Department of Biological and Environmental Engineering, Cornell University, Riley-Robb Hall, Ithaca, NY 14853, United States.
Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Queensland 4072, Australia.
Curr Opin Chem Biol. 2017 Dec;41:84-92. doi: 10.1016/j.cbpa.2017.10.003. Epub 2017 Nov 7.
The fermentation of synthesis gas (including carbon monoxide, carbon dioxide, and hydrogen) with anaerobic acetogens is an established biotechnological process that has recently been transferred to a commercial scale. The natural product spectrum of acetogens is natively restricted to acetate, ethanol, and 2,3-butanediol but is rapidly expanding to heterologous products. Syngas fermentation can achieve high carbon-efficiencies; however, the underlying metabolism is operating at a thermodynamic limit. This necessitates special enzymatic properties for energy conservation by acetogens. Therefore, the availability of cellular energy is considered to restrain the efficient production of energy-intense products with complex production pathways. The optimization of the feed-gas composition and other process parameters, genetic engineering, and integration with other biotechnologies is required to overcome this limitation.
利用合成气（包括一氧化碳、二氧化碳和氢气）发酵厌氧乙酸菌是一种成熟的生物技术工艺，最近已被转移到商业规模。乙酸菌的天然产物谱原本仅限于乙酸盐、乙醇和 2,3-丁二醇，但正在迅速扩展到异源产物。合成气发酵可以实现高碳效率；然而，潜在的代谢过程正在热力学极限下运行。这就需要乙酸菌具有特殊的酶学特性来进行能量保存。因此，细胞能量的可用性被认为限制了具有复杂生产途径的高能产品的高效生产。需要优化进料气组成和其他工艺参数、基因工程以及与其他生物技术的整合，以克服这一限制。
