Xylitol production by recombinant Corynebacterium glutamicum under oxygen deprivation.
Wild-type Corynebacterium glutamicum produced 0.6 g l(-1) xylitol from xylose at a productivity of 0.01 g l(-1) h(-1) under oxygen deprivation. To increase this productivity, the pentose transporter gene (araE) from C. glutamicum ATCC31831 was integrated into the C. glutamicum R chromosome. Consequent disruption of its lactate dehydrogenase gene (ldhA), and expression of single-site mutant xylose reductase from Candida tenuis (CtXR (K274R)) resulted in recombinant C. glutamicum strain CtXR4 that produced 26.5 g l(-1) xylitol at 3.1 g l(-1) h(-1). To eliminate possible formation of toxic intracellular xylitol phosphate, genes encoding xylulokinase (XylB) and phosphoenolpyruvate-dependent fructose phosphotransferase (PTS(fru)) were disrupted to yield strain CtXR7. The productivity of strain CtXR7 increased 1.6-fold over that of strain CtXR4. A fed-batch 21-h CtXR7 culture in mineral salts medium under oxygen deprivation yielded 166 g l(-1) xylitol at 7.9 g l(-1) h(-1), representing the highest bacterial xylitol productivity reported to date.
Sasaki
Miho
M
Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto, Japan.
Jojima
Toru
T
Inui
Masayuki
M
Yukawa
Hideaki
H
D000449:Aldehyde Reductase / Q000235:genetics; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D053898:Biosynthetic Pathways / Q000235:genetics*; D002175:Candida / Q000201:enzymology; D048230:Corynebacterium glutamicum / Q000235:genetics* / Q000378:metabolism*; D005285:Fermentation; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D055786:Gene Knockout Techniques; D005818:Genetic Engineering; D006836:Hydro-Lyases / Q000235:genetics; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010770:Phosphotransferases / Q000235:genetics; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D014993:Xylitol / Q000096:biosynthesis*; D014994:Xylose / Q000378:metabolism
C109577:AraE protein, bacteria; D001426:Bacterial Proteins; D005656:Fungal Proteins; D009004:Monosaccharide Transport Proteins; D011994:Recombinant Proteins; D014994:Xylose; D000449:Aldehyde Reductase; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C032700:xylulokinase; D006836:Hydro-Lyases; C045581:lactate dehydratase; D010100:Oxygen; D014993:Xylitol