Conductive iron oxide minerals accelerate syntrophic cooperation in methanogenic benzoate degradation.
Conductive iron oxide minerals accelerate syntrophic cooperation in methanogenic benzoate degradation.
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DOI：
10.1016/j.jhazmat.2015.03.039
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发表时间：
2015-08
影响因子：
13.6
通讯作者：
Zhuang Li;Jiahuan Tang;Yue-qiang Wang;Min Hu;Shungui Zhou
中科院分区：
文献类型：
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作者：
Zhuang Li;Jiahuan Tang;Yue-qiang Wang;Min Hu;Shungui Zhou
最近的研究表明，导电氧化铁矿物质可以促进自然和工程微生物生态系统中有机物（例如乙醇、丙酸盐和丁酸盐）产甲烷降解的互养代谢。这种增强的共养涉及直接种间电子转移（DIET），由微生物通过导电矿物质交换代谢电子提供动力。在这里，我们评估了导电铁氧化物（赤铁矿和磁铁矿）刺激苯甲酸盐产甲烷降解的可能性，苯甲酸盐是芳香族化合物厌氧代谢中的常见中间体。结果表明，89%~94%的苯甲酸盐氧化释放的电子在CH4生产中被回收，并且乙酸盐被认为是苯甲酸盐降解过程中唯一的含碳中间体。与无铁对照相比，在赤铁矿和磁铁矿存在下，产甲烷苯甲酸盐的降解率分别提高了 25% 和 53%。这种刺激作用可能是由饮食介导的产甲烷作用引起的，其中电子通过导电铁矿物质在互养伙伴之间转移。系统发育分析表明，芽孢杆菌科、消化球菌科和甲烷杆菌可能参与互养饮食的功能。考虑到土壤和沉积物中铁矿物的普遍存在，这项研究的结果将增进目前对厌氧环境中芳香烃自然生物衰减的理解。
Recent studies have suggested that conductive iron oxide minerals can facilitate syntrophic metabolism of the methanogenic degradation of organic matter, such as ethanol, propionate and butyrate, in natural and engineered microbial ecosystems. This enhanced syntrophy involves direct interspecies electron transfer (DIET) powered by microorganisms exchanging metabolic electrons through electrically conductive minerals. Here, we evaluated the possibility that conductive iron oxides (hematite and magnetite) can stimulate the methanogenic degradation of benzoate, which is a common intermediate in the anaerobic metabolism of aromatic compounds. The results showed that 89–94% of the electrons released from benzoate oxidation were recovered in CH4production, and acetate was identified as the only carbon-bearing intermediate during benzoate degradation. Compared with the iron-free controls, the rates of methanogenic benzoate degradation were enhanced by 25% and 53% in the presence of hematite and magnetite, respectively. This stimulatory effect probably resulted from DIET-mediated methanogenesis in which electrons transfer between syntrophic partners via conductive iron minerals. Phylogenetic analyses revealed thatBacillaceae,Peptococcaceae, andMethanobacteriumare potentially involved in the functioning of syntrophic DIET. Considering the ubiquitous presence of iron minerals within soils and sediments, the findings of this study will increase the current understanding of the natural biological attenuation of aromatic hydrocarbons in anaerobic environments.