R&D Center for Submarine Resources, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Nankoku, Kochi 783-8502, Japan; Department of Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA 92037, USA.
Department of Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA 92037, USA; Kochi Institute for Core Sample Research, JAMSTEC, Nankoku, Kochi 783-8502, Japan; Project Team for Development of New-generation Research Protocol for Submarine Resources, JAMSTEC, Nankoku, Kochi 783-8502, Japan; Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089, USA.
Bioelectrochemistry. 2017 Oct;117:74-82. doi: 10.1016/j.bioelechem.2017.06.003. Epub 2017 Jun 15.
Microbial fuel cells (MFCs) are one of the bioelectrochemical systems that exploit microorganisms as biocatalysts to degrade organic matters and recover energy as electric power. Here, we explored how the established electrogenic microbial communities were influenced by three different inoculum sources; anaerobic sludge of the wastewater plant, rice paddy field soil, and coastal lagoon sediment. We periodically characterized both electricity generation with sucrose consumption and 16S rRNA-basis microbial community composition. The electrochemical features of MFCs were slightly different among three inocula, and the lagoon sediment-inoculated MFC showed the highest performance in terms of the treatment time. Meanwhile, although the inoculated microbial communities were highly diverse and quite different, only twelve genera affiliated with δ-Proteobacteria, γ-Proteobacteria, Bacilli, Clostridia/Negativicutes or Bacteroidetes were abundantly enriched in all MFC anode communities. Within them, several fermentative genera were clearly different due to the inocula, while the inocula-specific phylotypes were identified in an electrogenic genus Geobacter. The relative abundances of phylotypes closely-related to Geobacter metallireducens were increased in later stages of all the sucrose-fed MFCs. These results indicate that key microbial members for the functional electrogenic community widely exist in natural ecosystems, but the community members presenting in inoculum sources affected the MFC performances.
微生物燃料电池（MFC）是一种生物电化学系统，它利用微生物作为生物催化剂来降解有机物并回收电能。在这里，我们探讨了三种不同接种物来源（废水厂的厌氧污泥、稻田土壤和沿海泻湖沉积物）对已建立的产电微生物群落的影响。我们定期对利用蔗糖消耗进行发电和基于 16S rRNA 的微生物群落组成进行了特征描述。三种接种物的 MFC 的电化学特性略有不同，泻湖沉积物接种的 MFC 在处理时间方面表现出最高的性能。同时，尽管接种的微生物群落高度多样且差异很大，但只有十二属与 δ-变形菌门、γ-变形菌门、芽孢杆菌门、梭菌门/阴沟肠杆菌门或拟杆菌门密切相关，在所有 MFC 阳极群落中都丰富地富集。在这些群落中，由于接种物的原因，一些发酵菌属明显不同，而在产电属 Geobacter 中鉴定出了接种物特异性的类群。与 Geobacter metallireducens 密切相关的类群的相对丰度在所有蔗糖喂养的 MFC 的后期阶段都增加了。这些结果表明，功能产电群落的关键微生物成员广泛存在于自然生态系统中，但接种物来源中存在的群落成员会影响 MFC 的性能。
