一株耐镉细菌的筛选、鉴定与性质研究

Screening,Identification and Characterization of A Cadmium Resistant Strain

从重金属镉污染土壤中分离筛选出一株耐镉能力为25mmol·L-1的细菌,根据形态学观察、生理生化实验和分子鉴定,确定为鞘氨醇单胞菌属(Sphingomonas sp.),命名为CdTB02。该菌株的最佳生长条件为:NaCl浓度1%、装液量30mL/250mL、pH值6.0、温度35℃;而在含1mmol·L-1 Cd2+的环境中,最佳耐镉生长条件为:NaCl浓度1%、装液量30mL/250mL、pH值7.0、温度30℃。镉吸附实验结果显示,菌株CdTB02在最佳耐镉生长条件下对Cd2+的吸附率达到94%以上,表明菌株CdTB02对治理镉污染能发挥一定的作用。

In this paper,a strain with maximum cadmium tolerated concentration of 25mmol·L-1 was isolated from the soil of heavy metal cadmium polluted area.It was identified as Sphingomonas sp.and named as CdTB02 by morphological observation,physiological-biochemical identification and molecular identification.The optimum growth conditions for strain CdTB02 were as follows：NaCl concentration of 1%,liquid loading of30mL/250 mL,pH value of 6.0and temperature of 35 ℃.In the environment of containing 1 mmol·L-1Cd2＋,the optimum growth conditions of cadmium resistance were as follows：NaCl concentration of 1%,liquid loading of 30mL/250 mL,pH value of 7.0and temperature of 30 ℃.Cadmium adsorption experiment showed that the adsorption rate of Cd2＋was more than 94% under the optimum growth conditions of cadmium resistance,which indicated that the strain CdTB02 could play an important role in the treatment of cadmium pollution.