[Numerical taxonomic studies on enterobacteria of surface-water (author's transl)]

435 enterobacterial strains of surface-water were tested in 35 physiological characters and classified numerically by a single-linkage procedure. The relations of similarity are shown in a "Vernetzungsdiagramm" (connected graph, Fig. 1). Tab. 1 specifies the characters of the taxa, which were formed graphically. The following facts are the result of this taxonomic classification: 1. 32% of the Escherichia group are KCN-positive. In addition it was found that 60% of the E. coli isolated from the faeces of wild ducks were KCN-positive. 2. The type strains of the species Enterobacter aerogenes and Klebsiella aerogenes show a far reaching conformity in their physiological character. The splitting into two genera does not seem to be of significance any longer. 3. By reason of the "Vernetzungsdiagramm" and the table of characters (Tab. 1) we propose to regroup the genera Enterobacter and Erwinia. The genus Erwinia represented here by bacteria of the Herbicola-Lathyri-group is clearly divided into two groups. In the discussion we propose for Erwinia I the name of Enterobacter agglomerans and for Erwinia II the name of Enterobacter herbicola. 4. The taxa Kluyvera and Levinea are placed in the vicinity of Enterobacter cloacae and Erwinia II (Enterobacter herbicola), respectively.