Bacterial Community Structure in the Drinking Water Microbiome Is Governed by Filtration Processes

Abstract

The bacterial community structure of a drinking water microbiome was characterized over three seasons using 16S rRNA gene based pyrosequencing of samples obtained from source water (a mix of a groundwater and a surface water), different points in a drinking water plant operated to treat this source water, and in the associated drinking water distribution system. Even though the source water was shown to seed the drinking water microbiome, treatment process operations limit the source water's influence on the distribution system bacterial community. Rather, in this plant, filtration by dual media rapid sand filters played a primary role in shaping the distribution system bacterial community over seasonal time scales as the filters harbored a stable bacterial community that seeded the water treatment processes past filtration. Bacterial taxa that colonized the filter and sloughed off in the filter effluent were able to persist in the distribution system despite disinfection of finished water by chloramination and filter backwashing with chloraminated backwash water. Thus, filter colonization presents a possible ecological survival strategy for bacterial communities in drinking water systems, which presents an opportunity to control the drinking water microbiome by manipulating the filter microbial community. Grouping bacterial taxa based on their association with the filter helped to elucidate relationships between the abundance of bacterial groups and water quality parameters and showed that pH was the strongest regulator of the bacterial community in the sampled drinking water system.

Pyrosequencing analysis of roof-harvested rainwater and river water used for domestic purposes in Luthengele village in the Eastern Cape Province of South Africa

“…At the genus taxonomic level the presence of large proportions of phylotypes belonging to the genera Acidovorax, Curvibacter and Gemmata, and the family Commamonadaceae in our study was similar to other findings in fresh water samples from around the world (Pinto et al 2012;Lautenschlager et al 2013;Navarro-noya et al 2013). …”

Bacterial community change through drinking water treatment processes

“…Eichler et al (2006) found that no major changes of bacterial community structures occurred after flocculation and sand filtration. In contrast, Pinto et al (2012) found that filtration by dual media rapid sand filters could shape the bacterial community in waters. Based on the significant difference between bacterial communities in raw water and on BAC, Soonglerdsongpha et al (2011) suggested that bacterial community structure changed along the BAC filtration process.…”

“…Pinto et al (2012) found that filtration by dual media rapid sand filters in a drinking water plant played a primary role in shaping the bacterial community in DWDS. The main aim of the current study was to assess bacterial community change through drinking water treatment processes.…”

Bacteria in drinking water sources of a First Nation reserve in Canada

“…Several studies have used high-throughput sequencing technologies to investigate bacterial community diversity in water distribution systems locations or components (Kwon, 2011;Pinto et al, 2012;Douterelo et al, 2013;Navarro-Noya et al, 2013). In a recent study, we highlight the importance for such investigations in First Nations communities in Canada (Fernando et al, 2016).…”