Detecting Changes in the Caenorhabditis elegans Intestinal Environment Using an Engineered Bacterial Biosensor

Data for the figures in the manuscript <br> https://pubs.acs.org/doi/10.1021/acssynbio.9b00166 Abstract:<br> <em>Caenorhabditis elegans</em> has become a key model organism within biology. In particular, the transparent gut, rapid growing time, and ability to create a defined gut microbiota make it an ideal candidate organism for understanding and engineering the host microbiota. Here we present the development of an experimental model that can be used to characterize whole-cell bacterial biosensors <em>in vivo</em>. A dual-plasmid sensor system responding to isopropyl β-d-1-thiogalactopyranoside was developed and fully characterized <em>in vitro</em>. Subsequently, we show that the sensor was capable of detecting and reporting on changes in the intestinal environment of <em>C. elegans</em> after introducing an exogenous inducer into the environment. The protocols presented here may be used to aid the rational design of engineered bacterial circuits, primarily for diagnostic applications. In addition, the model system may serve to reduce the use of current animal models and aid in the exploration of complex questions within general nematode and host–microbe biology.