一株具砷氧化和反硝化功能的无色杆菌的筛选和鉴定

利用含As3+肉汤培养基，从广西河池砷污染地区水样和沉积物样中通过多次分离、纯化获取砷耐受菌.进一步从砷耐受菌中筛选出在好氧条件下可以同时进行砷氧化和反硝化的多功能菌株cll-35. 对该菌株进行形态观察，并利用16S rDNA序列分析方法进行鉴定，发现该菌株为革兰氏阴性菌，与Achromobacter denitrificans strain 22426和Achromobacter xylosoxidans strain C8B的同源性均达99%；该菌株在NO₃-和As3+同时存在的条件下好氧反硝化能力和砷氧化速率均得到提高；在只含NO₃-的条件下，NO₃-的去除率为53.65%，而在As3+和NO₃-同时存在的条件下，NO₃-的去除率为75.27%.在不含NO₃-和含NO₃-的条件下，As3+的转化率都在99%以上，而在含NO₃-的条件下，As3+的氧化速率更快.这种相互促进可能与反硝化过程中的电子传递和砷氧化过程中的动态平衡有关. 

Screening and Identification of an Achromobacter Strain for Both Arsenic Oxidizing and Denitrifying Abilities

Water and sediment samples were taken from an arsenic-contaminated region in Hechi,Guangxi Province.Arsenite-resisting strains were isolated and purified several times from broth medium containing As3+.cll-35,the arsenite-oxidizer and aerobic denitrifier was further screened from arsenite-resisting strains.Morphological studies and 16S rDNA sequencing revealed that the isolate was Gram negative,and had 99% homogeneity to Achromobacter denitrificans strain 22426 and Achromobacter xylosoxidans strain C8B.The ...