Effects of Different Nutrient and Trace Metal Concentrations on Growth of the Toxic DinoflagellateGymnodinium catenatumIsolated from Korean Coastal Waters

Abstract

The effects of the addition of nutrients (nitrate: N; phosphate: P; and vitamin B-1) and trace metals (iron: Fe; Copper: Cu; and selenium: Se) on the growth ofGymnodinium catenatum, which was isolated from Korean coastal waters, were investigated. The Korean isolate ofG. catenatumgrew under a wide range of concentrations of N and P. Whilst high concentrations of N (> N: P ratio of 23.5) did not stimulate the growth rate, an enhanced growth rate and cell density were observed with the addition of P. The experimental addition of vitamin B(1)revealed thatG. catenatumis not dependent on vitamin B(1)for growth. Moreover, the addition of Fe and Cu resulted in no significant differences in the growth patterns and rates ofG. catenatumbetween the controls and treatments. It is thus possible that growth of the Korean isolate ofG. catenatumdoes not require high concentrations of Fe and Cu. However, the cell densities were enhanced in the stationary phases of treatments upon addition of Se, and the maximum cell densities were higher than those in the culture experiments upon additions of other nutrient and trace metals. Our findings indicate thatG. catenatumprefers P and Se for proliferation, rather than other nutritional sources.