【摘要】 从北京市远郊东三岔地区废弃的铅锌尾矿中筛选到1株强抗镉的细菌.通过细菌形态学观察、扫描电镜、X射线衍射能谱分析、甲基乙酰甲醇试验与酪氨酸水解试验等特征生理生化试验、菌株“G+C mol%”值以及16S rDNA扩增与序列测定,鉴定此菌株为蜡状芽孢杆菌(Bacillus cereus).分离菌株可以在镉浓度为1 000 mg/L的固体培养基平板上生长,表明菌株具有强抗镉的能力.进一步分析了菌株在添加Cd2+与未添加Cd2+的液体培养基中的生长曲线,并通过质粒消除试验证明该菌株的抗镉性质与抗性质粒的存在有关.更多还原

【Abstract】 A Gram-positive,aerobic,motile,spore-forming bacterium was isolated from a Pb-Zn mine tailing at suburb of Beijing City.The bacterial strain isolated could resist cadmium efficiently and it was able to grow well on media plates containing(1?000)(mg/L) cadmium.The DNA G + C content were found to be 60%.Phylogenetic analysis of the 16S rRNA gene revealed that this isolate was a member of the genus Bacillus.Two growth curves about this strain were drawn on media with and without cadmium.This strain harbors a plasmid putatively bearing essential cadmium resistant genes as demonstrated by a plasmid elimination experiment.The results of this study indicate that this strain has a better potential for cadmium resistance compared to other reports.The physiological characterization of the isolates also indicates the possible application of this strain for bioremediation of sites contaminated with cadmium.更多还原