Optical properties of dissolved organic matter relate to different depth-specific patterns of archaeal and bacterial community structure in the North Atlantic Ocean

• Published in: FEMS Microbiology Ecology
• Main Authors: Guerrero-Feijóo, E., Nieto-Cid, Mar, Dobal-Amador, Vladimir, Hernando-Morales, Víctor, Sintes, Eva, Álvarez, Marta, Balagué, Vanessa, Varela, Marta M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press 2017
• Subjects: Pyrosequencing; Diversity; DOM optical properties; Marine microbes; CARD-FISH; T-RFLP; ARISA; Deep sea; Atlantic waters; North Atlantic
• Online Access: http://hdl.handle.net/10261/154288; https://doi.org/10.1093/femsec/fiw224

14 páginas, 6 figuras, 4 tablas Prokaryotic abundance, activity and community composition were studied in the euphotic, intermediate and deep waters off the Galician coast (NW Iberian margin) in relation to the optical characterization of dissolved organic matter (DOM). Microbial (archaeal and bacterial) community structure was vertically stratified. Among the Archaea, Euryarchaeota, especially Thermoplasmata, was dominant in the intermediate waters and decreased with depth, whereas marine Thaumarchaeota, especially Marine Group I, was the most abundant archaeal phylum in the deeper layers. The bacterial community was dominated by Proteobacteria through the whole water column. However, Cyanobacteria and Bacteroidetes occurrence was considerable in the upper layer and SAR202 was dominant in deep waters. Microbial composition and abundance were not shaped by the quantity of dissolved organic carbon, but instead they revealed a strong connection with the DOM quality. Archaeal communities were mainly related to the fluorescence of DOM (which indicates respiration of labile DOM and generation of refractory subproducts), while bacterial communities were mainly linked to the aromaticity/age of the DOM produced along the water column. Taken together, our results indicate that the microbial community composition is associated with the DOM composition of the water masses, suggesting that distinct microbial taxa have the potential to use and/or produce specific DOM compounds Funding for the sampling and analysis was provided by the projects ‘Biodiversidade Funcional do Microplancton nas profundidades mariñas de Galicia’ (BIO-PROF, Ref. 10MMA604024PR, 2010–2013, Xunta de Galicia) and ‘Fuentes de Materia Orgánica y Diversidad Funcional del Microplancton en las aguas profundas del Atlántico Norte’ (MODUPLAN, Ref. CTM2011-24008-MAR, 2012–2015, Plan Nacional I + D + I) to MMV. MNC was funded by the CSIC Program ‘Junta para la Ampliación de Estudios’ co-financed by the ESF (reference JAE DOC 040) and the project FERMIO ...