Horizontal and Vertical Distribution of Protein Phosphatase Inhibitors of Microcystin Class in the Naktong River, Korea

Algae > Volume 14(1); 1999 > Article

Algae 1999;14(1): 67-72.

Vishal C. Srivastava, Ae Ran Choi, Woohyun Kim, Jin-Ae Lee

Department of Environmental Science, Inje University

ABSTRACT

Hepatotoxins from the family of microcystins were identified at the Noksan Station of the Naktong River. These hepatotoxins were detected in the water and cell at biologically active levels, based on their activity (in MYCST-RR equivalent units) by a highly sensitive protein phosphatase assay system and by high performance liquid chromatograph(HPLC). HPLC analysis of the cell sample showed that microcystin-RR was the dominant variant in the sample. The bloom materials of the Noksan Station were dominated by Microcystis aeruginosa species(96.6%). Horizontal and vertical distributions of these toxins were examined for the first time across the width of the Noksan Station. The concentrations of microcystins (MYCST-RR eq.) ranged from 19.1μg/l eq. at the Site I to non-detectable levels at 3m depth in the Site IV. The concentration of microcystin was correlated with Microcystis colony counts. The amounts of chlorophyll a ranged from 21.9 to 847.7 μg/l. The water temperature during sampling ranged from 25.0 to 28.2℃. The pH value was observed as high as 10.5 at the surface of Site I.

Key words: cyanobacteria, HPLC, microcystins, Microcystis, protein phosphatase