title: Electrochemical evaluation of cellular physiological status under stress in Escherichia coli with the rpoS-lacZ reporter gene.
abstract: We developed an electrochemical detection method for evaluating cellular physiological status based on the stringent response as a means to monitor cell viability. A reporter plasmid was constructed by inserting the beta-galactosidase gene (lacZ) under the control of the rpoS promoter, and then used to transform E. coli cells. Electrochemical responses from the products catalyzed by beta-galactosidase expressed by these E. coli cells were detected using the chronoamperometric technique in a nondestructive manner. Comparisons of response currents between the relA-positive strain and relA-negative strain revealed that increases in these currents were caused by the stringent response due to the stressful alcoholic environment, and thus as a model of stressful cultivating conditions. The current was proportional to the beta-galactosidase activity assayed by a conventional method that required the destruction of cells. The cellular physiological status, which depends on the stringent response as a viability marker, therefore, could then be evaluated online with a current using the rpoS-lacZ reporter gene in the relA-positive strain without pretreatment.
authors.affiliation: Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan.
authors.forename: Hisakage
authors.initials: H
authors.lastname: Funabashi
authors.forename: Miyuki
authors.initials: M
authors.lastname: Ishikawa
authors.forename: Masayasu
authors.initials: M
authors.lastname: Mie
authors.forename: Fumio
authors.initials: F
authors.lastname: Takahashi
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Yanagida
authors.forename: Masuo
authors.initials: M
authors.lastname: Aizawa
authors.forename: Eiry
authors.initials: E
authors.lastname: Kobatake
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D015374:Biosensing Techniques; D004563:Electrochemistry; D004784:Environmental Monitoring / Q000379:methods*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D000431:Ethanol / Q000494:pharmacology; D017930:Genes, Reporter; D007763:Lac Operon / Q000235:genetics; D012808:Sigma Factor / Q000235:genetics*; D001616:beta-Galactosidase / Q000032:analysis* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D000431:Ethanol; D001616:beta-Galactosidase