Improving the specificity of E. coli acetate/propionate exclusion biosensors via iterative engineering

Real-time monitoring of key indicators like acetate and propionate in anaerobic digesters (AD) is crucial for optimal biogas production. This paper discusses the improvements made to E. coli-based biosensors for acetate and propionate detection. By identifying and eliminating interfering metabolites, the biosensors’ accuracy was enhanced.

In the study, formate was found in AD reactor samples and interfered with existing E. coli biosensors. Using a technique called P1 phage transduction, researchers deleted two genes responsible for formate breakdown, eliminating this interference and improving the propionate biosensor’s accuracy.

For the acetate biosensor, a response to propionate was resolved by replacing a specific enzyme with one from yeast, ensuring precise acetate measurement.

The improved biosensors accurately measured acetate and propionate levels in real AD samples, matching results obtained through traditional methods, proving their reliability.