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

Abstract

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.