ANME‐1 archaea subsist on the very low energy of anaerobic oxidation of methane (AOM). Most marine sediments shift from net AOM in the sulfate methane transition zone (SMTZ) to methanogenesis in the methane zone (MZ) below it. In White Oak River estuarine sediments, ANME‐1 comprised 99.5% of 16S rRNA genes from amplicons and 100% of 16S rRNA genes from metagenomes of the Methanomicrobia in the SMTZ and 99.9% and 98.3%, respectively, in the MZ. Each of the 16 ANME‐1 OTUs (97% similarity) had peaks in the SMTZ that coincided with peaks of putative sulfate‐reducing bacteria Desulfatiglans sp. and SEEP‐SRB1. In the MZ, ANME‐1, but none of the putative sulfate‐reducing bacteria or cultured methanogens, increased with depth. Our meta‐analysis of public data showed only ANME‐1 expressed methanogenic genes during both net AOM and net methanogenesis in an enrichment culture. We conclude that ANME‐1 perform AOM in the SMTZ and methanogenesis in the MZ of White Oak River sediments. This metabolic flexibility may expand habitable zones in extraterrestrial environments, since it enables greater energy yields in a fluctuating energetic landscape.

中文翻译：

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ANME-1 古菌可能会驱动河口沉积物中的甲烷积累和清除

ANME-1 古菌以非常低的甲烷厌氧氧化 (AOM) 能量为生。大多数海洋沉积物从硫酸盐甲烷过渡区 (SMTZ) 的净 AOM 转变为其下方甲烷区 (MZ) 的产甲烷作用。在 White Oak River 河口沉积物中，ANME-1 包含 99.5% 的来自扩增子的 16S rRNA 基因和 100% 的来自 SMTZ 中甲烷微生物宏基因组的 16S rRNA 基因，在 MZ 中分别为 99.9% 和 98.3%。16 个 ANME-1 OTU（97% 相似性）中的每一个在 SMTZ 中都有峰值，与推定的硫酸盐还原细菌Desulfatiglan sp. 和 SEEP-SRB1。在 MZ 中，ANME-1 随深度增加，但没有假定的硫酸盐还原菌或培养的产甲烷菌。我们对公共数据的荟萃分析显示，在富集培养的净 AOM 和净产甲烷过程中，只有 ANME-1 表达产甲烷基因。我们得出结论，ANME-1 在 SMTZ 中进行 AOM，在 White Oak River 沉积物的 MZ 中进行产甲烷作用。这种代谢灵活性可能会扩大地外环境中的可居住区，因为它可以在波动的能量景观中实现更大的能量产量。