[Bacteria of the Flexibacter/Sporocytophaga group and violet-pigmented bacteria as indicators for hygienically doubtful drinking water].

Bacteria of the Flexibacter/Sporocytophaga group indicate, that drinking water is deficiently protected by the soil covering or may be infiltrated by surface waters. In South Bavaria those germs could be demonstrated in 1225 of 3743 samples from central water supplies and in 951 of 1714 samples from decentralized water supplies. F/Sp-bacteria could be isolated to a much greater extend from samples which were likewise polluted with Escherichia coli, coliforms and colony counts in excess. Over the year, bacteria of the F/Sp group are constantly distributed in contrast to E.coli or coliforms and will therefore constitute an useful indicator germ for hygienic hazardous drinking water supplies. In agreement with that violet-colored bacteria could also be isolated to a greater extend from polluted drinking water samples.