Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey, USA.
Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey, USA
Appl Environ Microbiol. 2018 Nov 30;84(24). doi: 10.1128/AEM.02029-18. Print 2018 Dec 15.
sp. strain A6 (A6), from the phylum, was recently identified as a microorganism that can carry out anaerobic ammonium (NH) oxidation coupled to iron reduction, a process also known as Feammox. Being an iron-reducing bacterium, A6 was studied as a potential electrode-reducing bacterium that may transfer electrons extracellularly onto electrodes while gaining energy from NH oxidation. species have been overlooked as electrogenic bacteria, and the importance of lithoautotrophic iron reducers as electrode-reducing bacteria at anodes has not been addressed. By installing electrodes in the soil of a forested riparian wetland where A6 thrives, in soil columns in the laboratory, and in A6-bioaugmented constructed wetland (CW) mesocosms and by operating microbial electrolysis cells (MECs) with pure A6 culture, the characteristics and performances of this organism as an electrode-reducing bacterium candidate were investigated. In this study, we show that sp. strain A6, a lithoautotrophic bacterium, is capable of colonizing electrodes under controlled conditions. In addition, A6 appears to be an electrode-reducing bacterium, since current production was boosted shortly after the CWs were seeded with enrichment A6 culture and current production was detected in MECs operated with pure A6, with the anode as the sole electron acceptor and NH as the sole electron donor. Most studies on electrogenic microorganisms have focused on the most abundant heterotrophs, while other microorganisms also commonly present in electrode microbial communities, such as strains, have been overlooked. The novel sp. strain A6 () is an iron-reducing bacterium that can colonize the surface of anodes in sediments and is linked to electrical current production, making it an electrode-reducing bacterium. Furthermore, A6 can carry out anaerobic ammonium oxidation coupled to iron reduction. Therefore, findings from this study open the possibility of using electrodes instead of iron as electron acceptors, as a means to promote A6 to treat NH-containing wastewater more efficiently. Altogether, this study expands our knowledge of electrogenic bacteria and opens the possibility of developing Feammox-based technologies coupled to bioelectric systems for the treatment of NH and other contaminants in anoxic systems.
sp. 菌株 A6（A6）属于门，最近被鉴定为一种能够进行厌氧氨（NH）氧化耦合铁还原的微生物，这一过程也被称为 Feammox。作为一种铁还原菌，A6 被研究为一种潜在的电极还原菌，它可以在从 NH 氧化中获得能量的同时，将电子从细胞外转移到电极上。 物种一直被忽视为产电细菌，而作为电极还原菌的自养铁还原菌在阳极中的重要性尚未得到解决。通过在 A6 大量繁殖的森林河岸湿地土壤中安装电极、在实验室土壤柱中以及在 A6 生物增强型人工湿地（CW）中安装电极，并使用纯 A6 培养物运行微生物电解池（MEC），研究了该生物体作为电极还原菌候选物的特性和性能。在这项研究中，我们表明， 种石生细菌能够在受控条件下定植于电极。此外，A6 似乎是一种电极还原菌，因为 CW 接种富集 A6 培养物后不久就会产生电流，并且在使用纯 A6 运行的 MEC 中也会检测到电流，阳极是唯一的电子受体，NH 是唯一的电子供体。大多数关于产电微生物的研究都集中在最丰富的异养菌上，而其他在电极微生物群落中也常见的微生物，如 菌株，却被忽视了。新型 sp. 菌株 A6（）是一种铁还原菌，能够在沉积物中的阳极表面定殖，并与电流产生有关，使其成为一种电极还原菌。此外，A6 可以进行厌氧氨氧化耦合铁还原。因此，本研究的发现为使用电极而不是铁作为电子受体提供了可能性，这是一种促进 A6 更有效地处理含 NH 废水的方法。总的来说，这项研究扩展了我们对产电细菌的认识，并为开发基于 Feammox 的技术与生物电系统相结合，用于处理缺氧系统中的 NH 和其他污染物提供了可能性。
