Exploring the microbial diversity associated with coral reef environments.

1. Exploring the microbial diversity associated with
coral reef environments. -Zeenat Tinwala
1072448
April 10th 2013

2. What is a coral reef?
 Most biologically diverse ecosystems
 Not only of hard and soft corals
 Fluctuations - alter both the diversity and abundances of others
 Water filtration and fish reproduction to shore line protection and erosion
prevention.
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3. Locations
 Great Barrier Reef—largest-off Queensland, Australia
 Mesoamerican Barrier Reef System—second largest
 New Caledonia Barrier Reef—second longest double barrier reef
http://www.nasa.gov/vision/earth/lookingatearth/coralreef_image.html 3

4. Biodiversity
 World's most productive ecosystems (Barnes et al., 1991)
 Fish, seabirds, sponges, cnidarians, worms, crustaceans, mollusks,
echinoderms, sea squirts, sea turtles and sea snakes
 Mutually beneficial relationship with a microscopic unicellular
 Reefs are chronically at risk of algal encroachment. (Glynn, 1990)
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5. Microbial Diversity
 Coral-algal symbiosis but little is known about other microbes
 Microbial assemblage/ Coral holobiont
 The microbial community fluctuate along seasonal and biogeographic ranges
 Roles that microorganisms play in coral physiology and immune function -
unknown
 Beneficial microbial assemblages - Antibiotics
 Detecting when and why shifts occur in healthy coral-microbial assemblages is
to a large extent unknown.
(Morrow, et al., 2012)
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6. (Ainsworth, Thurber, & Gates, 2010)
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7. Targeted goals of research
 Understand the microbial communities
 Change through time – Key to understand health of coral reefs
 Same species - different locations - distinct microbial communities
 Whether macroalgal extracts cause a detectable stress response in coral tissues
and/or a shift in coral-associated bacterial assemblages.
(Morrow, Ritson-Williams, Ross, Liles, & Paul, 2012)
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8. Methods used
 PCR amplification of 16S ribosomal gene
 DGGE analysis
 T-RFLP Terminal Restriction Fragment Length Polymorphism
 R-Project
 SSCP Single Stranded Conformation Polymorphism
 nMDS – Non-metric multidimensional scaling plot
 Sequence Analysis
 CHECK_CHIMERA
 CLUSTALX
 PAUP
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9. (Ainsworth, Thurber, & Gates, 2010)
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10. Characterization of microbial
community function
 Phylogenetic markers
 Example: cyanobacteria Prochlorococcus strains- almost identical 16S
sequences (97% similarity), but differ physiologically
 Vibrio splendidus - 70% of the 206 strains that make up a single Vibrio
splendidus ribotype cluster have differences in genome size even though the 16S
genes of these strains are <1% divergent
(Rocap, G.et al. 2003)
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11. Factors influencing Coral-Microbe
interaction
(Sokolow, 2009)
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12. Exploring a few locations
 Caribbean and Indo-Pacific Reefs
 Great Barrier Reef
 South China Sea
 Ningaloo Reef
© Gary Bell/Oceanwidelmages.com
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13. Caribbean & Indo-Pacific Reefs
 Dominant component of Black Band Disease (BBD)- cyanobacteria –
Phormidium corallyticum
 These cyanobacteria belong to at least 3 different taxa, the corals in each case
exhibit similar signs and patterns of BBD mat development.
 Environmental factors that lead to the development of BBD- Unknown
 The genetic diversity among the cyanobacteria that are part of the BBD mat -
help explain why BBD has been observed under many different environmental
conditions.
 Macroalgae both stimulated and inhibited coral reef-associated bacterial
cultures.
(Frias-Lopez, Bonheyo, Jin, & Fouke, 2003; Morrow KM, Paul VJ, Liles MR, 2011)
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14. Great Barrier Reef
 3 species of Acropora were compared at two locations (Magnetic Island and Orpheus
Island)
 Sequences from duplicate clone libraries of each species were consistent
 Gammaproteobacteria - Dominant
 Alphaproteobacteria
 Deltaproteobacteria
 Oculina patagonicain - infection with the bacterium Vibrio shiloi - Seasonal bleaching
Vibrio coralliilyticus - aetiological agent of bleaching and tissue lysis in Pocillopora
damicornis
 Vibro shiloi and Vibrio coralliilyticus have been confirmed as coral bleaching pathogens
(Banin et al., 2000; Ben-Haim and Rosenberg, 2002; Rosenberg and Ben-Haim, 2002)
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15. South China Sea
 5 species of gorgonian corals
collected in shallow waters.
 123 actinobacterial isolates were
recovered using 10 different isolation
media, and assigned to 11 genera
Streptomyces and Micromonospora -
dominant genera
 Actinobacteria could protect their
hosts against marine pathogens.
(Zhang et al., 2013)
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16. Ningaloo Reef
Effect of heat stress on coral-associated bacterial, Acropora tenuis, hosting
different Symbiodinium types
 Increase in the number of retrieved Vibrio affiliated sequences, these
sequences affiliated most closely with the coral pathogen, Vibrio coralliilyticus
 Thermal stress - shifts in coral-associated bacterial communities - deteriorating
coral health.
 Bacterial 16S rRNA clone were highly diverse, though dominated by a- and c-
Proteobacteria
 Responses of coral-associated bacterial communities exposed to heat stress can
differ for juvenile corals hosting different Symbiodinium partners.
Littman, Bourne, & Willis, 2010)
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17. Future directions
 Understand the role of specific microbial species in biogeochemical cycles.
Metagenomic and qPCR-based approaches combined with culture-independent
technologies such as single-cell genomics.
High-resolution fluorescent in situ hybridization and scanning electron
microscopy - where and when microbial species are established in host corals.
 Phase-shifts to alternative dominants that may have potent biochemical
defence mechanisms - what effect this will have on overall reef health and
physiology.
(Morrow, Ritson-Williams, Ross, Liles, & Paul, 2012)
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18. Refernces
Ainsworth, T. D., Thurber, R. V., & Gates, R. D. (2010). The future of coral reefs: a microbial
perspective. Trends Ecol Evol, 25(4), 233-240. doi: 10.1016/j.tree.2009.11.001
Frias-Lopez, J., Bonheyo, G. T., Jin, Q., & Fouke, B. W. (2003). Cyanobacteria associated with coral
black band disease in Caribbean and Indo-Pacific Reefs. Appl Environ Microbiol, 69(4), 2409-2413.
Littman, R. A., Bourne, D. G., & Willis, B. L. (2010). Responses of coral-associated bacterial
communities to heat stress differ with Symbiodinium type on the same coral host. Mol Ecol, 19(9),
1978-1990. doi: 10.1111/j.1365-294X.2010.04620.x
Morrow, K. M., Ritson-Williams, R., Ross, C., Liles, M. R., & Paul, V. J. (2012). Macroalgal extracts
induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals. PLoS One, 7(9),
e44859. doi: 10.1371/journal.pone.0044859
Sokolow, S. (2009). Effects of a changing climate on the dynamics of coral infectious disease: a review
of the evidence. Dis Aquat Organ, 87(1-2), 5-18. doi: 10.3354/dao02099
Zhang, X. Y., He, F., Wang, G. H., Bao, J., Xu, X. Y., & Qi, S. H. (2013). Diversity and antibacterial activity
of culturable actinobacteria isolated from five species of the South China Sea gorgonian corals. World
J Microbiol Biotechnol. doi: 10.1007/s11274-013-1279-3
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19. Banin, E., Israely, T., Kusmaro, A., Loya, Y., Orr, E., and Rosenberg, E. (2000) Penetration of the
coral-bleaching bacterium Vibrio shiloiinto Oculina patgonica. Appl Envi-ron Microbiol 66: 3031–
3036.
Banin, E., Israely, T., Fine, M., Loya, Y., and Rosenberg, E. (2001a) Role of endosymbiotic
zooxanthellae and coral mucus in the adhesion of the coral-bleaching pathogen Vibrio shiloito its
host. FEMS Microbiol Lett 199: 33–37.
Ben-Haim, Y., and Rosenberg, E. (2002) A novel Vibriosp. pathogen of the coral Pocillopora
damicornis. Mar Biol 141:47–55.
Barnes, R.S.K., and Mann, K.H. (1991). Fundamentals of Aquatic Ecology. Blackwell Publishing.
pp. 217–227. ISBN 0-632-02983-8. Retrieved November 26, 2008.
Glynn, P.W. (1990). In Dubinsky, Z. Ecosystems of the World v. 25-Coral Reefs. New York, NY:
Elsevier Science.
Rocap, G.et al. (2003) Genome divergence in two Prochlorococcus ecotypes reflects oceanic
niche differentiation.Nature424, 1042–1047
Morrow KM, Paul VJ, Liles MR, Chadwick NE (2011) Allelochemicals produced by Caribbean
macroalgae and cyanobacteria have species-specific effects on reef coral microorganisms. Coral
Reefs 30: 309–320.
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20. Thank you!!
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21. Questions?
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