文献类型：期刊文献

英文题名：Genetic analysis of D-xylose metabolism pathways in Gluconobacter oxydans 621H

作者：Zhang, Minhua[1];Wei, Liujing[1];Zhou, Yi[1];Du, Liqin[2];Imanaka, Tadayuki[1];Hua, Qiang[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Guangxi Univ, Coll Life Sci & Technol, Nanning 530005, Guangxi, Peoples R China

年份：2013

卷号：40

期号：3-4

起止页码：379

外文期刊名：JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY

收录：;EI(收录号：20242616521989);WOS:【SCI-EXPANDED(收录号:WOS:000316229600012)】；

基金：This study was financially supported by the National Natural Science Foundation of China (No. 31200025), National Basic Research Program of China (973 Program) (2012CB721101), Natural Science Foundation of Shanghai (11ZR1408100), and partially supported by National Special Fund for State Key Laboratory of Bioreactor Engineering (2060204), Shanghai Leading Academic Discipline Project (B505) and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Gluconobacter oxydans; Xylose metabolism; Membrane-bound glucose dehydrogenase; Xylitol dehydrogenase; Xylulose kinase

摘要：D-xylose is one of the most abundant carbohydrates in nature. This work focuses on xylose metabolism of Gluconobacter oxydans as revealed by a few studies conducted to understand xylose utilization by this strain. Interestingly, the G. oxydans 621H Delta mgdh strain (deficient in membrane-bound glucose dehydrogenase) was greatly inhibited when grown on xylose and no xylonate accumulation was observed in the medium. These experimental observations suggested that the mgdh gene was responsible for the conversion of xylose to xylonate in G. oxydans, which was also verified by whole-cell biotransformation. Since 621H Delta mgdh could still grow on xylose in a very small way, two seemingly important genes in the oxo-reductive pathway for xylose metabolism, a xylitol dehydrogenase-encoding gox0865 (xdh) gene and a putative xylulose kinase-encoding gox2214 (xk) gene, were knocked out to investigate the effects of both genes on xylose metabolism. The results showed that the gox2214 gene was not involved in xylose metabolism, and there might be other genes encoding xylulose kinase. Though the gox0865 gene played a less important role in xylose metabolism compared to the mgdh gene, it was significant in xylitol utilization in G. oxydans, which meant that gox0865 was a necessary gene for the oxo-reductive pathway of xylose in vivo. To sum up, when xylose was used as the carbon source, the majority of xylose was directly oxidized to xylonate for further metabolism in G. oxydans, whereas only a minor part of xylose was metabolized by the oxo-reductive pathway.