Coupling of heterotrophic bacteria to phytoplankton bloom development at different pCO 2 levels: a mesocosm study

By M. Allgaier, U. Riebesell, M. Vogt, R. Thyrhaug, Hans-Peter Grossart. 2008

142 citations recorded by the source corpus.

Abstract. The predicted rise in anthropogenic CO2 emissions will increase CO2 concentrations and decrease seawater pH in the upper ocean. Recent studies have revealed effects of pCO2 induced changes in seawater chemistry on a variety of marine life forms, in particular calcifying organisms. To test whether the predicted increase in pCO2 will directly or indirectly (via changes in phytoplankton dynamics) affect abundance, activities, and community composition of heterotrophic bacteria during phytoplankton bloom development, we have aerated mesocosms with CO2 to obtain triplicates with three different partial pressures of CO2 (pCO2): 350 μatm (1×CO2), 700 μatm (2×CO2) and 1050 μatm (3×CO2). The development of a phytoplankton bloom was initiated by the addition of nitrate and phosphate. In accordance to an elevated carbon to nitrogen drawdown at increasing pCO2, bacterial production (BPP) of free-living and attached bacteria as well as cell-specific BPP (csBPP) of attached bacteria were related to the C:N ratio of suspended matter. These relationships significantly differed among treatments. However, bacterial abundance and activities were not statistically different among treatments. Solely community structure of free-living bacteria changed with pCO2 whereas that of attached bacteria seemed to be independent of pCO2 but tightly coupled to phytoplankton bloom development. Our findings imply that changes in pCO2, although reflected by changes in community structure of free-living bacteria, do not directly affect bacterial activity. Furthermore, bacterial activity and dynamics of heterotrophic bacteria, especially of attached bacteria, were tightly correlated to phytoplankton development and, hence, may also potentially depend on changes in pCO2.

Subfields: Oceanography

View Paper: https://www.semanticscholar.org/paper/fb391be9a790f67f3373d93fc24dc1164b8620d3

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In Oceanography

Citations in the corpus

Ocean acidification and marine microorganisms : responses and consequences (2015, background): “Simulated mesocosm studies to elucidate the effect of future ocean pH shift on biofilms confirm changes in structure of heterotrophic planktonic free-living bacterial communities (Allgaier et al., 2008; Liu et al., 2010; Witt et al., 2011).”
Mechanisms of Microbial Carbon Sequestration in the Ocean - Future Research Directions (2014, background): “Although there is no clear impact of OA on bacterial abundance (Rochelle-Newall et al., 2004; Grossart et al., 2006; Allgaier et al., 2008; Paulino et al., 2008; Newbold et al., 2012; Brussaard et al., 2013), gross- and cellspecific bacterial production are usually stimulated by high pCO2…”
Effect of ocean acidification on microbial diversity and on microbe-driven biogeochemistry and ecosystem functioning (2010, background): “Allgaier et al. (2008) suggested that there was no difference in BPP among pCO2 treatments.”
Contrasting effects of ocean acidification on the microbial food web under different trophic conditions (2016, background): “In addition, contrasting results were also found in the magnitude and direction of the effect of OA on bacterial activity (Grossart et al., 2006; Allgaier et al., 2008; Motegi et al., 2013).”
Mesocosm CO 2 perturbation studies: from organism to community level (2008, background): “– diversity of free bacteria (Allgaier et al., 2008) – viral abundance and diversity (Larsen et al.”
Increased carbon dioxide availability alters phytoplankton stoichiometry and affects carbon cycling and growth of a marine planktonic herbivore (2012, background): “The effects of elevated pCO2 on bacteria have so far only been studied under the aspect of direct ocean acidification via changes in the pH, which seems to have little effect (Allgaier et al. 2008).”
Acidification increases microbial polysaccharide degradation in the ocean (2009, background): “In contrast, Allgaier et al. (2008) did not find differences in bacterial biomass production and carbon demand between the differentpCO2 treatments.”
Mesocosm Experiments as a Tool for Ecological Climate-Change Research (2013, unknown): “Comm L M M Allgaier et al. (2008) M Warming Inverts Eco S S M Alsterberg et al. (2012) M Nutrients Inverts Eco S S M M CO2_pH Corals Eco M S M Andersson et al. (2009) M CO2_pH Microinverts Eco L M S Antia et al. (2008) T CO2_fert Eu. micro.”
The biological pump in a high CO 2 world (2012, background): “Three mesocosm studies implied minor effects of ocean acidification on bacterial abundance (RochelleNewall et al. 2004, Grossart et al. 2006, Allgaier et al. 2008), but clearer shifts in bacterial community structure (Allgaier et al. 2008, Arnosti et al. 2011).”