Science Inventory

Identification of Bacterial Populations in Drinking Water Using 16S rRNA-Based Sequence Analyses

Citation:

REVETTA, R. P., A. C. PEMBERTON, R. Lamerdella, B. Iker, AND J. W. SANTO-DOMINGO. Identification of Bacterial Populations in Drinking Water Using 16S rRNA-Based Sequence Analyses. WATER RESEARCH. Elsevier Science Ltd, New York, NY, 44(5):1353-1360, (2010).

Impact/Purpose:

To inform public

Description:

Intracellular RNA is rapidly degraded in stressed cells and is more unstable outside of the cell than DNA. As a result, RNA-based methods have been suggested to study the active microbial fraction in environmental matrices. The aim of this study was to identify bacterial populations in drinking water by analyzing 16S rRNA-based clone libraries. Hollow-fiber ultrafiltration was used to concentrate bacterial communities from 40 liters of tap water collected at different times from a single point-of-use. Total RNA was extracted from the microbial concentrates and then used to develop 16S rRNA-based clone libraries. Operational taxonomic units (OTUs) were formed from 1236 partial 16S rRNA gene sequences from 18 different clone libraries representing three different months - June, August, and September. Phylogenetic analyses revealed that a large clade of yet to be cultured bacterial clones were the most predominant group, representing 51% of OTUs, and 91% of total sequences in the samples analyzed. Within the uncultured group, 44% of sequences were closely related to sequences retrieved from previous drinking water studies, including sequences retrieved from DNA-, and RNA-based studies. Overall, the results suggest that these bacteria are indeed among the most common metabolically-active drinking water bacteria. Bacterial groups represented in this study included proteobacteria, cyanobacteria, actinobacteria, Bacteroidetes, and Planctomycetes. The results from this study further improve our understanding of the molecular diversity and bacterial population dynamics of drinking water distribution system microbial communities. Moreover, these results provide the sequence foundation for the development of molecular assays that target active drinking water bacteria.