Effects of different nutrient and trace metal concentrations on growth of the toxic dinoflagellate Gymnodinium catenatum isolated from Korean coastal waters

Abstract

The effects of nutrient (nitrate: N, phosphate: P and vitamin B1) and trace metal (iron: Fe, Copper: Cu, and selenium: Se) additions on the growth of Gymnodinium catenatum, which was isolated from Korean coastal waters, were investigated. The Korean isolate of G. catenatum could grow in a wide range of N and P. The high concentrations of N (> N:P ratio of 23.5) did not stimulate the growth rate however the enhancements in the growth rate and cell density were observed with P additions. Vitamin B1 addition experiments revealed that G. catenatum does not require the vitamin B1 for the growth. In Fe and Cu addition experiments, no significant differences were observed in the growth patterns and rates of G. catenatum between controls and all treatments. It is possible that the growth of Korean isolate of G. catenatum is not dependent on high concentration of Fe and Cu. However, the cell densities were increased in the stationary phases of treatments with additions of Se, and the maximum cell densities were higher than those in culture experiments with additions of other nutrient and trace metal sources. Our findings indicate that G. catenatum prefers high concentrations of P and Se for the proliferation, rather than other nutritional sources.