title: Development of a highly specific and sensitive cadmium and lead microbial biosensor using synthetic CadC-T7 genetic circuitry.
abstract: 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.
authors.affiliation: Infection and Immunity Research Center, Korea Research Institute Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea; Biosystems & Bioengineering Program, University of Science and Technology (UST), Daejeon, Republic of Korea.
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea.
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Lim
authors.affiliation: Biosystems & Bioengineering Program, University of Science and Technology (UST), Daejeon, Republic of Korea; Superbacteria Research Center, KRIBB, Daejeon, Republic of Korea.
authors.forename: Haeyoung
authors.initials: H
authors.lastname: Jeong
authors.affiliation: Department of Bio-Food Materials, Silla University, Busan, Republic of Korea.
authors.forename: Sang-Jae
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Dong-Woo
authors.initials: DW
authors.lastname: Lee
authors.affiliation: Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea; Department of Mechanical Engineering, UNIST, Ulsan, Republic of Korea. Electronic address: tskim@unist.ac.kr.
authors.forename: Taesung
authors.initials: T
authors.lastname: Kim
authors.affiliation: Infection and Immunity Research Center, Korea Research Institute Bioscience and Biotechnology (KRIBB), Daejeon, Republic of Korea; Biosystems & Bioengineering Program, University of Science and Technology (UST), Daejeon, Republic of Korea. Electronic address: leesj@kribb.re.kr.
authors.forename: Sang Jun
authors.initials: SJ
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D002104:Cadmium / Q000032:analysis* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D007854:Lead / Q000032:analysis* / Q000378:metabolism; D046210:Microfluidic Analytical Techniques / Q000379:methods; D008969:Molecular Sequence Data; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D014157:Transcription Factors; D002104:Cadmium; D007854:Lead
keywords: CadC; Heavy metal ions; Microbial biosensor; Microfluidic device; T7 RNA polymerase