Transaldolase/glucose-6-phosphate isomerase bifunctional enzyme and ribulokinase as factors to increase xylitol production from D-arabitol in Gluconobacter oxydans.
Xylitol production from D-arabitol by the membrane and soluble fractions of Gluconobacter oxydans was investigated. Two proteins in the soluble fraction were found to have the ability to increase xylitol production. Both of these xylitol-increasing factors were purified, and on the basis of their NH(2)-terminal amino acid sequences the genes encoding both of the factors were cloned. Expression of the cloned genes in Escherichia coli showed that one of the xylitol-increasing factors is the bifunctional enzyme transaldolase/glucose-6-phosphate isomerase, and the other is ribulokinase. Using membrane and soluble fractions of G. oxydans, 3.8 g/l of xylitol were produced from 10 g/l D-arabitol after incubation for 40 h, and addition of purified recombinant transaldolase/glucose-6-phosphate isomerase or ribulokinase increased xylitol to 5.4 g/l respectively, confirming the identity of the xylitol-increasing factors.
Sugiyama
Masakazu
M
AminoScience Laboratories, Ajinomoto Co., Inc., Kawasaki-shi, Japan. masakazu_sugiyama@ajinomoto.com
Suzuki
Shun-ichi
S
Tonouchi
Naoto
N
Yokozeki
Kenzo
K
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000737:chemistry; D020600:Gluconobacter oxydans / Q000201:enzymology*; D005956:Glucose-6-Phosphate Isomerase / Q000378:metabolism*; D008969:Molecular Sequence Data; D009249:NADP / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013402:Sugar Alcohols / Q000378:metabolism; D014153:Transaldolase / Q000378:metabolism*; D014993:Xylitol / Q000378:metabolism*; D014996:Xylulose / Q000378:metabolism
D011994:Recombinant Proteins; D013402:Sugar Alcohols; D009249:NADP; D014996:Xylulose; D014153:Transaldolase; D017853:Phosphotransferases (Alcohol Group Acceptor); C022550:ribulokinase; D005956:Glucose-6-Phosphate Isomerase; D014993:Xylitol; C014999:arabitol