Mode of action of membrane-disruptive lytic compounds from the marine dinoflagellate Alexandrium tamarense

► We investigated the activity of lytic fractions of the marine dinoflagellate Alexandrium tamarense. ► The unknown substances are capable of lysing cells of protists, as a possible allelochemical mechanism. ► Membrane sterols may be involved in mediating lytic activity but the sterol composition does not explain the sensitivity/resistance of membranes.