Species-specific chemical control of thiazolidinedione derivative (TD49) on harmful and non-harmful algal bloom species

Abstract

To evaluate the algicidal effect of a newly developed algicide thiazolidinedione derivative, TD49, on non-harmful and harmful algal bloom (HAB) in aquatic ecosystems, culture experiments for twenty three target strains were conducted. We also examined the growth pattern (i.e., lag, logarithmic and stationary phases) of dinophyceae Heterocapsa circularisquama and rapidophyceae Heterosigma akashiwo under different concentrations of TD49; low (LL: 0.02 µM), middle (MM: 0.2 µM) and high concentrations (HH: 2 µM). The inhibitory ratios (%) of H. circularisquama and H. akashiwo at HH concentration were significantly high and the inhibitory ratio were changed depending on the growth phase as follows: logarithmic ≥ stationary > lag phase for H. circularisquama and logarithmic ≥ lag > stationary phase for H. akashiwo, respectively. The algicidal activity of TD49 on different harmful and non-harmful algae was determined as follows: unarmored HAB species > armored HAB species > diatoms > crytophyta species. Consequently, TD49 had effective algicidal activity against most HABs while it was safe to some non-harmful algae, implying that TD49 had a selective algicidal activity. Our results indicate that the TD49 is a potential agent for the control of HAB species in the enclosed and eutrophic water bodies.