Deciphering cryptic methane cycling: Coupling of methylotrophic methanogenesis and anaerobic oxidation of methane in hypersaline coastal wetland sediment
Deciphering cryptic methane cycling: Coupling of methylotrophic methanogenesis and anaerobic oxidation of methane in hypersaline coastal wetland sediment
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破译隐秘的甲烷循环：高盐度海岸湿地沉积物中甲烷的甲基营养产甲烷和厌氧氧化的耦合
DOI：
10.1016/j.gca.2021.03.021
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发表时间：
2021-04-21
影响因子：
5
通讯作者：
Treude, Tina
中科院分区：
文献类型：
--
作者：
Krause, Sebastian J. E.;Treude, Tina
最近的研究表明，在海洋沉积物的硫酸盐还原带中，甲烷的生成会促进甲烷的厌氧氧化，这就形成了“隐蔽的甲烷循环”一词。在这里，我们提出的甲烷和AOM在一个浅的高盐度池（类似于130 PSU）在南部加州沿海湿地之间的关系的研究。沉积物（顶部20厘米）进行地球化学分析，在体外泥浆实验，和放射性示踪剂培养使用S-35-SO 42-，C-14-单甲胺，和C-14-CH 4，研究硫酸盐还原，甲基营养型甲烷，AOM。使用适应的放射性同位素方法来跟踪14 C-单甲胺标记孵育中的隐蔽甲烷循环，孵育时间增加（1小时至3周）。结果表明，AOM（最大13 nmol cm（-3）d（-1））和硫酸盐还原活性（最大728 nmol cm（-3）d（-1））的峰值在顶部6 cm。低于6 cm，AOM活性继续（最大15 nmol cm（-3）d（-1）），而硫酸盐还原是不存在的，尽管67 mM的硫酸盐，这表明AOM耦合到铁的还原。甲烷浓度低（
Methanogenesis has recently been shown to fuel anaerobic oxidation of methane (AOM) within the sulfate-reducing zone of marine sediments, coining the term ``cryptic methane cycle". Here we present research on the relationship between methanogenesis and AOM in a shallow hypersaline pool (similar to 130 PSU) within a southern California coastal wetland. Sediment (top 20 cm) was subjected to geochemical analyses, in-vitro slurry experiments, and radiotracer incubations using S-35-SO42-, C-14-mono-methylamine, and C-14-CH4, to study sulfate reduction, methylotrophic methanogenesis, and AOM. An adapted radioisotope method was used to follow cryptic methane cycling in 14C-mono-methylamine labeling incubations with increasing incubation times (1 hour to three weeks). Results showed peaks in AOM (max 13 nmol cm(-3) d(-1)) and sulfate reduction activity (max 728 nmol cm(-3) d(-1)) within the top 6 cm. Below 6 cm, AOM activity continued (max 15 nmol cm(-3) d(-1)), while sulfate reduction was absent despite 67 mM sulfate, suggesting AOM was coupled to the reduction of iron. Methane concentrations were low (