Isolation of an antimicrobial compound produced by bacteria associated with reef-building corals.
Bacterial communities associated with healthy corals produce antimicrobial compounds that inhibit the colonization and growth of invasive microbes and potential pathogens. To date, however, bacteria-derived antimicrobial molecules have not been identified in reef-building corals. Here, we report the isolation of an antimicrobial compound produced by Pseudovibrio sp. P12, a common and abundant coral-associated bacterium. This strain was capable of metabolizing dimethylsulfoniopropionate (DMSP), a sulfur molecule produced in high concentrations by reef-building corals and playing a role in structuring their bacterial communities. Bioassay-guided fractionation coupled with nuclear magnetic resonance (NMR) and mass spectrometry (MS), identified the antimicrobial as tropodithietic acid (TDA), a sulfur-containing compound likely derived from DMSP catabolism. TDA was produced in large quantities by Pseudovibrio sp., and prevented the growth of two previously identified coral pathogens, Vibrio coralliilyticus and V. owensii, at very low concentrations (0.5 μg/mL) in agar diffusion assays. Genome sequencing of Pseudovibrio sp. P12 identified gene homologs likely involved in the metabolism of DMSP and production of TDA. These results provide additional evidence for the integral role of DMSP in structuring coral-associated bacterial communities and underline the potential of these DMSP-metabolizing microbes to contribute to coral disease prevention.
Climate Change Cluster (C3), University of Technology Sydney, Sydney, NSW, Australia; Australian Institute of Marine Science, Townsville, QLD, Australia; Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia; Marine Biology and Aquaculture, College of Science and Engineering, James Cook University of North Queensland, Townsville, QLD, Australia; AIMS@JCU, James Cook University, Townsville, QLD, Australia.
Jean-Baptiste
JB
Raina
Australian Institute of Marine Science , Townsville, QLD , Australia.
Dianne
D
Tapiolas
Australian Institute of Marine Science , Townsville, QLD , Australia.
Cherie A
CA
Motti
Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia; Research School of Biology, Australian National University, Canberra, ACT, Australia.
Sylvain
S
Foret
Victorian Life Sciences Computation Initiative, University of Melbourne , Melbourne, Victoria , Australia.
Torsten
0000-0001-6046-610X
T
Seemann
Section Chemical Ecology, Alfred Wegener Institute, Bremerhaven, Germany; University of New South Wales, Sydney, NSW, Australia.
Jan
J
Tebben
Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, Australia; Marine Biology and Aquaculture, College of Science and Engineering, James Cook University of North Queensland, Townsville, QLD, Australia.
Bette L
BL
Willis
Australian Institute of Marine Science, Townsville, QLD, Australia; Marine Biology and Aquaculture, College of Science and Engineering, James Cook University of North Queensland, Townsville, QLD, Australia.
David G
DG
Bourne
Alphaproteobacteria; Antimicrobial compounds; Coral-associated bacteria; Disease