Detection of organomercurials with sensor bacteria

Area of Science:

• Environmental Science
• Microbiology
• Biotechnology

Background:

• Mercury and its organic compounds, particularly methylmercury, pose significant environmental and health risks due to biomagnification and neurotoxicity.
• Accurate detection of organomercurial compounds is crucial for environmental monitoring and risk assessment.

Purpose of the Study:

• To construct and evaluate a recombinant whole-cell bacterial sensor for detecting organic mercury compounds.
• To assess the sensitivity of the engineered sensor for environmentally relevant organomercurials.

Main Methods:

• Construction of a bacterial sensor strain coexpressing firefly luciferase reporter and organomercurial lyase.
• Utilizing the mercury-inducible regulatory element from the broad-spectrum mer operon (pDU1358).
• Testing sensor sensitivity against methylmercury chloride, phenylmercury acetate, and dimethylmercury.

Main Results:

• The sensor demonstrated high sensitivity, detecting methylmercury chloride at 0.2 nM, phenylmercury acetate at 1 nM, and dimethylmercury at 10 microM.
• The sensor also responded to inorganic mercury.
• The engineered bacteria effectively detected organic mercury compounds by cleaving the mercury-carbon bond.

Conclusions:

• The developed whole-cell bacterial sensor is effective for detecting various organic mercury compounds at low concentrations.
• This sensor, potentially combined with inorganic mercury sensors, can facilitate the characterization of mercury contamination in environmental matrices.
• The study presents a promising tool for environmental monitoring of toxic mercury species.