Studies on Oxidative Fermentation

Part XIX. Catabolism of K-5-Ketogluconate by Acetobacter suboxydans. II

Abstract

Further investigations on the oxidation pro-ducts and the oxidative pathway of 5-ketoglu-conic acid by intact and dried cells of Acetobacter suboxydans ATCC 621 gave the following results.
(1) The yield of α-ketoglutaric acid was about 3 0 of 5-ketogluconic acid supplied as the substrate and the former acid produced did not undergo further oxidation.
(2) Besides acetic, succinic, a-ketoglutaric and
glycolic acids as reported in the previous paper, a little amount of pyruvic acid was found in the oxidation products by this organism.
(3) It was ascertained that dried cells of this organism which were capable of oxidizing 5-ketogluconic acid did not oxidize the members of the tricarboxylic acid cycle and related compounds except oxalacetic acid. This result suggests that tricarboxylic acid cycle may not be operative in the degradation processes of 5-ketogluconic acid.
(4) Glycolaldehyde was oxidized by this organism quantitatively but glycolic acid pro-duced could not be oxidized further.
(5) L-Tartaric acid could not be oxidized even though a little amount of glucose was added into the reaction system.