Lipolytic enzymes from endophytic microbes have been the focus of intense and growing research in view of the applicability of such enzymes in various industrial applications and endophytic microorganisms may emerge as a potential source of lipases with distinct characteristics. The current work involved purification and characterization of the lipase from an endophytic-bacteria isolated from the stem of Withania somnifera L. Dunal. Based on the analysis of morphology and 16S rDNA sequence, the endophytic bacteria was identified as Bacillus pumilus and designated as B. pumilus WSS5. Purified lipase from the B. pumilus WSS5 was found to be of 28 KDa as revealed by SDS-PAGE with optimum activity at 37°C and pH 8. The enzyme was found to be stable over a broad pH range of 6.0–9.0 and temperature stability was in the range of 10°C to 60°C. The enzyme activity was enhanced in the presence of organic solvents like Ethyl acetate, Methanol, 2-propanol, acetone, and ethanol. The stability of the enzyme in presence of various metal ions, surfactants, inhibitors, and kinetic parameters value suggested that this enzyme could be exploited in leather and detergent industries.
In addition, the stain removal potential of the crude and purified lipase was determined on cotton fabric pieces stained with vegetable oil. Lipase added to water along with detergent significantly enhanced the stain removal efficiency of a commercially available detergent. The current findings suggest the potential of B. pumilus WSS5 lipase owing to promising properties such as the alkali-thermostability, organic solvent-tolerance, and broad substrate specificity that makes it a strong candidate for application in detergent formulations, biotransformation, industries, and medicine. To our knowledge, this is the first report on the purification and characterization of lipase from bacterial endophyte isolated from the stem of Withania somnifera L. Dunal.