A new approach to microbial electrosynthesis is proposed, aimed at producing whole biomass from N₂ and inorganic carbon, by electrostimulation of complex microbial communities. On a carbon-based conductor under constant polarization (−0.7 V vs SHE), an electroactive biofilm was enriched with autotrophic nitrogen fixing microorganims and led to biomass synthesis at higher amounts (up to 18 fold), as compared to controls kept at open circuit (OC). After 110 days, the electron transfer had increased by 30-fold, as compared to abiotic conditions. Metagenomics evidenced Nif genes associated with autotrophs (both Archaea and Bacteria) only in polarized biofilms, but not in OC. With this first proof of concept experiment, we propose to call this promising field ‘bioelectrochemical nitrogen fixation’ (e-BNF): a possible way to ‘power’ biological nitrogen fixation, organic carbon storage and soil fertility against desertification, and possibly a new tool to study the development of early prokaryotic life in extreme environments.

提出了一种新的微生物电合成方法，旨在通过电刺激复杂的微生物群落，从N ₂和无机碳生产全部生物质。上下恒定的偏振（-0.7V的基于碳的导体VS SHE），电活性生物膜用自养固氮microorganims富集，导致生物质合成在较高量（高达18倍），相比于保持在开路控制（OC）。与非生物条件相比，在110天后，电子传递增加了30倍。元基因组学证明与自养生物有关的Nif基因（古细菌和细菌））仅在极化生物膜中使用，而在OC中则没有。借助这一概念验证实验，我们建议将这一有前途的领域称为“生物电化学固氮”（e- BNF）：为生物固氮，有机碳存储和土壤肥力抗荒漠化“提供动力”的一种可能方法，并且可能是一种新的方法。研究极端环境中早期原核生物发育的工具。