Untersuchungen über “direkten” Bakterienantagonismus

Bacterial Dissociation

“…Differences in initial growth rates (checked by viable counts only) and optimum levels of viable population were observed, and these differences were found to account for the fluctuations noted between the percentage of each variant present at various times after the start of mixed cultures. Earlier data indicative of similar mechanisms during the growth of pneumococcal variants can be found in the studies of Neufeld and Kuhn (172), and also among the observations made by Mohr (164) for mixed cultures containing S and R variants of Salmonella, Shigella dysenteriae, and clostridia, respectively (see also p. 90).5…”

Direct Antagonism in Mixed Bacterial Populations

“…Wynne (1947), using Aerobacter aerogenes as the antagonistic organism, noted a form of bacterial antagonism in which the presence of a specific antibiotic could not be demonstrated, nor could inhibition be explained by mechanisms such as the depletion of an essential metabolite. The concept of direct antagonism (Neufeld and Kuhn, 1934)-antibiosis in which close contact of the living cells of the antagonist with those of the inhibited organism appears to be essentialhas been used to explain this phenomenon. Bowling and Wynne (1951) and Wynne and Norman (1953) have investigated this problem further but without reaching a conclusive result.…”

The Effect of Metabolites Upon Growth and Variation of Brucella Abortus

“…Zamenhof (1946) and especially Ryan and Schneider (1949) obtained data in their studies with Escherichia coli that suggested an important role for such postulated factors in bacterial variation. Etinger-Tulczynska (1932), Neufeld and Kuhn (1934), and Mohr (1934) are among the earlier workers who assumed such effects but were unable to demonstrate their metabolic nature. Similarly, in studies with complex media, Braun (1946) was unable to demonstrate any effect of old culture filtrates upon the establishment of variants in B. abortus cultures.…”