抗Cd细菌J5的筛选和抗Cd^(2+)特性

Screening of Cadmium Resistant Bacterium J5 and Its Resistance to Cd^(2+)

从某冶炼厂污染土壤中分离出一株能高度抗镉和吸附镉的菌株J5,经初步鉴定为假单胞菌属(Pseudo-m onassp.)。研究结果表明该菌株在液体细菌培养基中耐硫酸镉高达40 mmol.L-1,琼脂平板上耐硫酸镉高达75mmol.L-1;J5产碱,有一定絮凝性;Cu2+和Cd2+的共同存在增加了对菌株J5的毒害,Cd2+浓度影响J5绿色色素的表达;活菌体的菌浓度对J5耐Cd2+能力影响很大,菌浓度愈大,耐性愈强,在0~1.5 mmol.L-1Cd2+浓度范围内,J5菌体的全细胞SDS-PAGE电泳图谱差异不明显;活菌体对100μg.mL-1Cd2+积累率为99.1%,吸附率达100%。

A bacterium strain J5 that could adsorb and highly resist on cadmium was isolated from the polluted soil around one smeltery.The preliminary identification suggested that the strain belonged to Pseudomonas sp.and could grow in the liquid bacteria medium including 40 mmol·L^(-1) cadmium sulphate and in the solid bacteria medium including 75 mmol·L^(-1) cadmium sulphate.J5 produced alkali and had flocculation reaction.The coexistence of Cu^(2+) and Cd^(2+) in the medium increased the toxicity to J5.Cd^(2+)concentration affected the expression of green pigment in J5.The concentration of strain J5 affected its tolerance to Cd^(2+),and the higher the concentration of J5,the stronger the resistance to Cd^(2+).When Cd^(2+) concentrations were between 0 and 1.5 mmol·L^(-1),SDS-PAGE electrophoresis charts of J5 whole cell were similar.The accumulation and the adsorption rate for 100 μg· mL^(-1) Cd^(2+) in living J5 was 99.1% and 100%,respectively.