title: Purification and characterization of solvent tolerant lipase from Bacillus sp. for methyl ester production from algal oil.
abstract: Lipase from Bacillus sp. isolated from the oil contaminated soil was purified by ammonium sulphate precipitation and ion-exchange chromatography with a 5.1-fold purification and 10.5% yield. SDS-PAGE analysis of the enzyme revealed the molecular mass of 24 kDa. The optimum pH and temperature for lipase activity were 6.5 and 37°C, respectively. The isolated lipase was stimulated by pretreatment with methanol and ethanol as well as by divalent metal ions Ca(2+), Mg(2+) and Mn(2+). The enzyme showed high activity towards oleic rich oils. The enzyme immobilized on celite could retain 90% lipase activity after eight cycles. Transesterification of Botryococcus sp. oil using the immobilized enzyme for 40 h resulted in 80% yield of fatty acid methyl esters which had good properties for use as biodiesel. Overall results suggested that the solvent tolerant Bacillus lipase can be a potential biocatalyst for methyl ester production.
authors.affiliation: Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Ramachandran
authors.initials: R
authors.lastname: Sivaramakrishnan
authors.affiliation: Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: aran.i@chula.ac.th.
authors.forename: Aran
authors.initials: A
authors.lastname: Incharoensakdi
mesh_terms: D001407:Bacillus / Q000201:enzymology*; D055162:Biocatalysis / Q000187:drug effects; D056804:Biofuels / Q000600:supply & distribution; D000460:Chlorophyta / Q000737:chemistry*; D002852:Chromatography, Ion Exchange; D007692:Diatomaceous Earth; D004591:Electrophoresis, Polyacrylamide Gel; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D004952:Esters / Q000737:chemistry / Q000378:metabolism*; D000431:Ethanol / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D000432:Methanol / Q000737:chemistry; D008970:Molecular Weight; D009821:Oils / Q000737:chemistry / Q000378:metabolism*; D019301:Oleic Acid / Q000378:metabolism; D012997:Solvents / Q000737:chemistry / Q000494:pharmacology*; D013696:Temperature
chemical_list: D056804:Biofuels; D004800:Enzymes, Immobilized; D004952:Esters; D009821:Oils; D012997:Solvents; D019301:Oleic Acid; D000431:Ethanol; D007692:Diatomaceous Earth; D008049:Lipase; D000432:Methanol
keywords: Bacillus sp.; Immobilization; Purification; Solvent tolerant lipase; Transesterification