A new tetrodotoxin-producing actinomycete, Nocardiopsis dassonvillei, isolated from the ovaries of puffer fish Fugu rubripes

Three puffer fishes, Fugu rubripes, collected from the Bohai Sea of China were examined for tetrodotoxin-producing microorganisms. An actinomycete isolated from the ovaries of the puffer fishes was found to produce tetrodotoxin. After being cultured at 28 °C for 7 days, cells were harvested by centrifuge and disrupted by ultrasonication. The toxin was purified from the cell lyzate by ultrafiltration, active charcoal column, Bio-gel-p2 and ion exchange column chromatography. Mouse neuroblastoma cell culture, thin-layer chromatography, fluorimetric spectrophotometry, UV-spectrophotometry and electrospray ionization mass spectrometry, together with mouse bioassay demonstrated that the isolated strain produced tetrodotoxin and related toxin during cultivation. Based on morphological, physiological, biochemical characteristics and 16S rDNA alignment, this strain was identified as Nocardiopsis dassonvillei. Our findings suggested that N. dassonvillei in the ovaries was closely related to the toxification of the puffer fish.