Dimethyl sulfide phytoplankton

The vast majority of sulfur at any given time is in the lithosphere. The atmosphere, hydrosphere, and biosphere, on the other hand, are where most transfer of sulfur takes place. The role of the biosphere often involves reactions that result in the movement of sulfur from one reservoir to another. The burning of coal by humans (which oxidizes fossilized sulfur to SO2 gas) and the reduction of seawater sulfate by phytoplankton which can lead to the creation of another gas, dimethyl sulfide (CH3SCH3), are examples of such processes. 

The only continuous major natural source of the sulfur in these aerosol particles is dimethyl sulfide from marine phytoplankton (algae). 

Dimethyl sulfide is derived primarily from the enzymatic hydrolysis of dimethylsulfoniopropionate(CH3)2S+CH2CH2COO DMSP),an osmoregulatory compound produced by a wide variety of marine phytoplankton [313,317]. Intracellular DMSP hydrolysis has been shown in phytoplankton [318], in macro algae [319], and also in bacteria following uptake of DMSP from seawater [320]. Reported seawater concentrations of dissolved dimethyl sulfide (< 0.1-90 nM) and DMSP (1 -1000 nM) vary with increasing depth, spatially from coastal areas to the open ocean, and also temporally from winter to summer [313-316]. 

Andreae [324,325] has described a gas chromatographic method for the determination of nanogram quantities of dimethyl sulfoxide in natural waters, seawater, and phytoplankton culture waters. The method uses chemical reduction with sodium borohydride to dimethyl sulfide, which is then determined gas-chromatographically using a flame photometric detector. 

DMS (dimethyl sulfide) Cloud formation and acidity Phytoplankton 15 to 33TgS 80... 

The distribution of dimethyl sulfide (DMS) in surface oceans and the principle source of DMS, dimethylsulfoniopropionate (DMSP) in phytoplankton, are reviewed. The distribution of DMSP in marine phytoplankton is widespread and shows considerable variation in concentration from species to species. 

KELLER ETAL. Dimethyl Sulfide Production in Marine Phytoplankton 171... 

Keller MD, Bellows WK, Guillard RRL (1989) Dimethyl sulfide production in marine phytoplankton. Acs Symp Ser 393 167-182... 

Dacey JWH, Wakeham SG (1986) Oceanic dimethyl sulfide production during zooplankton grazing on phytoplankton. Science 233 1314—1316... 

Liss PS, Malin G, Turner SM, Holligan PM (1994) Dimethyl sulfide and Phaeocystis a review. J Mar Syst 5 41-53 Long JD, Hay ME (2006) When intraspecific exceeds interspecific variance effects of phytoplankton morphology and growth phase on copepod feeding and fitness. Limnol Oceanogr 51 988-996... 

M.D. Keller, W.K. Bellows, R.R.L. Guillard (1988). A survey of dimethyl sulfide production in 12 classes of marine phytoplankton. In E. Saltzman, W. Cooper (Eds), Biogenic Sulfur in the Environment, (pp. 167-182). American Chemical Society, Washington, D.C. 

Nguyen, B. C., Beloriso, S., Mihalopoulos, N., Gostan, J., and Nival, P. (1988) Dimethyl sulfide production during natural phytoplanktonic blooms. Mar. Chem., 24, 133-141. 

Dimethyl sulfide (DMS), through its oxidation to sulfate in the troposphere, acts as a source of cloud condensation nuclei, thus potentially influencing the radiative balance of the atmosphere. DMS is formed in sea water through the microbial decomposition of dimethyl sulfonioproprionate (DMSP), a compound believed to act as an osmolyte in certain species of marine phytoplankton. The flux of DMS to the atmosphere is controlled by its concentration in surface sea waters, which is controlled in turn by the rate of its decomposition. Estimates indicate that 7-40% of the total turnover of DMS in the surface waters of the Pacific Ocean is due to the photosensitized destruction of this compound, illustrating the potential importance of this pathway in controlling the flux of DMS to the atmosphere. 

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