Detection of Bile Acids in Complex Matrices Using a Transcription Factor-Based Biosensor

Abstract

Bile acids play an important role in digestion and human health, are found throughout the gastrointestinal tract, and are excreted in feces. Therefore, bile acids are promising biomarkers for monitoring health and detecting fecal contamination in water sources.Here, we engineered a bile acid sensor by expressing the transcription factor BreR, a TetR-like repressor from Vibrio cholorae, in Escherichia coli. The sensor was further optimized by screening a promoter library. To further characterize the BreR sensor and increase its utility, we moved expression to a cell-free expression (CFE) system, resulting in an approximately 3 orders of magnitude increase in deoxycholic acid sensitivity. We next optimized this sensor to detect bile acids in fecal water, wastewater, and serum and transferred the CFE sensor to a paper-based assay to enhance fieldability.

ACS Biomaterials Science and Engineering Special Issue Editorial: Design and Evaluation of Engineered Probiotics

“…A number of teams in this special issue widened this sensor “bottleneck”. Beabout and co-workers designed and optimized a sensor to detect bile acids in a probiotic chassis, E. coli Nissle 1917 . Bile acids are essential components of the digestive system, and are known serum biomarkers for disease.…”

“…Beabout and co-workers designed and optimized a sensor to detect bile acids in a probiotic chassis, E. coli Nissle 1917. 17 Bile acids are essential components of the digestive system, and are known serum biomarkers for disease. Beabout and co-workers optimized sensor expression through screening a promotor library, and then took the innovative step of transferring the system to a cell-free expression system to expedite the DBTL cycle to optimize the sensor.…”

Metal–Organic Cage Receptors for Encapsulation and Sensing of Bile Acids

“…Additionally, with the assistance of indicators, the sensing of bile acids can also be realized with the receptors. Since changes in bile acid concentration and composition have a strong relation with diverse diseases, recognition and sensing of bile acids can have potential therapeutic applications . The existing techniques to identify this rely primarily on mass spectrometry …”

“…Since changes in bile acid concentration and composition have a strong relation with diverse diseases, recognition and sensing of bile acids can have potential therapeutic applications. 18 The existing techniques to identify this rely primarily on mass spectrometry. 19 Steroid recognition with synthetic supramolecular receptors is a long-standing pursuit.…”