生物工程强化微生物电合成转化CO_2的研究进展

微生物电合成(Microbial electrosynthesis,MES)可直接利用电能驱动微生物还原固定CO_2合成多碳化合物,为可再生新能源转化、精细化学品制备和生态环境保护提供新机遇。但是,微生物吸收胞外电极电子速率慢、产物合成效率低和产品品位不高,限制了MES实现工业化应用。在概述阴极电活性微生物吸收胞外电子的分子机制的基础上,重点综述近5年应用生物工程的理论和技术强化MES用于CO_2转化的策略与研究进展,包括改造和调控胞外电子传递通路和胞内代谢途径以及定向构建有限微生物混合培养菌群三方面,阐明了生物工程可有效突破MES中电子传递慢和可用代谢途径相对单一等瓶颈。针对目前生物工程在改进MES所面临的主要问题,从胞外电子传递机理研究、基因工具箱开发、组学技术与现代分析技术联用等角度展望了今后的研究方向。

Advances in Microbial Electrosynthesis for CO2 Conversion Boosted by Bioengineering

Microbial electrosynthesis (MES) is able to produce polycarbon chemicals through electricity driven reduction of CO₂ using electroactive microorganisms as biocatalysts, providing great potential for renewable energy conversion, fine chemical engineering and ecological environmental protection. However, the sluggish extracellular electron uptake rate between microorganisms and the electrode, the low productivity and value of products impede the industrial application of MES technology. After brief overview of molecular mechanism of extracellular electron transfer (EET) in cathodic electroactive microorganisms, the application strategy and progress of bioengineering in boosting MES for CO₂ conversion in recent five years, including transforming and regulating extracellular electron transfer (EET) route and intracellular metabolic pathway and constructing defined mixed culture, are reviewed comprehensively, thus expounding the commendable availability of biological engineering in breaking the bottleneck (such as low electron transport rate and few usable metabolic pathway) involved in MES. Finally, according to the present existing problems that limit the efficiency of bioengineering in improving MES, future research directions are discussed from the perspectives of exploring EET mechanism, developing genetic tools and coupling omics techniques with advanced analysis techniques.