Rates of DMSO reduction to DMS
| DMSO reduction rate |
|---|
| Approach: deuterium-labelled DMSO tracer; D6-DMS formation measured by GC-MS |
| Context: in situ incubations, lab |
| Spatial scale: point sample |
| Temporal scale: 4–12 h |
| Units: nM d-1; rate constants h-1 or d-1 |
| Community captured: all |
| Co-measurements: (none specified in inventory) |
Method Overview
The reduction of dimethylsulfoxide (DMSO) to dimethylsulfide (DMS) is measured by adding fully deuterium-labelled D6,13C2-DMSO (or D6-DMSO) to seawater samples. Bacteria possessing DMSO reductase enzymes reduce the deuterated DMSO to D6-DMS, which is distinguishable from natural DMS (mass 62 vs. 62+6=68) by GC-MS analysis. The rate of D6-DMS accumulation, corrected for the fractional labelling of the DMSO pool, gives the gross DMSO reduction rate[1]. DMSO reduction is a significant biological DMS production pathway that is often overlooked relative to DMSP cleavage.
Scale of measurement
Point samples from sealed serum vials to prevent DMS volatilization during the 4–12 h incubation.
Data generated
Gross DMSO reduction rate (nM d-1) and first-order rate constant (d-1). Relative to total DMS production, this reveals the contribution of DMSO reduction vs. DMSP cleavage.
Units & currency
Units are nM d-1 or h-1/d-1 (rate constants). The currency is sulfur metabolite (DMS).
Sample size
Typical samples are < 200 mL in volume.
Repositories & databases
Limitations
Steady-state intracellular and dissolved DMSO pool dynamics are assumed. Bottle artifacts can alter community composition and DMSO availability. The labelled DMSO must equilibrate rapidly with the endogenous DMSO pool for accurate rate estimation.
Example Applications & Protocols
Classic examples
- McNabb & Tortell (2025) A potential photo-protective, antioxidant function for DMSO in marine phytoplankton [1]
Recent applications
- Herr et al. (2020) Potential roles of dimethylsulfoxide in regional sulfur cycling in the NE subarctic Pacific [2]
Common calculations/conversions
- DMSO reduction rate = d[D6-DMS]/dt × ([DMSO]total / [D6-DMSO]added).
References
- ↑ 1.0 1.1 McNabb, M. L., & Tortell, P. D. (2025). A potential photo-protective, antioxidant function for DMSO in marine phytoplankton. PLOS ONE, 20(2), e0317951. https://doi.org/10.1371/journal.pone.0317951
- ↑ Herr, A. E., Bass, M., Granger, J., & Tortell, P. D. (2020). Potential roles of dimethylsulfoxide in regional sulfur cycling and phytoplankton physiological ecology in the NE subarctic Pacific. Limnology and Oceanography, 66(1), 76–94. https://doi.org/10.1002/lno.11589