Institute for Biogeochemistry and Marine Chemistry, University of Hamburg, Bundesstr. 55, 20146, Hamburg, Germany.
Environ Microbiol. 2013 Aug;15(8):2384-93. doi: 10.1111/1462-2920.12112. Epub 2013 Mar 26.
Anaerobic methanotrophic archaea (ANME) are ubiquitous in marine sediments where sulfate dependent anaerobic oxidation of methane (AOM) occurs. Despite considerable progress in the understanding of AOM, physiological details are still widely unresolved. We investigated two distinct microbial mat samples from the Black Sea that were dominated by either ANME-1 or ANME-2. The (13) C lipid stable isotope probing (SIP) method using labelled substances, namely methane, bicarbonate, acetate, and methanol, was applied, and the substrate-dependent methanogenic capabilities were tested. Our data provide strong evidence for a versatile physiology of both, ANME-1 and ANME-2. Considerable methane production rates (MPRs) from CO2 -reduction were observed, particularly from ANME-2 dominated samples and in the presence of methane, which supports the hypothesis of a co-occurrence of methanotrophy and methanogenesis in the AOM systems (AOM/MPR up to 2:1). The experiments also revealed strong methylotrophic capabilities through (13) C-assimilation from labelled methanol, which was independent of the presence of methane. Additionally, high MPRs from methanol were detected in both of the mat samples. As demonstrated by the (13) C-uptake into lipids, ANME-1 was found to thrive also under methane free conditions. Finally, C35 -isoprenoid hydrocarbons were identified as new lipid biomarkers for ANME-1, most likely functioning as a hydrogen sink during methanogenesis.
产甲烷厌氧古菌（ANME）广泛存在于海洋沉积物中，这些沉积物中存在硫酸盐依赖型的甲烷厌氧氧化（AOM）过程。尽管人们对 AOM 的理解已经取得了相当大的进展，但生理细节仍然存在广泛的未解之谜。我们研究了来自黑海的两个截然不同的微生物席样本，它们分别由 ANME-1 或 ANME-2 主导。我们应用了（13）C 脂质稳定同位素探测（SIP）方法，使用标记物质，即甲烷、碳酸氢盐、乙酸盐和甲醇，并测试了底物依赖性的产甲烷能力。我们的数据为 ANME-1 和 ANME-2 的多功能生理学提供了强有力的证据。我们观察到相当高的 CO2 还原产生的甲烷速率（MPRs），特别是在 ANME-2 主导的样本中，并且在甲烷存在的情况下，这支持了 AOM 系统中甲烷营养和产甲烷共生的假说（AOM/MPR 高达 2:1）。实验还揭示了通过标记甲醇的（13）C 同化产生的强烈的甲基营养能力，这独立于甲烷的存在。此外，在两个席样本中均检测到了来自甲醇的高 MPRs。如（13）C 进入脂质的摄取所证明的那样，ANME-1 也能在没有甲烷的条件下茁壮成长。最后，C35 异戊二烯烃被鉴定为 ANME-1 的新脂质生物标志物，它们很可能在产甲烷过程中作为氢汇发挥作用。
