Algicidal Effects of a Newly Developed Thiazolidinedione Derivative, TD49, on Dinoflagellate Akashiwo sanguinea

To evaluate the algicidal impact of a newly developed algicide thiazolidinedione derivative,TD49, on dinophyceae Akashiwo sanguinea in aquatic ecosystems, tentative culture experiments for thetarget species were conducted in small (SS), middle (MS), and large scale (LS) culture vessels. When TD49was introduced at the final concentration of 2 µM in SS and MS, as well as 1 µM in LS, the abundance of A.sanguinea decreased significantly in all the treatments. On the other hand, total phytoplankton abundance,except A. sanguinea in the TD49 treatments, gradually increased with culture time, which implies that a celldestruction of A. sanguinea by TD49 is a major cause of the population growth by other phytoplanktonspecies. Also, A. sanguinea was easily destroyed, which was likely to be a source of extracellularsubstances. In particular, a pH decrease was significant in the treatments than in the control, which indicatesthat the water in the treatments has been acidified, due to an increase in the heterotrophic metabolisms ofbacteria and degradation of A. sanguinea cells. Our results indicate that the TD49 substance is the potentialagents for the control of A. sanguinea in the enclosed and eutrophic water bodies.Key words :Akashiwo sanguinea, algicidal effect, thiazolidinedione, ecosystem*Corresponding author. E-mail : yokim@kordi.re.kr