CHEMILUMINESCENCE DETECTION OF RED TIDE PHYTOPLANKTON CHATTONELLA MARINA

摘要

A sensitive method was developed for monitoring the cell concentration of red tide phytoplankton Chattonella marina, which frequently caused fish death via an obscure mechanism, 2-Methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin-3-one (MCLA), a Cypyridina luciferin analog, which emits light strongly at 465 nm in the presence of superoxide, was applied as a chemiluminescence probe, The MCLA-dependent chemiluminescence of room-cultured axenic C, marina was efficiently suppressed by adding superoxide dismutase (20 units mL(-1)) to the phytoplankton suspension but not by filtering out the plankton cells, indicating the chemiluminescence was due to the superoxide released from C. marina, Several species of other tested phytoplankton, such as Heterosigma akashiwo, Skeletonema costatum, Chaetoceros sociale, and Porphyridium cruentrum did not induce this chemiluminescence whereas Chattonella antiqua showed characteristic similar to C, marina, suggesting that this method has specificity for the Chattonella genus, As compared with the cell density of C. marina during the red tide seasons, the detection limit of 200 cells mL(-1) based on this luminescent method is considered to be applicable for C, marina detection in the early stage of its red tides.