View source for Rates of DMSO reduction to DMS

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* [[Page authors|Page authors]]: [[PRIMO]]
* [[Responsible curator|Responsible curator]]:  [[User:Hagi BucknWise|Hagen Buck-Wiese]]
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{| class="model-ib" style="float:right; margin-left:1em; margin-bottom:1em;"
! DMSO reduction rate
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| '''Approach:''' deuterium-labelled DMSO tracer; D<sub>6</sub>-DMS formation measured by GC-MS
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| '''Context:''' ''in situ'' incubations, lab
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| '''Spatial scale:''' point sample
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| '''Temporal scale:''' 4–12 h
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| '''Units:''' nM d<sup>-1</sup>; rate constants h<sup>-1</sup> or d<sup>-1</sup>
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| '''Community captured:''' all
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| '''Co-measurements:''' (none specified in inventory)
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== Method Overview ==

The reduction of dimethylsulfoxide (DMSO) to dimethylsulfide (DMS) is measured by adding fully deuterium-labelled D<sub>6</sub>,<sup>13</sup>C<sub>2</sub>-DMSO (or D<sub>6</sub>-DMSO) to seawater samples. Bacteria possessing DMSO reductase enzymes reduce the deuterated DMSO to D<sub>6</sub>-DMS, which is distinguishable from natural DMS (mass 62 vs. 62+6=68) by GC-MS analysis. The rate of D<sub>6</sub>-DMS accumulation, corrected for the fractional labelling of the DMSO pool, gives the gross DMSO reduction rate<ref name="McNabb2025">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</ref>. 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<sup>-1</sup>) and first-order rate constant (d<sup>-1</sup>). Relative to total DMS production, this reveals the contribution of DMSO reduction vs. DMSP cleavage.

=== Units & currency ===

Units are nM d<sup>-1</sup> or h<sup>-1</sup>/d<sup>-1</sup> (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'' <ref name="McNabb2025" />

=== Recent applications ===
* Herr et al. (2020) ''Potential roles of dimethylsulfoxide in regional sulfur cycling in the NE subarctic Pacific'' <ref name="Herr2020">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</ref>

=== Common calculations/conversions ===
* DMSO reduction rate = d[D<sub>6</sub>-DMS]/dt × ([DMSO]<sub>total</sub> / [D<sub>6</sub>-DMSO]<sub>added</sub>).

== References ==

[[Category:Main Pages|Model types]]