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oai:recercat.cat:10256/134082024-06-18T11:07:30Zcom_2072_452955com_2072_2054col_2072_452958col_2072_453077col_2072_453080

Diversity of Miscellaneous Crenarchaeotic Group archaea in freshwater karstic lakes and their segregation between planktonic and sediment habitats Fillol Homs, Mireia Sànchez Melsió, Alexandre Gich Batlle, Frederic Borrego i Moré, Carles Ministerio de Ciencia e Innovación (Espanya) Ministerio de Economía y Competitividad (Espanya) Microbiologia d'aigua dolça Freshwater microbiology Microbiologia -- Cultius i medis de cultiu Microbiology -- Cultures and culture media Sediments marins Marine sediments The Miscellaneous Crenarchaeotic Group (MCG) is an archaeal lineage whose members are widespread and abundant in marine sediments. MCG archaea have also been consistently found in stratified euxinic lakes. In this work, we have studied archaeal communities in three karstic lakes to reveal potential habitat segregation of MCG subgroups between planktonic and sediment compartments. In the studied lakes, archaeal assemblages were strikingly similar to those of the marine subsurface with predominance of uncultured Halobacteria in the plankton and Thermoplasmata and MCG in anoxic, organic-rich sediments. Multivariate analyses identified sulphide and dissolved organic carbon as predictor variables of archaeal community composition. Quantification of MCG using a newly designed qPCR primer pair that improves coverage for MCG subgroups prevalent in the studied lakes revealed conspicuous populations in both the plankton and the sediment. Subgroups MCG-5a and -5b appear as planktonic specialists thriving in euxinic bottom waters, while subgroup MCG-6 emerges as a generalist group able to cope with varying reducing conditions. Besides, comparison of DNA- and cDNA-based pyrotag libraries revealed that rare subgroups in DNA libraries, i.e. MCG-15, were prevalent in cDNA-based datasets, suggesting that euxinic, organic-rich sediments of karstic lakes provide optimal niches for the activity of some specialized MCG subgroups This research was funded by projects ARCANOX (Ref. CGL2009-13318-C02–02) and ARCOS (ref. CGL2012–33033) from the Spanish Ministry of Economy and Competitiveness (MINECO) 2015-01 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/10256/13408 http://hdl.handle.net/10256/13408 eng info:eu-repo/semantics/altIdentifier/doi/10.1093/femsec/fiv020 info:eu-repo/semantics/altIdentifier/issn/0168-6496 info:eu-repo/semantics/altIdentifier/eissn/1574-6941 MICINN/PN 2010-2012/CGL2009-13318-C02-02 info:eu-repo/grantAgreement/MINECO//CGL2012-33033/ES/CONTRIBUCION DE LAS ARCHAEA NO CULTIVADAS EN EL RECICLAJE DE CARBONO ORGANICO EN SEDIMENTOS/ Tots els drets reservats info:eu-repo/semantics/openAccess application/pdf Wiley © FEMS Microbiology Ecology, 2015, vol. 91, p. fiv020 Articles publicats (D-B)