The construction of recombinant Saccharomyces cerevisiae expressing NADH-preferring xylitol reductase
Intracellular redox imbalance caused by the different co-factors specificity of xylitol reductase (XR) and xylitol dehydrogenase (XDH) has been thought to be one of the main factors of xylitol excretion and lower ethanol yield. In this study, both the genes m1 and xyl2 encoding NADH-preferring XR (M) and XDH, respectively, were introduced into Saccharomyces cerevisiae AH109 to obtain the recombinant strain AH-M-XDH. The recombinant strain AH-XR-XDH expressing XR ixyl1) and XDH (xyl2) was used as the control. The recombinant strains were screened by SC/-Leu/-Trp nutrientdeficient medium. The positive transformants were cultured under O2 -limited conditions in a yeast minimal medium with glucose plus xylitol, and the ethanol productions were measured by HPLC. The results indicated that the xylitol utilization was significantly increased in the strain AH-M-XDH. The ethanol yield in the strain AH-M-XDH was 16％ higher than the control and the xylitol excretion was 41. 4％ lower than the control. This study suggested that key enzymes in the xylitol metabolism constracted by gentic engineering could enhance xylitol utilization and ethanol production in recombinant Saccharomyces cerevisiae.
ethanol xylose reductase(XR) xylitol dehydrogenase(XDH) saccharomyces cerevisiae (S. cerevisiae)
Chunli Chu Xiaozhao Deng Jing Kong Yun Zhang Zhongcan Wang Chunlei Li Juan Wei
College of Biological Science and Technology, China Pharmaceutical University, Nanjing, 210009, Chin Center of Disease Prevention and Control, Nanjing Command, Nanjing, 210002, China School of Basic Medicine, Nanjing Medical University, Nanjing, 210029, China
国际会议
南京
英文
35-39
2010-05-12（万方平台首次上网日期，不代表论文的发表时间）