Semicontinuous Detection of 1,2-Dichloroethane in Water Samples Using Xanthobacter autotrophicus GJ 10 Encapsulated in Chitosan Beads

Abstract

A semicontinuous microbial assay for the determination of halogenated short-chain hydrocarbons in water samples was developed. The bacterium Xanthobacter autotrophicus GJ 10 forms dehalogenating enzymes, which liberate the halides in 1,2-dichloroethane as halogen ions. Cells of the organism were immobilized in chitosan beads and placed into a tube reactor, whose outlet was connected to a flow-through cell with chloride-selective potentiometric electrodes. Water samples were delivered continuously to the system, and the EMF was recorded. Both the difference in EMF between blank and sample and the velocity of the EMF change were used for calibration. The detection limit for 1,2-dichloroethane was below 0.5 mg/ L; the relative standard deviation was <10%. The effects of several parameters like flow rate and cell density were studied in detail.

Development of a Fiber Optic Enzymatic Biosensor for 1,2-dichloroethane

“…The same group also developed continuous and semi-continuous assay systems that coupled small immobilized cell bioreactors to ionselective electrodes (Peter et al 1996b(Peter et al , 1997a. One of these systems, which used X. autotrophicus GJ10, detected DCA at 0.5 mg/l (Peter et al 1997b). A similar concept had been described earlier by Henrysson and Mattiasson (1993) for dichloromethane using the dehalogenase expressed in whole cells of Hyphomicrobium DM2.…”

Haloalkane dehalogenases: Biotechnological applications

“… Biotechnological applications of HLDs. Summary of reported applications of DatA [35], DbeA (Prudnikova et al, in preparation), DbjA [45, 47, 57, 61, 63, 125], DhaA [14, 44, 45, 47, 57, 66, 78, 79, 83, 87, 89, 92, 94, 96, 105–115, 125], DhlA [75, 76, 93, 97], DmbA [44, 89], DmlA [47], DpcA [38] and LinB [28, 44, 45, 47, 57, 61, 89, 95]. Abbreviations: BSA, bovine serum albumin; CB, 1‐chlorobutane, DCA; 1,2‐dichloroethane; DKR, dynamic kinetic resolution; KR, kinetic resolution; POI, protein of interest; TCP, 1,2,3‐trichloropropane; TEV, cleavage site for TEV protease.…”

“…Detection of chemicals using biosensors provides a simple and rapid alternative to the traditional analytical techniques, such as gas and liquid chromatography, which are time‐consuming, expensive and not suitable for continuous measurements [92–95]. Initial attempts to construct biosensors for halogenated substrates (Supporting information, Table S6) led to a system with dehalogenating cells immobilized in polymer beads as a biological component and ion selective electrodes as a transducer [96, 97].…”

“…The performance of the biosensor is critically influenced by the selection of an appropriate immobilization method for the biological component. The dehalogenating cells were encapsulated on the transducer [92–94, 96, 97], while the purified enzyme was covalently bound [95]. Two previous reports on covalent immobilization of HLDs described covalent binding of DhaA onto alumina support impregnated by polyethyleneimine [67] and combination of affinity and covalent binding of DhlA on iron oxide nanoparticles [99].…”

Voltammetric detection of organohalides by redox catalysis: improved sensitivity by immobilisation within a cubic phase liquid crystal

“…For this reason, there has been interest in the detection of organohalides by electrochemistry, as this is one possible route to simple handheld sensors. Reported methods have involved potentiometric detection following organohalide breakdown by microorganisms, 3,4 impedance-based detection of sorption into a conducting polymer, 5 and voltammetric detection by accumulation in a sol-gel, 6 as part of a collector-generator process, 7 or by redox catalysis with an immobilised metal complex. [8][9][10][11][12][13][14] This last method has been the most intensively studied technique.…”