Enhancing the sensitivity of a two-stage continuous toxicity monitoring system through the manipulation of the dilution rate

Man Bock Gu, Geun Cheol Gil, Joong Hyun Kim

Research output: Contribution to journalArticle

13 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)283-288
Number of pages6
JournalJournal of Biotechnology
Issue number3
Publication statusPublished - 2002 Feb 28
Externally publishedYes



  • Dilution rate
  • Recombinant bioluminescent bacteria
  • Sensitivity
  • Toxicity
  • Whole cell biosensor

ASJC Scopus subject areas

  • Biotechnology

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