Characterization of nitrifying populations in chloraminated drinking water distribution systems by TRFLP analysis

Nitrification is a common operational problem encountered by chloraminating drinking water utilities that can result in water quality violations. Studies on nitrifying bacteria in these systems are limited to the use of culture-based methods, which yield biased results due to the selective recovery of strains capable of growing in the culturing medium and require extended incubations due to the slow growth rate of these bacteria. A terminal restriction fragment length polymorphism protocol targeting the 16S rDNA gene is developed to allow the rapid identification of ammonia and nitrite-oxidizing bacteria. This protocol and another that targets the ammonia monooxygenase gene for ammonia-oxidizer identification were applied to samples from a pilot-scale chloraminated system to characterize the diversity of nitrifying bacteria. This is an abstract of a paper presented at the 221st ACS National Meeting (San Diego, CA 4/1-5/2001).