Electromicrobial production (EMP) systems can store renewable energy and CO₂ in many-carbon molecules inaccessible to abiotic electrochemistry. Here, we develop a multiphysics model to investigate the fundamental and practical limits of EMP enabled by direct electron uptake. We also identify potential electroautotrophic organisms and metabolic engineering strategies to enable electroautotrophy in organisms lacking the native capability. Systematic model comparisons of microbial respiration and carbon fixation strategies revealed that, under aerobic conditions, the CO₂ fixation rate is limited to < 6 μmol/cm²/hr by O₂ mass transport despite efficient electron utilization. In contrast, anaerobic nitrate respiration enables CO₂ fixation rates > 50 μmol/cm²/hr for microbes using the reductive tricarboxylic acid cycle. Phylogenetic analysis, validated by recapitulating experimental demonstrations of electroautotrophy, predicted multiple probable electroautotrophic organisms and a significant number of genetically tractable strains that require heterologous expression of < 5 proteins to gain electroautotrophic function. The model and analysis presented here will guide microbial engineering and reactor design for practical EMP systems.

电微生物生产 (EMP) 系统可以将可再生能源和 CO ₂存储在非生物电化学无法获得的许多碳分子中。在这里，我们开发了一个多物理场模型来研究通过直接电子吸收实现的 EMP 的基本和实际限制。我们还确定了潜在的电自养生物和代谢工程策略，以在缺乏天然能力的生物中实现电自养。微生物呼吸和碳固定策略的系统模型比较表明，在有氧条件下，尽管有效的电子利用，但通过 O _{2传质，CO 2}固定速率限制在 < 6 μmol/cm ^{2 /hr。}相比之下，厌氧硝酸盐呼吸使 CO₂使用还原性三羧酸循环的微生物的固定率 > 50 μmol/cm ^{2 /hr。}系统发育分析，通过概括电自养的实验证明进行验证，预测了多种可能的电自养生物和大量遗传易处理的菌株，这些菌株需要异源表达<5种蛋白质才能获得电自养功能。这里介绍的模型和分析将指导实际 EMP 系统的微生物工程和反应器设计。