Optimization of production of lipase from Staphylococcus hominis using response surface methodology

Abstract

Lipases, versatile hydrolytic enzymes are gaining more importance in environmental applications such as treatment of fat, oil and grease (FOG) containing wastewater, pretreatment of solid waste/industrial wastewater for anaerobic treatment etc. The use of lipase enzyme in pre/treating such wastewaters and solid wastes are considered as greener and sustainable approach compared to physical and/or chemical methods. The maximum production of lipases is indispensable for economical point of view. Therefore, the present study attempts to improve the production of lipase from Staphylococcus hominis MTCC 8980 by optimizing physical factors namely pH, temperature and agitation in batch shake flasks. The experiments were designed using full factorial central composite design (CCD) and the results were analyzed using response surface methodology (RSM). Total twenty experiments were conducted to optimize the pH, temperature and agitation speed for maximum production of lipase. The regression model could explain the variation of 94.09% (R2 = 94.09). The analysis of variance (ANOVA) from response model indicates that temperature and agitation significantly influence the lipase production (p value <0.05). The interaction term for pH and agitation was found to have positive significant effect on lipase production. The model predicted 1.5 fold increase in lipase activity (1.85 U) under optimized conditions of pH (8.0), temperature (33.1°C) and agitation speed (178 rpm).