title: High-resolution sequencing reveals unexplored archaeal diversity in freshwater wetland soils.
abstract: Despite being key contributors to biogeochemical processes, archaea are frequently outnumbered by bacteria, and consequently are underrepresented in combined molecular surveys. Here, we demonstrate an approach to concurrently survey the archaea alongside the bacteria with high-resolution 16S rRNA gene sequencing, linking these community data to geochemical parameters. We applied this integrated analysis to hydric soils sampled across a model methane-emitting freshwater wetland. Geochemical profiles, archaeal communities, and bacterial communities were independently correlated with soil depth and water cover. Centimeters of soil depth and corresponding geochemical shifts consistently affected microbial community structure more than hundreds of meters of lateral distance. Methanogens with diverse metabolisms were detected across the wetland, but displayed surprising OTU-level partitioning by depth. Candidatus Methanoperedens spp. archaea thought to perform anaerobic oxidation of methane linked to iron reduction were abundant. Domain-specific sequencing also revealed unexpectedly diverse non-methane-cycling archaeal members. OTUs within the underexplored Woesearchaeota and Bathyarchaeota were prevalent across the wetland, with subgroups and individual OTUs exhibiting distinct occupancy and abundance distributions aligned with environmental gradients. This study adds to our understanding of ecological range for key archaeal taxa in a model freshwater wetland, and links these taxa and individual OTUs to hypotheses about processes governing biogeochemical cycling.
authors.affiliation: Department of Integrative Biology, University of Colorado Denver, Denver, CO, USA.
authors.forename: Adrienne B
authors.identifier: 0000-0002-2000-088X
authors.initials: AB
authors.lastname: Narrowe
authors.affiliation: Department of Microbiology, The Ohio State University, Columbus, OH, USA.
authors.forename: Jordan C
authors.initials: JC
authors.lastname: Angle
authors.affiliation: Department of Microbiology, The Ohio State University, Columbus, OH, USA.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Daly
authors.affiliation: School of Environment and Natural Resources, The Ohio State University, Columbus, OH, USA.
authors.forename: Kay C
authors.initials: KC
authors.lastname: Stefanik
authors.affiliation: Department of Microbiology, The Ohio State University, Columbus, OH, USA.
authors.forename: Kelly C
authors.initials: KC
authors.lastname: Wrighton
authors.affiliation: Department of Integrative Biology, University of Colorado Denver, Denver, CO, USA.
authors.forename: Christopher S
authors.identifier: 0000-0002-9448-8144
authors.initials: CS
authors.lastname: Miller
mesh_terms: D001105:Archaea / Q000145:classification* / Q000235:genetics*; D001419:Bacteria / Q000145:classification* / Q000235:genetics; D044822:Biodiversity; D019641:DNA, Archaeal / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D005618:Fresh Water / Q000382:microbiology; D059014:High-Throughput Nucleotide Sequencing; D007501:Iron / Q000378:metabolism; D008697:Methane / Q000378:metabolism*; D059013:Microbial Consortia / Q000235:genetics*; D010084:Oxidation-Reduction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil; D012988:Soil Microbiology; D053833:Wetlands
chemical_list: D019641:DNA, Archaeal; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012987:Soil; D007501:Iron; D008697:Methane