Designing a bacterial biosensor for detection of mercury in water solutions

Abstract

Due to increasing advances in physical and chemical techniques for the assessment of pollutants in the environment, there is an immediate demand for a bioassay that can report both the presence of an analyte and its biological effects. In accordance with this need, there has been a fast growth in whole-cell biosensor technology. In this study we aimed to design a whole-cell bacterial biosensor to detect mercury in liquid solutions. The Pseudomonas pBS228 merR gene and its related promoter/operator was synthesized by Bioneer. The green fluorescence protein (GFP) gene was used as a reporter. GFP was cloned downstream of the merR gene. The construct, including the merR promoter, gene, and GFP, was cloned in a pUC19 vector and transferred into E. coli BL21 (DE3) bacteria. Transformed bacteria were used as whole-cell biosensors for detecting mercury. Mercury detection was monitored by means of microscopy and fluorometry techniques. Transformed BL21 (DE3) biosensors responded mainly to Hg(II), with the lowest detectable concentration being 10 -8 M during a 3-h exposure induction period. Our results demonstrated that the noninfectious bacterial biosensors developed in the present study could be beneficial and enforceable in detection of mercury in contaminated water samples at concentrations as low as 10 -8 M.

MerR‐fluorescent protein chimera biosensor for fast and sensitive detection of Hg2+ in drinking water

“…Although the results indicate that MerR:EYFP biosensor is promising for real water sample analysis with good reproducibility and reliability, the biosensor performance should also be tested in industrial water samples with high concentrations of ions and organic substances. A whole‐cell bacterial biosensor using GFP gene as the reporter has been previously reported . MerR:EYFP biosensor should also be compared with whole‐cell Hg biosensors for use in environmental samples.…”

Development of a Cell-Free Optical Biosensor for Detection of a Broad Range of Mercury Contaminants in Water: A Plasmid DNA-Based Approach

“…16,17 Previously, mercury-based whole-cell biosensors were reported with different reporter genes capable of detecting different mercury concentrations. 18 Among these, the microorganism-based method has gained popularity, where the contaminant-induced expression of the LucFF gene and subsequent luminescence production is measured for sensing applications. Still, there are many disadvantages of the whole-cell and LucFF-based biosensors.…”

Determinantes Genéticos Y Sus Mecanismos De Acción Implicados en La Resistencia Bacteriana a Metales Pesados: Una Revisión.

“…10 -4 y 10 -8 M Hg 2+ merR-gfp (81) Biosensor bacteriano de células completas para la detección de cadmio. Las plantas transgénicas redujeron 4 veces más la concentración de mercurio a diferencia de los controles.…”