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Title: Kinetics and response of a Pseudomonas fluorescens HK44 biosensor

Journal Article · · Biotechnology and Bioengineering
;  [1]; ; ; ;  [2]
  1. Oak Ridge National Lab., TN (United States). Chemical Technology Div.
  2. Univ. of Tennessee, Knoxville, TN (United States). Center for Environmental Biotechnology

Polycyclic aromatic hydrocarbons (PAH) are persistent environmental contaminants that are toxic and carcinogenic. Hundreds of sites exist nationwide that are highly contaminated at concentrations greater than grams PAH per kilogram of soil. These sites range from 1 to over 100 acres. Indigenous soil organisms have demonstrated their ability to degrade these compounds. 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 {times} 10{sup {minus}2} dm{sup 3} g{sup {minus}1} min{sup {minus}1}.

OSTI ID:
566327
Journal Information:
Biotechnology and Bioengineering, Vol. 54, Issue 5; Other Information: PBD: 5 Jun 1997
Country of Publication:
United States
Language:
English