一株抗镉细菌的分离鉴定及其抗性基因定位的初步研究

Isolation, identification and preliminary studies on the resistance gene detection of a Cd-resisting bacterium

报道了从长期重金属镉处理土壤中分离纯化 ,获得一株可在含镉 2 0 0mg L的培养基上正常生长的抗镉细菌菌株 ,编号为DKC1.经对该菌株进行形态观察、Biolog生理生化分析、G +Cmol%测定及 16SrDNA序列同源性比较 ,该菌株鉴定为Ral stoniaeutropha .利用RDPⅡ数据库的PhylipInterface进行了系统发育地位分析 ,构建了进化树 ,并对KDC1菌株进行了抗重金属谱测定 ,结果表明该菌株对镉有较高的抗性 (35 0mg L)而对其它重金属耐性较低 ,通过质粒检测 ,该菌株含有一较大质粒 ,抗镉基因位于质粒上 .

A bacterial strain DKC1, which was capable of growing on soil concentration 350?mg/L Cd, was isolated from Cd contaminated soil.The strain was identified as Ralstonia eutropha based on Biolog-GN, G+C mol%, analysis of the 16S rDNA sequence. Using Phylip Interface in RDPⅡ data|base,unrooted phylogenetic tree was constructed based on the 16S rDNA sequence of strain DKC1.Strain DKC1 had high resistance to Cd (30?mg/L) but lower resistance to other heavy metals. The strain had a big plasmid, whose Cd|resistance genes are located on its plasmid.