A multi-channel bioluminescent bacterial biosensor for the on-line detection of metals and toxicity. Part I: design and optimization of bioluminescent bacterial strains

Abstract

This study describes the construction of inducible bioluminescent strains via genetic engineering along with their characterization and optimization in the detection of heavy metals. Firstly, a preliminary comparative study enabled us to select a suitable carbon substrate from pyruvate, glucose, citrate, diluted Luria-Bertani, and acetate. The latter carbon source provided the best induction ratios for comparison. Results showed that the three constructed inducible strains, Escherichia coli DH1 pBzntlux, pBarslux, and pBcoplux, were usable when conducting a bioassay after a 14-h overnight culture at 30 °C. Utilizing these sensors gave a range of 12 detected heavy metals including several cross-detections. Detection limits for each metal were often close to and sometimes lower than the European standards for water pollution. Finally, in order to maintain sensitive bacteria within the future biosensor-measuring cell, the agarose immobilization matrix was compared to polyvinyl alcohol (PVA). Agarose was selected because the detection limits of the bioluminescent strains were not affected, in contrast to PVA. Specific detection and cross-detection ranges determined in this study will form the basis of a multiple metals detection system by the new multi-channel Lumisens3 biosensor.

Selective detection of gold using genetically engineered bacterial reporters

“…Growth phase and cell's nutritional condition may influence not only the reporter expression, but also the envelope status, affecting ion permeability (Charrier et al, 2011;Kohlmeier et al, 2007). Thus, we evaluated the response of the transgenic E. coli golTSB reporter strain to Au and Cu ions under different conditions.…”

“…In fact, most of the designed MerR-based biosensors display high sensitivity but low selectivity because the sensor proteins cross-react with a group of related metal ions (Harms, 2007;Hynninen and Virta, 2010;Magrisso et al, 2008). For example, previously constructed Cu biosensors based on CueR, the monovalent metal sensor of the MerR family, detect Cu but also Ag and Au, as the regulator is similarly sensitive to any of these metals (Charrier et al, 2011;Hakkila et al, 2004;Riether et al, 2001;Stoyanov and Brown, 2003). This makes the use of these bioreporters unsuitable for particular applications.…”

Application of internal standard method in recombinant luminescent bacteria test

“…The detection range of Hg 2+ was from 5 nmol/L to 10 μmol/L, and distinct luminescence could be detected in 30 min. The use of recombinant luminescent bacteria based on the mer gene had the potential to be a proper method for online monitoring of bioavailable mercury, but many issues needed more research before field application (Charrier et al, 2011). One of the most important issues was to avoid the false negative problem.…”

A low cost color-based bacterial biosensor for measuring arsenic in groundwater

“…Other studies reported that the bioluminescent As biosensors responded to other metals (e.g. Cd, Pb, Sn) with various detection limits (Hakkila et al, 2004;Charrier et al, 2011). This might attribute to different P ars and arsR sequences and lux reporter for the biosensors as it has been previously reported that the bioluminescent bacteria were not specific to only one metal but rather to a range of metals (Binet and Poole, 2000;Riether et al, 2001;Charrier et al, 2011).…”