HEPATOTOXIC MICROCYSTINS AND NEUROTOXIC ANATOXIN-A IN CYANOBACTERIAL BLOOMS FROM KOREAN LAKES

Cyanobacterial bloom samples were collected in the warm season during 1992-1995 from the 12 lakes in Korea. Six species each of Microcystis and Anabaena, and two of Oscillatoria were identified in these lakes. The cyanotoxins of 47 samples collected from the lakes were identified as microcystins-RR, -YR, -LR; desmethyl-7-microcystin-LR (7-DMLR), pl us anatoxin-a. Microcystins were the main components of these cyanotox ins, while anatoxin-a was detected in samples from a few lakes. Thirty -four of the 47 samples, included microcystins and the total amounts o f microcystin ranged between 20-1500 mu g/g freeze-dried bloom materia l. In four of the 26 samples, the samples contained anatoxin-a, though the amounts varied. The total microcystin concentration in 30 samples from the lakes was equal to the cellular microcystin in these lakes b ecause no extracellular microcystin was detected. All the lakes except for Lakes Younglang and Mijae are a source of drinking water, so the presence of cyanotoxin can be a potential threat and requires more att ention to water treatment, (C) 1998 by John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 225-234, 1998.