Metabolic engineering of Saccharomyces cerevisiae for efficient production of pure L-(+)-lactic acid.
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.
Ishida
Nobuhiro
N
Biotechnology Laboratory, Toyota Central R&D Labs Inc., Aichi 480-1192, Japan. e1168@mosk.tytlabs.co.jp
Saitoh
Satoshi
S
Ohnishi
Toru
T
Tokuhiro
Kenro
K
Nagamori
Eiji
E
Kitamoto
Katsuhiko
K
Takahashi
Haruo
H
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*
D011994:Recombinant Proteins; D019344:Lactic Acid; D007770:L-Lactate Dehydrogenase; D011767:Pyruvate Decarboxylase