Detection of dichloromethane with a bioluminescent (lux) bacterial bioreporter

Abstract

The focus of this research effort was to develop an autonomous, inducible, lux-based bioluminescent bioreporter for the real-time detection of dichloromethane. Dichloromethane (DCM), also known as methylene chloride, is a volatile organic compound and one of the most commonly used halogenated solvents in the U.S., with applications ranging from grease and paint stripping to aerosol propellants and pharmaceutical tablet coatings. Predictably, it is released into the environment where it contaminates air and water resources. Due to its classification as a probable human carcinogen, hepatic toxin, and central nervous system effector, DCM must be carefully monitored and controlled. Methods for DCM detection usually rely on analytical techniques such as solid-phase microextraction (SPME) and capillary gas chromatography or photoacoustic environmental monitors, all of which require trained personnel and/or expensive equipment. To complement conventional monitoring practices, we have created a bioreporter for the self-directed detection of DCM by taking advantage of the evolutionary adaptation of bacteria to recognize and metabolize chemical agents. This bioreporter, Methylobacterium extorquens DCM( lux ), was engineered to contain a bioluminescent luxCDABE gene cassette derived from Photorhabdus luminescens fused downstream to the dcm dehalogenase operon, which causes the organism to generate visible light when exposed to DCM. We have demonstrated detection limits down to 1.0 ppm under vapor phase exposures and 0.1 ppm under liquid phase exposures with response times of 2.3 and 1.3 h, respectively, and with specificity towards DCM under relevant industrial environmental monitoring conditions.

‘Aggregation-Induced Emission’ Active Mono-Cyclometalated Iridium(III) Complex Mediated Efficient Vapor-Phase Detection of Dichloromethane

“…The excessive usage and the high volatility of DCM result in significant contamination of water and air [ 5 ]. In general, the detection of DCM relies on gas chromatography [ 6 , 7 ], mass spectroscopy [ 8 ], or bioluminescent markers [ 9 ]. All these techniques require considerable time, high cost, and significant effort.…”

Transcriptional regulation of organohalide pollutant utilisation in bacteria

“…Finally, regulatory processes can also be exploited not only to improve degradation of organohalides, but also to monitor and predict bioremediation potential, as well as to evaluate their bioavailability and quantify them in natural environments (Lopes et al 2012;Hua et al 2015;Whangsuk et al 2016;Farhan Ul Haque et al 2017). Bioreporter strains expressing a fluorescent protein as a function of organohalide identity and concentration have been developed (e.g.…”

Detection of Organic Compounds with Whole-Cell Bioluminescent Bioassays

“…In the liquid phase, the reporter could detect DCM between a range of 1.2 μM–12 mM, and the induction time was relatively decreased compared to aerosolized samples, requiring only 0.5 h at the 12-mM concentration. Regardless of the medium used (aerosol or liquid) there was a correlation between bioluminescent output and DCM concentration at an R 2 value of 0.99 [51]. In contrast to the nonspecific reaction of tod - and sep -based systems, this level of specificity and dose–response kinetics highlights what can be achieved by modulating the selectivity of the upstream regulatory element that is used for bioreporter generation.…”