Reversal of Penicillin Inhibition by a Yeast Extract

Abstract

THE preparation from yeast of a growth-factor for Corynebacterium diphtheri^1,2 has shown the active concentrates to be complex mixtures containing amino-acids and peptides, one of the latter yielding on hydrolysis serine, glycine and glutamic acid. Attempted removal of the reducing substances present by osazone formation led to destruction of the activity, and some component of the mixture gave a positive reaction in the Elson and Morgan³ test for amino-sugars ; the colour produced was not, however, identical with that obtained with glucosamine, and the conditions required suggested the presence of an acylated amino-aldehyde. With a mixture of such complexity there was nothing to indicate that these observations were interconnected ; but certain speculative considerations based on the above led to the search for a relationship between the active extract and the inhibitory effect of penicillin on Gram-positive micro-organisms. This search was encouraged by the similarity between certain of the components of the yeast preparation and the fragments obtained on partial hydrolysis of penicillin.