Article

Characterization of geographically distinct bacterial communities associated with coral mucus produced by Acropora spp. and Porites spp.

Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, United Kingdom.
Applied and Environmental Microbiology (Impact Factor: 3.95). 05/2012; 78(15):5229-37. DOI: 10.1128/AEM.07764-11
Source: PubMed

ABSTRACT Acropora and Porites corals are important reef builders in the Indo-Pacific and Caribbean. Bacteria associated with mucus produced by Porites spp. and Acropora spp. from Caribbean (Punta Maroma, Mexico) and Indo-Pacific (Hoga and Sampela, Indonesia) reefs were determined. Analysis of pyrosequencing libraries showed that bacterial communities from Caribbean corals were significantly more diverse (H', 3.18 to 4.25) than their Indonesian counterparts (H', 2.54 to 3.25). Dominant taxa were Gammaproteobacteria, Alphaproteobacteria, Firmicutes, and Cyanobacteria, which varied in relative abundance between coral genera and region. Distinct coral host-specific communities were also found; for example, Clostridiales were dominant on Acropora spp. (at Hoga and the Mexican Caribbean) compared to Porites spp. and seawater. Within the Gammproteobacteria, Halomonas spp. dominated sequence libraries from Porites spp. (49%) and Acropora spp. (5.6%) from the Mexican Caribbean, compared to the corresponding Indonesian coral libraries (<2%). Interestingly, with the exception of Porites spp. from the Mexican Caribbean, there was also a ubiquity of Psychrobacter spp., which dominated Acropora and Porites libraries from Indonesia and Acropora libraries from the Caribbean. In conclusion, there was a dominance of Halomonas spp. (associated with Acropora and Porites [Mexican Caribbean]), Firmicutes (associated with Acropora [Mexican Caribbean] and with Acropora and Porites [Hoga]), and Cyanobacteria (associated with Acropora and Porites [Hoga] and Porites [Sampela]). This is also the first report describing geographically distinct Psychrobacter spp. associated with coral mucus. In addition, the predominance of Clostridiales associated with Acropora spp. provided additional evidence for coral host-specific microorganisms.

Download full-text

Full-text

Available from: Leanne J. Hepburn, May 28, 2014
0 Followers
 · 
113 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Understanding the patterns of microbial diversity and their composition in seawater is necessary to assess the impacts of microbes on marine ecosystem. Although the potential roles of microbes in the ocean have been studied, their diversity and relationship with environmental factors remain unclear. In this study, we adopted a 16S rRNA gene tag-pyrosequencing technique to investigate the bacterial communities associated with two different water masses from Tongyoung in the South Sea of Korea. Our results revealed highly diverse bacterial communities up to 900 Operational Taxonomic Units (OTUs) estimated from each seawater which was collected in the month of March and May, when the environmental conditions including temperature differed significantly: 7.2°C and 17.6°C in March and May, respectively. Altogether, 13 bacterial phyla were recovered from the seawater, of which Proteobacteria was the most dominant group. In addition, the value of the Shannon index, which measures the evenness of the distribution of individuals among OTUs, in May is higher than that in March, indicating that it displays a wider diversity of bacteria. Interestingly, the proportion of pathogenic bacteria was significantly increased in the month of May compared to March, suggesting that pathogenic bacteria were increasingly emerging in May. In particular, Pseudoalteromonas and Vibrio spp. were determined as major pathogenic bacteria from both water masses, of which Vibrio spp. were dominant.
    Ocean Science Journal 09/2014; 49(3):193-200. DOI:10.1007/s12601-014-0019-4
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Members of the Roseobacter clade are equipped with a tremendous diversity of metabolic capabilities, which in part explains their success in so many different marine habitats. Ideas on how this diversity evolved and is maintained are reviewed, focusing on recent evolutionary studies exploring the timing and mechanisms of Roseobacter ecological diversification. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
    Microbiology and molecular biology reviews: MMBR 12/2014; 78(4):573-587. DOI:10.1128/MMBR.00020-14 · 15.26 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Early establishment of coral-microbial symbioses is fundamental to the fitness of corals, but comparatively little is known about the onset and succession of bacterial communities in their early life history stages. In this study, bacterial associates of the coral Acropora millepora were characterized throughout the first year of life, from larvae and 1 week-old juveniles reared in laboratory conditions in the absence of the dinoflagellate endosymbiont Symbiodinium, to field-outplanted juveniles with established Symbiodinium symbioses and sampled at 2 weeks, and at 3, 6 and 12 months. Using an amplicon pyrosequencing approach, the diversity of both nitrogen-fixing bacteria and of bacterial communities overall was assessed through analysis of nifH and 16S rRNA genes, respectively. The consistent presence of sequences affiliated with diazotrophs of the order Rhizobiales (23 to 58% of retrieved nifH sequences; 2 to 12% of 16S rRNA sequences), across all samples from larvae to 12 month-old coral juveniles, highlights the likely functional importance of this nitrogen-fixing order to the coral holobiont. Dominance of Roseobacter-affiliated sequences (>55% of retrieved 16S rRNA sequences) in larvae and 1week-old juveniles, and the consistent presence of sequences related to Oceanospirillales and Altermonadales throughout all early life history stages, signifies their potential importance as coral associates. Increased diversity of bacterial communities once juveniles were transferred to the field, particularly of Cyanobacteria and Deltaproteobacteria, demonstrates horizontal (environmental) uptake of coral-associated bacterial communities. Although overall bacterial communities were dynamic, bacteria with likely important functional roles remain stable throughout early life stages of Acropora millepora.This article is protected by copyright. All rights reserved.
    Molecular Ecology 08/2014; 23(19). DOI:10.1111/mec.12899 · 5.84 Impact Factor