Abstract—

Methane oxidation rates and diversity of methane-oxidizing microorganisms were studied in the upper sediment layers of the Laptev Sea (methane seep area, Lena fore-delta, shelf, and upper slope not affected by seeps and river flow). The highest methane concentrations and methane oxidation rates (up to 1.16 µmol СН₄ dm⁻³ day⁻¹) were revealed at the seep stations. Carbon dioxide was the main product of methane oxidation at all stations. Sequencing of the 16S rRNA gene fragments revealed microorganisms of the class Gammaproteobacteria, order Methylococcales. Since the share of methanotrophs was high at the sites of constant gas seepage (up to 1.93% of the total read number), they could be detected by sequencing of the native samples. Phylogenetic diversity of methane-oxidizing bacteria was not high, and all detected microorganisms belonged to the Deep-Sea 1 cluster. On the phylogenetic tree, the sequences formed a cluster together with the genus Methyloprofundus. Members of the genera Methylomonas and Methylobacter related to methanotrophs inhabiting freshwater ecosystems were revealed in enrichments from the coastal stations sediment samples.

中文翻译：

---

拉普捷夫海上部沉积层中好氧甲烷氧化菌的甲烷氧化活性和系统发育多样性

摘要——

研究了拉普捷夫海上层沉积物（甲烷渗漏区、勒拿前三角洲、陆架和不受渗流和河流流量影响的上坡）的甲烷氧化速率和甲烷氧化微生物的多样性。最高的甲烷浓度和甲烷氧化速率（高达 1.16 µmol СН ₄ dm ^-3天^-1）在渗漏站显示。二氧化碳是所有站点甲烷氧化的主要产物。16S rRNA基因片段的测序揭示了Gammaproteobacteria类微生物，为了Methylococcales. 由于甲烷氧化菌在恒定气体渗漏部位的比例很高（高达总读数的 1.93%），因此可以通过对天然样品进行测序来检测它们。甲烷氧化细菌的系统发育多样性不高，所有检测到的微生物都属于深海1菌群。在系统发育树上，这些序列与Methyloprofundus属一起形成了一个簇。在沿海站沉积物样本的富集中揭示了与居住在淡水生态系统中的甲烷氧化菌相关的甲基单胞菌属和甲基杆菌属的成员。