title: Production of a lipolytic enzyme originating from Bacillus halodurans LBB2 in the methylotrophic yeast Pichia pastoris.
abstract: A gene encoding a lipolytic enzyme amplified from the alkaliphilic bacterium Bacillus halodurans LBB2 was cloned into the pPICZalphaB vector and integrated into the genome of the protease deficient yeast strain Pichia pastoris SMD1168H. This previously undescribed enzyme was produced in active form, and cloning in frame with the Saccharomyces cerevisiae secretion signal (alpha-factor) enabled extracellular accumulation of correctly processed enzyme, with an apparent molecular mass of 30 kDa. In shake-flask cultivations, very low production levels were obtained, but these were significantly improved by use of a "batch-induced" cultivation technique which allowed a maximum enzyme activity of 14,000 U/l using p-nitrophenyl butyrate (C-4) as a substrate and a final extracellular lipolytic enzyme concentration of approximately 0.2 g/l. Partial characterization of the produced enzyme (at pH 9) revealed a preference for the short-chain ester (C-4) and significant but lower activity towards medium (C5-C6) and long (C16 and C18) fatty acid chain-length esters. In addition, the enzyme exhibited true lipase activity (7,300 U/l) using olive oil as substrate and significant levels of phospholipase activity (6,400 U/l) by use of a phosphatidylcholine substrate, but no lysophospholipase activity was detected using a lysophosphatidylcholine substrate.
authors.affiliation: Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, 22100, Lund, Sweden.
authors.forename: Santosh O
authors.initials: SO
authors.lastname: Ramchuran
authors.forename: Virginia A
authors.initials: VA
authors.lastname: Vargas
authors.forename: Rajni
authors.initials: R
authors.lastname: Hatti-Kaul
authors.forename: Eva Nordberg
authors.initials: EN
authors.lastname: Karlsson
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D000069463:Olive Oil; D010740:Phospholipases / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D010843:Pichia / Q000201:enzymology / Q000235:genetics*; D010938:Plant Oils / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D013379:Substrate Specificity
chemical_list: D004269:DNA, Bacterial; D000069463:Olive Oil; D010938:Plant Oils; D011994:Recombinant Proteins; D010740:Phospholipases