Department of Marine Sciences and Convergent Technology, Hanyang University ERICA Campus, Ansan, 15588, Republic of Korea.
Marine Environment Research, Division, National Institute of Fisheries Science, Busan, Republic of Korea.
Sci Rep. 2022 Oct 5;12(1):16597. doi: 10.1038/s41598-022-21184-6.
Migration of methane-rich fluids at submarine cold seeps drives intense microbial activity and precipitation of authigenic carbonates. In this study, we analyzed microbially derived authigenic carbonate samples recently recovered from active gas hydrate mounds on the southwestern slope of the Chukchi Borderlands (CB), western Arctic Ocean. Our main aim was to characterize the distribution patterns of trace elements in carbonate-hosted lipid fractions to assess metalloenzyme requirements of microbes involved in anaerobic oxidation of methane (AOM). We measured stable isotopes, trace elements, lipid biomarkers, and genomic DNA, and results indicate the dominance of AOM-related lipid biomarkers in studied carbonate samples, as well as a predominant occurrence of the anaerobic methanotrophic archaea (ANME)-1. We also report evidence for significant preferential enrichments of various trace elements (Li, Ni, Co, Cu, Zn, and Mo) in the total lipid fractions of CB carbonates, relative to elemental compositions determined for corresponding carbonate fractions, which differ from those previously reported for other seep sites. We hypothesize that trace element enrichments in carbonate-hosted lipid fractions could vary depending on the type of AOM microbial assemblage. Additional work is required to further investigate the mechanisms of lipid-bound trace elements in cold seep carbonates as potential metalloenzymes in AOM.
海底冷泉中富含甲烷的流体迁移驱动了强烈的微生物活动和自生碳酸盐的沉淀。在这项研究中，我们分析了最近从北极西部楚科奇边缘海域（CB）西南斜坡上活跃的天然气水合物丘中回收的微生物衍生自生碳酸盐样品。我们的主要目的是描述碳酸盐中脂质成分中微量元素的分布模式，以评估参与甲烷厌氧氧化（AOM）的微生物对金属酶的需求。我们测量了稳定同位素、微量元素、脂质生物标志物和基因组 DNA，结果表明，在所研究的碳酸盐样品中，AOM 相关的脂质生物标志物占主导地位，同时也存在大量的厌氧甲烷氧化古菌（ANME-1）。我们还报告了证据表明，与相应碳酸盐部分的元素组成相比，CB 碳酸盐中总脂质部分中各种微量元素（Li、Ni、Co、Cu、Zn 和 Mo）存在明显的优先富集，这与以前在其他渗流点报告的情况不同。我们假设，碳酸盐中脂质结合微量元素的富集程度可能取决于 AOM 微生物组合的类型。需要进一步研究冷渗碳酸盐中作为 AOM 潜在金属酶的脂质结合痕量元素的机制。
