Isolation and characterization of haloacetic acid-degradingAfipiaspp. from drinking water

Abstract

Haloacetic acids are a class of disinfection byproducts formed during the chlorination and chloramination of drinking water that have been linked to several human health risks. In this study, we isolated numerous strains of haloacetic acid-degrading Afipia spp. from tap water, the wall of a water distribution pipe, and a granular activated carbon filter treating prechlorinated water. These Afipia spp. harbored two phylogenetically distinct groups of alpha-halocarboxylic acid dehalogenase genes that clustered with genes previously detected only by cultivation-independent methods or were novel and did not conclusively cluster with the previously defined phylogenetic subdivisions of these genes. Four of these Afipia spp. simultaneously harbored both the known classes of alpha-halocarboxylic acid dehalogenase genes (dehI and dehII), which is potentially of importance because these bacteria were also capable of biodegrading the greatest number of different haloacetic acids. Our results suggest that Afipia spp. have a beneficial role in suppressing the concentrations of haloacetic acids in tap water, which contrasts the historical (albeit erroneous) association of Afipia sp. (specifically Afipia felis) as the causative agent of cat scratch disease.

Haloacetic acid-degrading bacterial communities in drinking water systems as determined by cultivation and by terminal restriction fragment length polymorphism of PCR-amplified haloacid dehalogenase gene fragments

“…2004), can deplete the pool of HAAs in drinking water. Finally, micro‐organisms in drinking water and the walls of the distribution pipes can biodegrade HAAs (Zhang et al. 2009a,b).…”

“…2001), activated sludge (McRae et al. 2004; Kerr and Marchesi 2006) and drinking water systems (Zhang et al. 2009a,b).…”

“…Previous research, therefore, has had limited success in understanding the organisms that are potentially responsible for degrading HAAs in drinking water distribution systems. Zhang et al. (2009a,b) isolated numerous Afipia spp., which harboured phylogenetically related dehI and/or dehII genes with differing abilities to biodegrade different HAAs.…”

Biodegradation of chloro- and bromobenzoic acids: Effect of milieu conditions and microbial community analysis

“…Afipia sp. is known to degrade haloacetic acids [32] and was isolated, for example, from alkylated phenol degrading activated sludge or drinking water [32,33]. Several OTUs within the 3-CBA batch sample set are related to Sphingobacteriales (Fig.…”

Evaluate HAA removal in biologically active carbon filters using the ICR database

“…Since HAAs were found to be easily biodegradable, preformed HAAs (by prechlorination or intermediate chlorination) could be reduced by biodegradation in distribution systems or within treatment processes [11][12][13][14][15][16]. GAC has low adsorption capacities for HAAs.…”