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Characterization of chlorinated and chloraminated drinking water microbial communities in a distribution system simulator using pyrosequencing data analysis
Citation:
REVETTA, R. P., R. S. Matlib, C. Curioso, AND J. W. SANTO-DOMINGO. Characterization of chlorinated and chloraminated drinking water microbial communities in a distribution system simulator using pyrosequencing data analysis . Presented at ASM 111th General Meeting, New Orleans, LA, May 21 - 24, 2011.
Impact/Purpose:
To inform the public.
Description:
The molecular analysis of drinking water microbial communities has focused primarily on 16S rRNA gene sequence analysis. Since this approach provides limited information on function potential of microbial communities, analysis of whole-metagenome pyrosequencing data was used to simultaneously determine microbial composition and functional genes associated with chlorine- and chloramine-treated drinking water samples. Biomass from 100 L samples was concentrated using ultrafiltration and used in DNA extractions. A total of 1,024,242 and 849,349 high quality reads averaging 345 and 386 base pairs were generated for chlorine and chloramine samples, respectively. Less than 3% of the sequencing data assembled into contigs of at least 500bp. More sequences mapped to COGs in the chlorinated sample (70,630 vs. 29,226). COGs involved in energy production and conversion and amino acid, lipid, and inorganic ion transport and metabolism were more abundant in the chlorinated sample. Secondary metabolite biosynthesis, transport and catabolism were better represented in the chloraminated sample. A greater number of microbial groups were represented in the chlorinated sample based on predicted COGs, although bacterial, archaeal, eukaryotic, and viral genes were identified in both samples. While the vast majority of sequences could not be phylogenetically assigned, of those that could, Proteobacteria were the most abundant group in both samples. Alpha, delta, and gamma Proteobacteria were more numerous in the chlorinated sample while there were more beta Proteobacteria COGs in the chloraminated sample. Other differences in overall structure were noted, specifically, cyanobacteria and Clostridia were more frequently found in the chlorinated sample, whereas Actinobacteria and Bacteroidetes COGS were more frequent in the chloraminated sample. Overall, this study further confirms that drinking water harbors microbial communities that are complex in composition and functional diversity. The data suggest that disinfection treatment could influence the overall microbial genetic dynamics of drinking water. Changes in functional diversity may impact the overall integrity of water distribution systems and as a result the microbial quality of water.