镉污染  ; 土壤  ; 细菌  ; 分离  ; 鉴定

通过盆栽试验，研究镉对柱花草土壤细菌类群的影响。结果表明：采用2.0和5.0 mg/kg Cd(NO3)2·4H2O处理柱花草根系土壤，制成菌液，以不加镉的土壤菌液为对照，涂布计数得出2.0和5.0 mg/kg的镉浓度属于抑制微生物生长的浓度。再从其中分离出20株菌株进行鉴定，其中1#和8#、2#和13#、9#和18#为同一菌种，鉴定结果1#、11#、16#为噬菌胞属(Cytophaga)，2#、7#、20#为微球菌属(Micrococcus)，3#、12#为芽孢杆菌属(Bacillus)，4#为芽孢八叠球菌属(Sporosarcina)，5#为黄单胞菌属(Xanthomonas)，6#为色杆菌属(Chromobacterium)，9#为根瘤菌属(Rhizobium)，10#、14#为肠杆菌属(Enterobacter)，15#为固氮菌属(Azotobacter)，17#为德克斯氏菌属(Derxia)，19#为沙雷氏菌属(Serratia)。

cadmium contamination  ;  soil  ;  bacterium  ;  separation  ;  identify

Pot experiment is conducted to study the effect of cadmium on bacteria of Stylosanthes rhizoshpere soil. Stylosanthes root system was treated with cadmium concentrations of 2.0 mg/kg and 5.0 mg/kg. contrasting with control group（with no cadmium）, the bacteria liquid was made from root soil. Spreaded plate and counted bacterial numbers，the result showed cadmium with concentrations of 2.0 mg/kg and 5.0 mg/kg could inhibited growth of microbe. Twenty strains（1#～20#）of bacteria were isolated from the soil. 1# and 8#, 2# and 3#, 9# and 18# are the same. These strains of bacteria were identified. The strains 1#, 2#, 3#, 4#, 5#, 6#, 7#, 9#, 10#, 11#, 12#, 14#, 15#, 16#, 17#, 19#, 20# are named Cytophaga, Micrococcus, Bacillus, Sporosarcina, Xanthomonas, Chromobacterium, Micrococcus, Rhizobium, Enterobacter, Cytophaga, Bacillus, Enterobacter, Azotobacter, Cytophaga, Derxia, Serratia and Micrococcus.