Optimization of lipase production in a triple impeller bioreactor

Abstract

The fermentation kinetics for the synthesis of lipase by Candida rugosa has been studied in a batch system in a 2 l batch bioreactor. The studies illustrated the influence of gas–liquid mass transfer coefficient on the cell growth and hence the lipase production. In order to maintain sufficient oxygen concentration for the optimum cell growth and lipase activity, fermentation has been carried out using triple impeller system at an operating speed of 600 rpm (optimum operating speed as found in the earlier work) and at different aeration rates. Gas-flow rate of 50.34 cc/s has been observed to be optimum. Under optimized conditions of the bioreactor, cell production was enhanced and the lipase activity increased by 2.5 folds. The Monod's kinetics was fitted to the data of the operating parameters to understand the cell growth and substrate consumption. Luedking and Piret model was applied to the data to determine the relationship between the cell growth and lipase production. The lipase production was found to be microbial growth associated function.