Isolation and identification of lipase producing microbial isolates from soil samples of Kangra region of Himachal Pradesh

Abstract

newline Abstract newlineLipases (triacylglycerol acylhydrolases, EC 3.1.1.3) catalyze the hydrolysis and the synthesis of esters formed from glycerol and long-chain fatty acids. Lipases occur widely in nature, but only microbial lipases are commercially significant. This work was undertaken for the isolation, screening and identification of the lipase producing microbial isolates from soil sample. Four soil samples of agricultural field D1, M1, N1 and G1 were collected from four different sites of Kangra district of Himachal Pradesh respectively. Lipase producing microorganisms were isolated using nutrient agar media supplemented with Tween 80. Screening was done on the basis of zones of clearance around them. Identification of the microbial isolates was done on the basis of morphological and various biochemical tests. The isolates were identified i.e. Staphylococcus and E.coli species according to Bergey s Manual of Systematic Bacteriology. The isolates identified were assayed for the production of lipase by spectrophotometrically using p-nitrophenyl palmitate as a substrate. The isolates were isolated from different soil samples which are capable of producing lipase above 3 U/ml in 24-72 hr of incubation. Optimization of physico-chemical conditions like pH and temperature were done and the bacterial, strain showed maximum lipase production at pH 7 and the temperature showed maximum lipase production at 37°C. In this study precipitation and immobilization of the lipase was done by ammonium sulphate and sodium alginate entrapment method respectively to see the effect of lipase activity on the isolates. However, it showed that after precipitation the lipase activity increases and after immobilization the lipase activity decreases of the isolates.