Complex organic matter degradation by secondary consumers in chemolithoautotrophy-based subsurface geothermal ecosystems.

Autor: Paul R; Microbiology Department, University of Tennessee, Knoxville, TN, United States of America., Rogers TJ; Microbiology Department, University of Tennessee, Knoxville, TN, United States of America., Fullerton KM; Microbiology Department, University of Tennessee, Knoxville, TN, United States of America., Selci M; Department of Biology, University of Naples 'Federico II', Naples, Italy., Cascone M; Department of Biology, University of Naples 'Federico II', Naples, Italy., Stokes MH; Microbiology Department, University of Tennessee, Knoxville, TN, United States of America., Steen AD; Microbiology Department, University of Tennessee, Knoxville, TN, United States of America., de Moor JM; Observatorio Volcanológico y Sismológico de Costa Rica (OVSICORI) Universidad Nacional, Heredia, Costa Rica.; Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM, United States of America., Chiodi A; Instituto de Bio y Geociencias del NOA (IBIGEO, UNSa-CONICET), Salta, Argentina., Stefánsson A; NordVulk, Institute of Earth Sciences, University of Iceland, Reykjavík, Iceland., Halldórsson SA; NordVulk, Institute of Earth Sciences, University of Iceland, Reykjavík, Iceland., Ramirez CJ; Servicio Geologico Ambiental, Heredia, Costa Rica., Jessen GL; Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile.; Center for Oceanographic Research COPAS COASTAL, Universidad de Concepción, Concepción, Chile., Barry PH; Marine Chemistry & Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States of America., Cordone A; Department of Biology, University of Naples 'Federico II', Naples, Italy., Giovannelli D; Department of Biology, University of Naples 'Federico II', Naples, Italy.; Marine Chemistry & Geochemistry Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States of America.; National Research Council-Institute of Marine Biological Resources and Biotechnologies-CNR-IRBIM, Ancona, Italy.; Department of Marine and Coastal Science, Rutgers University, New Brunswick, NJ, United States of America.; Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan., Lloyd KG; Microbiology Department, University of Tennessee, Knoxville, TN, United States of America.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2023 Aug 18; Vol. 18 (8), pp. e0281277. Date of Electronic Publication: 2023 Aug 18 (Print Publication: 2023).
DOI: 10.1371/journal.pone.0281277
Abstrakt: Microbial communities in terrestrial geothermal systems often contain chemolithoautotrophs with well-characterized distributions and metabolic capabilities. However, the extent to which organic matter produced by these chemolithoautotrophs supports heterotrophs remains largely unknown. Here we compared the abundance and activity of peptidases and carbohydrate active enzymes (CAZymes) that are predicted to be extracellular identified in metagenomic assemblies from 63 springs in the Central American and the Andean convergent margin (Argentinian backarc of the Central Volcanic Zone), as well as the plume-influenced spreading center in Iceland. All assemblies contain two orders of magnitude more peptidases than CAZymes, suggesting that the microorganisms more often use proteins for their carbon and/or nitrogen acquisition instead of complex sugars. The CAZy families in highest abundance are GH23 and CBM50, and the most abundant peptidase families are M23 and C26, all four of which degrade peptidoglycan found in bacterial cells. This implies that the heterotrophic community relies on autochthonous dead cell biomass, rather than allochthonous plant matter, for organic material. Enzymes involved in the degradation of cyanobacterial- and algal-derived compounds are in lower abundance at every site, with volcanic sites having more enzymes degrading cyanobacterial compounds and non-volcanic sites having more enzymes degrading algal compounds. Activity assays showed that many of these enzyme classes are active in these samples. High temperature sites (> 80°C) had similar extracellular carbon-degrading enzymes regardless of their province, suggesting a less well-developed population of secondary consumers at these sites, possibly connected with the limited extent of the subsurface biosphere in these high temperature sites. We conclude that in < 80°C springs, chemolithoautotrophic production supports heterotrophs capable of degrading a wide range of organic compounds that do not vary by geological province, even though the taxonomic and respiratory repertoire of chemolithoautotrophs and heterotrophs differ greatly across these regions.
Competing Interests: The authors have declared that no competing interests exist.
(Copyright: © 2023 Paul et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
Databáze: MEDLINE
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