Anode biofilm transcriptomics reveals outer surface components essential for high density current production in Geobacter sulfurreducens fuel cells.
Anode biofilm transcriptomics reveals outer surface components essential for high density current production in Geobacter sulfurreducens fuel cells.
复制标题
DOI：
10.1371/journal.pone.0005628
复制
发表时间：
2009-05-20
期刊：
影响因子：
3.7
通讯作者：
Lovley DR
中科院分区：
文献类型：
--
作者：
Nevin KP;Kim BC;Glaven RH;Johnson JP;Woodard TL;Methé BA;Didonato RJ;Covalla SF;Franks AE;Liu A;Lovley DR
研究了硫还原地杆菌将电子通过相对较厚的(>；50微米)生物膜转移到作为唯一电子受体的电极上的机理。硫还原地杆菌的生物膜生长在以石墨阳极为电子受体的流通式体系中，或以富马酸为唯一电子受体的同一石墨表面。富马酸生长的生物膜不能立即产生显著的电流，这表明与产生电流的生物膜有很大的生理差异。微阵列分析显示，在当前收获的生物膜中，有13个基因的转录水平显著高于其他生物膜。升幅最大的是Pila，即Pila下游的基因，以及两个外c型膜细胞色素OmcB和OmcZ的基因。下调的基因包括外膜c型细胞色素基因、OMCs基因和OMCT基因。生物膜生长过程中基因转录水平的定量RT-PCR结果与基因芯片结果一致。在电流采集细胞中，OMCZ和外表面c型细胞色素OMCE含量较高，OMCs含量较少。在Pila、omcB、omcs、omce或omcZ下游的Pila基因缺失的菌株中，只有Pila或omcZ的缺失严重抑制了当前的生产和生物膜的形成。相反，当富马酸作为电子受体时，这些基因缺失对石墨表面生物膜的形成没有影响。这些结果表明，收获电流生长的生物膜特别适合电子转移到电极，并且，除了菌毛，OmcZ是通过分化的硫还原革兰氏菌生物膜向电极转移电子的关键成分。
The mechanisms by which Geobacter sulfurreducens transfers electrons through relatively thick (>50 µm) biofilms to electrodes acting as a sole electron acceptor were investigated. Biofilms of Geobacter sulfurreducens were grown either in flow-through systems with graphite anodes as the electron acceptor or on the same graphite surface, but with fumarate as the sole electron acceptor. Fumarate-grown biofilms were not immediately capable of significant current production, suggesting substantial physiological differences from current-producing biofilms. Microarray analysis revealed 13 genes in current-harvesting biofilms that had significantly higher transcript levels. The greatest increases were for pilA, the gene immediately downstream of pilA, and the genes for two outer c-type membrane cytochromes, OmcB and OmcZ. Down-regulated genes included the genes for the outer-membrane c-type cytochromes, OmcS and OmcT. Results of quantitative RT-PCR of gene transcript levels during biofilm growth were consistent with microarray results. OmcZ and the outer-surface c-type cytochrome, OmcE, were more abundant and OmcS was less abundant in current-harvesting cells. Strains in which pilA, the gene immediately downstream from pilA, omcB, omcS, omcE, or omcZ was deleted demonstrated that only deletion of pilA or omcZ severely inhibited current production and biofilm formation in current-harvesting mode. In contrast, these gene deletions had no impact on biofilm formation on graphite surfaces when fumarate served as the electron acceptor. These results suggest that biofilms grown harvesting current are specifically poised for electron transfer to electrodes and that, in addition to pili, OmcZ is a key component in electron transfer through differentiated G. sulfurreducens biofilms to electrodes.
登录
查看更多内容
影响因子：
4.4
作者：
LOVLEY, DR;PHILLIPS, EJP
通讯作者：
PHILLIPS, EJP
影响因子：
3.2
作者：
Butler, JE;Glaven, RH;Lovley, DR
通讯作者：
Lovley, DR
影响因子：
5
作者：
Jung, Sokhee;Regan, John M.
通讯作者：
Regan, John M.
影响因子：
3.2
作者：
Leang, C;Adams, LA;Lovley, DR
通讯作者：
Lovley, DR
影响因子：
3.2
作者：
Kim, BC;Qian, XL;Lovley, DR
通讯作者：
Lovley, DR