Determination of Zinc, Cadmium and Lead Bioavailability in Contaminated Soils at the Single-Cell Level by a Combination of Whole-Cell Biosensors and Flow Cytometry

Sensors

Quentin Hurdebise²  Cຝric Tarayre²  Christophe Fischer²  Gilles Colinet¹  Serge Hiligsmann²  Frank Delvigne² 

[1] Bât. G1 Systèmes Sol-Eau, Avenue Maréchal Juin 27, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium; E-Mail:;Bât. G1 Bio-Industries, Passage des Déportés 2, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium; E-Mails:

关键词: flow cytometry;    Escherichia coli pP_ZntAgfp;    cadmium;    lead;    zinc;    bioavailability;    whole-cell biosensors;   

DOI  :  10.3390/s150408981

来源: mdpi

【 摘 要 】

Zinc, lead and cadmium are metallic trace elements (MTEs) that are widespread in the environment and tend to accumulate in soils because of their low mobility and non-degradability. The purpose of this work is to evaluate the applicability of biosensors as tools able to provide data about the bioavailability of such MTEs in contaminated soils. Here, we tested the genetically-engineered strain Escherichia coli pP_ZntAgfp as a biosensor applicable to the detection of zinc, lead and cadmium by the biosynthesis of green fluorescent protein (GFP) accumulating inside the cells. Flow cytometry was used to investigate the fluorescence induced by the MTEs. A curvilinear response to zinc between 0 and 25 mg/L and another curvilinear response to cadmium between 0 and 1.5 mg/L were highlighted in liquid media, while lead did not produce exploitable results. The response relating to a Zn²⁺/Cd²⁺ ratio of 10 was further investigated. In these conditions, E. coli pP_ZntAgfp responded to cadmium only. Several contaminated soils with a Zn²⁺/Cd²⁺ ratio of 10 were analyzed with the biosensor, and the metallic concentrations were also measured by atomic absorption spectroscopy. Our results showed that E. coli pP_ZntAgfp could be used as a monitoring tool for contaminated soils being processed.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.