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Published on: February 7, 2018
A bacterial biosensor for oxidative stress using the constitutively expressed redox-sensitive protein roGFP2
Carlos R Arias-Barreiro1, Keisuke Okazaki1, Apostolos Koutsaftis1,2
1Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan.
Sensors (Basel, Switzerland)
|December 14, 2011
Summary
A novel bacterial biosensor, E. coli-roGFP2, rapidly detects cellular oxidation induced by various chemical toxicants. This high-throughput system offers a faster alternative to conventional oxidative stress sensors for environmental monitoring.
Area of Science:
- Environmental Science
- Biotechnology
- Toxicology
Background:
- Cellular oxidation is a critical indicator of environmental stress and toxicant exposure.
- Conventional bacterial oxidative stress sensors often lack speed and high-throughput capability.
- Redox-sensitive fluorescent proteins offer potential for rapid and sensitive detection of cellular redox changes.
Purpose of the Study:
- To develop and characterize a rapid, high-throughput bacterial biosensor for detecting chemically induced cellular oxidation.
- To assess the sensitivity and response kinetics of the biosensor to a range of oxidative and heavy metal toxicants.
- To elucidate the underlying mechanisms of biosensor response to environmental stressors.
Main Methods:
- Development of an Escherichia coli (E. coli) strain constitutively expressing redox-sensitive green fluorescent protein 2 (roGFP2).
- Utilized a double-wavelength ratiometric approach to quantify roGFP2 disulfide formation, indicating oxidation.
- Tested biosensor response to various chemical oxidants (e.g., H2O2, menadione) and heavy metals (e.g., Cd2+, Cu2+) at different concentrations and time points.
Main Results:
- The E. coli-roGFP2 biosensor detected cellular oxidation within seconds to minutes, significantly faster than conventional sensors.
- Specific lowest observable effect concentrations (LOECs) were determined for multiple toxicants.
- Responses varied between oxidants and heavy metals, with oxidants showing concentration-dependent sigmoid curves and heavy metals exhibiting less clear patterns.
- roGFP2 sensitivity to redox potential changes and thiol modification was confirmed through integrated in vivo and in vitro assays.
Conclusions:
- The E. coli-roGFP2 biosensor is a highly specific and rapid tool for detecting chemical-induced cellular oxidation.
- This technology provides a comprehensive and efficient system for identifying toxicants that perturb cellular redox homeostasis.
- The developed biosensor holds promise for environmental monitoring and toxicological screening applications.
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