Physiological and Ecological Functions of DMSP

An inherent property of osmolytes is that they lower the freezing point depressions of cells (Kirst 1996). Therefore, DMSP may also be acting as a cryoprotectant in algae exposed to freezing temperatures. However, Kirst (1996) argues that cellular concentrations of DMSP are too low to produce a significant freezing point depression. 

Several papers have commented that DMSP may function as a methyl donor (Challenger and Simpson 1948 Dubnoff and Borsook 1948 Visscher et al. 1994 Marc et al. 1995 Kirst 1996), but the importance of this process in marine macroalgae is not known. Marine bacteria can demethylate DMSP to methanethiol via 3-methiolpropionate or following the cleavage of DMSP into DMS and acrylate (Kiene and Taylor 1988 Taylor and Gilchrist 1991 Gonzalez et al. 1999) however, the fate of the methyl groups was not determined in these studies. 

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