两株土壤耐镉细菌的筛选分离及与CdS-TGA纳米颗粒相互作用的研究

Isolation of Two Cd-resistant Bacterial Strains from Heavy Metal Contaminated Soil and Their Interactions with Cd S-TGA Nanoparticles

由受重金属镉污染严重的化工厂土壤中,筛选分离获得两株镉耐受性加强的菌株,菌体长1.0~2.0μm,宽0.5~0.8μm,单个细胞呈杆状,单菌落分别呈淡黄色与乳白色,经鉴定为Enterobacter sp.与Serratia sp.。对所分离细菌的最适生长条件、镉离子最小抑制浓度及抗生素抗性进行了检测和优化,并进一步研究了硫化镉-巯基乙酸纳米颗粒与细菌的相互作用,发现纳米颗粒浓度在150μg/m L时细菌增殖基本停滞;过氧化物酶和超氧化物歧化酶酶活测试显示纳米颗粒对酶抑制性较Cd2＋更为强烈,细胞形态受到严重破坏。

Two Cd-resistant bacterial strains were isolated from heavy metal contaminated soil. The morphology of bacterial ceils was observed as rhabdoid in shape, 0.5 -0.8μm in width and 1.0-2.0 μm in length, yellow and white in color. The two bacterial strains Were characterized as Enterobacter sp. and Serratia sp. The minimum inhibitory concentration （MIC） of Cd^2＋, the optimum growth conditions and antibiotic resistance features of the two strains were tested and optimized. Interactions between the two strains and CdS- TGA nanoparticles were further investigated. It was found that bacterial growth was strongly inhibited by nanoparticles at a concentration up to 150 μg/mL. Peroxidase and superoxide dismutase activities of bacteria were much more inhibited by CdS-TGA nanoparticles than Cd^2＋. In addition, damage of bacterial cell morphology caused by CdS-TGA nanoparticles was also observed.