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Updated: Aug 11, 2026
Bacterial Detection & Identification Using Electrochemical Sensors
Published on: April 23, 2013
A panel of visual bacterial biosensors for the rapid detection of genotoxic and oxidative damage: A proof of concept
Chang-Ye Hui1, Shun-Yu Hu2, Xue-Qin Yang1
1Department of Pathology & Toxicology, Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen, China.
Abstract:
The emergence of new compounds during the past decade requires a high-throughput screening method for toxicity assay. The stress-responsive whole-cell biosensor is a powerful tool to evaluate direct or indirect damages of biological macromolecules induced by toxic chemicals. In this proof-of-concept study, nine well-characterized stress-responsive promoters were first selected to assemble a set of blue indigoidine-based biosensors. The PuspA-based, PfabA-based, and PgrpE-based biosensors were eliminated due to their high background. A dose-dependent increase of visible blue signal was observed in PrecA-, PkatG-, and PuvrA-based biosensors, responsive to potent mutagens, including mitomycin and nalidixic acid, but not to genotoxic lead and cadmium. The PrecA, PkatG, and Ppgi gene promoters were further fused to a purple deoxyviolacein synthetic enzyme cluster. Although high basal production of deoxyviolacein is unavoidable, an enhanced visible purple signal in response to mitomycin and nalidixic acid was observed as dose-dependent, especially in PkatG-based biosensors. The study shows that a set of stress-responsive biosensors employing visible pigment as a reporter is pre-validating in detecting extensive DNA damage and intense oxidative stress. Unlike widely-used fluorescent and bioluminescent biosensors, the visual pigment-based biosensor can become a novel, low-cost, mini-equipment, and high-throughput colorimetric device for the toxicity assessment of chemicals. However, combining multiple improvements can further improve the biosensing performance in future studies.
Insights
New whole-cell biosensors use visible pigments for toxicity screening. These stress-responsive systems effectively detect DNA damage and oxidative stress from chemicals like mitomycin, offering a low-cost, high-throughput alternative.
Area of Science:
- Biotechnology
- Toxicology
- Microbial Engineering
Background:
- High-throughput toxicity assays are crucial for evaluating new chemical compounds.
- Stress-responsive whole-cell biosensors can detect chemical-induced damage to biological macromolecules.
- Visible pigment reporters offer a low-cost alternative to fluorescent or bioluminescent systems.
Purpose of the Study:
- To develop and validate novel whole-cell biosensors using visible pigments for toxicity assessment.
- To screen stress-responsive promoters for optimal performance in detecting genotoxicity and oxidative stress.
- To establish a proof-of-concept for a colorimetric, high-throughput toxicity screening method.
Main Methods:
- Selection and assembly of nine stress-responsive promoters into indigoidine-based biosensors.
- Elimination of high-background biosensors (PuspA, PfabA, PgrpE).
- Fusion of selected promoters (PrecA, PkatG, Ppgi) with a deoxyviolacein enzyme cluster for purple pigment production.
Main Results:
- PrecA-, PkatG-, and PuvrA-based biosensors showed dose-dependent blue signal increases in response to mutagens (mitomycin, nalidixic acid).
- These biosensors did not respond to genotoxic metals (lead, cadmium).
- PkatG-based deoxyviolacein biosensors exhibited enhanced purple signal increases with dose-dependent mutagen exposure, despite basal production.
Conclusions:
- Visible pigment-based stress-responsive biosensors are effective for detecting DNA damage and oxidative stress.
- These novel biosensors offer a low-cost, mini-equipment, high-throughput colorimetric method for chemical toxicity assessment.
- Further improvements can enhance the performance of these visual pigment-based biosensing systems.
