The Relationship of Some Bacterial Plant Pathogens to the Coliform Bacteria (Abstract)

Cultural and biochemical tests commonly used in the characterization of the coliform bacteria have been applied to 12 species of bacterial plant pathogens including Bacillus amylovorus, B. tracheiphilus, B. salicis, B. carotovorus, B. phytophthorus, B. atrosepticus, B. aroideae, B. melonis, B. lathyri, B. anans, Bacterium dissolvens and Bact. stewardii. These were studies comparatively with type cultures of Escherichia coli, E. freundii, Aerobacter aerogenes, A. cloacae, Proteus vulgaris and Serratia marcescens. Only one species, Bacterium dissolvens, was found to belong to the coliform bacteria. On the basis of these studies it should be considered a member of the genus Aerobacter. The soft rot bacteria, Bacillus carotovorus, B. phytophthorus, B. atrosepticus, B. aroideae and B. melonis, while closely related, were found to be distinct from the coliform bacteria in a number of important respects. They appeared to show a remarkably close relationship to Serratia marcescens. Bacillus amylovorus, B. tracheiphilus and B. salicis have been previously shown to constitute the genus Erwinia and to be only remotely related to the coliform bacteria. On the basis of this study Bacterium stewardii appeared to be closely related to the species of Erwinia, but its exact relationship is still a matter of doubt. Bacillus lathyri and B. annas appeared to be more closely related to Serratia marcescens than to the coliform bacteria