Use of response surface method for maximizing the production of arginine deiminase by Pseudomonas putida

•First report on Arginine deiminase production from Pseudomonas putida using RSM.•Optimum conditions for ADI production were established in shake flasks.•ADI production was assessed in a 14 L bioreactor under the optimized conditions.•Repressor effect of aeration on ADI production was observed in 14 L bioreactor.•Substantial improvement of 4.5-folds in ADI titre was achieved.

Statistically designed experiments were used to optimize the production of arginine deiminase (ADI) by Pseudomonas putida KT2440 in batch culture. A Plackett-Burman design involving eleven factors showed that ADI production was most influenced by the initial pH and the initial concentrations of glucose and yeast extract. A central composite experimental design showed that the optimal values of these factors were 8.0, 10 g/L and 12.5 g/L, respectively. The other components of the optimal culture medium were bacto peptone 7.5 g/L, Triton X–100 0.30% (v/v), and arginine 3 g/L, for a culture temperature of 25 °C. Compared with the basal medium, the ADI activity in the optimized medium had nearly 4.5-fold increase (4.31 U/mL). The optimized medium was then used for a further study of ADI production in a 14 L stirred tank bioreactor. The agitation speed and the aeration rates were varied to determine suitable values of these variables.