VIRAL CONTROL OF EMILIANIA-HUXLEYI BLOOMS

Virus and virus-like particles (VLP) have been observed in all major a lgal classes. Few host-virus systems of microalgae have until now been brought into culture and extensively studied. For Emiliania huxleyi w e have been able to describe viral infection during blooms in mesocosm s and in landlocked fjords. Evidence of viral lysis of E. huxleyi duri ng blooms in the North Sea has also been obtained. We have also develo ped a plaque assay for E. huxleyi virus with which we have been able t o isolate a virus that could be propagated in the laboratory. This vir us isolate lost its virulence possibly due to defective interfering pa rticles (DI). The sizes of viruses related to E. huxleyi indicate two major groups, one with a particle diameter of 180 nm and one with a he ad diameter of 140 nm.