AME 15:211-216 (1998)  -  doi:10.3354/ame015211

Effect of temperature on the algicidal activity and the stability of HaV (Heterosigma akashiwo virus)

Keizo Nagasaki*, Mineo Yamaguchi

Red Tide Biology Section, Red Tide Research Division, Nansei National Fisheries Research Institute, 2-17-5 Maruishi, Ohno, Saeki, Hiroshima 739-0452, Japan

ABSTRACT: The effect of temperature on the algicidal activity and stability of HaV (Heterosigma akashiwo virus), which infects the harmful bloom causing alga, H. akashiwo (Raphidophyceae), was determined by growing H. akashiwo culture inoculated with HaV under various conditions. Temperature and growth stage of the host culture are considered to be important factors determining the algicidal activity of HaV. The optimum temperature for the algicidal activity of HaV ranged from 20 to 25°C. Comparing the viral susceptibility of H. akashiwo strains and the algicidal activity of the HaV clones at different temperatures, both were suggested to be phenotypically diverse. Effect of temperature on the stability of HaV was also evaluated. HaV showed a relatively rapid decrease in infectious titer even when preserved at 5°C in the dark. The data is discussed in relation to the behavior of HaV in natural environments and the disintegration mechanism of H. akashiwo red tide.

KEY WORDS: HaV · Heterosigma akashiwo · Raphidophyceae · Harmful algal bloom · Red tide · Virus · Algicidal activity · Infectivity · Susceptibility · Temperature

Full text in pdf format