Organosulfides inhibit growth and photosynthetic activity of algae and cyanobacteria

We report the inhibitory effects of various volatile organic sulfide (VOS) compounds on algal and cyanobacterial species (bloom forming motile dinoflagellate Peridinium gatunense, toxic cyanobacterium Microcystis sp., chlorophyte Chlorella sp. and diatom Nitzschia sp.) isolated from Lake Kinneret, Israel. Several VOS compounds severely inhibited various physiological activities in the tested phytoplankton species. Based on these results, we propose that compounds such as dimethyl sulfide (widespread in oceanic and fresh water environments in association with algal blooms), may affect the development and composition of phytoplankton population through allelopathic interactions.