Diversities of coral-associated bacteria differ with location, but not species, for three acroporid corals on the Great Barrier Reef

Abstract

Patterns in the diversity of bacterial communities associated with three species of Acropora (Acropora millepora, Acropora tenuis and Acropora valida) were compared at two locations (Magnetic Island and Orpheus Island) on the Great Barrier Reef to better understand the nature and specificity of coral-microbial symbioses. Three culture-independent techniques demonstrated consistent bacterial communities among replicate samples of each coral species, confirming that corals associate with specific microbiota. Profiles were also conserved among all three species of Acropora within each location, suggesting that closely related corals of the same genus harbor similar bacterial types. Bacterial community profiles of A. millepora at Orpheus Island were consistent in samples collected throughout the year, indicating a stable community despite temporal changes. However, DGGE and T-RFLP profiles differed on corals from different reefs. Nonmetric multidimensional scaling of T-RFLP profiles showed that samples grouped according to location rather than coral species. Although similar sequences were retrieved from clone libraries of corals at both Magnetic and Orpheus Island, differences in the relative dominant bacterial ribotypes within the libraries drive bacterial community structure at different geographical locations. These results indicate certain bacterial groups associated specifically with corals, but the dominant bacterial genera differ between geographically-spaced corals.

The dynamics of microbial partnerships in the coral Isopora palifera

“…Alphaproteobacteria and Gammaproteobacteria were the two constant predominant groups in I. palifera, as seen in previous observations on the coral Acropora (a coral genus closely related to Isopora) in the Great Barrier Reef (Hong et al, 2009;Littman et al, 2009). Both of these bacterial groups comprised 410% proportions of the bacterial communities in Acropora and I. palifera.…”

“…Environmental factors were considerable drivers of the structure of the coral-associated bacterial community, as also suggested by other studies Garren et al, 2009;Hong et al, 2009;Littman et al, 2009). Three factors (seawater temperature, sunlight intensity and rainfall) were available and included in this study in the association analysis with the bacterial groups.…”

“…Coral-associated bacteria are highly diverse (Rohwer et al, 2002) and their population compositions are affected by environmental factors such as geographic differences (Hong et al, 2009;Littman et al, 2009), seasonal changes Hong et al, 2009), coastal pollution (Klaus et al, 2007) and nutrient status (Garren et al, 2009). They potentially have functions relating to coral health, nutrition and disease (Reshef et al, 2006;Rosenberg et al, 2007;Wegley et al, 2007), but their definitive role remains unclear.…”

Investigating the Driving Mechanisms Behind Differences in Bleaching and Disease Susceptibility Between Two Scleractinian Corals, Pseudodiploria Strigosa and Diploria Labyrinthiformis

“…Coral are known to maintain distinct bacterial communities that vary among coral species and/or genera (Littman et al 2009). In the present study the NMDS plots reveal that the Winter bacterial communities of D. labyrinthiformis and P.…”

“…In addition to the protective physical properties, the SML also contains a microbial community that is crucial to the health of the coral (Bythell and Wild 2011). In the past ten years many studies have focused upon the composition and role of this microbial community Kellogg 2004;Bourne 2005;Guppy and Bythell et al 2006;Littman et al 2009;Shnit-Orland and Kushmaro 2009;Vega Thurber et al 2009;Meron et al 2011;Sweet et al 2011). This body of research has led to the development of the coral probiotic hypothesis, stating that coral-associated microbes may serve to protect their host based on their ability to rapidly evolve protection mechanisms .…”