via Flickr under the public domain license

Shifting Focus to the Good Bacteria in Water

Often on this blog, we talk about biofilms in water systems or water-borne pathogens. Even when we discuss the drinking water microbiome, it is seldom with a focus on any particularly beneficial bacteria. Although there has been some discussion about what essentially amounts to probiotics for water, there seems to be little literature in the area of beneficial bacteria in water.

A recent news article from the Economic Times discusses a new study from Lund University in Sweden. They claim that “A glass of clean drinking water contains ten million ‘good’ bacteria which may help purify the water and keep it safe.” They say that much like the human microbiome, the drinking water microbiome consists of beneficial bacteria that keep it clean and healthy. The paper from Lund University (Lührig et al, 2015) goes into more detail and explanation. Here is the abstract:

Next-generation sequencing of the V1-V2 and V3 variable regions of the 16S rRNA gene generated a total of 674,116 reads that described six distinct bacterial biofilm communities from both water meters and pipes. A high degree of reproducibility was demonstrated for the experimental and analytical work-flow by analyzing the communities present in parallel water meters, the rare occurrence of biological replicates within a working drinking water distribution system. The communities observed in water meters from households that did not complain about their drinking water were defined by sequences representing Proteobacteria (82—87%), with 22—40% of all sequences being classified as Sphingomonadaceae. However, a water meter biofilm community from a household with consumer reports of red water and flowing water containing elevated levels of iron and manganese had fewer sequences representing Proteobacteria (44%); only 0.6% of all sequences were classified as Sphingomonadaceae; and, in contrast to the other water meter communities, markedly more sequences represented Nitrospira and Pedomicrobium. The biofilm communities in pipes were distinct from those in water meters, and contained sequences that were identified as Mycobacterium, Nocardia, Desulfovibrio, and Sulfuricurvum. The approach employed in the present study resolved the bacterial diversity present in these biofilm communities as well as the differences that occurred in biofilms within a single distribution system, and suggests that next-generation sequencing of 16S rRNA amplicons can show changes in bacterial biofilm communities associated with different water qualities.

via Flickr under the public domain license
via Flickr under the public domain license

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Alex Alexiev

Alex Alexiev is a recent UC Davis graduate with a BS in microbiology working in Jonathan Eisen’s lab on aquariums as part of the microbiology of the built environment.