A Thermophilic Gram-Negative Nitrate-Reducing Bacterium, Calditerrivibrio nitroreducens, Exhibiting Electricity Generation Capability
A Thermophilic Gram-Negative Nitrate-Reducing Bacterium, Calditerrivibrio nitroreducens, Exhibiting Electricity Generation Capability
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DOI：
10.1021/es402749f
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发表时间：
2013-11-05
影响因子：
11.4
通讯作者：
Sato, Kozo
中科院分区：
文献类型：
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作者：
Fu, Qian;Kobayashi, Hajime;Sato, Kozo
为了利用嗜热外生电的潜在多样性，两室微生物燃料电池（MFC）接种了嗜热厌氧消化池污泥，并在 55 摄氏度下运行，无需补充外源氧化还原介体。 MFC运行200小时后产生的最大功率密度为823 mW m(-2)。分子系统发育分析表明，阳极上的微生物种群以与嗜热硝酸盐还原菌硝基还原热弧菌密切相关的物种为主，在纯培养物中已分离出该菌株的菌株（Yu37-1）。因此，将硝基还原梭菌菌株Yu37-1的纯培养物接种到MFC中以检查发电能力。在没有外源介体的情况下，MFC 可稳定发电，最大功率密度为 272 mW m(-2)，运行时间超过 400 小时。更换培养基后几小时内MFC电流恢复到原来的水平，表明发电是由阳极微生物引起的。循环伏安法表明，具有相似电势（-0.14和-0.17 V）的氧化还原系统（E-3和E-c）分别对污泥来源的聚生体和C. 硝基还原菌Yu37-1的产电活动做出了主要贡献。这项研究对硝基还原梭菌进行了生物电化学表征，作为嗜热革兰氏阴性外生电极的第一个例子。
To exploit the potential diversity of thermophilic exoelectrogens, two-chamber microbial fuel cells (MFCs) were inoculated with thermophilic anaerobic digester sludge and operated at 55 degrees C without supplementing with exogenous redox mediator. The MFC generated a maximum power density of 823 mW m(-2) after 200 h of operation. Molecular phylogenetic analyses suggested that the microbial population on the anode was dominated by a species closely related to a thermophilic nitrate-reducing bacterium Calditerrivibrio nitroreducens, for which a strain (Yu37-1) has been isolated in pure culture. Thus, a pure culture of the C. nitroreducens strain Yu37-1 was inoculated into MFC to examine the electricity generation capability. Without an exogenous mediator, MFCs stably produced electricity with a maximum power density of 272 mW m(-2) for >400 h of operation. The MFC current recovered to the original level within few hours after medium replacement, suggesting that the electricity generation was caused by the anodic microorganisms. Cyclic voltammetry indicated that redox systems (E-3 and E-c) with similar potentials (-0.14 and -0.17 V) made the main contributions to the exoelectrogenic activities of the sludge-derived consortium and C. nitroreducens Yu37-1, respectively. This study undertook the bioelectrochemical characterization of C. nitroreducens as the first example of a thermophilic Gram-negative exoelectrogen.