Comparative genomics: Dominant coral bacterium Endozoicomonas acroporae metabolizes Dimethylsulfoniopropionate (DMSP)

Dominant coral-associated Endozoicomonas bacteria species are hypothesized to play a role in the coral-sulfur cycle by metabolizing Dimethylsulfoniopropionate (DMSP) into Dimethylsulfide (DMS); however, no sequenced genome to date harbors genes for this process. In this study, we assembled high-quality (>95% complete) genomes of strains of a recently added species Endozoicomonas acroporae (Acr-14T, Acr-1 and Acr-5) isolated from the coral Acropora muricata and performed comparative genomic analysis on genus Endozoicomonas. We identified the first DMSP CoA-transferase/lyase-a dddD gene homolog found in all E. acroporae strains and functionally characterized bacteria capable of metabolizing DMSP into DMS via the DddD cleavage pathway using RT-qPCR and gas chromatography (GC). Furthermore, we demonstrated that E. acroporae strains can use DMSP as the sole carbon source and have genes arranged in an operon like manner to link DMSP metabolism to the central carbon cycle. This study confirms the role of Endozoicomonas in the coral sulfur cycle.