Mechanism of inhibition by acetic acid of the germination of spores of aspergillus niger

Abstract

IT was shown in a previous paper1 that lower fatty acids in molasses inhibit in their undissociated form the germination of Aspergillus niger spores. It is therefore not possible in the production of citric acid by fermentation of sugars from beet molasses to start with an acid substrate, as is usual in synthetic media ; the acids present, already at pH nearing 4.8, inhibit spore germination. Acetic acid shows the greatest differences in effect when changing from a neutral to an acid medium. © 1957 Nature Publishing Group.