title: Ammonia- and nitrite-oxidizing bacterial communities in a pilot-scale chloraminated drinking water distribution system.
abstract: Nitrification in drinking water distribution systems is a common operational problem for many utilities that use chloramines for secondary disinfection. The diversity of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in the distribution systems of a pilot-scale chloraminated drinking water treatment system was characterized using terminal restriction fragment length polymorphism (T-RFLP) analysis and 16S rRNA gene (ribosomal DNA [rDNA]) cloning and sequencing. For ammonia oxidizers, 16S rDNA-targeted T-RFLP indicated the presence of Nitrosomonas in each of the distribution systems, with a considerably smaller peak attributable to Nitrosospira-like AOB. Sequences of AOB amplification products aligned within the Nitrosomonas oligotropha cluster and were closely related to N. oligotropha and Nitrosomonas ureae. The nitrite-oxidizing communities were comprised primarily of Nitrospira, although Nitrobacter was detected in some samples. These results suggest a possible selection of AOB related to N. oligotropha and N. ureae in chloraminated systems and demonstrate the presence of NOB, indicating a biological mechanism for nitrite loss that contributes to a reduction in nitrite-associated chloramine decay.
authors.affiliation: Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706-1691, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Regan
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Harrington
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Noguera
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D041841:Bradyrhizobiaceae / Q000145:classification* / Q000235:genetics; D002700:Chloramines / Q000494:pharmacology*; D003001:Cloning, Molecular; D004275:DNA, Ribosomal / Q000032:analysis; D017753:Ecosystem; D020459:Genes, rRNA; D008969:Molecular Sequence Data; D009573:Nitrites / Q000378:metabolism*; D010084:Oxidation-Reduction; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods; D014881:Water Supply
chemical_list: D002700:Chloramines; D004275:DNA, Ribosomal; D009573:Nitrites; D012336:RNA, Ribosomal, 16S; D000641:Ammonia