-VJ6 by ammonium sulphate salt precipitation which showed activity of 56.6 U/ml at 80% precipitation and dialyzed enzyme extract having activity of 56.0 U/ml with protein content of 70 mg/ml was obtained. SDS-PAGE showed a molecular weight of 31 kDa. L-glutaminase from bacterial sources is reported to have high industrial application for their stability.C (56.0 U/ml) and pH of 6.0 (57.6 U/ml). Nutritional parameters, carbon and nitrogen sources also played an efficient role in enhancing the yield. Among the different carbon sources, glucose with concentration (10 g/l) showed maximum activity of 58.4 U/ml and among different nitrogen sources yeast extract (2 g/l) showed maximum activity of 58.9 U/ml. L-glutaminase was partially purified from cell free extracts of Pseudomonas-VJ6 by ammonium sulphate salt precipitation which showed activity of 56.6 U/ml at 80% precipitation and dialyzed enzyme extract having activity of 56.0 U/ml with protein content of 70 mg/ml was obtained. SDS-PAGE showed a molecular weight of 31 kDa. L-glutaminase from bacterial sources is reported to have high industrial application for their stability.