Microbial functional structure of Montastraea faveolata, an important Caribbean reef‐building coral, differs between healthy and yellow‐band diseased colonies

Abstract

A functional gene array (FGA), GeoChip 2.0, was used to assess the biogeochemical cycling potential of microbial communities associated with healthy and Caribbean yellow band diseased (YBD) Montastraea faveolata. Over 6700 genes were detected, providing evidence that the coral microbiome contains a diverse community of archaea, bacteria and fungi capable of fulfilling numerous functional niches. These included carbon, nitrogen and sulfur cycling, metal homeostasis and resistance, and xenobiotic contaminant degradation. A significant difference in functional structure was found between healthy and YBD M. faveolata colonies and those differences were specific to the physical niche examined. In the surface mucopolysaccharide layer (SML), only two of 31 functional categories investigated, cellulose degradation and nitrification, revealed significant differences, implying a very specific change in microbial functional potential. Coral tissue slurry, on the other hand, revealed significant changes in 10 of the 31 categories, suggesting a more generalized shift in functional potential involving various aspects of nutrient cycling, metal transformations and contaminant degradation. This study is the first broad screening of functional genes in coral-associated microbial communities and provides insights regarding their biogeochemical cycling capacity in healthy and diseased states.

Coral transcriptome and bacterial community profiles reveal distinct Yellow Band Disease states inOrbicella faveolata

“…OTUs frequently found in diseased colonies were often related to bacteria that have been associated with fecal or gut communities. This evidence supported the idea that a healthy microbial community may be destabilized by high nutrients (Bruno et al, 2003;Kimes et al, 2010) and terrestrial run-off. Fluctuations in community structure could exacerbate YBD.…”

Coral reef invertebrate microbiomes correlate with the presence of photosymbionts

“…The diversity of microbial communities associated with corals and sponges is known to be influenced by host interactions (Wegley et al, 2007;Kimes et al, 2010;Raina et al, 2010;Fan et al, 2012), the production of antimicrobial compounds (Ritchie, 2006;Shnit-Orland and Kushmaro, 2009) and environmental conditions (Hong et al, 2009;Ceh et al, 2011). Recent studies, however, indicate that other members of the coral holobiont (in particular Symbiodinium dinoflagellates) also influence microbial community structure through release of complex carbon-containing exudates including dimethylsulfoniopropionate (DMSP; Ikeda and Miyachi, 1995;Raina et al, 2009Raina et al, , 2010.…”

Imaging the uptake of nitrogen-fixing bacteria into larvae of the coral Acropora millepora

“…Consequently, symbioses with nitrogen-fixing organisms (diazotrophs) that convert the abundant gas dinitrogen (N 2 ) into more usable forms like ammonium (NH 4 + ) provide important supplemental sources of nitrogen. Although evidence is mounting that nitrogen-fixing bacteria are associated with corals (Shashar et al, 1994;Lesser et al, 2004Lesser et al, , 2007Kvennefors and Roff 2009;Olson et al, 2009;Kimes et al, 2010;Lema et al, 2012;Santos et al, 2014;Lema et al, 2014a,b), to date the location of nitrogen-fixing bacteria within coral tissues and evidence that fixed nitrogen is available to corals or their endosymbiotic algae, Symbiodinium, remains elusive. Techniques such as nanoscale secondary ion mass spectrometry (NanoSIMS), which is able to map enriched stable isotope (for example, 13 C, 15 N and so on) tracers at the cellular scale, provides a powerful tool for co-locating diazotrophs within coral tissues.…”