Taxonomic and Functional Metagenomic Signature of Turfs in the Abrolhos Reef System (Brazil)

PLoS One. 2016 Aug 22;11(8):e0161168. doi: 10.1371/journal.pone.0161168. eCollection 2016.

Abstract

Turfs are widespread assemblages (consisting of microbes and algae) that inhabit reef systems. They are the most abundant benthic component in the Abrolhos reef system (Brazil), representing greater than half the coverage of the entire benthic community. Their presence is associated with a reduction in three-dimensional coral reef complexity and decreases the habitats available for reef biodiversity. Despite their importance, the taxonomic and functional diversity of turfs remain unclear. We performed a metagenomics and pigments profile characterization of turfs from the Abrolhos reefs. Turf microbiome primarily encompassed Proteobacteria (mean 40.57% ± s.d. 10.36, N = 1.548,192), Cyanobacteria (mean 35.04% ± s.d. 15.5, N = 1.337,196), and Bacteroidetes (mean 11.12% ± s.d. 4.25, N = 424,185). Oxygenic and anoxygenic phototrophs, chemolithotrophs, and aerobic anoxygenic phototrophic (AANP) bacteria showed a conserved functional trait of the turf microbiomes. Genes associated with oxygenic photosynthesis, AANP, sulfur cycle (S oxidation, and DMSP consumption), and nitrogen metabolism (N2 fixation, ammonia assimilation, dissimilatory nitrate and nitrite ammonification) were found in the turf microbiomes. Principal component analyses of the most abundant taxa and functions showed that turf microbiomes differ from the other major Abrolhos benthic microbiomes (i.e., corals and rhodoliths) and seawater. Taken together, these features suggest that turfs have a homogeneous functional core across the Abrolhos Bank, which holds diverse microbial guilds when comparing with other benthic organisms.

MeSH terms

  • Ammonia / metabolism
  • Animals
  • Anthozoa / physiology
  • Bacteroidetes
  • Biodiversity
  • Brazil
  • Coral Reefs
  • Cyanobacteria / classification
  • Cyanobacteria / genetics*
  • Cyanobacteria / metabolism
  • DNA Barcoding, Taxonomic
  • DNA, Bacterial / genetics*
  • Metagenomics*
  • Microbial Consortia / genetics
  • Microbiota / genetics*
  • Nitrogen / metabolism
  • Photosynthesis
  • Phylogeny*
  • Pigments, Biological / biosynthesis
  • Principal Component Analysis
  • Proteobacteria / classification
  • Proteobacteria / genetics*
  • Proteobacteria / metabolism
  • Seawater / microbiology
  • Sulfonium Compounds / metabolism
  • Sulfur / metabolism

Substances

  • DNA, Bacterial
  • Pigments, Biological
  • Sulfonium Compounds
  • Sulfur
  • Ammonia
  • dimethylpropiothetin
  • Nitrogen

Grants and funding

The authors received funding from National Counsel of Technological and Scientific Development (CNPq), Coordination for the Improvement of Higher Education Personnel (CAPES), Rio de Janeiro Research Foundation (FAPERJ) for this work.