Production of extracellular Pullulanase by NP 7 bacteria using OFAT methodology

Abstract

Pullulanase is a debranching enzyme that spilts explicitly α-1,6 glycosidic bonds. It is widely used in starch saccharification, in production of glucose, fructose as well as maltotriose syrup and bioethanol production. Pullulanase is produced by submerged fermentation process that requires optimization of physical and chemical parameters to achieve higher activity and make this process cost effective. The present study aimed the optimization of physical as well as chemical parameters of production medium. The optimization includes physical parameters such as inoculum size, incubation time, temperature, pH and agitation rate while chemical parameters include carbon source, nitrogen source and different metal ions. From the optimization study, it was found that highest pullulanase production was achieved after 48 hours of incubation at 45ºC temperature, pH 7 and 120 rpm. Optimization of chemical parameters reveals that incorporation of starch (1%) and 0.2mMole/L of calcium chloride in the media gave significant increase in enzyme activity. The maximum productivity achieved after optimization was 139.33 U/ml using OFAT method which was four times higher.