Metabolic engineering strategies to enable microbial electrosynthesis utilization of CO₂: recent progress and challenges

Abstract

Microbial electrosynthesis (MES) is a promising technology that mainly utilizes microbial cells to convert CO₂ into value-added chemicals using electrons provided by the cathode. However, the low electron transfer rate is a solid bottleneck hindering the further application of MES. Thus, as an effective strategy, genetic tools play a key role in MES for enhancing the electron transfer rate and diversity of production. We describe a set of genetic strategies based on fundamental characteristics and current successes and discuss their functional mechanisms in driving microbial electrocatalytic reactions to fully comprehend the roles and uses of genetic tools in MES. This paper also analyzes the process of nanomaterial application in extracellular electron transfer (EET). It provides a technique that combines nanomaterials and genetic tools to increase MES efficiency, because nanoparticles have a role in the production of functional genes in EET although genetic tools can subvert MES, it still has issues with difficult transformation and low expression levels. Genetic tools remain one of the most promising future strategies for advancing the MES process despite these challenges.

Graphical Abstract

Microbial electrosynthesis (MES) is a promising carbon dioxide fixation technology that is both green and environmentally beneficial. However, MES is currently plagued by inefficiency and a scarcity of products. Metabolic engineering has been employed to enhance carbon sequestration efficiency and product abundance by enhancing extracellular electron uptake (EEU) and introducing carbon fixation pathways.

Keywords:

• Microbial electrosynthesis
• CO₂
• genetic tools
• extracellular electron transfer
• nanoparticles
• one-carbon transform

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Key R&D Program of China [2022YFC2106000], the National Natural Science Foundation of China [22038012, 32271477, 42077030], the Science and Technology Program of Fujian Province, China [2020NZ012015, 2020Y4002], and the Fundamental Research Funds for the Central Universities of China [20720190001, 20720220012].