THE BACTERIAL OXIDATION OF PHENYLACETIC ACID

The bacterial oxidation of aromatic compounds closely related in chemical structure may proceed by different pathways. Thus, while the main features of the breakdown of mandelic acid are established, those of phenylacetate are not, except insofar as it is known to follow a different route (Stanier, 1950). The di-vergencies may possibly indicate a difference in the mode of ring fission; and since it is established that mandelic acid and certain other aromatic compounds give rise to,-ketoadipic acid (Kilby, 1948, 1951; Stanier, 1950), we have in-vestigated the production of keto acids in phenylacetate metabolism. At the same time we have attempted to determine whether the reactions of the tri-carboxylic acid cycle play a part in these oxidations, and whether there is any evidence under favorable conditions for an abridged cycle as postulated by Barron, Ardao, and Hearon (1950) for Corynebacterium creatinovorans and termed by them the "dicarboxylic acid cycle". Pyruvic acid accumulates in aerated cultures of Aerobacter aerogenes growing on glucose or various dicarboxylic acids only when its rate of production exceed