Isolation and Identification of Strain ZY-23 Producing Tetrodotoxin

Abstract:

A total of 35 bacterial strains were isolated from the ovarian of Globefish. It was confirmed that 11 bacterial strains among them were capable of producing tetrodotoxin using mouse bioassay method and the toxin concentrations in the cultures of 6 bacterial strains were above 400 ng/mL. Based on the morphology, physiological and biochemical characteristics, the strain ZY-23, one of the bacterial strains, was identified preliminarily as Serratia liquefaciens. The phylogenetic analysis showed that 16S rRNA sequence of the bacterial strain ZY-23 had 99% homology to that of Serratia sp. Tp5. The result of fluorimetric spectrophotometry indicated that there was the same fluorescence peak of the fermentation broth as that of the standard substance, suggesting that the strain ZY-23 indeed produced tetrodotoxin.