1. Phytoplankton‐derived zwitterionic gonyol and dimethylsulfonioacetate interfere with microbial dimethylsulfoniopropionate sulfur cycling
- Author
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Gebser, B., Thume, K., Steinke, M., and Pohnert, G.
- Subjects
volatile sulfur species ,Bacteria ,Sulfur Compounds ,fungi ,Sulfonium Compounds ,lcsh:QR1-502 ,Original Articles ,inhibition ,lcsh:Microbiology ,gonyol ,Phytoplankton ,Seawater ,Original Article ,dimethylsulfoniopropionate ,metabolism ,Sulfur - Abstract
The marine sulfur cycle is substantially fueled by the phytoplankton osmolyte dimethylsulfoniopropionate (DMSP). This metabolite can be metabolized by bacteria, which results in the emission of the volatile sulfur species methanethiol (MeSH) and the climate‐cooling dimethylsulfide (DMS). It is generally accepted that bacteria contribute significantly to DMSP turnover. We show that the other low molecular weight zwitterionic dimethylsulfonio compounds dimethylsulfonioacetate (DMSA) and gonyol are also widely distributed in phytoplankton and can serve as alternative substrates for volatile production. DMSA was found in 11 of the 16 surveyed phytoplankton species, and gonyol was detected in all haptophytes and dinoflagellates. These prevalent zwitterions are also metabolized by marine bacteria. The patterns of bacterial MeSH and DMS release were dependent on the zwitterions present. Certain bacteria metabolize DMSA and gonyol and release MeSH, in others gonyol inhibited DMS‐producing enzymes. If added in addition to DMSP, gonyol entirely inhibited the formation of volatiles in Ruegeria pomeroyi. In contrast, no substantial effect of this compound was observed in the DMSP metabolism of Halomonas sp. We argue that the production of DMSA and gonyol and their inhibitory properties on the release of volatiles from DMSP has the potential to modulate planktonic sulfur cycling between species., Marine sulfur cycling depends to a large extent on the transformation of the dominant algal osmolyte dimethylsulfoniopropionate (DMSP). We show that other low molecular weight zwitterionic dimethylsulfonio (DMS)‐compounds, including dimethylsulfonioacetate (DMSA) and gonyol can serve as alternative substrates fueling the pool of volatile sulfur species from the oceans. We demonstrate that these prevalent zwitterions from algae are metabolized by marine bacteria and that gonyol acts as an inhibitor of bacterial metabolism of the abundant oceanic dimethylsulfoniopropionate. We thus argue that the prevalence of DMSA and gonyol and their inhibitory properties of DMSP‐metabolism modulates the planktonic sulfur cycle and the flux of climate‐active DMS to the atmosphere.
- Published
- 2020