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Monochloramine disinfection kinetics of Nitrosomonas europaea by propidium monoazide quantitative PCR and Live/Dead BacLight Methods
Citation:
WAHMAN, D., K. A. KLEIER, AND J. G. PRESSMAN. Monochloramine disinfection kinetics of Nitrosomonas europaea by propidium monoazide quantitative PCR and Live/Dead BacLight Methods. APPLIED AND ENVIRONMENTAL MICROBIOLOGY. American Society for Microbiology, Washington, DC, 75(17):5555-5562, (2009).
Impact/Purpose:
To inform public
Description:
Monochloramine disinfection kinetics were determined for the pure culture ammonia-oxidizing bacterium Nitrosomonas europaea (ATCC 19718) by two culture independent methods: (1) LIVE/DEAD® BacLight™ (LD) and (2) propidium monoazide quantitative PCR (PMA-qPCR). Both methods were first verified with mixtures of heat-killed (nonviable) and non-heat-killed (viable) cells before conducting a series of batch disinfection experiments with stationary phase cultures (batch grown seven days) at pH 8.0; 25°C; and 5, 10, and 20 mg Cl2/L monochloramine. Two data sets were generated based on the viability method used: (1) LD and (2) PMA-qPCR. These two data sets were used to estimate kinetic parameters for the Delayed Chick-Watson disinfection model through a Bayesian analysis implemented in WinBUGS. This analysis provided parameter estimates of 490 mg Cl2-min/L for the lag coefficient (b) and 1.6 x 10-3 to 4.0 x 10-3 L/mg Cl2-min for the Chick-Watson disinfection rate constant (k). While estimates of “b” were similar for both data sets, the LD data set resulted in a greater k estimate compared with the PMA-qPCR data set, implying that the PMA-qPCR viability measure was more conservative than LD. For N. europaea, the lag phase was not previously reported with culture-independent methods, and may have implications for nitrification in drinking water distribution systems. This is the first published application of a PMA-qPCR method for disinfection kinetic model parameter estimation as well as its application to N. europaea or monochloramine. Ultimately, this PMA-qPCR method will allow evaluation of monochloramine disinfection kinetics for mixed culture bacteria in drinking water distribution systems.
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For further information (PDF, NA pp, 5 KB, about PDF)MONOCHLORAMINE DISINFECTION KINETICS OF NITROSOMONAS EUROPAEA BY PROPIDIUM MONOAZIDE QUANTITATIVE PCR AND LIVE/DEAD BACLIGHT METHODS
