Your weekend update : Microbes and drinking water Diversity of ribosomal 16 S DNA-and RNA-based bacterial community in an office buildin \ ng drinking water system –

Next-generation sequencing of 16S ribosomal RNA genes (rDNA) and ribosomal RNA (rRNA) was used to characterize water and biofilm microbiome collected from a drinking water distribution system of an office building after its first year of operation. (...) Microbial communities differed between water and biofilms, between cold and hot water systems, locations in the building and between water rRNA and rDNA libraries, as shown by clear clusters in principal component analysis (PcoA). By using the rRNA method, we found that not all bacterial community members were active (e.g. Legionella spp.) while other members showed increased activity in some locations; e.g. Pseudomonas spp. in hot water circulations’ biofilm and order Rhizobiales and Limnohabitans spp. in stagnated locations’ water and biofilm. (...) rRNA-based methods may be better than rDNA-based methods for evaluating human health implications as rRNA methods can be used to describe the active bacterial fraction. This study indicates that copper as a pipeline material might have an adverse impact on the occurrence of Mycobacterium spp. The activity of Legionella spp. maybe questionable when detected solely by using DNA-based methods.