US Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53711, USA.
Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Dr, Madison, WI, 53711, USA.
Biotechnol J. 2019 Sep;14(9):e1800441. doi: 10.1002/biot.201800441. Epub 2019 Aug 5.
Currently, microbial conversion of lignocellulose-derived glucose and xylose to biofuels is hindered by the fact that most microbes (including Escherichia coli [E. coli], Saccharomyces cerevisiae, and Zymomonas mobilis) preferentially consume glucose first and consume xylose slowly after glucose is depleted in lignocellulosic hydrolysates. In this study, E. coli strains are developed that simultaneously utilize glucose and xylose in lignocellulosic biomass hydrolysate using genome-scale models and adaptive laboratory evolution. E. coli strains are designed and constructed that coutilize glucose and xylose and adaptively evolve them to improve glucose and xylose utilization. Whole-genome resequencing of the evolved strains find relevant mutations in metabolic and regulatory genes and the mutations' involvement in sugar coutilization is investigated. The developed strains show significantly improved coconversion of sugars in lignocellulosic biomass hydrolysates and provide a promising platform for producing next-generation biofuels.
目前，微生物将木质纤维素衍生的葡萄糖和木糖转化为生物燃料受到阻碍，因为大多数微生物（包括大肠杆菌[E. coli]、酿酒酵母和运动发酵单胞菌）优先消耗葡萄糖，并且在木质纤维素水解物中葡萄糖耗尽后缓慢消耗木糖。在这项研究中，使用基因组规模模型和适应性实验室进化，开发了能够同时利用木质纤维素生物质水解物中的葡萄糖和木糖的大肠杆菌菌株。设计和构建了共利用葡萄糖和木糖的大肠杆菌菌株，并对其进行适应性进化以提高葡萄糖和木糖的利用效率。对进化菌株的全基因组重测序发现了代谢和调节基因中的相关突变，并研究了这些突变在糖共利用中的作用。开发的菌株在木质纤维素生物质水解物中的糖共转化中表现出显著提高，为生产下一代生物燃料提供了有前景的平台。
