Growth characteristics of Heterosigma akashiwo virus and its possible use as a microbiological agent for red tide control

The growth characteristics of Heterosigma akashiwo virus clone 01 (HaV01) w ere examined by performing a one-step growth experiment. The virus had a la tent period of 30 to 33 h and a burst size of 7.7 x 10(2) lysis-causing uni ts in an infected cell, Transmission electron microscopy showed that the vi rus particles formed on the peripheries of viroplasms, as observed in a nat ural H akashiwo cell, Inoculation of HaV01 into a mixed algal culture conta ining four phytoplankton species, H, akashiwo H93616, Chattonella antiqua ( a member of the family Raphidophyceae), Heterocapsa triquetra (a member of the family Dinophyceae), and Ditylum brightwellii (a member of the family B acillariophyceae), resulted in selective growth inhibition of H, akashiwo, Inoculation of HaV01 and H; akashiwo H93616 into a natural seawater sample produced similar results, However, a natural H, akashiwo red tide sample di d not exhibit any conspicuous sensitivity to HaV01, presumably because of t he great diversity of the host species with respect to virus infection, The growth characteristics of the lytic virus infecting the noxious harmful al gal bloom-causing alga were considered, and the possibility of using this v irus as a microbiological agent against If, akashiwo red tides is discussed .