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16S rRNA Gene Sequence Analysis of Drinking Water Using RNA and DNA Extracts as Targets for Clone Library Development
Citation:
REVETTA, R. P., B. Iker, AND J. W. SANTO-DOMINGO. 16S rRNA Gene Sequence Analysis of Drinking Water Using RNA and DNA Extracts as Targets for Clone Library Development. Presented at American Society for Microbiology 110th General Meeting, San Diego, CA, May 23 - 27, 2010.
Impact/Purpose:
To inform the public
Description:
We examined the bacterial composition of chlorinated drinking water using 16S rRNA gene clone libraries derived from RNA and DNA extracted from twelve water samples collected in three different months (June, August, and September of 2007). Phylogenetic analysis of 1234 and 1117 RNA-based and DNA-based clone sequences, respectively, showed that unclassified Bacteria were the most abundant sequences, representing on average 57% of all sequences analyzed. Other phylogenetic groups identified included Cyanobacteria (5% RNA; 4% DNA), Actinobacteria (1% RNA; 10% DNA), Bacteroidetes (<1% RNA; 7% DNA), and Proteobacteria (36% RNA; 23% DNA). Interestingly, Alpha-Proteobacteria was 10 to 18 times more abundant in the RNA-based clones than in the DNA-based libraries. Operational taxonomic unit (OTU) analyses indicated that 31 OTUs were shared between all RNA- and DNA-based libraries at 98% similarity, however, representing only 10% of the total observed OTUs. Diversity indices (Chao1) indicated that the richness (number of phylotypes) of RNA and DNA shared OTUs was slightly higher in June and August (25, and 23) than in September (18). By contrast, similarity in community membership (Jaccard = 0.11 June, 0.09 August, and 0.12 September) and community structure (thetaYC=0.23 June, 0.16 August, and 0.25 September) suggested that August bacterial communities are different than June and September. The results from this study further improve our understanding of the molecular diversity and bacterial population dynamics of drinking water microbial communities. Since the same eubacterial primer set was used in this study, these results have implications regarding the identity and potential activity level of bacterial populations within drinking water microbial communities.
