Seasonal variability of microbial respiration and bacterial and archaeal community composition in the upper twilight zone

Type : ACL
Nature : Production scientifique
Au bénéfice du Laboratoire : Oui
Statut de publication : Publié
Année de publication : 2013
Auteurs (7) : WEINBAUER Markus,g LIU J MOTEGI Chiaki MAIER Conny PEDROTTI Maria-luiza DAI M,h GATTUSO Jean-pierre
Revue scientifique : Aquatic Microbial Ecology
Volume : 71
Fascicule : 2
Pages : 99-115
DOI : 10.3354/ame01666
URL : <go to isi>://wos:000329951800001
Abstract : The mesopelagic ('twilight') zone of the ocean is the sandwich layer between euphotic surface waters and the deep ocean. The physical, chemical, and biological processes in this layer strongly influence the marine carbon cycle, although some surprising knowledge gaps remain, e.g. with respect to microbial communities. We therefore determined biological parameters such as microbial abundances, community respiration, and bacterial and archaeal community composition (as assessed by 16S rRNA gene PCR denaturing gradient gel electrophoresis, DGGE) over a seasonal time scale (at ca. 46 d intervals for 433 d) at a coastal mesopelagic site in the NW Mediterranean Sea (Point C, 300 m depth) and related them to physicochemical parameters. Some chemical and most biological parameters showed strong variability, thus confirming the emerging view that this water layer is more dynamic than previously thought. Community respiration was likely influenced by seasonal changes as indicated by its indirect relationship with water density. The high detected community respiration rates (0.23-1.65 mu mol O-2 l(-1) d(-1)) confirm that the twilight zone plays a critical role as a hub between surface and deep water. Statistical analyses indicate that water stratification, dissolved organic carbon, and transparent exopolymeric particles were controlling factors of bacterial community composition, whereas the archaeal community was likely controlled by other mechanisms. A sequence analysis of DGGE bands and a literature comparison suggests some specificity of the mesopelagic zone regarding bacterial and archaeal community composition, thus further confirming the peculiarity of this water layer.
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Commentaire : Times Cited: 0 Dai, Minhan/G-3343-2010 0
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Citation :
Weinbauer MG, Liu J, Motegi C, Maier C, Pedrotti M-L, Dai MH, Gattuso J-P (2013) Seasonal variability of microbial respiration and bacterial and archaeal community composition in the upper twilight zone. Aquat Microb Ecol 71: 99-115 | doi: 10.3354/ame01666