Turbulence-driven shifts in holobionts and planktonic microbial assemblages in St. Peter and St. Paul Archipelago, Mid-Atlantic Ridge, Brazil.
The aim of this study was to investigate the planktonic and the holobiont Madracis decactis (Scleractinia) microbial diversity along a turbulence-driven upwelling event, in the world's most isolated tropical island, St Peter and St Paul Archipelago (SPSPA, Brazil). Twenty one metagenomes were obtained for seawater (N = 12), healthy and bleached holobionts (N = 9) before, during and after the episode of high seawater turbulence and upwelling. Microbial assemblages differed between low turbulence-low nutrient (LLR) and high-turbulence-high nutrient (HHR) regimes in seawater. During LLR there was a balance between autotrophy and heterotrophy in the bacterioplankton and the ratio cyanobacteria:heterotrophs ~1 (C:H). Prochlorales, unclassified Alphaproteobacteria and Euryarchaeota were the dominant bacteria and archaea, respectively. Basic metabolisms and cyanobacterial phages characterized the LLR. During HHR C:H < < 0.05 and Gammaproteobacteria approximated 50% of the most abundant organisms in seawater. Alteromonadales, Oceanospirillales, and Thaumarchaeota were the dominant bacteria and archaea. Prevailing metabolisms were related to membrane transport, virulence, disease, and defense. Phages targeting heterotrophs and virulence factor genes characterized HHR. Shifts were also observed in coral microbiomes, according to both annotation-indepent and -dependent methods. HHR bleached corals metagenomes were the most dissimilar and could be distinguished by their di- and tetranucleotides frequencies, Iron Acquision metabolism and virulence genes, such as V. cholerae-related virulence factors. The healthy coral holobiont was shown to be less sensitive to transient seawater-related perturbations than the diseased animals. A conceptual model for the turbulence-induced shifts is put forward.
Laboratory of Microbiology, Institute of Biology, Federal University of Rio de Janeiro Rio de Janeiro, Brazil.
Ana Paula B
AP
Moreira
Laboratory of Microbiology, Institute of Biology, Federal University of Rio de Janeiro Rio de Janeiro, Brazil.
Pedro M
PM
Meirelles
Fundação Centro Universitário Estadual da Zona Oeste (Uezo) Rio de Janeiro, Brazil.
Eidy de O
Ede O
Santos
Diretoria de Pesquisa Científica, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro Rio de Janeiro, Brazil.
Gilberto M
GM
Amado-Filho
Department of Environment and Engineering, Federal University of Paraíba Rio Tinto, Brazil.
Ronaldo B
RB
Francini-Filho
Laboratory of Microbiology, Institute of Biology, Federal University of Rio de Janeiro Rio de Janeiro, Brazil.
Cristiane C
CC
Thompson
Laboratory of Microbiology, Institute of Biology, Federal University of Rio de Janeiro Rio de Janeiro, Brazil.
Fabiano L
FL
Thompson
Atlantic Ocean; Madracis decactis; Scleractinia; metagenomics; oceanic islands