Abstract

Objective: This is a study on the condition optimization of production of l-arginine deiminase (ADI) by Vibrio alginolytics 1374. To increase the production quantity, it could be helpful in the production of ADI for the therapeutic use in the future.

Method: Vibrio alginolyticus 1374; GU726873 is a gram negative rod shaped marine bacteria isolated from chirala beach of Andhra Pradesh. It was screened for the enzyme production in minimal arginine medium by dye based method. Further the activity was confirmed calorimetrically by estimating the levels of l-citrulline. The potential of isolated novel strain for ADI production was analyzed under submerged fermentation with different process parameters and medium constituents. The enzyme thus obtained was purified by ammonium sulphate fractionation, ion exchange and gel permeation chromatography. The purity of enzyme was detected by polyacrylamide gel electrophoresis.

Result: The maximum yield of enzyme production was achieved in a seawater based medium at pH 8, 37°C, 2% inoculum concentration and 2% l-arginine concentration for 120 h. The medium when supplemented with carbon source, it improved the enzyme production from 172 to 192 IU/ml with 2% maltose. Addition of 2% soybean meal also improved the ADI production (183.56 IU/ml). The enzyme was purified to near homogeneity (1161.2 fold).The enzyme was found to have specific activity of about 280.6 IU/mg with molecular weight of about 48kDa.

Conclusion: This novel strain has an immense potential as an industrial organism for the large scale production of ADI for the therapeutic use in the future.

Keywords: L-Arginine deiminase (ADI), Vibrio alginolyticus 1374; GU726873, ion exchange chromatography, gel permeation chromatography.

Graphical Abstract