Biogeochemical evidence of anaerobic methane oxidation on active submarine mud volcanoes on the continental slope of the Canadian Beaufort Sea

• Published in: Biogeosciences
• Main Authors: D.-H. Lee, J.-H. Kim, Y. M. Lee, A. Stadnitskaia, Y. K. Jin, H. Niemann, Y.-G. Kim, K.-H. Shin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2018
• Subjects: Ecology; QH540-549.5; Life; QH501-531; Geology; QE1-996.5; Beaufort Sea
• Online Access: https://doi.org/10.5194/bg-15-7419-2018; https://doaj.org/article/9327899f9e924031a2e948a07de8466a

In this study, we report lipid biomarker patterns and phylogenetic identities of key microbial communities mediating anaerobic oxidation of methane (AOM) in active mud volcanoes (MVs) on the continental slope of the Canadian Beaufort Sea. The carbon isotopic compositions ( δ 13 C ) of sn -2- and sn -3-hydroxyarchaeol showed the highly 13 C -depleted values ( − 114 ‰ to − 82 ‰) associated with a steep depletion in sulfate concentrations within 0.7 m of sediment depths. This suggested the presence of methanotrophic archaea involved in sulfate-dependent AOM, albeit in a small amount. The ratio of sn -2-hydroxyarchaeol to archaeol (> 1) and operational taxonomic units (OTUs) indicated that the anaerobic methanotrophic archaea (ANME) clades ANME-2c and ANME-3 were involved in AOM. Higher δ 13 C values of archaeol and biphytanes (BPs; <math xmlns="http://www.w3.org/1998/Math/MathML" id="M6" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">55.2</mn><mo>±</mo><mn mathvariant="normal">10.0</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="b8a30afc3a6a907d1421600169c03687"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-15-7419-2018-ie00001.svg" width="64pt" height="10pt" src="bg-15-7419-2018-ie00001.png"/></svg:svg> ‰ and <math xmlns="http://www.w3.org/1998/Math/MathML" id="M7" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">39.3</mn><mo>±</mo><mn mathvariant="normal">13.0</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="8ab88b064bf7877fe9242b053f754cf0"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-15-7419-2018-ie00002.svg" width="64pt" ...