太湖激浪鱼内脏中藻毒素降解菌的筛选及其特性研究

针对蓝藻分泌的微囊藻毒素引起的水污染问题,从太湖激浪鱼内脏中筛选出1株能够降解藻毒素的菌株,命名为JZ-4。采用实验室分离纯化的藻毒素作为惟一碳源、氮源,考察了菌株降解MC-LR的特性及其动力学模型;并通过生理生化、16S r DNA基因序列分析及其系统发育树分析对菌种进行鉴定。降解试验表明,菌株JZ-4能够在分离提纯的藻毒素混合液中生长,并且具有较强的降解藻毒素的能力,7 d内能把初始浓度为13.98μg/L的MC-LR降解到1.43μg/L,降解率为89.77%;菌株JZ-4对MC-LR降解符合一级反应动力学模型,其方程式为Se=S0exp(-0.301 6t)。经16S r DNA基因序列及其系统发育分析表明,该菌与杀鲑气单胞菌(Aeromonas salmonicida)的相似性最高,达98%。

Isolation and Identification of Microcystin-degrading Bacteria from Internal Organs of the Surf Fish Living in Taihu Lake and Its Features

For the problem of water pollution caused by algal toxins,a bacterial strain was identified and isolated,named JZ-4 capable of degrading microcystins from internal organs of the surf fish living in Taihu Lake. The characteristic of strain JZ-4 and kinetics model of degradation of microcystin-LR,as the sole carbon source,nitrogen source were studied. The strain JZ-4 was identifiedthrough the physiological and biochemical,16S rDNA gene sequence analysis and phylogenetic tree analysis. The experiments showed that the strain JZ-4 could grow in the mixed medium. JZ-4 strain degrades the microcystin-LR from 13.98 mg/L to 1.43 mg/L. The degradation rate was 89.77%. Degradation dynamics equation of strains JZ-4 could show as Se=S0exp(-0.3016t). Through 16S rDNA gene sequence and phylogenetic tree analysis showed that it had a 98% similarity to Aeromonas salmonicida.