A Biosensor for Detection of Indole Metabolites

Area of Science:

• Microbiology
• Synthetic Biology
• Biochemistry

Background:

• Microbial indole metabolites are crucial signaling molecules in human health, agriculture, and antibiotic resistance.
• Indole-3-aldehyde (I3A) is a microbially produced metabolite linked to anti-inflammatory effects via the aryl hydrocarbon receptor pathway.
• Existing methods for detecting indole metabolites are limited, especially at host-microbe interfaces.

Purpose of the Study:

• To engineer and characterize a novel biosensor for the specific detection of indole-3-aldehyde (I3A).
• To provide a new tool for studying microbial signaling and its role in various biological contexts.
• To expand the toolkit for synthetic biology applications involving indole metabolites.

Main Methods:

• Bioinformatic mining of protein databases to identify potential sensors for indole metabolites.
• Engineering of an *E. coli* strain with a single plasmid containing a chimeric two-component system for I3A detection.
• Characterization of the I3A receptor to determine binding site residues and detection range.

Main Results:

• Successful development of a functional biosensor for indole-3-aldehyde (I3A).
• Characterization confirmed specific binding site residues within the I3A receptor.
• The biosensor demonstrates a detection range of 0.1-10 μM for I3A.

Conclusions:

• The novel I3A biosensor enables the detection of this important microbial metabolite.
• This tool facilitates research into indole metabolite signaling at host-microbe interfaces.
• The engineered system offers valuable new components for synthetic biology.