title: Enhancing the sensitivity of a two-stage continuous toxicity monitoring system through the manipulation of the dilution rate.
abstract: Optimization of the dilution rates has been studied to provide an enhanced sensitivity to toxicity by several recombinant bioluminescent Escherichia coli strains, TV1061 (grpE::luxCDABE), DPD2794 (recA::luxCDABE) and DPD2540 (fabA::luxCDABE), in the two-stage continuous toxicity monitoring system. It was found that the sensitivity of both TV1061 and DPD2794 to a pulse injection of phenol and mitomycin C increased with a decrease in the dilution rate. The sensitivity, however, for all the strains to step injections of the toxic chemicals was found to increase with an increase in the dilution rate up to a certain dilution rate and then decreased, mainly due to the rapid washing out of the injected chemicals. The response kinetics of the strains were explained by evaluating the mode of action of the recombinant bioluminescent bacteria to toxicity with the dilution rate, the operating parameter of minibioreactors under consideration in this study.
authors.affiliation: Department of Environmental Science and Engineering, Advanced Environmental Monitoring Research Center (ADEMRC), Kwangju Institute of Science and Technology (K-JIST), 1 Oryong-dong, Puk-gu, Kwangju 500-712, South Korea. mbgu@kjist.ac.kr
authors.forename: Man Bock
authors.initials: MB
authors.lastname: Gu
authors.forename: Geun Cheol
authors.initials: GC
authors.lastname: Gil
authors.forename: Joong Hyun
authors.initials: JH
authors.lastname: Kim
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D019149:Bioreactors / Q000382:microbiology; D015374:Biosensing Techniques / Q000379:methods; D004784:Environmental Monitoring / Q000379:methods*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D008163:Luminescent Measurements; D016685:Mitomycin / Q000378:metabolism / Q000633:toxicity*; D019800:Phenol / Q000378:metabolism / Q000633:toxicity*; D011994:Recombinant Proteins / Q000235:genetics; D012680:Sensitivity and Specificity; D014157:Transcription Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; C085427:LuxI protein, Bacteria; D011994:Recombinant Proteins; D014157:Transcription Factors; D019800:Phenol; D016685:Mitomycin