Bourgade Barbara, Minton Nigel P, Islam M Ahsanul
Department of Chemical Engineering, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK.
BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University Park, University of Nottingham, Nottingham, Nottinghamshire, NG7 2RD, UK.
FEMS Microbiol Rev. 2021 Mar 16;45(2). doi: 10.1093/femsre/fuab008.
Unabated mining and utilisation of petroleum and petroleum resources and their conversion to essential fuels and chemicals have drastic environmental consequences, contributing to global warming and climate change. In addition, fossil fuels are finite resources, with a fast-approaching shortage. Accordingly, research efforts are increasingly focusing on developing sustainable alternatives for chemicals and fuels production. In this context, bioprocesses, relying on microorganisms, have gained particular interest. For example, acetogens use the Wood-Ljungdahl pathway to grow on single carbon C1-gases (CO2 and CO) as their sole carbon source and produce valuable products such as acetate or ethanol. These autotrophs can, therefore, be exploited for large-scale fermentation processes to produce industrially relevant chemicals from abundant greenhouse gases. In addition, genetic tools have recently been developed to improve these chassis organisms through synthetic biology approaches. This review will focus on the challenges of genetically and metabolically modifying acetogens. It will first discuss the physical and biochemical obstacles complicating successful DNA transfer in these organisms. Current genetic tools developed for several acetogens, crucial for strain engineering to consolidate and expand their catalogue of products, will then be described. Recent tool applications for metabolic engineering purposes to allow redirection of metabolic fluxes or production of non-native compounds will lastly be covered.
石油及石油资源的持续开采与利用，以及它们转化为基本燃料和化学品的过程，已造成了严重的环境后果，加剧了全球变暖和气候变化。此外，化石燃料是有限资源，短缺问题日益临近。因此，研究工作越来越聚焦于开发可持续的化学品和燃料生产替代方案。在此背景下，依赖微生物的生物过程引发了特别关注。例如，产乙酸菌利用伍德-柳格达尔途径，以单一碳源C1气体（二氧化碳和一氧化碳）作为唯一碳源生长，并生产乙酸或乙醇等有价值的产品。因此，这些自养生物可用于大规模发酵过程，从丰富的温室气体中生产工业相关化学品。此外，最近还开发了基因工具，通过合成生物学方法改良这些底盘生物。本综述将聚焦于对产乙酸菌进行基因和代谢改造的挑战。首先将讨论在这些生物中成功进行DNA转移所面临的物理和生化障碍。接着将描述为几种产乙酸菌开发的当前基因工具，这些工具对于菌株工程以巩固和扩展其产品目录至关重要。最后将涵盖最近用于代谢工程目的的工具应用，以实现代谢通量的重定向或非天然化合物的生产。
