Quorum sensing signals enhance the electrochemical activity and energy recovery of mixed-culture electroactive biofilms
Quorum sensing signals enhance the electrochemical activity and energy recovery of mixed-culture electroactive biofilms
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群体感应信号增强混合培养电活性生物膜的电化学活性和能量回收
DOI：
10.1016/j.bios.2017.06.024
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发表时间：
2017-11-15
影响因子：
12.6
通讯作者：
Zhou, Shungui
中科院分区：
文献类型：
--
作者：
Chen, Shanshan;Jing, Xianyue;Zhou, Shungui
外源性或内源性群体感应信号分子对混合培养电活性生物膜（EABs）的影响，特别是胞外聚合物（EPS）和胞外产电菌在EABs内通过直接电子传递机制的影响尚不清楚。本研究的重点是酰基高丝氨酸内酯（AHLs），最常见的QS信号分子的革兰氏阴性菌，混合培养EABs的影响。结果表明，外源性和内源性AHLs均起到了提高EABs电化学活性的调节作用。内源AHLs使MFC的能量回收率从20.5% ± 3.9%提高到28.3% ± 4.1%，外源AHLs使MFC的能量回收率进一步提高到36.2% ± 5.1%;内源AHLs使MFC的启动期从13天缩短到10天，外源AHLs使MFC的启动期进一步缩短到4天。外源性和内源性AHLs的影响是非瞬时的。它们改善了一些固有特性，即电极相关生物量、生物膜致密性和活/死细胞的比率，以获得上级EAB。同时，内源和外源AHLs均提高了EPS的浓度和氧化还原活性。此外，内源AHLs增强了EPS组分的多样性。值得注意的是，Geoboacter sp.是一种典型的直接电子传递机制的微生物，其相对丰度是通过外源AHLs来提高的，尽管迄今为止在该属中还没有已知的化学QS相关基因或蛋白的报道。这些发现将增加目前的理解QS在EAB和开放的机会，通过QS调节混合培养MFC。
The impacts of exogenous or endogenous quorum sensing (QS) signaling molecules on mixed-culture electroactive biofilms (EABs), especially extracellular polymeric substances (EPS) and exoelectrogens using direct electron transfer mechanism inside EABs are poorly understood. This research focuses on the influence of acylhomoserine lactones (AHLs), the most common QS signaling molecules for gram negative bacteria, on mixed-culture EABs. Results indicated that both exogenous and endogenous AHLs played the role as regulators to improve the electrochemical activities of EABs. The energy recovery of MFCs increased from 20.5% +/- 3.9% to 28.3% +/- 4.1% with endogenous AHLs and further rose to 36.2% +/- 5.1% with exogenous AHLs, and the start-up period of MFCs shortened from 13 days to 10 days with endogenous AHLs and further reduced to 4 days in the presence of exogenous AHLs. The influences of exogenous and endogenous AHLs were non instantaneous. They improved some intrinsic properties, i.e. the electrode-associated biomass, the biofilm compactness and the ratio of live/dead cells to obtain superior EABs. Meanwhile, both endogenous and exogenous AHLs increased the concentration and redox activities of EPS. Besides, endogenous AHLs enhanced the diversity of EPS components. Noteworthily, the relative abundance of Geoboacter sp. which is the typical microbe using direct electron transfer mechanism is raised by exogenous AHLs, though so far neither known chemical QS-related gene nor protein has been reported in this genus. These findings will increase the current understanding of QS in EABs and open up an opportunity for regulating mixed-culture MFCs via QS.