一株高效MC-RR降解菌的分离鉴定及其降解特性

Isolation and identification of a MC-RR degradation bacillus and its degradation characteristics

为了得到一株具有降解微囊藻毒素-RR(MC-RR)特性的产芽孢菌株,采用加热富集芽孢菌的方法,从太湖分离到一株MC-RR降解菌CM1,该菌对MC-RR具有强烈的降解特性。通过形态学特征、生理生化特征及16S rDNA序列分析鉴定该菌株属于耐硼赖氨酸芽孢杆菌(Lysinibacillus boronitolerans)。通过研究温度和pH值对菌株CM1降解MC-RR能力的影响,发现菌株CM1在60 h将MC-RR由12.77μg/mL降解到1.67μg/mL,降解率达86.90%,最适降解温度为37℃,最适pH值为7.0。CM1菌株的胞外物质和胞内物质均能降解MC-RR,但胞内物质具有更强烈的降解特性,12 h可以将7.27μg/mL的MC-RR完全降解。为丰富MC-RR降解菌纯菌种研究以及在去除水体中MC-RR应用研究方面提供了理论基础。

In order to obtain a bacillus which can degrade microcystin-RR, a MC-RR degradation bacterium CM1 was isolated from Taihu Lake by heating for gathering of bacterial spore. The CM1 was identified as Lysinibacillus boronitolerans by morphological features, physiological and biochemical characteristics, as well as phylogenetic analysis of 16S rDNA sequences. The effects of the temperature and pH on the biodegradation activity of MC-RR by strain CM1 were investigated, iVIC-RR was degraded from 12.77 μg/mL to 1.67 μg/mL in 60 h with the degradation rate of 86.90%. The optimal temperature and pH for biodegradation of MC-RR were 37℃ and 7.0, respectively. Based on the research of MC-RR degradation by the extracellular and intracellular substances, both of them could degrade MC-RR, furthermore, intracellular substance had a stronger degradation ac- tivity, MC-RR of 7.27 μg/mL could be completely degradated in 12 h. The research of pure MC-RR degradation bacteria and removing MC-RR in water was useful for the further application of the bacteria of L. boronitolerarts.