This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Haddix, P. L. Articles by LeChevallier, M. W. Search for Related Content PubMed PubMed Citation Articles by Haddix, P. L. Articles by LeChevallier, M. W. Agricola Articles by Haddix, P. L. Articles by LeChevallier, M. W.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, February 2004, p. 850-854, Vol. 70, No. 2
0099-2240/04/$08.00+0     DOI: 10.1128/AEM.70.2.850-854.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Characterization of Bioluminescent Derivatives of Assimilable Organic Carbon Test Bacteria

American Water Quality Control and Research Laboratory, Belleville, Illinois 62220-3102,¹ American Water, Inc., Voorhees, New Jersey 08043²

Received 4 August 2003/ Accepted 23 October 2003

The assimilable organic carbon (AOC) test is a standardized measure of the bacterial growth potential of treated water. We describe the design and initial development of an AOC assay that uses bioluminescent derivatives of AOC test bacteria. Our assay is based on the observation that bioluminescence peaks at full cell yield just prior to the onset of the stationary phase during growth in a water sample. Pseudomonas fluorescens P-17 and Spirillum sp. strain NOX bacteria were mutagenized with luxCDABE operon fusion and inducible transposons and were selected on minimal medium. Independent mutants were screened for high luminescence activity and predicted AOC assay sensitivity. All mutants tested were able to grow in tap water under AOC assay conditions. Strains P-17 I5 (with p-aminosalicylate inducer) and NOX I3 were chosen for use in the bioluminescence AOC test. Peak bioluminescence and plate count AOC were linearly related for both test bacteria, though data suggest that the P-17 bioluminescence assay requires more consistent luminescence monitoring. Bioluminescence results were obtained 2 or 3 days postinoculation, compared with 5 days for the ATP luminescence AOC assay and 8 days for the plate count assay. Plate count AOC assay results for nonmutant and bioluminescent bacteria from 36 water samples showed insignificant differences, indicating that the luminescent bacteria retained a full range of AOC measurement capability. This bioluminescence method is amenable to automation with a microplate format with programmable reagent injection.