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bioRxiv · 10.1101/2024.10.08.617249

An Autonomous Microbial Sensor Enables Long-term Detection of TNT Explosive in Natural Soil

Essington, E. A.·Vezeau, G. E.·Cetnar, D. P.·Grandinette, E.·Bell, T. H.·Salis, H. M.
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Abstract

Microbes can be engineered to detect target chemicals, but when they operate in real-world environments, it remains unclear how competition with natural microbes affect their performance over long time periods. We engineered sensors and memory-storing genetic circuits inside Bacillus subtilis to sense and respond to the TNT explosive, using predictive models for rational design. We characterized their ability to detect TNT in a natural soil system, measuring single-cell and population-level behavior over a 28-day period. The autonomous microbial sensor activated its response by 14-fold when exposed to low TNT concentrations and maintained stable activation for over 21 days, exhibiting exponential decay dynamics at the population-level with a half-life of about 5 days. Our results show that engineered soil bacteria can carry out long-term detection of an important chemical in natural soil with competitive growth dynamics serving as additional biocontainment.

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Essington, E. A., Vezeau, G. E., Cetnar, D. P., Grandinette, E., Bell, T. H., Salis, H. M.. 2024-10-08. An Autonomous Microbial Sensor Enables Long-term Detection of TNT Explosive in Natural Soil. https://doi.org/10.1101/2024.10.08.617249

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