Purification and characterization of a new cold active lipase, EnL A from Emericella nidulans NFCCI 3643

Abstract

A mesophilic fungi producing an extracellular cold-active lipase was isolated from the soil samples of palm oil mill effluent dump sites, Pedavegi, West Godavari Dist, A.P. India and was identified as Emericella nidulans. The enzyme was purified by ammonium sulfate fractionation followed by hydrophobic interaction chromatography using phenyl sepharose. The enzyme was 35 fold pure compared to crude with a specific activity of 1494.51 U/mg. SDS PAGE analysis revealed that the protein is monomeric with a MW of ˜54 kDa and zymogram analysis showed that the purified protein was active. Characterization studies revealed that the temperature optimum was at 30°C and an optimum pH of 5. The K_m and V_max values were found to be 0.61 mM and 322.58 mM/min.mg, respectively. Sequencing of the purified protein by MALDI TOF-MS analysis followed by BLAST P analysis indicated that the protein is a putative secretary lipase from E. nidulans. Search of lipase engineering data base (LED) revealed that this protein belongs to a newly introduced super family of Candida antarctica lipase A like and to the homologous family of Aspergillus lipase like.

Key words: Cold active lipase, Emericella nidulans, hydrophobic interaction chromatography, Candida antarctica lipase A like.