Dominant coral bacterium Endozoicomonas acroporae metabolizes DMSP

Dominant coral associated Endozoicomonas bacteria species have been long hypothesized to play a role in the global sulfur cycle by metabolizing Dimethylsulfoniopropionate (DMSP) into Dimethylsulfide (DMS), which releases sulfur into the atmosphere; however, no sequenced genome to date harbors genes for this process. We assembled high-quality (>95 % complete) genomes of two new strains (Acr-1 and Acr-5) of a recently added species Endozoicomonas acroporae isolated from the coral Acropora muricata . We identified and functionally characterized the first DMSP lyase;a dddD gene homolog found in all E. acroporae , capable of metabolizing DMSP into DMS via the DddD cleavage pathway using RT-qPCR and GC. Comparative genomic analysis identified that Endozoicomonas has high genomic divergence and a high percentage oxidative stress responsive genes and that E. acroporae strains have the highest number of Type III secretion system genes (T3SS) in the genus. This study confirms the role of the genus Endozoicomonas in the global sulfur cycle.