Eddie Brian J, Wang Zheng, Malanoski Anthony P, Hall Richard J, Oh Steve D, Heiner Cheryl, Lin Baochuan, Strycharz-Glaven Sarah M
ASEE Post Doctoral Fellow, United States Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375, USA.
United States Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375, USA.
Int J Syst Evol Microbiol. 2016 Jun;66(6):2178-2185. doi: 10.1099/ijsem.0.001006. Epub 2016 Mar 7.
Biocathode communities are of interest for a variety of applications, including electrosynthesis, bioremediation, and biosensors, yet much remains to be understood about the biological processes that occur to enable these communities to grow. One major difficulty in understanding these communities is that the critical autotrophic organisms are difficult to cultivate. An uncultivated, electroautotrophic bacterium previously identified as an uncultivated member of the family Chromatiaceae appears to be a key organism in an autotrophic biocathode microbial community. Metagenomic, metaproteomic and metatranscriptomic characterization of this community indicates that there is likely a single organism that utilizes electrons from the cathode to fix CO2, yet this organism has not been obtained in pure culture. Fluorescence in situ hybridization reveals that the organism grows as rod-shaped cells approximately 1.8 × 0.6 µm, and forms large clumps on the cathode. The genomic DNA G+C content was 59.2 mol%. Here we identify the key features of this organism and propose 'Candidatus Tenderia electrophaga', within the Gammaproteobacteria on the basis of low nucleotide and predicted protein sequence identity to known members of the orders Chromatiales and Thiotrichales.
生物阴极群落因包括电合成、生物修复和生物传感器在内的多种应用而受到关注，但对于使这些群落得以生长的生物过程，仍有许多有待了解。理解这些群落的一个主要困难在于关键的自养生物难以培养。一种先前被鉴定为未培养的着色菌科成员的未培养电自养细菌，似乎是自养生物阴极微生物群落中的关键生物。对该群落的宏基因组、宏蛋白质组和宏转录组表征表明，可能存在一种利用来自阴极的电子固定二氧化碳的单一生物，但尚未获得该生物的纯培养物。荧光原位杂交显示，该生物以约1.8×0.6 µm的杆状细胞形式生长，并在阴极上形成大的团块。基因组DNA的G+C含量为59.2 mol%。在此，我们确定了该生物的关键特征，并基于与着色菌目和硫发菌目的已知成员的低核苷酸和预测蛋白质序列同一性，在γ-变形菌纲内提出“候选嗜电嫩杆菌（Candidatus Tenderia electrophaga）”。
