Marine Roseobacter Clade Bacteria Decelerate the Conversion of Dimethylsulfoniopropionate under Ocean Acidification

Ocean acidification has been an alarming issue that is jeopardizing the marine environment and ecology. Marine Roseobacter clade bacteria mediate important biogeochemical cycles in the ocean and are an indispensable sector of marine ecology. However, seldom has research attempted to unveil the effects of ocean acidification on bacteria in the Roseobacter clade, leaving a gap in understanding the environmental and ecological impacts of global climate change and ocean acidification. Here, we evaluated the effects of acidification on Roseovarius nubinhibens, a representative strain in the marine Roseobacter clade. We found that a marginal decrease in pH was influential enough to inhibit cell growth and induce cellular responses at the system level. We determined the essential role of glutathione metabolism in response to a lower pH via combined RNA sequencing, biochemical analysis, and CRISPR-Cas genome editing. Finally, we observed that a lower pH decelerated the metabolism of dimethylsulfoniopropionate, a key precursor for the global sulfur cycle and the formation of clouds, which would probably hasten global climate changes. Taking together, we believe that our study provides a missing puzzle piece toward a comprehensive understanding of the effects of global climate change and ocean acidification on our planet.