1株具有耐镉降解微囊藻毒素细菌的分离鉴定

Isolation and Identification of a Cadmium-Tolerating Bacterial Strain with Biodegrading Microcystins and Lysing Algae

从安徽镜湖腐烂的蓝藻中筛选出1株细菌,命名为R1,该菌株具有较强的耐镉、溶藻以及可降解微囊藻毒素能力,经16S r DNA序列对比分析鉴定,R1属于气单胞菌属(Aeromonas)。该菌株对Cd^(2+)有很好的耐受性,在含有50 mg/L Cd^(2+)的培养基中仍能正常生长;细菌通过分泌胞外物质溶解铜绿微囊藻,且该胞外物质耐高温,属非核酸或多糖类物质,丙氨酸和苯丙氨酸协同作用而溶藻;在0. 1 mg/L Cd^(2+)存在的情况下,细菌溶藻能力增强;微囊藻毒素的初始浓度为1. 84 mg/L时,7 d时间降解率为40. 2%。

A bacterial strain named as R1 was screened out from rotten blue green algae in Jinghu Lake （Mirror Lake） in Anhui. The strain had the tolerance to cadmium and capable of lysing algae and degradation of microcystins. Through comparative analysis with 16S rDNA sequences, R1 belongs to the genus of Aeromonas . The strain has a good tolerance to Cd 2＋ , and can normally grow in medium containing 50 mg/L of Cd 2＋ , the strain dissolved Microcystis aeruginosa by secreting extracellular substances, and it was well tolerated to high temperature, the substance belongs to non-nucleic acid or polysaccharide, the algae-lysis was synergetic effect of alanine and phenylalanine. In the condition of the existence of 0.1 mg/L of Cd 2＋ , the ability of algae-lysing was enhanced; when initial concentration of microcystins was at 1.84 mg/L, degradation rate of the strain was at 40.2% in seven days.