Anaerobic methane oxidation in metalliferous hydrothermal sediments: influence on carbon flux and decoupling from sulfate reduction.
Anaerobic methane oxidation in metalliferous hydrothermal sediments: influence on carbon flux and decoupling from sulfate reduction.
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DOI：
10.1111/j.1462-2920.2012.02825.x
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发表时间：
2012-10
影响因子：
5.1
通讯作者：
S. Wankel;M. M. Adams-M.;David T. Johnston;Colleen M Hansel;S. B. Joye;Peter R. Girguis
中科院分区：
文献类型：
--
作者：
S. Wankel;M. M. Adams-M.;David T. Johnston;Colleen M Hansel;S. B. Joye;Peter R. Girguis
甲烷厌氧氧化（AOM）是一个全球性的重要汇，调节着甲烷从沉积物进入海洋和大气的通量。在这里，我们研究嗜中温嗜热AOM热液沉积物中回收的中谷喷口领域，胡安德富卡岭。使用连续流沉积物生物反应器和分批培养，我们的特点是（i）AOM有助于净溶解无机碳通量的程度，（ii）AOM和硫酸盐还原（SR）率作为温度的函数和（iii）已知的厌氧甲烷氧化菌（ANME）的分布和密度。在沉积物生物反应器中，无机碳稳定同位素质量平衡结果表明，AOM占无机碳产生的16%和86%之间，强调AOM在这些沉积物中的无机碳通量的作用。在90°C时，AOM在没有SR的情况下发生，表明AOM与SR的显著解耦。富含类似于混合价铁氧化物的含Fe（III）矿物，如绿色锈，表明这些含金属沉积物中AOM与Fe（III）还原的耦合潜力。虽然SR细菌只观察到在较冷的温度沉积物，ANME结盟ANME-1核糖体，包括一个假定的ANME-1C组，被发现在所有的温度制度，并代表了很大比例的古菌群落。在音乐会上，这些结果扩展和重塑我们的理解的高温甲烷生物地球化学的性质，提供了深入了解嗜热厌氧甲烷营养的生理和生态，并建议AOM可能发挥核心作用，调节生物溶解无机碳通量的深海从全球洋中脊热液喷口系统的有机贫，含金属沉积物。
The anaerobic oxidation of methane (AOM) is a globally significant sink that regulates methane flux from sediments into the oceans and atmosphere. Here we examine mesophilic to thermophilic AOM in hydrothermal sediments recovered from the Middle Valley vent field, on the Juan de Fuca Ridge. Using continuous-flow sediment bioreactors and batch incubations, we characterized (i) the degree to which AOM contributes to net dissolved inorganic carbon flux, (ii) AOM and sulfate reduction (SR) rates as a function of temperature and (iii) the distribution and density of known anaerobic methanotrophs (ANMEs). In sediment bioreactors, inorganic carbon stable isotope mass balances results indicated that AOM accounted for between 16% and 86% of the inorganic carbon produced, underscoring the role of AOM in governing inorganic carbon flux from these sediments. At 90°C, AOM occurred in the absence of SR, demonstrating a striking decoupling of AOM from SR. An abundance of Fe(III)-bearing minerals resembling mixed valent Fe oxides, such as green rust, suggests the potential for a coupling of AOM to Fe(III) reduction in these metalliferous sediments. While SR bacteria were only observed in cooler temperature sediments, ANMEs allied to ANME-1 ribotypes, including a putative ANME-1c group, were found across all temperature regimes and represented a substantial proportion of the archaeal community. In concert, these results extend and reshape our understanding of the nature of high temperature methane biogeochemistry, providing insight into the physiology and ecology of thermophilic anaerobic methanotrophy and suggesting that AOM may play a central role in regulating biological dissolved inorganic carbon fluxes to the deep ocean from the organic-poor, metalliferous sediments of the global mid-ocean ridge hydrothermal vent system.