Browsing by Author "Wagner, Michael"

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Ecophysiology of an uncultivated lineage of 'Aigarchaeota' from an oxic, hot spring filamentous 'streamer' community
(2015-06) Beam, Jacob P.; Jay, Zackary J.; Schmid, Markus C.; Rusch, Douglas B.; Romine, Margaret F.; Jennings, Ryan deM.; Kozubal, Mark A.; Tringe, Susannah G.; Wagner, Michael; Inskeep, William P.
The candidate archaeal phylum ‘Aigarchaeota’ contains microorganisms from terrestrial and subsurface geothermal ecosystems. The phylogeny and metabolic potential of Aigarchaeota has been deduced from several recent single-cell amplified genomes; however, a detailed description of their metabolic potential and in situ transcriptional activity is absent. Here, we report a comprehensive metatranscriptome-based reconstruction of the in situ metabolism of Aigarchaeota in an oxic, hot spring filamentous ‘streamer’ community. Fluorescence in situ hybridization showed that these newly discovered Aigarchaeota are filamentous, which is consistent with the presence and transcription of an actin-encoding gene. Aigarchaeota filaments are intricately associated with other community members, which include both bacteria (for example, filamentous Thermocrinis spp.) and archaea. Metabolic reconstruction of genomic and metatranscriptomic data suggests that this aigarchaeon is an aerobic, chemoorganoheterotroph with autotrophic potential. A heme copper oxidase complex was identified in the environmental genome assembly and highly transcribed in situ. Potential electron donors include acetate, fatty acids, amino acids, sugars and aromatic compounds, which may originate from extracellular polymeric substances produced by other microorganisms shown to exist in close proximity and/or autochthonous dissolved organic carbon (OC). Transcripts related to genes specific to each of these potential electron donors were identified, indicating that this aigarchaeon likely utilizes several OC substrates. Characterized members of this lineage cannot synthesize heme, and other cofactors and vitamins de novo, which suggests auxotrophy. We propose the name Candidatus ‘Calditenuis aerorheumensis’ for this aigarchaeon, which describes its filamentous morphology and its primary electron acceptor, oxygen.
Roadmap for naming uncultivated Archaea and Bacteria
(2020-08) Murray, Alison E.; Freudenstein, John; Gribaldo, Simonetta; Hatzenpichler, Roland; Hugenholtz, Philip; Kampfer, Peter; Konstantinidis, Konstantinos T.; Lane, Christopher E.; Papke, R. Thane; Parks, Donovan H.; Rossello-Mora, Ramon; Stott, Matthew B.; Sutcliffe, Iain C.; Thrash, J. Cameron; Venter, Stephanus N.; Whitman, William B.; Acinas, Silvia G.; Amann, Rudolf I.; Anantharaman, Karthik; Armengaud, Jean; Baker, Brett J.; Barco, Roman A.; Bode, Helge B.; Boyd, Eric S.; Brady, Carrie L.; Carini, Paul; Chain, Patrick S. G.; Colman, Daniel R.; DeAngelis, Kristen M.; Asuncion de los Rios, Maria; Estrada-de los Santos, Paulina; Dunlap, Christopher A.; Eisen, Jonathan A.; Emerson, David; Ettema, Thisjs J. G.; Eveillard, Damien R.; Girguis, Peter R.; Hentschel, Ute; Hollibaugh, James T.; Hug, Laura A.; Inskeep, William P.; Ivanova, Elena P.; Klenk, Hans-Peter; Li, Wen-Jun; Lloyd, Karen G.; Loffler, Frank E.; Makhalanyane, Thulani P.; Moser, Duane P.; Nunoura, Takuro; Palmer, Marike; Parro, Victor; Pedros-Alio, Carlos; Probst, Alexander J.; Smits, Theo H. M.; Steen, Andrew D.; Steenkamp, Emma T.; Spang, Anja; Stewart, Frank J.; Tiedje, James M.; Vandamme, Peter; Wagner, Michael; Wang, Feng-Ping; Yarza, Pablo; Hedlund, Brian P.; Reysenbach, Anna-Louise
The assembly of single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) has led to a surge in genome-based discoveries of members affiliated with Archaea and Bacteria, bringing with it a need to develop guidelines for nomenclature of uncultivated microorganisms. The International Code of Nomenclature of Prokaryotes (ICNP) only recognizes cultures as ‘type material’, thereby preventing the naming of uncultivated organisms. In this Consensus Statement, we propose two potential paths to solve this nomenclatural conundrum. One option is the adoption of previously proposed modifications to the ICNP to recognize DNA sequences as acceptable type material; the other option creates a nomenclatural code for uncultivated Archaea and Bacteria that could eventually be merged with the ICNP in the future. Regardless of the path taken, we believe that action is needed now within the scientific community to develop consistent rules for nomenclature of uncultivated taxa in order to provide clarity and stability, and to effectively communicate microbial diversity.