Saini Mukesh, Lin Li-Jen, Chiang Chung-Jen, Chao Yun-Peng
Department of Chemical Engineering, Feng Chia University 100 Wenhwa Road, Taichung 40724, Taiwan.
Department of Medical Research, China Medical University Hospital , Taichung 40447, Taiwan.
J Agric Food Chem. 2017 Nov 22;65(46):10040-10047. doi: 10.1021/acs.jafc.7b04275. Epub 2017 Nov 7.
The microbial production of n-butanol using glucose and xylose, the major components of plant biomass, can provide a sustainable and renewable fuel as crude oil replacement. However, Escherichia coli prefers glucose to xylose as programmed by carbohydrate catabolite repression (CCR). In this study, a synthetic consortium consisting of two strains was developed by transforming the CCR-insensitive strain into a glucose-selective strain and a xylose-selective strain. Furthermore, the dual culture was reshaped by distribution of the synthetic pathway of n-butanol into two strains. Consequently, the co-culture system enabled effective co-utilization of both sugars and production of 5.2 g/L n-butanol at 30 h. The result leads to the conversion yield and productivity accounting for 63% of the theoretical yield and 0.17 g L h, respectively. Overall, the technology platform as proposed is useful for production of other value-added chemicals, which require complicated pathways for their synthesis by microbial fermentation of a sugar mixture.
利用植物生物质的主要成分葡萄糖和木糖进行微生物法生产正丁醇，可为原油替代提供一种可持续的可再生燃料。然而，受碳水化合物分解代谢物阻遏（CCR）调控，大肠杆菌优先利用葡萄糖而非木糖。在本研究中，通过将对CCR不敏感的菌株改造为葡萄糖选择性菌株和木糖选择性菌株，构建了一个由两株菌组成的合成菌群。此外，通过将正丁醇合成途径分布到两株菌中，对双培养体系进行了重塑。因此，该共培养系统能够有效共利用两种糖类，并在30小时时生产出5.2 g/L的正丁醇。该结果使得转化率和生产速率分别达到理论产量的63%和0.17 g L h。总体而言，所提出的技术平台对于生产其他增值化学品很有用，这些化学品需要复杂的途径通过糖混合物的微生物发酵来合成。
