Lipase from Bacillus pumilus RK31: Production, Purification and Some Properties

Abstract

Abstract: A new lipolytic strain of Bacillus sp. was isolated from oil contaminated soil sample. On measurement of biochemical parameters and 16S rDNA sequence information the strain was identified as Bacillus pumilus RK31 (NCBI accession no GQ463238). The lipase purification steps involved, 60 % ammonium sulphate saturation, gel filtration chromatography using Sephadex G200 and ion exchange chromatography with DEAE cellulose. A purification fold of 186 was achieved following only three step purification process with specific activity of 3525.6 U/mg to apparent homogeneity as evident by a single band of 62.2kDa on sodium dodecyl sulphate polyacrylamide gel electrophoresis and reverse phase HPLC chromatogram. The purified enzyme 1 1 1 exhibited optimum activity at temperature 60°C, pH 6.0, Km of 1.83 mM l and the Vmax of 10.0 mM l min. EDTA-K almost completely inhibited the lipase activity. The enzyme had property to tolerate a wide range of organic solvents which make it attractive towards industrial applications. Key words: Purification fold Characterization Lipase Column chromatography INTRODUCTION food, compost heaps, coal tips and hot springs [4]. Microbial lipases are of special interest because of their Among many ubiquitous enzymes, lipases stability in organic solvents, lack of requirement for