[Electron supply strategies for microbial carbon fixation: a review]

Given the rapid development of technologies in biochemical engineering and genetic engineering, biological capture, conversion and utilization of greenhouse gases (carbon dioxide and methane) into value-added products have been progressed rapidly. The efficiency of electron transfer and energy supply are essential for microbial carbon fixation. In this review, the concepts of direct and indirect electron transfer chains in methanotrophic and chemoautotrophic microbes were introduced firstly. Subsequently, the strategies of supplying light and electrical energy as well as their effects on metabolic flux, synthetic pathway and energy supply efficiency during microbial carbon fixation were discussed. Finally, solutions and application prospects to address the key technical challenges of microbial carbon fixation were discussed.