Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

The role of microorganisms in coral health, disease and evolution

Key Points

  • Scleractinian (hard) corals live in close association with abundant and diverse microorganisms. Different groups of microorganisms are present in the mucus surface layer, skeleton and tissues.

  • These symbiotic microorganisms benefit their host by various mechanisms, including photosynthesis, nitrogen fixation, digestion of complex nutrients and prevention of infections by pathogens. Conversely, under environmental stress conditions, certain microorganisms can cause coral bleaching and other diseases.

  • Climate change, water pollution and over-fishing are the three most frequently cited environmental stress factors participating in the rise of infectious diseases of coral. Recent studies have provided direct experimental evidence demonstrating how each of these factors contribute to microbial induced coral disease.

  • In the case of the best-studied coral disease, bleaching of Oculina patagonica by Vibrio shiloi, many of the virulence mechanisms have been shown to be induced by elevated temperature.

  • In the past five years, O. patagonica has become resistant to V. shiloi infection. To explain this finding, the coral probiotic hypothesis has been presented, which posits that a dynamic relationship exists between symbiotic microorganisms and corals at different environmental conditions, bringing about a selection for the most advantageous coral holobiont.

  • Generalization of the coral probiotic hypothesis has led us to propose the hologenome theory of evolution. This theory proposes that microorganisms have an important role in the evolution of animals and plants.

Abstract

Coral microbiology is an emerging field, driven largely by a desire to understand, and ultimately prevent, the worldwide destruction of coral reefs. The mucus layer, skeleton and tissues of healthy corals all contain large populations of eukaryotic algae, bacteria and archaea. These microorganisms confer benefits to their host by various mechanisms, including photosynthesis, nitrogen fixation, the provision of nutrients and infection prevention. Conversely, in conditions of environmental stress, certain microorganisms cause coral bleaching and other diseases. Recent research indicates that corals can develop resistance to specific pathogens and adapt to higher environmental temperatures. To explain these findings the coral probiotic hypothesis proposes the occurrence of a dynamic relationship between symbiotic microorganisms and corals that selects for the coral holobiont that is best suited for the prevailing environmental conditions. Generalization of the coral probiotic hypothesis has led us to propose the hologenome theory of evolution.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: The structure of coral tissue.
Figure 2: Infectious diseases of coral.
Figure 3: Infection of the coral Oculina patagonica by Vibrio shiloi.
Figure 4: Coral resistance to Vibrio shiloi infection.

References

  1. Sebens, K. Biodiversity of coral reefs: what are we losing and why? Amer. Zool. 34, 115–133 (1994).

    Article  Google Scholar 

  2. Costanza, et al. The value of the world's ecosystem services and natural capital. Nature 387, 253–260 (1997).

    CAS  Article  Google Scholar 

  3. Bourne, D. G. & Munn, C. B. Diversity of bacteria associated with the coral Pocillopora damicornis from the Great Barrier Reef. Environ. Microbiol. 7, 1162–1174 (2005).

    CAS  PubMed  Article  Google Scholar 

  4. Koren, O. & Rosenberg, E. Bacteria associated with mucus and tissues of the coral Oculina patagonica in summer and winter. Appl. Environ. Microbiol. 72, 5254–5259 (2006).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  5. Pantos, et al. The bacterial ecology of a plague-like disease affecting the Caribbean coral Montastraea annularis. Environ. Microbiol. 5, 370–382 (2003).

    CAS  PubMed  Article  Google Scholar 

  6. Ritchie, K. B. & Smith, G. W. in Coral Health and Disease (eds Rosenberg, E. & Loya, Y.) 259–264 (Springer, Berlin, New York, 2004).

    Book  Google Scholar 

  7. Rohwer, F., Breitbart, M., Jara, J., Azam, F. & Knowlton, N. Diversity of bacteria associated with the Caribbean coral Montastraea franksi. Coral Reefs 20, 85–91 (2001).

    Article  Google Scholar 

  8. Rohwer, F., Seguritan, V., Azam, F. & Knowlton, N. Diversity and distribution of coral-associated bacteria. Mar. Ecol. Prog. Ser. 243, 1–10 (2002).

    Article  Google Scholar 

  9. Kellogg, C. A Tropical Archaea: diversity associated with the surface microlayer of corals. Mar. Ecol. Progr. Ser. 273, 81–88 (2004).

    CAS  Article  Google Scholar 

  10. Rohwer, F & Kelly, S. in Coral Health and Disease (eds Rosenberg, E. & Loya, Y.) 265–277 (Springer, Berlin, New York, 2004).

    Book  Google Scholar 

  11. Brandt, K. Über die morphologische und physiologische Bedeutung des Chlorophylls bei Tieren. Mitt Zool Stat Neapol 4, 191 (1883).

    Google Scholar 

  12. Klebbs, G. Ein kleiner Beitrag zur Kenntnis der Peridineen. Bot. Z. 10, 46–47 (1884).

    Google Scholar 

  13. Taylor, D. L. in Symbiosis and the Sea (ed. Vernberg, C. B. W.) 245–262 (Univ. South Carolina Press, Columbia, 1974).

    Google Scholar 

  14. Pawlowski, J., Holzmann, M., Fahrni, J. F., Pochon, X. & Lee, J. J. Molecular identification of algal endosymbionts in large miliolid foraminifera: 2. Dinoflagellates. J. Eukaryot. Microbiol. 48, 368–373 (2001).

    CAS  PubMed  Article  Google Scholar 

  15. Pochon, X., Pawlowski, J., Zaninetti, L. & Rowan, R. High genetic diversity and relative specificity among Symbiodinium-like endosymbiotic dinoflagellates in soritid foraminiferans. Mar. Biol. 139, 1069–1078 (2001).

    Article  Google Scholar 

  16. Baker, A. C. Flexibility and specificity in coral–algal symbiosis: diversity, ecology and biogeography of Symbiodinium. Ann. Rev. Ecol. Syst. 34, 661–689 (2003).

    Article  Google Scholar 

  17. Baker, A. C. in Coral Health and Disease. (eds Roseberg, E. & Loya, Y.) 177–194 (Springer, Berlin, New York, 2004).

    Book  Google Scholar 

  18. Fallowski, P. G., Dubinsky, Z., Muscatine, L. & Porter, J. W. Light and the bioenergetics of a symbiotic coral. Bioscience 34, 705–709 (1984).

    Article  Google Scholar 

  19. Muscatine, L. in Coral Reefs: Ecosystems of the World (eds Goodall, D. W. & Dubinsky, Z.) 25, 75–87 (Elsevier, Amsterdam, 1990).

    Google Scholar 

  20. Kühl, M., Cohen, Y., Tage, D., Jorgensen, B. & Revsbech, B. Microenvironment and photosynthesis of zooxanthellae in scelcatinian corals studied with microsensors for O2, pH and light. Mar. Ecol. Prog. Ser. 117, 159–172 (1995).

    Article  Google Scholar 

  21. Banin, E., Vassilakos, D., Orr, E., Martinez, R. J. & Rosenberg, E. Superoxide dismutase is a virulence factor produced by the coral bleaching pathogen Vibrio shiloi. Curr. Microbiol. 46, 418–422 (2003).

    CAS  PubMed  Article  Google Scholar 

  22. Rowan, R. & Knowlton, N. Intraspecific diversity and ecological zonation in coral-algal symbiosis. Proc. Natl Acad. Sci. USA 92, 2850–2853 (1995).

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  23. Baker, A. C. & Rowan, R. Diversity of symbiotic dinoflagaellates (zooxanthellae) in scleractinian corals of the Caribbean and eastern Pacific. Proc. 8th Int. Coral Reef Symp. Panama 2, 1301–1305 (1997).

    CAS  Google Scholar 

  24. Baker, A. C. Reef corals bleach to survive change. Nature 411, 765–766 (2001).

    CAS  PubMed  Article  Google Scholar 

  25. LaJeunesse, T. C. et al. Low symbiont diversity in southern Great Barrier Reef corals relative to those of the Caribbean. Limnol. Oceanogr. 48, 2046–2054 (2003).

    Article  Google Scholar 

  26. Ducklow, H. W. & Mitchel, R. Bacterial populations and adaptations in the mucus layers on living corals. Limnol. Oceanogr. 24, 715–725 (1979).

    Article  Google Scholar 

  27. Shashar, N., Cohen, Y., Loya, Y. & Sar, N. Nitrogen fixation (acetylene reduction) in stony corals: evidence for coral–bacteria interactions. Mar. Ecol. Prog. Ser. 111, 259–264 (1994).

    CAS  Article  Google Scholar 

  28. Ritchie, K. B. & Smith, W. G. Carbon-source utilization of coral-associated marine heterotrophs. J. Mar. Biotechnol. 3, 107–109 (1995).

    Google Scholar 

  29. Ritchie, K. B. & Smith, W. G. Physiological comparisons of bacterial communities from various species of scleractinian corals. Proc. 8th Int. Coral Reef Symp. 1, 521–526 (1997).

    Google Scholar 

  30. Williams, V. M., Viner, A. B. & Broughton, W. L. Nitrogen fixation (acetylene reduction) associated with the living coral Acropora variabilis. Mar. Biol. 94, 531–535 (1987).

    Article  Google Scholar 

  31. Lesser, M. P., Mazel, C. H., Gorbunov, M. Y. & Falkowski, P. G. Discovery of symbiotic nitrogen-fixing cyanobacteria in corals. Science 305, 997–1000 (2004).

    CAS  PubMed  Article  Google Scholar 

  32. Brown, B. E. & Bythell, J. C. Perspectives on mucus secretion in reef corals. Mar. Ecol. Progr. Ser. 296, 291–309 (2005).

    CAS  Article  Google Scholar 

  33. Ferrer, L. M. & Szmant, A. M. Nutrient regeneration by the endolithic community in coral skeletons. Proc. 6th Int. Coral Reef Symp. Australia 3, 1–4 (1988).

    Google Scholar 

  34. Fine, M. & Loya, Y. Endolithic algae — an alternative source of energy during coral bleaching. Proc. R. Soc. Lond. B 269, 1205–1210 (2002).

    Article  Google Scholar 

  35. Shlicther, D, Zscharnach, H. & Krisch, H. Transfer of photoassimilates from endolithic algae to coral tissue. Naturwissenschaften 82, 561–564 (1995).

    Article  Google Scholar 

  36. Webster, et al. Metamorphosis of a scleractinian coral in response to microbial biofilms. Appl. Environ. Microbiol. 70, 1213–1221 (2004).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  37. Wegley, et al. Coral-associated Archaea. Mar. Ecol. Prog. Ser. 273, 89–96 (2004).

    CAS  Article  Google Scholar 

  38. Davy, et al. Viruses: agents of coral disease? Dis. Aquat. Org. 69, 101–110 (2006).

    CAS  Article  Google Scholar 

  39. Hughes, T. P. et al. Climate change, human impacts, and the resilience of coral reefs. Science 301, 929–933 (2003).

    CAS  PubMed  Article  Google Scholar 

  40. Goreau, T. J., Hayes, R. L. & Strong, A. E. Tracking South Pacific coral reef bleaching by satellite and field observations. Proc. 8th Int. Coral Reef Symp. 2, 1491–1494 (1997).

    Google Scholar 

  41. Hayes, R. L. & Goreau, N. I. The significance of emerging diseases in the tropical coral reef ecosystem. Revista de Biological Tropical 46, 173–185 (1998).

    Google Scholar 

  42. Hoegh-Guldberg, O. Climate change, coral bleaching and the future of the world's coral reefs. Mar. Freshwater Res. 50, 839–866 (1999).

    Article  Google Scholar 

  43. Kushmaro, A., Loya, Y., Fine, M. & Rosenberg, E. Bacterial infection and coral bleaching. Nature 380, 396 (1996).

    CAS  Article  Google Scholar 

  44. Kushmaro, A., Rosenberg, E., Fine, M. & Loya, Y. Bleaching of the coral Oculina patagonica by Vibrio AK-1. Mar. Ecol. Prog. Ser. 147, 159–165 (1997).

    Article  Google Scholar 

  45. Ben-Haim Y, Rosenberg, E. A novel Vibrio sp. pathogen of the coral Pocillopora damicornis. Mar. Biol. 141, 47–55 (2002).

    Article  Google Scholar 

  46. Ben-Haim, Y., Zicherman-Keren, M. & Rosenberg, E. Temperature-regulated bleaching and lysis of the coral Pocillopora damicornis by the novel pathogen Vibrio coralliilyticus. Appl. Envir. Microbiol. 69, 4236–4242 (2003).

    CAS  Article  Google Scholar 

  47. Fine, M. & Loya. Y. The coral Oculina patagonica: a new immigrant to the Mediterranean coast of Israel. Isr. J. Zool. 41, 81 (1995).

    Google Scholar 

  48. Kushmaro, A., Rosenberg, E., Fine, M., Ben-Haim, Y. & Loya, Y. Effect of temperature on bleaching of the coral Oculina patagonica by Vibrio shiloi AK-1. Mar. Ecol. Prog. Ser. 171, 131–137 (1998).

    Article  Google Scholar 

  49. Rosenberg, E. & Falkowitz, L. The Vibrio shiloi/Oculina patagonica model system of coral bleaching. Ann. Rev. Microbiol. 58, 143–159 (2004).

    CAS  Article  Google Scholar 

  50. Ritchie, K. B., Dennis, J. H., McGrath, T. & Smith, G. W. Bacteria associated with bleached and non-bleached areas of Montastraea annularis. Proc. Symp. Nat. Hist. Bahamas 5, 75–80 (1994).

    Google Scholar 

  51. Harvell, et al. Climate and disease risks for terrestrial and marine biota. Science 296, 2158–2162 (2002).

    CAS  PubMed  Article  Google Scholar 

  52. Szmant, A. M. Nutrient enrichment on coral reefs: is it a major cause of coral reef decline? Estuaries 25, 743–766 (2002).

    CAS  Article  Google Scholar 

  53. Jackson, et al. Historical over-fishing and the recent collapse of coastal ecosystems. Science 293, 629–637 (2001).

    CAS  PubMed  Article  Google Scholar 

  54. Intergovernmental Panel on Climate Change (IPCC). Climate change 2001: IPCC third assessment report. IPCC web site [online], (2001).

  55. Toren, A., Landau, L., Kushmaro, A., Loya, Y. & Rosenberg, E. Effect of temperature on adhesion of Vibrio strain AK-1 to Oculina patagonica and on coral bleaching. Appl. Environ. Microb. 64, 1379–1384 (1998).

    CAS  Google Scholar 

  56. Banin, E., Sanjay, K. H., Naider, F. & Rosenberg, E. Proline-rich peptide from the coral pathogen Vibrio shiloi that inhibits photosynthesis of zooxanthellae. Appl. Environ. Microbiol. 67, 1536–1541 (2001).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  57. Bruno, J. F., Petes, L. E., Harvell, C. D. & Hettinger, A. Nurtient enrichment can increase the severity of coral diseases. Ecol. Lett. 6, 1056–1061 (2003).

    Article  Google Scholar 

  58. Kline, D. I., Kuntz, N. M., Breitbart, M., Knowlton, N. & Rohwer, F. Role of elevated organic carbon levels and microbial activity in coral mortality. Mar. Ecol. Prog. Ser. 314, 119–125 (2006).

    CAS  Article  Google Scholar 

  59. McCook, L. J., Jompa, J. & Diaz-Pulido, G. Competition between corals and algae on coral reefs: a review of evidence and mechanisms. Coral Reefs 19, 400–417 (2001).

    Article  Google Scholar 

  60. Smith, et al. Indirect effects of algae on coral: algae-mediated, microbe-induced coral mortality. Ecol. Lett. 9, 835–845 (2006).

    PubMed  Article  Google Scholar 

  61. Reshef, L., Koren, O., Loya, Y., Zilber-Rosenberg, I. & Rosenberg, E. The coral probiotic hypothesis. Environ. Microbiol. 8, 2068–2073 (2006).

    CAS  PubMed  Article  Google Scholar 

  62. Mullen, K. M., Peters, E. C & Harvell, C. D. in Coral Health and Disease (eds Rosenberg, E. & Loya, Y.) 377–399 (Springer, Berlin, New York, 2004).

    Book  Google Scholar 

  63. Koh, E. G. L. Do scleractinian corals engage in chemical warfare against microbes? J. Chem. Ecol. 23, 379–398 (1997).

    CAS  Article  Google Scholar 

  64. Castillo, I., Lodeiros, C., Nunez, M. & Campos, I. In vitro study of antibacterial substances produced by bacteria associated with various marine organisms. Rev. Biol. Trop. 49, 1213–1221 (2001).

    CAS  PubMed  Google Scholar 

  65. Ritchie, K. B. Regulation of microbial populations by coral surface mucus and mucus-associated bacteria. Mar. Ecol. Prog. Ser. 322, 1–14 (2006).

    CAS  Article  Google Scholar 

  66. Geffen, Y. & Rosenberg E. Stress-induced rapid release of antibacterials by scleractinian corals. Mar. Biol. 146, 931–935 (2005).

    Article  Google Scholar 

  67. Denner, et al. Aurantimonas coralicida gen. nov., sp. nov., the causative agent of white plague type II on Caribbean scleractinian corals. Int. J. Syst. Evol. Microbiol. 53, 1115–1122 (2003).

    CAS  PubMed  Article  Google Scholar 

  68. Richardson, L. L. & Aronson, R. B. Infectious diseases of reef corals. Proc. 9th Intl. Coral Reef Symp. Indonesia 2, 1225–1230 (2002).

    Google Scholar 

  69. Brown, B. E., Dunne, R. P., Goodson, M. S. & Douglas, A. E. Marine ecology — bleaching patterns in reef corals. Nature 404, 142–143 (2000).

    CAS  PubMed  Article  Google Scholar 

  70. Rohwer, F., Breitbart, M., Jara, J., Azam, F. & Knowlton, K. Diversity of bacteria associated with the Caribbean coral Montastraea franksi. Coral Reefs 20, 85–91 (2001).

    Article  Google Scholar 

  71. Martin-Laurent, et al. DNA extraction from soils: old bias for new microbial diversity analysis methods. Appl. Environ. Microbiol. 67, 2354–2359 (2001).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  72. Polz, M. F. & Cavanaugh, C. M. Bias in template-to-product ratios in multi-template PCR. Appl. Environ. Microbiol. 64, 3724–3730 (1998).

    CAS  PubMed  PubMed Central  Google Scholar 

  73. Forney, L., Zhou, X. & Brown. C. J. Molecular microbial ecology: land of the one-eyed king. Curr. Opin. Microbiol. 7, 210–220 (2004).

    CAS  PubMed  Article  Google Scholar 

  74. Frias-Lopez, J., Zerkle, A. L., Bonheyo, G. T. & Fouke, B. W. Partitioning of bacterial communities between seawater and healthy, black band diseased, and dead coral surfaces. Appl. Environ. Microbiol. 68, 2214–2228 (2002).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  75. Cooney, V. et al. Characterization of the bacterial consortium associated with black band disease in coral using molecular microbiological techniques. Environ. Microbiol. 4, 401–413 (2002).

    PubMed  Article  Google Scholar 

  76. Sekar, R., Mills, D. K., Remily, E. R., Voss, J. D. & Richardson, L. L. Microbial communities in the surface mucopolysaccharide layer and the black band microbial mat of black band-diseased Siderastrea siderea. Appl. Environ. Microbiol. 72, 5963–5973 (2006).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  77. Casas, V. et al. Widespread association of a Rickettsiales-like bacterium with reef-building corals. Environ. Microbiol. 6, 1137–1148 (2004).

    PubMed  Article  Google Scholar 

  78. Banin, E., Israely, T., Fine, M., Loya, Y. & Rosenberg, E. Role of endosymbiotic zooxanthellae and coral mucus in the adhesion of the coral-bleaching pathogen Vibrio shiloi to its host. FEMS Microbiol. Lett. 199, 33–37 (2001).

    CAS  PubMed  Article  Google Scholar 

  79. Banin, E. et al. Penetration of the coral-bleaching bacterium Vibrio shiloi into Oculina patagonica. Appl. Environ. Microbiol. 66, 3031–3036 (2000).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  80. Ben-Haim, Y., Banin, E., Kushmaro, A., Loya, Y. & Rosenberg, E. Inhibition of photosynthesis and bleaching of zooxanthellae by the coral pathogen Vibrio shiloi. Environ. Microbiol. 1, 223–229 (1999).

    CAS  PubMed  Article  Google Scholar 

  81. Israely, T., Banin, E. & Rosenberg, E. Growth, differentiation and death of Vibrio shiloi in coral tissue as a function of seawater temperature. Aquat. Microb. Ecol. 24, 1–8 (2001).

    Article  Google Scholar 

  82. Sussman, M., Loya, Y., Fine, M. & Rosenberg, E. The marine fireworm Hermodice carunculata is a winter reservior and spring-summer vector for the coral-bleaching pathogen Vibrio shiloi. Environ. Microbiol. 5, 250–255 (2003).

    PubMed  Article  Google Scholar 

  83. Smith, G. W., Ives, L. D., Nagelkerken, I. A. & Ritchie K. B. Caribbean sea fan mortalities. Nature 383, 487 (1996).

    CAS  Article  Google Scholar 

  84. Geiser, D. M. Taylor, J. W., Fitchie, K. B. & Smith, G. W. Cause of sea fan death in the West Indies. Nature 394, 137–138 (1998).

    CAS  Article  Google Scholar 

  85. Jokiel, P. L. & Coles S. L. Response of Hawaiian and other Indo Pacific reef corals to elevated temperatures. Coral Reefs 8, 155–162 (1990).

    Article  Google Scholar 

  86. Ritchie, K. B. & Smith, G. W. Preferential carbon utilization by surface bacterial communities from water mass, normal and white-band diseased Acropora cervicornis. Mol. Mar. Biol. Biotechnol. 4, 345–352 (1995).

    CAS  Google Scholar 

  87. Barash, Y., Sulam, R., Loya, Y. & Rosenberg, E. Bacterial strain BA-3 and a filterable factor cause a white plague-like disease in corals from the Eilat coral reef. Aquat. Microb. Ecol. 40, 183–189 (2005).

    Article  Google Scholar 

  88. Thompson, et al. Thalassomonas loyana sp. nov., a causative agent of the white plague-like disease of corals on the Eilat coral reef. Int. J. Syst. Evol. Microbiol. 56, 365–368 (2006).

    CAS  PubMed  Article  Google Scholar 

  89. Patterson, et al. The etiology of white pox a lethal disease of the Caribbean elkhorn coral, Acropora palmata. Proc. Natl Acad. Sci. USA 99, 8725–8730 (2002).

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  90. Cervino, et al. Relationship of Vibrio species infection and elevated temperatures to yellow blotch/band disease in Caribbean corals. Appl. Environ. Microbiol. 70, 6855–6864 (2004).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  91. Richardson, L. L. in Coral Health and Disease (eds Rosenberg, E. & Loya, Y.) 325–336 (Springer, Berlin, New York, 2004).

    Book  Google Scholar 

Download references

Acknowledgements

This research was supported by funds provided by the Israel Center for the Study of Emerging Diseases and the Coral Reef Targeted Research Program (CRTR). The CRTR is a partnership between the Global Environment Facility, the World Bank, the University of Queensland, NOAA and research institutions.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Eugene Rosenberg.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Related links

Related links

FURTHER INFORMATION

Eugene Rosenberg's homepage

CORIS major reef-building coral diseases homepage

CRC reef research centre homepage

Global coral disease database

Khaled bin sultan living oceans foundation web site

NOAA coral health and monitoring program

Reefbase web site

Reef relief web site

The coral disease homepage

Glossary

Scleractinian coral

Scleractinian, stony or hard corals as they are often referred to, are animals that are responsible for building coral reefs.

Mutualistic interaction

A close ecological relationship, between two (or more) species, from which both species benefit.

Symbiodinium

(Gr. Symbion living together and Gr. dinos whirling). A genus of dinoflagellate algae. It is the dominant genus of algal symbiont in reef-building corals.

Surface mucus layer

A chemically complex viscoelastic gel layer that surrounds coral. Much of the mucus originates from zooxanthellae. It is secreted from epidermal mucus cells and subsequently modified by resident microorganisms.

Holobiont

The host organism and all of its associated symbiotic microorganisms.

Oxygen radical

An atom or group of atoms that have one or more unpaired electrons. A prominent feature of radicals is that they have extremely high chemical reactivity.

SYBR gold staining

A technique for counting bacteria and viruses in environmental samples. Particles that contain either DNA or RNA emit a bright and stable yellow-green fluorescence that can be enumerated by epifluorescence microscopy.

Endolithic community

A group of organisms that live inside the pore space of rocks, in this case the space within the coral skeleton.

Coral bleaching

The whitening of corals due to the loss of their symbiotic zooxanthellae or the pigments associated with the algae.

Koch's postulates

The four criteria designed to establish a causal relationship between an infecting microorganism and a disease.

Heterotrophic bacteria

Microorganisms that use organic molecules as their main source of carbon and energy.

Alleopathy

The harmful effect of one organism to another caused by the release of chemical compounds.

Viable-but-not-culturable (VBNC) state

When in this state, bacteria can no longer grow and form colonies on conventional culture media, but they show metabolic activity, maintain pathogenicity and, in some cases, return to active growth under appropriate conditions.

Hologenome

The combined genomes of the holobiont.

Commensalism

A symbiosis in which one organism is benefited and the other is neither benefited nor harmed.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Rosenberg, E., Koren, O., Reshef, L. et al. The role of microorganisms in coral health, disease and evolution. Nat Rev Microbiol 5, 355–362 (2007). https://doi.org/10.1038/nrmicro1635

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nrmicro1635

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing