Diversity and distribution of coral-associated bacteria

Abstract

Coral reefs are the most biodiverse of all marine ecosystems; however, very little is known about prokaryotic diversity in these systems. To address this issue, we sequenced over 1000 bacterial 16S rDNAs from 3 massive coral species (Montastraea franksi, Diploria strigosa, and Porites astreoides) in Panama and Bermuda. Analysis of only 14 coral samples yielded 430 distinct bacterial ribotypes. Statistical analyses suggest that additional sequencing would have resulted in a total of 6000 bacterial ribotypes. Half of the sequences shared < 93% identity to previously published 16S sequences, and therefore probably represent novel bacterial genera and species; this degree of novelty was substantially higher than that observed for other marine samples. Samples from the Panama corals were more diverse than those from Bermuda, paralleling diversity gradients seen in metazoans. The coral-bacteria associations were non-random. Different coral species had distinct bacterial communities, even when physically adjacent, while bacterial communities from the same coral species separated by time (~1 yr) or space (3000 km) were similar. Analysis of the branching coral Porites furcata showed that bacterial ribotypes can also be structured spatially within colonies. Therefore, corals and reefs represent landscapes of diverse, ecologically structured prokaryotic communities. KEY WORDS: Coral · Bacteria · 16S rDNA · Biodiversity Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 243: [1][2][3][4][5][6][7][8][9][10] 2002 1973, Mitchell & Chet 1975, Ducklow & Mitchell 1979, Pascal & Vacelet 1981, Segel & Ducklow 1982, Herndl & Velimirov 1986, Paul et al. 1986, Williams et al. 1987, Shashar et al. 1994, Ritchie & Smith 1995, 1997, Santavy 1995, Kushmaro et al. 1996, Santavy & Peters 1997, Frias-Lopez et al. 2002. Whether these communities are just passive associations with water column bacteria or if they are specific associations with ecological importance is in dispute. Ritchie & Smith (1997) used carbon source utilization patterns of bacteria cultured from the mucus layer (aka: mucopolysaccharide layer, MPSL; coral surface microlayer, CMS) to demonstrate that Caribbean coral species had unique, species-specific mucus-associated microbial communities. Rohwer et al. (2001) built upon this work and used a 16S rDNA culture-independent method (PCR and denaturing gradient gel electrophoresis, DGGE) to demonstrate that Montastraea franksi had a diverse bacterial community that was similar in 25 samples from 5 reefs, up to 10 km apart. Comparison of coralassociated and overlaying water column bacterial communities in this study showed that there is almost no overlap . Similarly, Frias-Lopez et al. (2002) and Durkin et al. (unpubl.) found the bacteria in overlaying water were not the same as those associated with corals. Santavy (1995) observed that Porites astreoides harbors a bacterial species, possibly Moraxella sp., that forms ovoids within P. astreoides and seems to participate ...

Evidence for rapid, tide-related shifts in the microbiome of the coral Coelastrea aspera

“…(Smith and Douglas 1987), and many studies have focused on the 'shuffling' and 'switching' of algal types in response to changing thermal environments (van Oppen et al 2009). However, recently it has been recognized that, in addition to the algal symbionts, corals also host a highly diverse and specific microbiome which includes bacteria, archaea, fungi, protists and viruses (Rohwer et al 2002). Much less is known about this coral microbiome, particularly with respect to the dynamics of microbial partners through coral development (Thompson et al 2014), aging (Williams et al 2015) and their responses to changing environments (Morrow et al 2012;Hester et al 2015;Glasl et al 2016;Röthig et al 2016).…”

The impact of reduced pH on the microbial community of the coral Acropora eurystoma

“…Scleractinian corals, the primary framework builders of coral reefs, comprise a mutualistic interaction between the coral and a dinoflagellate of the genus Symbiodinium, and also contain diverse populations of microorganisms (Bacteria, Archaea, Eucarya and viruses) (Rohwer et al, 2001(Rohwer et al, , 2002Pantos et al, 2003;Kellogg, 2004;Ritchie and Smith, 2004;Bourne and Munn, 2005;Koren and Rosenberg, 2006) that have apparently co-evolved with the corals (Ritchie and Smith, 2004;Rohwer and Kelly, 2004). This has recently led to the idea that the host (coral animal) and its associated microorganisms should be considered as a holobiont (Rohwer et al, 2002;Rosenberg et al, 2007).…”

Bacterial diversity and White Plague Disease-associated community changes in the Caribbean coral Montastraea faveolata

“…Reef-building corals are associated with a dynamic, highly diverse consortium of microorganisms that includes protists, bacteria, archaea and endolithic algae and fungi (Shashar and Stambler, 1992;Bentis et al, 2000;Rohwer et al, 2002;Baker, 2003;Kellogg, 2004;Wegley et al, 2004;Rosenberg et al, 2007;Harel et al, 2008). To study the phylogenetic diversity of the bacterial and archaeal components, sequencing the 16S rRNA gene (16S rDNA) is commonly used because of its ability to identify the species without the need for laboratory cultivation.…”