产河豚毒素(TTX)菌株ZY-23的分离与鉴定

Isolation and Identification of Strain ZY-23 Producing Tetrodotoxin

从河豚卵巢中分离得到35株细菌,利用小鼠生物法检测获11株产河豚毒素(TTX)菌株,其中有6株菌产TTX含量达400ng/mL以上,对其中ZY-23菌株进行传统分类学方法鉴定,初步鉴定为液化沙雷氏菌(Serratia liquefaciens)。16SrRNA基因序列分析,ZY-23菌株与Serratiasp.Tp5的亲缘关系最近,相似度达99%。用荧光检测分析其发酵液,发现在423nm处与标准品具有相同的发射峰,初步证实发酵液含有TTX。

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 spectropho- tometry 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.