Li Xin, Wang Jie, Tan Zhouliang, Ma Liang, Lu Dong, Li Wenjian, Wang Jufang
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, Gansu, 730000, China; Gansu Key Laboratory of Microbial Resources and Application, Institute of Modern Physics, Chinese Academy of Sciences, China.
Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuang, 610041, China.
J Hazard Mater. 2018 Jul 5;353:1-8. doi: 10.1016/j.jhazmat.2018.03.036. Epub 2018 Mar 26.
Heavy metal pollution is harmful to the environment and to human health. Resistant strains can grow in adverse conditions and store heavy metals to reduce their damage. The Cd resistant mutant strain C2, which was irradiated by the C beams, can grow in Cd medium ranging from 20 to 100 mg L when compared with the original strain. Attempting to discern the cause of the resistance, the phenotype and antioxidant defense system were analyzed. SEM images showed that when exposed to Cd, gaps on the cell surface were filled with a complex granular compound. FT-IR demonstrated that the alcoholic hydroxyl group, amino, and amide groups combined with ions. Moreover, responses of antioxidant defense system were different in the Cd groups. The expression of SOD peaked at 24 h in high concentrations of Cd; the content of GSH increased gradually and was significantly affected by cultivation time. The MDA and CAT had the strongest response to 20 mg L Cd, and the related metabolic pathway of CAT might play a key role in the resistance to high concentrations of Cd. The result indicated that the applicability of C2 could provide potential biotechnology for treatment of wastewaters and soils with Cd pollutions.
重金属污染对环境和人类健康有害。抗性菌株能够在不利条件下生长并储存重金属以减轻其危害。与原始菌株相比，经碳离子束辐照获得的镉抗性突变菌株C2能够在20至100 mg/L的镉培养基中生长。为了探究抗性产生的原因，对其表型和抗氧化防御系统进行了分析。扫描电子显微镜图像显示，当暴露于镉时，细胞表面的间隙被一种复杂的颗粒状化合物填充。傅里叶变换红外光谱表明，醇羟基、氨基和酰胺基与离子结合。此外，镉处理组中抗氧化防御系统的反应有所不同。在高浓度镉处理下，超氧化物歧化酶（SOD）的表达在24小时达到峰值；谷胱甘肽（GSH）的含量逐渐增加，且受培养时间的显著影响。丙二醛（MDA）和过氧化氢酶（CAT）对20 mg/L镉的反应最强，CAT的相关代谢途径可能在高浓度镉抗性中起关键作用。结果表明，C2菌株的适用性可为镉污染废水和土壤的处理提供潜在的生物技术。
