Effect of water velocity on the early development of manganese-depositing biofilm in a drinking-water distribution system

A study of the development of biofilm colonizing the surfaces of pipes in a drinking-water distribution system has shown that water velocity significantly influenced the nature and physiological activity of the biofilm. Biofilm developed at a velocity of 0.5 m s−1 actively oxidized and deposited manganese, but at 0.01 m s−1 no manganese was deposited. Budding bacteria were the dominant microorganisms depositing manganese but a variety of other organisms were also present in the biofilms. The budding bacteria oxidizing manganese were Pedomicrobium manganicum and Metallogenium.