Evaluation of membrane filters for the determination of numbers of coliform bacteria in water.

Since the report by Goetz (1947) on the nature and use of membrane filters in Germany, a number of papers have appeared in this country on membrane filter technics for the bacteriological analysis of water. Interest in the use of these membranes was particularly stimulated in 1951 following the publication of papers by Clark et al. (1951) and Goetz and Tsuneishi (1951). These investigators described membrane filter procedures for the determination of coliform and other bacteria in water and concluded that they might have distinct advantages over the MPN procedures of Standard Methods for the Examination of Water and Sewage (A.P.H.A. 1946). Further studies on the use of membrane filters for the bacteriological examination of water have been reported in this country by Clark et a?. (1952); Goetz et al. (1952); Slanetz (1952); Bush (1952); Goetz (1953); Yee et al. (1953); Laubusch et al. (1953); Hajna and Damon (1954); Levin and Laubusch (1954); and Kabler (1954). In Europe, Zsigmondy and Bachmann (1918) were the first to develop procedures for the efficient production of membranes for bacteriological purposes. Elford in England and Grabar in France also developed technics for the production of similar membranes on a small scale. As a result of Zsigmondy's efforts while at the University of Goettingen, the membranes were produced on a commercial basis by the MembranfilterGesellschaft, Satorius-Worke, Goettingen, Germany. This plant is still in active operation and the senior author had an opportunity to visit it while in Germany in 1952. Membrane filters were apparently first used to test for coliform bacteria in water in Russia in 1933. They have been used to a considerable extent for this purpose in Germany since 1943. Grossmann and Beling (1944) published a paper on procedures for determination of coliforms and members of the typhoid-paratyphoid group in drinking water by means of membrane filters. Other papers on this subject were published in Germany by Kruse (1949), and Fast (1953). These investigators concluded that the membrane filter method is a rapid and efficient means for the determination of the sanitary quality of drinking water. Taylor et al. (1953) compared membrane filter tech-