Biosynthetic strategy of ferrous sulfide (FeS) through Shewanella oneidensis MR-1 in bioelectrochemical systems has been extensively explored to maintain bettered electron transfer performance. In this study, the simultaneous FeS biosynthesis and CO2 reduction were conducted in the microbial electrosynthesis (MES) system, aiming at improving electron transfer efficiency as well as acetate production. It was shown that the FeS was successfully biomineralized and then loaded onto the sludge in the Fe3+/S2O32−/MR-1 group, of which the acetate accumulation increased by 87.50%, 64.63% and 33.66% than the control, MR-1 and Fe3+/S2O32− groups. Also, electrochemical performance revealed by the CV analysis was enhanced, whereas the increased EPS accumulation and intracellular electron transfer activity by the biosynthesized FeS could also be proved. Moreover, the biogenic FeS enriched the abundances of acetogenic and sulfur-utilizing species as Acetobacterium, Clostridium_sensu_stricto_13, Sulfuricurvum and Desulfovibrio. Meanwhile, strongly positive correlations between Shewanella, the sulfur utilizers and acetogens were confirmed in the Fe3+/S2O32−/MR-1 group. With improved electron transfer efficiency and the boosted acetate accumulation, the in-situ biogenic FeS might be promising for CO2 capture and utilization.

中文翻译：

---

原位生物 FeS 通过使用微生物电合成 （MES） 捕获和增值来促进乙酸盐的积累


在生物电化学系统中通过 Shewanella oneidensis MR-1 对硫化亚铁 （FeS） 的生物合成策略已被广泛探索，以保持更好的电子转移性能。在本研究中，在微生物电合成 （MES） 系统中同时进行了 FeS 生物合成和 CO2 还原，旨在提高电子转移效率和乙酸盐生产。结果表明，Fe3+/S2O32−/MR-1组FeS成功生物矿化，然后负载到污泥上，其中乙酸盐积累量比对照、MR-1和Fe3+/S2O32−组分别增加了87.50%、64.63%和33.66%。此外，CV 分析揭示的电化学性能得到增强，同时也可以证明生物合成的 FeS 增加的 EPS 积累和细胞内电子转移活性。此外，生物 FeS 富集了乙酰杆菌、Clostridium_sensu_stricto_13、硫藻和脱硫菌等产乙酸菌和硫利用物种的丰度。同时，在 Fe3+/S2O32−/MR-1 组中证实了希瓦氏菌、硫利用剂和乙酸原之间的强正相关。随着电子转移效率的提高和乙酸盐积累的增加，原位生物 FeS 可能在 CO2 捕获和利用方面有前景。