Sugiyama Masakazu, Suzuki Shun-ichi, Tonouchi Naoto, Yokozeki Kenzo
AminoScience Laboratories, Ajinomoto Co., Inc., Kawasaki-shi, Japan.
Biosci Biotechnol Biochem. 2003 Dec;67(12):2524-32. doi: 10.1271/bbb.67.2524.
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.
研究了氧化葡萄糖酸杆菌的膜组分和可溶性组分从D-阿拉伯糖醇生产木糖醇的情况。发现可溶性组分中的两种蛋白质具有提高木糖醇产量的能力。纯化了这两种木糖醇增产因子，并根据它们的NH(2)-末端氨基酸序列克隆了编码这两种因子的基因。在大肠杆菌中克隆基因的表达表明，其中一种木糖醇增产因子是双功能酶转醛醇酶/葡萄糖-6-磷酸异构酶，另一种是核糖激酶。使用氧化葡萄糖酸杆菌的膜组分和可溶性组分，在10 g/l D-阿拉伯糖醇孵育40 h后产生了3.8 g/l的木糖醇，添加纯化的重组转醛醇酶/葡萄糖-6-磷酸异构酶或核糖激酶分别将木糖醇提高到5.4 g/l，证实了木糖醇增产因子的特性。
