Bacterial Vesicles Mediate Extracellular Electron Transfer
Bacterial Vesicles Mediate Extracellular Electron Transfer
复制标题
细菌囊泡介导细胞外电子转移
DOI：
10.1021/acs.estlett.9b00707
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发表时间：
2020-01-01
影响因子：
10.9
通讯作者：
Zhou, Shungui
中科院分区：
文献类型：
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作者：
Liu, Xing;Jing, Xianyue;Zhou, Shungui
许多革兰氏阴性细菌在正常生长过程中会释放外膜泡(OMV)到周围环境中，OMV具有多种生物学和环境功能(例如，毒力因子转运、水平基因转移、仲裁信号、细胞防御和细胞间通讯)。然而，OMV在地杆菌中的产生还没有报道，它们在细胞外电子传递(EET)中的作用也是未知的。在这里，我们第一次证明，硫还原地杆菌释放含有丰富的细胞色素的OMV，可以促进EET从微生物细胞到阳极。Gebacter细胞释放的OMVS不仅促进外源EET(在单氏希瓦氏杆菌MR-1中的电流密度提高1.73倍)，而且还赋予非外源EET(硫还原菌突变株Delta omcZ和大肠埃希氏菌)生电能力。这些功能主要归因于结合或包裹在OMV上的C型细胞色素的丰富。我们的发现表明，氧化还原活性的OMV可以作为促进自然生态系统中EET的共享介质，代表着一种生态上重要但被忽视的生物电子传递过程。
Many Gram-negative bacteria are known to release outer membrane vesicles (OMVs) into the surrounding environment during normal growth; OMVs perform diverse biological and environmental functions (e.g., virulence factor transport, horizontal gene transfer, quorum signaling, cellular defense, and cell-to-cell communication). However, the production of OMVs has not been reported in Geobacter species, and their role in extracellular electron transfer (EET) is unknown. Here, we demonstrate, for the first time, that Geobacter sulfurreducens releases OMVs containing abundant cytochromes that can promote EET from microbial cells to an anode. OMVs released by Geobacter cells not only promote exoelectrogen EET (1.73-fold higher current density in Shewanella oneidensis MR-1) but also confer electrogenic ability to non-exoelectrogens (G. sulfurreducens mutant strain Delta omcZ and Escherichia coli). These functions are mainly attributed to the abundance of c-type cytochromes bound on or entrapped in OMVs. Our findings suggest that redox-active OMVs can serve as shared mediators facilitating EET in natural ecosystems, representing an ecologically important but overlooked biological electron transfer process.