title: Metabolic engineering of Saccharomyces cerevisiae for efficient production of pure L-(+)-lactic acid.
abstract: We developed a metabolically engineered Saccharomyces cerevisiae, which produces optically pure L-lactic acid efficiently using cane juice-based medium. In this recombinant, the coding region of pyruvate decarboxylase (PDC)1 was completely deleted, and six copies of the bovine L-lactate dehydrogenase (L-LDH) genes were introduced on the genome under the control of the PDC1 promoter. To confirm optically pure lactate production in low-cost medium, cane juice-based medium was used in fermentation with neutralizing conditions. L-lactate production reached 122 g/L, with 61% of sugar being transformed into L-lactate finally. The optical purity of this L-lactate, that affects the physical characteristics of poly-L-lactic acid, was extremely high, 99.9% or over.
authors.affiliation: Biotechnology Laboratory, Toyota Central R&D Labs Inc., Aichi 480-1192, Japan. e1168@mosk.tytlabs.co.jp
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ishida
authors.forename: Satoshi
authors.initials: S
authors.lastname: Saitoh
authors.forename: Toru
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Kenro
authors.initials: K
authors.lastname: Tokuhiro
authors.forename: Eiji
authors.initials: E
authors.lastname: Nagamori
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kitamoto
authors.forename: Haruo
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D002417:Cattle; D003001:Cloning, Molecular / Q000379:methods; D005240:Feasibility Studies; D024861:Genetic Enhancement / Q000379:methods*; D007770:L-Lactate Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D019344:Lactic Acid / Q000302:isolation & purification / Q000378:metabolism*; D010865:Pilot Projects; D011401:Promoter Regions, Genetic; D015202:Protein Engineering / Q000379:methods*; D011767:Pyruvate Decarboxylase / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D019344:Lactic Acid; D007770:L-Lactate Dehydrogenase; D011767:Pyruvate Decarboxylase