【摘要】 从农药厂的工业废水和污泥的混合物中分离到高效降解除草剂阿特拉津的藤黄微球菌(Micrococcusluteus)AD3菌株。以聚乙烯醇(PVA)为包埋材料进行AD3菌株的固定化,对影响固定化细胞降解阿特拉津的因素(如阿特拉津浓度、温度、pH)和操作稳定性进行了研究。结果表明,在最适条件下(30℃、pH7.2、阿特拉津浓度500mg/L)固定化细胞的阿特拉津降解速度明显高于游离细胞。固定化细胞在低温、低pH和高阿特拉津浓度条件下的阿特拉津降解率,以及贮存和操作稳定性,也明显好于游离细胞。固定化细胞在15℃、pH7.2、阿特拉津浓度为500mg/L的条件下培养72h以后,阿特拉津降解率为90%,在相同条件下游离细胞的降解率仅为35%。固定化细胞在pH5.0、30℃、阿特拉津浓度为500mg/L的条件下培养72h以后,降解率为96%,在相同条件下游离细胞的降解率仅为40%。固定化细胞能够快速降解1000mg/L的阿特拉津,而游离细胞则不能。稳定性实验表明,固定化细胞重复使用30次以后其降解活力没有明显降低。更多还原

【Abstract】 A high efficiency atrazine-degrading bacterium, Micrococcus luteus AD3, was isolated from the mixture of industrial wastewater and sludge. Polyvinyl alcohol (PVA) was used as a gel matrix to immobilize the strain AD3. Factors affecting atrazine degradation by immobilized cells, such as atrazine concentrations, temperature, and pH, and operational stability of immobilized cells, were investigated. The results showed that under the optimal conditions (30℃、pH 7.2、atrazine 500mg/L) immobilized cells had a higher atrazine degradation rate than that of free cells. Immobilized cells were cultured at 15℃ for 72 hours in minimal medium containing 500mg/L of atrazine (pH 7.2), the atrazine degradation rate was 90%. However, at the same conditions, the degradation rate by free cells was only 35%. Immobilized cells were cultured at pH 5.0, 30℃ for 72 hours in minimal medium containing 500mg/L of atrazine, the atrazine degradation rate was 96%. However, at the same conditions, the degradation rate by free cells was only 40%. Immobilized cells were capable of degrading 1000mg/L atrazine in minimal medium, while free cells were unable. Stability test revealed that immobilized cells can be used repeatedly for at least 30 times without significant decrease in atrzaine degradation activity.更多还原