Effect of increased pCO2 on bacterial assemblage shifts in response to glucose addition in Fram Strait seawater mesocosms

• Main Authors: Ray, Jessica L, Töpper, Birte, An, Shu, Silyakova, Anna, Spindelböck, Joachim, Thyrhaug, Runar, DuBow, Michael S, Thingstad, Tron Frede, Sandaa, Ruth-Anne
• Format: Dataset
• Language: English
• Published: PANGAEA 2012
• Subjects: Algae abundance; Alkalinity; total; Aragonite saturation state; Arctic; Bacteria; abundance; Bacterial production; Bicarbonate ion; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Class; Community composition and diversity; Entire community; EXP; Experiment; Family; Field experiment; Fram_Strait_OA; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gene expression (incl. proteomics); Incubation duration; Mesocosm or benthocosm; OA-ICC; Ocean Acidification International Coordination Centre; Open ocean; Operational taxonomic unit; Other metabolic rates; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; Phosphate; Polar; Salinity; Sequence abundance; Sequence coverage; Silicate; Species; Temperature; water; Treatment; Greenland; East Greenland; east greenland current; Fram Strait; Ocean acidification; Shannon
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.831208; https://doi.org/10.1594/PANGAEA.831208

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 CO2 (pCO2). 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 pCO2 was eliminated at 400 µatm pCO2. These results suggest that the response potential of marine bacteria to DOC input may be altered under acidified conditions.