Although most bacteria are removed from drinking water before it reaches our lips, a few strains survive the filtration and chlorination steps designed to clean the water. Researchers from the University of Michigan tracked down the sources of bacteria, and found that beneficial populations, could be selected by slightly changing the acidity of the water.
The main source of bacterial diversity, surprisingly, was the filters designed to remove the organic matter on which bacteria feed. These filters were shown to play a major role in shaping the bacterial community in the drinking water, suggesting that changing how the filters are cleaned could also steer the microbial community toward beneficial bacteria. The results were published online in last month (July 16) in Environmental Science & Technology.