Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China.
Bioresour Technol. 2011 Oct;102(19):9206-15. doi: 10.1016/j.biortech.2011.06.058. Epub 2011 Aug 9.
A K270R mutation of xylose reductase (XR) was constructed by site-direct mutagenesis. Fermentation results of the F106X and F106KR strains, which carried wild type XR and K270R respectively, were compared using different substrate concentrations (from 55 to 220 g/L). After 72 h, F106X produced less ethanol than xylitol, while F106KR produced ethanol at a constant yield of 0.36 g/g for all xylose concentrations. The xylose consumption rate and ethanol productivity increased with increasing xylose concentrations in F106KR strain. In particular, F106KR produced 77.6g/L ethanol from 220 g/L xylose and converted 100 g/L glucose and 100g/L xylose into 89.0 g/L ethanol in 72h, but the corresponding values of F106X strain are 7.5 and 65.8 g/L. The ethanol yield of F106KR from glucose and xylose was 0.42 g/g, which was 82.3% of the theoretical yield. These results suggest that the F106KR strain is an excellent producer of ethanol from xylose.
通过定点突变构建了木糖还原酶（XR）的 K270R 突变体。比较了携带野生型 XR 和 K270R 的 F106X 和 F106KR 菌株在不同底物浓度（从 55 至 220 g/L）下的发酵结果。72 h 后，F106X 产生的乙醇少于木糖醇，而 F106KR 在所有木糖浓度下均以 0.36 g/g 的恒产率产生乙醇。在 F106KR 菌株中，木糖消耗率和乙醇生产率随着木糖浓度的增加而增加。特别是，F106KR 从 220 g/L 木糖中生产了 77.6 g/L 乙醇，并且在 72 h 内将 100 g/L 葡萄糖和 100 g/L 木糖转化为 89.0 g/L 乙醇，而 F106X 菌株的相应值分别为 7.5 和 65.8 g/L。F106KR 从葡萄糖和木糖生产乙醇的产率为 0.42 g/g，是理论产率的 82.3%。这些结果表明，F106KR 菌株是从木糖生产乙醇的优秀生产者。
