The Bacteriostatic and Bactericidal Action of Great Salt Lake Water

Abstract

Although saturated with salt, the water of this lake contained an average of 167 bacteria per ml. which grow on nutrient lake water agar. Most of these were obligate halophiles whose multiplication was inhibited by diluting the lake water with more than 50% freshwater. Few or no bacteria from sewage, soil or the human mouth grew on lake water media and 10% lake water proved bacteriostatic for over 3/4 of the freshwater spp. Great Salt Lake water was also bactericidal for freshwater bacteria including the mixed microflora from native habitats as well as pure cultures of Escherichia coli and Staphylococcus albus. Laboratory acclimatized stock cultures were far more resistant than recently isolated species. Marine bacteria which are generally regarded as being halotolerant were killed by a few minutes'' exposure to Great Salt Lake water. Bacteria isolated from lake water at places remote from possibilities of terrestrial contamination are apparently species indigenous to the lake. They have become acclimatized to the increasing salt concns. during the time the water of old Lake Bonneville has evaporated, leaving its saline remnant, Great Salt Lake. The chem. composition of the lake water is given. The latter had a total salinity of 27.6% in Dec. 1935.