The microbial making and breaking of dimethylsulfoniopropionate and related compounds

Dimethylsulfoniopropionate (DMSP) is one of Earth’s most abundant organosulfur compounds, made by marine algae, bacteria, corals and plants to cope with diverse environmental stressors and predation. Once released into the environment, DMSP serves as a widespread signalling molecule and a source of carbon, sulfur and/or energy for marine organisms. Diverse organisms can also produce a suite of DMSP-related compounds (DRCs) with important biological roles and environmental impacts, including the climate-cooling gases dimethylsulfide and methanethiol (MeSH) that are generated through microbial DMSP catabolism or H2S/MeSH S-methylation. This Review reports the current understanding of DMSP and DRC biosynthesis and catabolism, emphasizing recent discoveries that challenged common beliefs on their sources and fates. It explores the biodiversity, regulation and importance of the genes and pathways that drive the production, import and degradation of these sulfur compounds. Finally, it highlights current challenges and priority areas to guide future DMSP and DRC research. This Review reports the current understanding of the microbially mediated dimethylsulfoniopropionate cycle—the biodiversity, regulation and importance of genes and pathways that impact this sulfur compound.