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 Wahman, D. G. Articles by Speitel, G. E. Search for Related Content PubMed PubMed Citation Articles by Wahman, D. G. Articles by Speitel, G. E., Jr. Agricola Articles by Wahman, D. G. Articles by Speitel, G. E.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, December 2005, p. 7980-7986, Vol. 71, No. 12
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.12.7980-7986.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Cometabolism of Trihalomethanes by Nitrosomonas europaea

The University of Texas at Austin, Department of Civil, Architectural and Environmental Engineering, 1 University Station, Austin, Texas 78712

Received 28 June 2005/ Accepted 4 August 2005

The ammonia-oxidizing bacterium Nitrosomonas europaea (ATCC 19718) was shown to degrade low concentrations (50 to 800 µg/liter) of the four trihalomethanes (trichloromethane [TCM], or chloroform; bromodichloromethane [BDCM]; dibromochloromethane [DBCM]; and tribromomethane [TBM], or bromoform) commonly found in treated drinking water. Individual trihalomethane (THM) rate constants () increased with increasing THM bromine substitution, with TBM > DBCM > BDCM > TCM (0.23, 0.20, 0.15, and 0.10 liters/mg/day, respectively). Degradation kinetics were best described by a reductant model that accounted for two limiting reactants, THMs and ammonia-nitrogen (NH₃-N). A decrease in the temperature resulted in a decrease in both ammonia and THM degradation rates with ammonia rates affected to a greater extent than THM degradation rates. Similarly to the THM degradation rates, product toxicity, measured by transformation capacity (T_c), increased with increasing THM bromine substitution. Because both the rate constants and product toxicities increase with increasing THM bromine substitution, a water's THM speciation will be an important consideration for process implementation during drinking water treatment. Even though a given water sample may be kinetically favored based on THM speciation, the resulting THM product toxicity may not allow stable treatment process performance.