Statistical optimization of culture conditions by response surface methodology for the enhanced production of a cytotoxic pigment from Pseudomonas stutzeri JGI 52

Abstract

A pigment (PY3) with cytotoxic properties was isolated from a bacterial strain, Pseudomonas stutzeri JGI 52.To enhance the production of this promising pigment, various media components and parameters viz., carbon and nitrogen source, mineral components, temperature, pH and incubation time were optimized in the current study. Maximum amount of pigment was produced at temperature 37°C, pH 7.5 and incubation time 72 h. Based on the conventional method of optimization, lactose, beef extract, MgSO4and pH were identified as the most important contributors towards pigment production. To investigate the combined interactive effects of relevant process variables for enhancing pigment production, statistical optimization through Response surface methodology (RSM) and central composite design (CCD) were employed. The optimum culture conditions for maximum pigment yield were 0.52 % lactose, 1.01 % beef extract, 1.003% MgSO4 and 7.5 pH and 37 °C temperature, which resulted in 2.5 fold higher pigment yield than the controls.