Lactose Fermenting Anaerobes in Soil and Their Relation to Sanitary Water Analysis

Abstract

The suggestion has been made that the search for lactose fermenting anaerobes be made routinely in place of, or in addition to, the lactose fermenting aerobesrobes (Bacterium coli). The purpose of this work was to determine the advisability of such a procedure. If lactose fermenting anaerobes are to serve as an index of fecal pollution in water, it must be shown that they are constantly present in feces and that they are not found in large numbers in soil or elsewhere in nature where they might get into water supplies. Furthermore, as stated by Levine 1 , it ought to be shown that they are able to exist in water for a short time (but only for a short time) after the water has been freed from pathogens. It would seem requisite also that they be readily susceptible to detection without too much time, equipment, or effort.

There is no doubt that lactose fermenting anærobes, including Clostridium welchii, are normally present in human feces, but not all authors have found them in all samples studied, possibly because of the technical difficulties of the isolation of anaerobes.

As to their incidence in nature outside of the intestinal tract, opinions differ. Greer 2 , pointing out the importance of lactose fermenting anaerobes, ignores the possibility of their wide distribution in soil. Topley and Wilson 3 believe that the normal habitat of anaerobes is soil, and that their presence in sewage and feces is incidental. This opinion, while possibly extreme, is, in the light of the literature and the work to be reported, probably nearer the correct one than that of Greer, and others, namely, that Cl. Welchii is to some extent an index of fecal pollution.