title: Construction and application of a zinc-specific biosensor for assessing the immobilization and bioavailability of zinc in different soils.
abstract: 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.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Pulin
authors.initials: P
authors.lastname: Liu
authors.forename: Qiaoyun
authors.initials: Q
authors.lastname: Huang
authors.forename: Wenli
authors.initials: W
authors.lastname: Chen
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D005959:Glucosidases / Q000032:analysis / Q000378:metabolism; D007763:Lac Operon; D016958:Pseudomonas putida / Q000378:metabolism; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D015032:Zinc / Q000032:analysis* / Q000737:chemistry
chemical_list: D012987:Soil; D012989:Soil Pollutants; D005959:Glucosidases; D015032:Zinc