Multiple copies of a cadC homolog encoding a heavy metal-responsive transcription factor were found in the genome of a bacterium isolated from ocean sediment, and the heavy metal responses of the encoded proteins were characterized using a fluorescence reporter assay. Each CadC regulator exhibited distinct specificity in response to heavy metal ions, indicating their potential use as modular heavy metal biosensors. Next, we constructed CadC-controlled T7 RNA transcription systems for intracellular signal amplification, i.e., higher sensitivity. Flow cytometry revealed that cadmium and lead ions could be recognized specifically by CadC-T7 biosensors, which could be combined with a microfluidic platform to generate heavy metal biosensor devices with increased sensitivity. Our results demonstrate the successful development of synthetic CadC-T7 genetic circuitry for use in improved heavy metal biosensor microfluidic devices.
Bibliographical noteFunding Information:
This work was supported by grants from the Next-Generation BioGreen 21 Program ( SSAC, PJ01111802 and PJ01118601 ), Rural Development Administration, and the KRIBB Research Initiative Program, Republic of Korea.
© 2015 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Biomedical Engineering