School of Life Sciences and Chemical Technology, Ngee Ann Polytechnic, 535 Clementi Road, Singapore, 599489, Singapore.
Bioprocess Biosyst Eng. 2019 May;42(5):883-896. doi: 10.1007/s00449-019-02090-0. Epub 2019 Feb 28.
Industrial production of lignocellulosic ethanol requires a microorganism utilizing both hexose and pentose, and tolerating inhibitors. In this study, a hydrolysate-cofermenting Saccharomyces cerevisiae strain was obtained through one step in vivo DNA assembly of pentose-metabolizing pathway genes, followed by consecutive adaptive evolution in pentose media containing acetic acid, and direct screening in biomass hydrolysate media. The strain was able to coferment glucose and xylose in synthetic media with the respective maximal specific rates of glucose and xylose consumption, and ethanol production of 3.47, 0.38 and 1.62 g/g DW/h, with an ethanol titre of 41.07 g/L and yield of 0.42 g/g. Industrial wheat straw hydrolysate fermentation resulted in maximal specific rates of glucose and xylose consumption, and ethanol production of 2.61, 0.54 and 1.38 g/g DW/h, respectively, with an ethanol titre of 54.11 g/L and yield of 0.44 g/g. These are among the best for wheat straw hydrolysate fermentation through separate hydrolysis and cofermentation.
工业生产木质纤维素乙醇需要一种既能利用己糖又能利用戊糖，又能耐受抑制剂的微生物。在这项研究中，通过在含有乙酸的戊糖培养基中连续进行适应性进化和在生物质水解物培养基中直接筛选，一步体内 DNA 组装戊糖代谢途径基因，获得了一种水解物共发酵酿酒酵母菌株。该菌株能够在含有葡萄糖和木糖的合成培养基中共发酵，葡萄糖和木糖的最大比消耗速率分别为 3.47、0.38 和 1.62 g/g DW/h，乙醇产量为 41.07 g/L，产率为 0.42 g/g。工业小麦秸秆水解物发酵的葡萄糖和木糖最大比消耗速率分别为 2.61、0.54 和 1.38 g/g DW/h，乙醇产量分别为 54.11 g/L 和 0.44 g/g。这是通过单独水解和共发酵发酵小麦秸秆水解物的最佳结果之一。
