Optical fiber bioluminescent whole-cell microbial biosensors to genotoxicants

Abstract

Conservation of water resources calls for ever stricter regulatory measures and better monitoring systems. Whole-cell bacterial sensors have been genetically engineered to react to target toxicants by the induction of a selected promoter and the subsequent production of bioluminescent light through a recombinant lux reporter. In order to create a one-step assay, we have designed a new, self-contained, disposable optical fiber sensor module and a customized photodetector system that integrates these microorganisms. A photon-counting photomultiplier tube-based instrument was constructed. Optical fiber tip cores were covered with adlayer films consisting of calcium alginate containing bioluminescent bacterial sensors of genotoxicants. Multiplying these steps thickened the adlayer in increments, increasing the number of bacterial reporters attached to the optical fiber transducer. These whole cell optrodes are responsive to external traces of DNA damaging agents such as mitomycin C. Light production was shown to be dose-dependent and proportional to the number of bacterial layers.

Detection of bioavailable heavy metals in EILATox‐Oregon samples using whole‐cell luminescent bacterial sensors in suspension or immobilized onto fibre‐optic tips

“…As was reported previously, the etched fibre-optic tips have higher light coupling capacity (Polyak et al, 2000), Table 1 therefore we used reduced optical fibres (350 ± 5 µm, as measured by light microscopy) obtained by incubating fibre tips in 48% hydrogen fluoride (HF) for 10 min.…”

Wastewater Toxicity Assessment by Whole Cell Biosensor

“…A novel approach to the problem is the use of fibre optics as the transducer, with subsequent electronic amplification [237]. Subsequent optimisation procedures have been aimed at producing a self-contained bioluminescent sensor which is reagentless and stable.…”

An innovative strategy for immobilization of receptor proteins on to an optical fiber by use of poly(pyrrole-biotin)

“…The instrumental arrangement for the chemiluminescence measurements has been described elsewhere [5,6]. A Hamamatsu HC135-01 photomultiplier tube (PMT) sensor module was used for chemiluminescence measurements, combining the sensitivity of a photomultiplier tube with the intelligence of a microcontroller.…”

“…Reported methods for immobilizing bioreceptors, include adsorption [3], entrapment in a gel matrix [4,5,6], cross-linking by means of a multifunctional reagent [1,7,8,9,10,11,12], covalent bonding on to a membrane [13] or by means of an avidin-biotin linkage [13,14,15]. This last method, avidin-biotin immobilization, has achieved wide acceptance in recent years for binding biological species to surfaces in both analytical and preparative applications [16,17].…”