Abstract
Genetically engineered microbial biosensors have yet to realize commercial success in environmental applications due, in part, to difficulties associated with transducing and transmitting traditional bioluminescent information. Bioelectrochemical systems (BESs) output a direct electric signal that can be incorporated into devices for remote environmental monitoring. Here, we describe a BES-based biosensor with genetically encoded specificity for a toxic metal. By placing an essential component of the metal reduction (Mtr) pathway of Shewanella oneidensis under the control of an arsenic-sensitive promoter, we have genetically engineered a strain that produces increased current in response to arsenic when inoculated into a BES. Our BES-based biosensor has a detection limit of ~40μM arsenite with a linear range up to 100μM arsenite. Because our transcriptional circuit relies on the activation of a single promoter, similar sensing systems may be developed to detect other analytes by the swap of a single genetic part.
•We developed a bioelectrochemical system (BES)-based environmental biosensor.•The biosensor includes a genetically encoded specificity for a toxic metal.•We genetically engineered a Shewanella oneidensis biosensing strain.•The biosensing strain produces current in response to arsenic in a BES.•We found a detection limit of ~40μM arsenite and a linear range up to 100μM.