title: Anaerobic Methane-Oxidizing Microbial Community in a Coastal Marine Sediment: Anaerobic Methanotrophy Dominated by ANME-3.
abstract: The microbial community inhabiting the shallow sulfate-methane transition zone in coastal sediments from marine Lake Grevelingen (The Netherlands) was characterized, and the ability of the microorganisms to carry out anaerobic oxidation of methane coupled to sulfate reduction was assessed in activity tests. In vitro activity tests of the sediment with methane and sulfate demonstrated sulfide production coupled to the simultaneous consumption of sulfate and methane at approximately equimolar ratios over a period of 150 days. The maximum sulfate reduction rate was 5 μmol sulfate per gram dry weight per day during the incubation period. Diverse archaeal and bacterial clades were retrieved from the sediment with the majority of them clustered with Euryarchaeota, Thaumarcheota, Bacteroidetes, and Proteobacteria. The 16S rRNA gene sequence analysis showed that the sediment from marine Lake Grevelingen contained anaerobic methanotrophic Archaea (ANME) and methanogens as archaeal clades with a role in the methane cycling. ANME at the studied site mainly belong to the ANME-3 clade. This study provides one of the few reports for the presence of ANME-3 in a shallow coastal sediment. Sulfate-reducing bacteria from Desulfobulbus clades were found among the sulfate reducers, however, with very low relative abundance. Desulfobulbus has previously been commonly found associated with ANME, whereas in our study, ANME-3 and Desulfobulbus were not observed simultaneously in clusters, suggesting the possibility of independent AOM by ANME-3.
authors.affiliation: UNESCO-IHE, Westvest-7, P.O. Box 3015, Delft, 2601, DA, The Netherlands. s.bhattarai@unesco-ihe.org.
authors.forename: Susma
authors.initials: S
authors.lastname: Bhattarai
authors.affiliation: UNESCO-IHE, Westvest-7, P.O. Box 3015, Delft, 2601, DA, The Netherlands.
authors.forename: Chiara
authors.initials: C
authors.lastname: Cassarini
authors.affiliation: UNESCO-IHE, Westvest-7, P.O. Box 3015, Delft, 2601, DA, The Netherlands.
authors.forename: Graciela
authors.initials: G
authors.lastname: Gonzalez-Gil
authors.affiliation: Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA, Utrecht, The Netherlands.|Center for Geomicrobiology, Department of Bioscience, Aarhus University, Ny Munkegade 114, 8000, Aarhus, Denmark.
authors.forename: Matthias
authors.initials: M
authors.lastname: Egger
authors.affiliation: Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA, Utrecht, The Netherlands.
authors.forename: Caroline P
authors.initials: CP
authors.lastname: Slomp
authors.affiliation: State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Dongchuan Rd. 800, Shanghai, 200240, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Di Biasio 43, 03043, Cassino, FR, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Esposito
authors.affiliation: UNESCO-IHE, Westvest-7, P.O. Box 3015, Delft, 2601, DA, The Netherlands.
authors.forename: Piet N L
authors.initials: PNL
authors.lastname: Lens
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000145:classification / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000145:classification / Q000378:metabolism*; D019015:Geologic Sediments / Q000382:microbiology*; D060106:Lakes / Q000382:microbiology; D008697:Methane / Q000378:metabolism*; D009426:Netherlands; D010084:Oxidation-Reduction; D019642:RNA, Archaeal / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D017423:Sequence Analysis, RNA
chemical_list: D019642:RNA, Archaeal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D008697:Methane
keywords: ANME; Anaerobic oxidation of methane; Archaea; Bacteria; Coastal sediments; Marine Lake Grevelingen; Sulfate reduction