[Effects of UV-B radiation enhancement on DNA damage of three red-tide microalgae species].

The ecotoxicological and biochemical study with Heterosigma akashiwo, Alexandrium tamarense and Skeletonema costatum showed that the test three species of red-tide microalgae had different sensitivities to UV-B radiation enhancement, and the order from high to low was Heterosigma akashiwo, Alexandrium tamarense and Skeletonema costatum. The DNA damage of algal cells increased with UV-B radiation enhancement, being more notable in Heterosigma akashiwo than in Alexandrium tamarense and Skeletonema costatum, and in Alexandrium tamarense than in Skeletonema costatum. The DNA damage of Heterosigma akashiwo and Alexandrium tamarense could be significantly repaired (P < 0.05) after 6 days of UV-B radiation removal, and that of Skeletonema costatum could be significantly repaired (P < 0.05) after 3 days, which illustrated that the DNA damage of three red-tide microalgae species could not indicate the damaged degree of marine microalgae resulted from UV-B radiation enhancement.