Cloning of the Xylitol Dehydrogenase Gene fromGluconobacter oxydansand Improved Production of Xylitol fromD-Arabitol

Complete genome sequence of the acetic acid bacterium Gluconobacter oxydans

“…1). In addition, three proteins were identified that may play a critical role in biotechnological applications for the synthesis of L-sorbose (NADPH-dependent sorbose reductase and fructose-forming sorbitol dehydrogenase) and xylitol (xylitol dehydrogenase) [29][30][31] .…”

Coenzyme Specificity of Enzymes in the Oxidative Pentose Phosphate Pathway ofGluconobacter oxydans

“…2,3) The conversion of Darabitol to xylitol by G. oxydans involves the reduction of Dxylulose to xylitol, which is catalysed by an NADHdependent xylitol dehydrogenase. Therefore, for ecient con version, regeneration of NADH is essential.…”

Transaldolase/Glucose-6-phosphate Isomerase Bifunctional Enzyme and Ribulokinase as Factors to Increase Xylitol Production fromD-Arabitol inGluconobacter oxydans

“…Our previous stu dies suggested that enhancement of NADH supply was essential for increasing the yield of xylitol from Darabitol in G. oxydans, 8,10) but the NADH genera tion mechanism of G. oxydans remained unclear.…”

“…8,9) Neverthe less, some Dxylulose still remained in the reaction mixture, even using recombinant strains of G. oxyd ans that had 11fold higher XDH activity than the wildtype strain. 10) From a practical point of view, increasing the conversion rate of Dxylulose to xylitol would improve the yield of xylitol and rene the manufacturing process.…”

“…It was suggested that the ethanol was oxidized by an NADdependent soluble alcohol dehydrogenase, resulting in the regeneration of NADH. 8,10) Since XDH is highly specic for NADH, it requires a sup ply of NADH for the ecient conversion of Dxylu lose to xylitol.…”