In order to achieve carbon neutrality and green economy, people use biorefinery technology to transform and utilize CO2. Microbial electrosynthesis (MES) is an emerging technology that converts CO2 into chemicals by electrically driven biocatalysts. Currently, the low efficiency of microbial carbon sequestration, an incomplete understanding of electron transfer mechanisms, low synthesis rate, and poor applicability of reactor components have been the limiting factors for the large-scale application of MES. In this paper, the mechanisms of electron supply in the MES system, including through electrodes and electron donors such as H2, formic acid, CO, and other molecules, are systematically reviewed based on how cathodic microorganisms obtain electrons. It is an effective method to improve electron transport efficiency by modifying conductive nanowires of electroactive microorganisms and optimizing the expression of microbially associated hydrogenase, formate dehydrogenase and CO dehydrogenase using synthetic biology techniques. Additionally, cathode modification aimed at improving electron transfer rates between microbes and electrodes, enhancing the biocompatibility, and providing more reducing power can facilitate the generation of value-added products. In addition to enhancing the electron transfer efficiency of the cathode, the construction of a reactor with high efficiency of gas-liquid-solid mass transfer and electron transfer, the reduction of anode potential for water electrolysis, and the regulation of microbial activity are also important strategies to enhance MES performance. In the future, it is necessary to further elucidate the mechanism of microbial electron transport and strengthen the performance of MES by means of synthetic biological communities, and by designing a more efficient electrode interface that balances electron transfer rate, substrate mass transfer and biocompatibility. In terms of the scaling-up of reaction devices, electron transfer and gas mass transfer can be improved through the combination of various methods, and integrating product separation processes can promote the further development of the technology and provide new ideas for the realization of the “Carbon Peak and Carbon Neutrality” goal.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |