Wei Na, Oh Eun Joong, Million Gyver, Cate Jamie H D, Jin Yong-Su
†Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
∥Departments of Molecular and Cell Biology and Chemistry, University of California at Berkeley, Berkeley, California 94720, United States.
ACS Synth Biol. 2015 Jun 19;4(6):707-13. doi: 10.1021/sb500364q. Epub 2015 Jan 27.
The inability of fermenting microorganisms to use mixed carbon components derived from lignocellulosic biomass is a major technical barrier that hinders the development of economically viable cellulosic biofuel production. In this study, we integrated the fermentation pathways of both hexose and pentose sugars and an acetic acid reduction pathway into one Saccharomyces cerevisiae strain for the first time using synthetic biology and metabolic engineering approaches. The engineered strain coutilized cellobiose, xylose, and acetic acid to produce ethanol with a substantially higher yield and productivity than the control strains, and the results showed the unique synergistic effects of pathway coexpression. The mixed substrate coutilization strategy is important for making complete and efficient use of cellulosic carbon and will contribute to the development of consolidated bioprocessing for cellulosic biofuel. The study also presents an innovative metabolic engineering approach whereby multiple substrate consumption pathways can be integrated in a synergistic way for enhanced bioconversion.
发酵微生物无法利用源自木质纤维素生物质的混合碳成分，这是阻碍具有经济可行性的纤维素生物燃料生产发展的一个主要技术障碍。在本研究中，我们首次使用合成生物学和代谢工程方法，将己糖和戊糖的发酵途径以及一条乙酸还原途径整合到一株酿酒酵母菌株中。该工程菌株能够同时利用纤维二糖、木糖和乙酸来生产乙醇，其产量和生产率比对照菌株显著更高，结果显示了途径共表达的独特协同效应。混合底物共利用策略对于完全高效利用纤维素碳至关重要，并将有助于纤维素生物燃料的整合生物加工的发展。该研究还提出了一种创新的代谢工程方法，通过这种方法可以以协同方式整合多种底物消耗途径，以增强生物转化。
