Purification and characterization of Pseudomonas aeruginosa lipase produced by SSF of deoiled Jatropha seed cake

A solvent stable lipase from Pseudomonas aeruginosa PseA is described. The lipase was produced by solid-state fermentation of deoiled Jatropha seed cake and purified by ultrafiltration and gel filtration chromatography using Sephadex G-100. The purified lipase was characterized for its enzymatic properties and stability. It exhibited remarkable stability in a wide range of organic solvents up to 75% (v/v) concentrations. Circular dichroism and intrinsic fluorescence spectra were recorded to investigate the effect of organic solvents on the secondary and tertiary structures. The secondary structure of the lipase was predominantly α-helical which remained unperturbed even at high concentration of organic solvents after 24 h of exposure. Highly hydrophobic tetradecane caused loss of activity and structure of lipase. The solvent stable lipase was exploited for an efficient synthesis of ethyl butyrate in n-hexane medium.