Elevated production of dimethylsulfide resulting from viral infection of cultures of Phaeocystis pouchetii

The effects of viral lysis on dimethyl sulfide (DMS) and particulate and dissolved dimethylsulfoniopropionate (DMSP) concentrations were studied in batch cultures of Phaeocystis pouchetii infected with a strain-specific viral isolate. After 20 h, DMS concentration had increased by fourfold over the levels observed in the control cultures, and this increased to eightfold 45 h after addition of viral particles. The results suggest that viral lysis of DMSP-containing phytoplankton cells should be considered alongside autolysis, grazing, and bacterial activity as a process that can influence DMS concentrations in seawater. Further research will be necessary to determine the importance of viruses in the biogeochemical DMS cycle in the natural environment.