Relationship between Indole Production, Nitrite Production and Carbohydrate Fermentation in Vibrio cholerae

Abstract

Vibrio cholerae produces indole in the presence of nitrite even though the formen cannot always be demonstrated as such by standard test procedures. The results of present experiments indicate that the inhibition of a positive indole reaction by nitrite may be due to the interaction of nitrite with the para-dimethyl-amino-benzaldehyde in the indole reagent. Several factors, such as strain differences, pH change of culture medium, nature of fermentable carbohydrates, are also associated with the inhibition of indole production in the presence of fermentable substrates. The way in which these factors, singly or in combination, affect this inhibition is not known.