D-lactic acid production by metabolically engineered Saccharomyces cerevisiae.
Poly D-lactic acid is an important polymer because it improves the thermostability of poly L-lactic acid by the stereo complex formation. We constructed a metabolically engineered Saccharomyces cerevisiae that produces D-lactic acid efficiently. In this recombinant, the coding region of pyruvate decarboxylase 1 (PDC1) was completely deleted, and two copies of the D-lactate dehydrogenase (D-LDH) gene from Leuconostoc mesenteroides subsp. mesenteroides strain NBRC3426 were introduced into the genome. The D-lactate production reached 61.5 g/l, the amount of glucose being transformed into D-lactic acid being 61.2% under neutralizing conditions. Additionally, the yield of free D-lactic acid was also shown to be 53.0% under non-neutralizing conditions. It was confirmed that D-lactic acid of extremely high optical purity of 99.9% or higher. Our finding obtained the possibility of a new approach for pure d-lactic acid production without a neutralizing process compared with other techniques involving lactic acid bacteria and transgenic Escherichia coli.
Ishida
Nobuhiro
N
Biotechnology Laboratory, Toyota Central R&D Labs Inc., 41-1 Nagakute-yokomichi, Aichi 480-1192, Japan. e1168@mosk.tytlabs.co.jp
Suzuki
Tomiko
T
Tokuhiro
Kenro
K
Nagamori
Eiji
E
Onishi
Toru
T
Saitoh
Satoshi
S
Kitamoto
Katsuhiko
K
Takahashi
Haruo
H
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D005285:Fermentation; D005818:Genetic Engineering / Q000379:methods*; D007770:L-Lactate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid / Q000096:biosynthesis* / Q000378:metabolism; D007934:Leuconostoc / Q000235:genetics; D008969:Molecular Sequence Data; D011767:Pyruvate Decarboxylase / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D007773:Lactates; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D019344:Lactic Acid; D007770:L-Lactate Dehydrogenase; C101504:PDC1 protein, S cerevisiae; D011767:Pyruvate Decarboxylase