Carbonate-hosted microbial communities are prolific and pervasive methane oxidizers at geologically diverse marine methane seep sites
| Autor: | Jeffrey J. Marlow, Daniel Hoer, Amy Gartman, Victoria J. Orphan, Sean P. Jungbluth, Marko S. Chavez, Noreen Tuross, Peter R. Girguis, Mohamed Y. El-Naggar, Linda M. Reynard |
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| Rok vydání: | 2021 |
| Předmět: |
16S
Geological Phenomena Endolith endolith Carbonates methane seep Microbiology Deep sea Methane Mesocosm chemistry.chemical_compound Earth Atmospheric and Planetary Sciences RNA Ribosomal 16S Seawater Ribosomal Multidisciplinary Geography methane oxidation Microbiota Biological Sciences Kinetics Petroleum seep Microbial population biology chemistry Environmental chemistry Physical Sciences Anaerobic oxidation of methane RNA Environmental science Carbonate metabolic rates Oxidation-Reduction |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America Proceedings of the National Academy of Sciences of the United States of America, vol 118, iss 25 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.2006857118 |
| Popis: | Significance Methane is a strong greenhouse gas that plays a key role in Earth’s climate. At methane seeps, large amounts of methane move upward through the seafloor, where microbial communities consume much of it. A full accounting of methane’s sources and sinks has evaded researchers—in part, perhaps, because key habitats including carbonate rock mounds have been largely neglected. We sampled seven methane seeps representing four geological settings and found that all sites had rock-hosted microbes capable of consuming methane; in lab-based incubations, some did so at the highest rates reported to date. We demonstrate several factors that help determine a sample’s methane-consuming potential and propose that carbonate rocks at methane seeps may represent a methane sink of far-reaching importance. At marine methane seeps, vast quantities of methane move through the shallow subseafloor, where it is largely consumed by microbial communities. This process plays an important role in global methane dynamics, but we have yet to identify all of the methane sinks in the deep sea. Here, we conducted a continental-scale survey of seven geologically diverse seafloor seeps and found that carbonate rocks from all sites host methane-oxidizing microbial communities with substantial methanotrophic potential. In laboratory-based mesocosm incubations, chimney-like carbonates from the newly described Point Dume seep off the coast of Southern California exhibited the highest rates of anaerobic methane oxidation measured to date. After a thorough analysis of physicochemical, electrical, and biological factors, we attribute this substantial metabolic activity largely to higher cell density, mineral composition, kinetic parameters including an elevated Vmax, and the presence of specific microbial lineages. Our data also suggest that other features, such as electrical conductance, rock particle size, and microbial community alpha diversity, may influence a sample’s methanotrophic potential, but these factors did not demonstrate clear patterns with respect to methane oxidation rates. Based on the apparent pervasiveness within seep carbonates of microbial communities capable of performing anaerobic oxidation of methane, as well as the frequent occurrence of carbonates at seeps, we suggest that rock-hosted methanotrophy may be an important contributor to marine methane consumption. |
| Databáze: | OpenAIRE |
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