Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
Appl Biochem Biotechnol. 2013 Oct;171(3):555-68. doi: 10.1007/s12010-013-0414-9. Epub 2013 Aug 15.
Xylose mother liquor (XML) is a by-product of xylose production through acid hydrolysis from corncobs, which can be used potentially for alternative fermentation feedstock. Sixteen Clostridia including 13 wild-type, 1 industrial strain, and 2 genetically engineered strains were screened in XML, among which the industrial strain Clostridium acetobutylicum EA 2018 showed the highest titer of solvents (12.7 g/L) among non-genetic populations, whereas only 40% of the xylose was consumed. An engineered strain (2018glcG-TBA) obtained by combination of glcG disruption and expression of the D-xylose proton-symporter, D-xylose isomerase, and xylulokinase was able to completely utilize glucose and L-arabinose, and 88% xylose in XML. The 2018glcG-TBA produced total solvents up to 21 g/L with a 50% enhancement of total solvent yield (0.33 g/g sugar) compared to that of EA 2018 (0.21 g/g sugar) in XML. This XML-based acetone-butanol-ethanol fermentation using recombinant 2018glcG-TBA was estimated to be economically promising for future production of solvents.
木糖母液 (XML) 是玉米芯酸水解生产木糖的副产物，可作为替代发酵原料。从 XML 中筛选了 16 株梭菌，包括 13 株野生型、1 株工业菌株和 2 株基因工程菌株，其中工业菌株丙酮丁醇梭菌 EA 2018 在非遗传种群中的溶剂产量最高（12.7 g/L），但仅消耗了 40%的木糖。通过 glcG 敲除和表达 D-木糖质子载体、D-木糖异构酶和木酮糖激酶，构建了一株工程菌株（2018glcG-TBA），该菌株能够完全利用葡萄糖和 L-阿拉伯糖以及 XML 中的 88%木糖。与 EA 2018（0.21 g/g 糖）相比，2018glcG-TBA 在 XML 中产生的总溶剂高达 21 g/L，总溶剂得率提高了 50%（0.33 g/g 糖）。使用重组 2018glcG-TBA 进行基于 XML 的丙酮丁醇乙醇发酵，预计在未来的溶剂生产中具有经济前景。
