Spatial Homogeneity of Bacterial Communities Associated with the Surface Mucus Layer of the Reef-Building Coral Acropora palmata

PLoS One. 2015 Dec 14;10(12):e0143790. doi: 10.1371/journal.pone.0143790. eCollection 2015.

Abstract

Coral surface mucus layer (SML) microbiota are critical components of the coral holobiont and play important roles in nutrient cycling and defense against pathogens. We sequenced 16S rRNA amplicons to examine the structure of the SML microbiome within and between colonies of the threatened Caribbean reef-building coral Acropora palmata in the Florida Keys. Samples were taken from three spatially distinct colony regions--uppermost (high irradiance), underside (low irradiance), and the colony base--representing microhabitats that vary in irradiance and water flow. Phylogenetic diversity (PD) values of coral SML bacteria communities were greater than surrounding seawater and lower than adjacent sediment. Bacterial diversity and community composition was consistent among the three microhabitats. Cyanobacteria, Bacteroidetes, Alphaproteobacteria, and Proteobacteria, respectively were the most abundant phyla represented in the samples. This is the first time spatial variability of the surface mucus layer of A. palmata has been studied. Homogeneity in the microbiome of A. palmata contrasts with SML heterogeneity found in other Caribbean corals. These findings suggest that, during non-stressful conditions, host regulation of SML microbiota may override diverse physiochemical influences induced by the topographical complexity of A. palmata. Documenting the spatial distribution of SML microbes is essential to understanding the functional roles these microorganisms play in coral health and adaptability to environmental perturbations.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Anthozoa / microbiology*
  • Anthozoa / physiology
  • Bacteria / genetics
  • Bacteria / growth & development
  • Bacteria / isolation & purification*
  • Biodiversity
  • Coral Reefs
  • Florida
  • Microbiota*
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics
  • Seawater / microbiology
  • Sequence Analysis, RNA

Substances

  • RNA, Ribosomal, 16S

Grants and funding

This research project was supported by the National Science Foundation Ecology of Infectious Diseases grant #1015342 awarded to JWP, EKL, and JPW. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.