Production of D-lactic acid by Corynebacterium glutamicum under oxygen deprivation.
In mineral salts medium under oxygen deprivation, Corynebacterium glutamicum exhibits high productivity of L-lactic acid accompanied with succinic and acetic acids. In taking advantage of this elevated productivity, C. glutamicum was genetically modified to produce D-lactic acid. The modification involved expression of fermentative D-lactate dehydrogenase (D-LDH)-encoding genes from Escherichia coli and Lactobacillus delbrueckii in L-lactate dehydrogenase (L-LDH)-encoding ldhA-null C. glutamicum mutants to yield strains C. glutamicum DeltaldhA/pCRB201 and C. glutamicum DeltaldhA/pCRB204, respectively. The productivity of C. glutamicum DeltaldhA/pCRB204 was fivefold higher than that of C. glutamicum DeltaldhA/pCRB201. By using C. glutamicum DeltaldhA/pCRB204 cells packed to a high density in mineral salts medium, up to 1,336 mM (120 g l(-1)) of D-lactic acid of greater than 99.9% optical purity was produced within 30 h.
Okino
Shohei
S
Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan. mmg-lab@rite.or.jp
Suda
Masako
M
Fujikura
Keitaro
K
Inui
Masayuki
M
Yukawa
Hideaki
H
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D048230:Corynebacterium glutamicum / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005818:Genetic Engineering; D007770:L-Lactate Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D019344:Lactic Acid / Q000031:analogs & derivatives / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010957:Plasmids
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D019344:Lactic Acid; D007770:L-Lactate Dehydrogenase; D010100:Oxygen