机构地区: 深圳职业技术学院建筑与环境工程学院
出 处: 《环境科学》 2012年第9期3214-3219,共6页
摘 要: 通过贫营养原水曝气培养法,以SBR方式驯化和稳定运行2个月,分离得到1株能够降解除草剂阿特拉津的降解菌株,命名为L-6.在以阿特拉津为唯一氮源(500 mg.L-1)的无机盐液体培养基中培养96 h后,降解率达到89.2%.扫描电镜观察发现该降解菌株细胞呈长杆状.提取菌株的DNA,进行16S rRNA基因序列分析,并构建系统进化树.结果表明该菌株与GenBank数据库中多株Pseudomonas菌株16S rRNA基因的同源性在99%以上.结合生理生化检测,判断该降解菌为假单胞菌属(Pseudomonas sp.).碳源利用实验发现,降解菌株L-6可以利用葡萄糖、果糖和柠檬酸钠生长,不能利用蔗糖、乳糖和淀粉.环境因素对降解效率的影响实验表明,温度在30℃,初始pH 7~9条件下,降解效率最佳. An atrazine-degrading bacterial strain named L-6 was isolated from the sludge mixture of the sewage treatment plant by cultivating in raw water with limited nutrition and aeration and was domesticated steadily using SBR(Sequencing Batch Reactor) for two months.The degradation rate of atrazine in inorganic liquid culture medium with atrazine as the sole source of nitrogen could reach 89.2% after 96 hours.The cells showed shape of long rod under scanning electron microscope.After extraction of genomic DNA and PCR amplification,the 16S rRNA gene sequences were used for homology analysis and construction of phylogenetic trees.The results suggested that the 16S rRNA gene sequence of L-6 had up to 99% homology with those of many strains of Pseudomonas strains in GenBank database.With physiological and biochemical reactions,the strain L-6 was identified as Pseudomonas sp.Carbon use test indicated that L-6 can utilize glucose,fructose and citric acid sodium as carbon sources,but could not use sucrose,lactose or starch.The optimum degradation conditions were optimized as following:temperature 30℃,initial pH 7-9.