Artificial electron acceptors decouple archaeal methane oxidation from sulfate reduction
Artificial electron acceptors decouple archaeal methane oxidation from sulfate reduction
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DOI：
10.1126/science.aad7154
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发表时间：
2016-02
期刊：
影响因子：
56.9
通讯作者：
Silvan Scheller;Hang Yu;G. Chadwick;S. E. McGlynn;V. Orphan
中科院分区：
文献类型：
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作者：
Silvan Scheller;Hang Yu;G. Chadwick;S. E. McGlynn;V. Orphan
海洋沉积物中的长期伙伴解偶联甲烷咀嚼古菌与硫酸盐还原菌密切耦合，形成互养关系。然而，令人惊讶的是，这些古细菌并不一定需要它们的细菌伴侣才能生存或生长。舍勒等人对深海甲烷渗漏沉积物进行了稳定同位素培养实验（见Rotaru和Thamdrup的《透视》）。几组甲烷氧化古菌可以使用一系列可溶性电子受体，而不是耦合到活跃的细菌硫酸盐还原。这种解耦的途径表明，甲烷氧化古生菌细胞外转移电子，甚至可能具有呼吸海底沉积物中丰富的铁和锰矿物的能力。《科学》，本期第703页;另见第658页人工电子受体通过代谢使深海甲烷氧化古菌与其互养伙伴细菌分离。[Also参见Rotaru和Thamdrup的观点]甲烷与硫酸盐的氧化是全球碳循环中重要的微生物代谢。在海洋甲烷渗漏中，这一过程是由与硫酸盐还原菌（SRB）共生的厌氧甲烷氧化古菌（ANME）财团介导的。人们对这种未培养的共生伙伴关系中潜在的相互依赖性知之甚少。我们使用的速率测量和单细胞稳定同位素探测相结合，以证明在深海沉积物中的ANME可以分解代谢和合成代谢解耦从他们的共生SRB合作伙伴使用可溶性人工氧化剂。ANME仍然维持高速率的甲烷氧化在硫酸盐作为终端氧化剂的情况下，贷款支持的假设，种间胞外电子转移是甲烷厌氧氧化的互养机制。
Long-term partners uncoupled Methane-munching archaea in marine sediments live closely coupled to sulfate-reducing bacteria in a syntrophic relationship. Surprisingly, however, these archaea do not necessarily need their bacterial partners to survive or grow. Scheller et al. performed stable isotope incubation experiments with deep-sea methane seep sediments (see the Perspective by Rotaru and Thamdrup). Several groups of methane-oxidizing archaea could use a range of soluble electron acceptors instead of coupling to active bacterial sulfate reduction. This decoupled pathway shows that methane-oxidizing archaea transfer electrons extracellularly and may even possess the capacity to respire iron and manganese minerals that are abundant in seafloor sediments. Science, this issue p. 703; see also p. 658 Artificial electron acceptors metabolically decouple deep-sea methanotrophic archaea from their syntrophic partner bacteria. [Also see Perspective by Rotaru and Thamdrup] The oxidation of methane with sulfate is an important microbial metabolism in the global carbon cycle. In marine methane seeps, this process is mediated by consortia of anaerobic methanotrophic archaea (ANME) that live in syntrophy with sulfate-reducing bacteria (SRB). The underlying interdependencies within this uncultured symbiotic partnership are poorly understood. We used a combination of rate measurements and single-cell stable isotope probing to demonstrate that ANME in deep-sea sediments can be catabolically and anabolically decoupled from their syntrophic SRB partners using soluble artificial oxidants. The ANME still sustain high rates of methane oxidation in the absence of sulfate as the terminal oxidant, lending support to the hypothesis that interspecies extracellular electron transfer is the syntrophic mechanism for the anaerobic oxidation of methane.