By a News Reporter-Staff News Editor at Biotech Week -- Data detailed on Ethanol have been presented. According to news originating from Anhui, People's Republic of China, by NewsRx correspondents, research stated, "Thermo-tolerant yeast Kluyveromyces marxianus is able to utilize a wide range of substrates, including xylose; however, the xylose fermentation ability is weak because of the redox imbalance under oxygen-limited conditions. Alleviating the intracellular redox imbalance through engineering the coenzyme specificity of NADPH-preferring xylose reductase (XR) and improving the expression of XR should promote xylose consumption and fermentation."
Our news journalists obtained a quote from the research from the University of Science and Technology, "In this study, the native xylose reductase gene (Kmxyl1) of the K. marxianus strain was substituted with XR or its mutant genes from Pichia stipitis (Scheffersomyces stipitis). The ability of the resultant recombinant strains to assimilate xylose to produce xylitol and ethanol at elevated temperature was greatly improved. The strain YZB014 expressing mutant PsXR N272D, which has a higher activity with both NADPH and NADH as the coenzyme, achieved the best results, and produced 3.55 g l(-1) ethanol and 11.32 g l(-1) xylitol-an increase of 12.24-and 2.70-fold in product at 42 °C, respectively. A 3.94-fold increase of xylose consumption was observed compared with the K. marxianus YHJ010 harboring KmXyl1. However, the strain YZB015 expressing a mutant PsXR K21A/N272D, with which co-enzyme preference was completely reversed from NADPH to NADH, failed to ferment due to the low expression."
According to the news editors, the research concluded: "So in order to improve xylose consumption and fermentation in K. marxianus, both higher activity and co-enzyme specificity change are necessary."
For more information on this research see: Improving ethanol and xylitol fermentation at elevated temperature through substitution of xylose reductase in Kluyveromyces marxianus. Journal of Industrial Microbiology & Biotechnology, 2013;40(3-4):305-16. Journal of Industrial Microbiology & Biotechnology can be contacted at: Nature Publishing Group, 345 Park Avenue South, New York, NY 10010-1707, USA. (Springer - www.springer.com; Journal of Industrial Microbiology & Biotechnology - www.springerlink.com/content/1367-5435/)
The news correspondents report that additional information may be obtained from B. Zhang, School of Life Science, University of Science and Technology of China, Hefei, Anhui, People's Taiwan. Additional authors for this research include L. Li, J. Zhang, X. Gao, D. Wang and J. Hong (see also Ethanol).
The publisher's contact information for the Journal of Industrial Microbiology & Biotechnology is: Nature Publishing Group, 345 Park Avenue South, New York, NY 10010-1707, USA.
Keywords for this news article include: Asia, Anhui, Alcohols, Ethanolamines, People's Republic of China.
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