Characteristics of Organic Substances Produced from Cochlodinium polykrikoides (Dinophyceae)

doi:2006.21.2.253

Algae > Volume 21(2); 2006 > Article

Algae 2006;21(2): 253-259. doi: https://doi.org/10.4490/algae.2006.21.2.253

Yang Soon Kang¹^*, Jung No Kwon² and Kyoung Ho An¹

¹Marine Harmful Organism Research Team, National Fisheries Research & Development Institute, Pusan 619-902, Korea
²Research Planning Team, National Fisheries Research & Development Institute, Pusan 619-902, Korea

ABSTRACT

Organic substances are released from phytoplankton cells during all phases of growth. The type and amounts of organic substance excreted and the effects of nutrient limitation are often highly species-specific. Dinoflagellate, Cochlodinium polykrikoides grown in batch culture produced an exopolysaccharide. Exopolysaccharide and intracellular polysaccharide concentrations increased as C. polykrikoides cultures progressed from exponential phase, through stationary phase, to declining phase. In the exponential phase, the concentration of exopolysaccharide was relatively low, but in the stationary phase, it showed a rapid increase which seemed to coincide with the depletion of nitrate from the medium. Of the 20 amino acids analyzed, proline dominated in the organic matter of all cultures ranging from 48.2 to 79.9 nmol L?1, and constituting the 20-90% of total amino acids, and followed by histamine varying from 0.7 to 47.5 nmol L?1. Leucine and cysteine were also abundant in the stationary phase. The release rates of exopolysaccharide and intracellualr polysaccharide were higher the end of stationary phase than in the exponential phase. Exopolysaccharide concentration per cell was more than two times higher during the end of stationary phase than that in exponential phase. C. polykrikoides produced extracellular polysaccharide at a rate of 47.04 pg cell?1 day?1.

Key words: amino acids, Cochlodinium polykrikoides, exopolysaccharide