Immobilization of Extremophile Bacillus Licheniformis Lipase on Silica & Celite Matrices & its Characterization

A purified alkaline thermotolerant lipase from Bacillus licheniformis MTCC-10498 was immobilized on Silica and Celite-545 matrices. The swelling capacity of silica and celite was recorded as 1.04 and 1.6 times respectively. The purified lipase (2.0 U/ml; protein content 0.06 mg and specific activity 32 U/mg) was used for immobilization by adsorption on silica and celite. The silica and celite showed 85.7% and 80%binding/ retention of purified lipase. The immobilized enzyme possessed a specific activity of 28 U/mg and 26.8 U/mg respectively. The optimal activity of purified lipase, silica bound, celite-bound was seen at pH 8.0 and at temperature of 55 ?C (2.0 ? 0.01; 1.211 ? 0.01; 1.216 ? 0.02).The hydrolytic activity of purified lipase and immobilized lipase was maximum for p-NPP. The hydrolytic activity of purified lipase, silica bound and celite bound lipase preparation reduced to approx. 50%, in 3 h. The presence of metal salts and EDTA inhibited lipase activity of purified, silica bound and celite bound lipase. Presence of PMSF (20mM) in the reaction mixture severely decreased the hydrolytic activities.