title: Yeast whole-cell biocatalyst constructed by intracellular overproduction of Rhizopus oryzae lipase is applicable to biodiesel fuel production.
abstract: Yeast whole-cell biocatalysts for lipase-catalyzed reactions were constructed by intracellularly overproducing Rhizopus oryzae lipase (ROL) in Saccharomvces cerevisiae MT8-1. The gene encoding lipase from R. orvzae IFO4697 was cloned, and intracellular overproduction systems of a recombinant ROL with a pro-sequence (rProROL) were constructed. When rProROL from R. oryzae IFO4697 was produced under the control of the 5'-upstream region of the isocitrate lyase gene of Candida tropicalis (UPR-ICL) at 30 degrees C for 98 h by two-stage cultivation using SDC medium (SD medium with 2% casamino acids) containing 2.0% and 0.5% glucose, intracellular lipase activity reached levels up to 474.5 IU/l. These whole-cell biocatalysts were permeabilized by air-drying and used for the synthesis of methyl esters (MEs), a potential biodiesel fuel, from plant oil and methanol in a solvent-free and water-containing system. The ME content in the reaction mixture was 71 wt% after a 165-h reaction at 37 degrres C with stepwise addition of methanol. These results indicate that an efficient whole-cell biocatalyst can be prepared by intracellular overproduction of lipase in yeast cells and their permeabilization.
authors.affiliation: Division of Molecular Science, Graduate School of Science and Technology, Kobe University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsumoto
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: M
authors.initials: M
authors.lastname: Kaieda
authors.forename: M
authors.initials: M
authors.lastname: Ueda
authors.forename: A
authors.initials: A
authors.lastname: Tanaka
authors.forename: H
authors.initials: H
authors.lastname: Fukuda
authors.forename: A
authors.initials: A
authors.lastname: Kondo
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D002384:Catalysis; D005742:Gasoline; D008049:Lipase / Q000096:biosynthesis*; D010539:Permeability; D012233:Rhizopus / Q000201:enzymology*; D012441:Saccharomyces cerevisiae / Q000235:genetics*
chemical_list: D005742:Gasoline; D008049:Lipase