Effect of increased pCO(2) on bacterial assemblage shifts in response to glucose addition in Fram Strait seawater mesocosms.

• Published in: FEMS Microbiology Ecology
• Main Authors: Ray, Jessica L, Töpper, Birte, An, Shu, Silyakova, Anna, Spindelböck, Joachim, Thyrhaug, Runar, Dubow, Michael S, Thingstad, T Frede, Sandaa, Ruth-Anne
• Other Authors: Institut de génétique et microbiologie Orsay (IGM), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: [SDV.BBM]Life Sciences [q-bio]/Biochemistry; Molecular Biology; Greenland; East Greenland; east greenland current; Fram Strait; Ocean acidification; Shannon
• Online Access: https://hal.archives-ouvertes.fr/hal-00757197; https://doi.org/10.1111/j.1574-6941.2012.01443.x

International audience Ocean acidification may stimulate primary production through increased availability of inorganic carbon in the photic zone, which may in turn change the biogenic flux of dissolved organic carbon (DOC) and the growth potential of heterotrophic bacteria. To investigate the effects of ocean acidification on marine bacterial assemblages, a two-by-three factorial mescosom experiment was conducted using surface sea water from the East Greenland Current in Fram Strait. Pyrosequencing of the V1-V2 region of bacterial 16S ribosomal RNA genes was used to investigate differences in the endpoint (Day 9) composition of bacterial assemblages in mineral nutrient-replete mesocosms amended with glucose (0 μm, 5.3 μm and 15.9 μm) under ambient (250 μatm) or acidified (400 μatm) partial pressures of CO(2) (pCO(2) ). All mesocosms showed low richness and diversity by Chao1 estimator and Shannon index, respectively, with general dominance by Gammaproteobacteria and Flavobacteria. Nonmetric multidimensional scaling analysis and two-way analysis of variance of the Jaccard dissimilarity matrix (97% similarity cut-off) demonstrated that the significant community shift between 0 μm and 15.9 μm glucose addition at 250 μatm pCO(2) was eliminated at 400 μatm pCO(2) . These results suggest that the response potential of marine bacteria to DOC input may be altered under acidified conditions.