title: Kinetics and response of a Pseudomonas fuorescens HK44 biosensor.
abstract: The reporter bacterium, Pseudomonas fluorescens HK44 (HK44), was characterized in an immobilized state to investigate utility for deployment as a remote sensor in the subsurface. A packed-bed reactor with alginate-immobilized HK44 simulated hydrodynamic conditions such as might be found in a subsurface environment. The reporter bacterium, HK44, harbors a reporter plasmid, pUTK21, which contains a transcriptional fusion between the nahG gene in the lower pathway of the catabolic plasmic NAH7 and a luxCDABE gene cassette. The upper nah pathway and the lux pathway in pUTK21 are induced by salicylate. The lux enzymes catalyze the light reaction. HK44 demonstrated a quantitative relationship between salicylate concentration and degradation. Light intensity mimicked salicylate concentration, whereas degradation was first order in biomass and first order in salicylate concentration, with a degradation constant of 2.23 x 10(-2) dm(3) g(-1) min(-1).
authors.affiliation: Chemical Technology Division, Oak Ridge National Laboratory, P.O. Box 2008 MS-6046, Oak Ridge, Tennessee 37831-6046, USA.
authors.forename: O F
authors.initials: OF
authors.lastname: Webb
authors.forename: P R
authors.initials: PR
authors.lastname: Bienkowski
authors.forename: U
authors.initials: U
authors.lastname: Matrubutham
authors.forename: F A
authors.initials: FA
authors.lastname: Evans
authors.forename: A
authors.initials: A
authors.lastname: Heitzer
authors.forename: G S
authors.initials: GS
authors.lastname: Sayler