State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
Environ Pollut. 2012 May;164:66-72. doi: 10.1016/j.envpol.2012.01.023. Epub 2012 Feb 14.
The inducibility and specificity of different czcRS operons in Pseudomonas putida X4 were studied by lacZ gene fusions. The data of β-glycosidase activity confirmed that the czcR3 promoter responded quantitatively to zinc. A zinc-specific biosensor, P. putida X4 (pczcR3GFP), was constructed by fusing a promoterless enhanced green fluorescent protein (egfp) gene with the czcR3 promoter in the chromosome of P. putida X4. In water extracts of four different soils amended with zinc, the reporter strain detected about 90% of the zinc content of the samples. Both the bioavailability assessment and the sequential extraction analysis demonstrated that the immobilization of zinc was highly dependent on the physico-chemical properties of soils. The results also showed that the lability of zinc decreased over time. It is concluded that the biosensor constitutes an alternative system for the convenient evaluation of zinc toxicity in the environment.
通过 lacZ 基因融合，研究了铜绿假单胞菌 X4 中不同 czcRS 操纵子的诱导性和特异性。β-葡糖苷酸酶活性数据证实 czcR3 启动子对锌具有定量响应。通过将无启动子增强型绿色荧光蛋白（egfp）基因与铜绿假单胞菌 X4 染色体中的 czcR3 启动子融合，构建了锌特异性生物传感器 P. putida X4（pczcR3GFP）。在添加锌的四种不同土壤的水提取物中，报告菌株检测到样品中约 90%的锌含量。生物有效性评估和连续提取分析均表明，锌的固定化高度依赖于土壤的物理化学性质。结果还表明，锌的不稳定性随时间降低。因此，可以得出结论，该生物传感器构成了一种替代系统，可用于方便地评估环境中锌的毒性。
