Identification of altro-heptulose and l-threitol as products of meso-erythritol oxidation by Acetobacter suboxydans

In addition to the main product l -erythrulose, altro -heptulose and l -threitol were found in medium in which meso -erythritol was undergoing oxidation by Acetobacter suboxydans . These compounds were isolated by paper chromatography and identified by their dibenzylidene derivatives. It was established that threitol had the l -configuration by measuring the optical rotation. Another compound present in the medium appeared to be heptulose phosphate by its chromatographic behavior. The formation of altro -heptulose was not detected when sorbitol ( d -glucitol), ribitol (adonitol), d -mannitol, d -ribose, or l -erythrulose were used as substrates. No heptulose formation was observed when meso -erythritol was oxidized by Acetobacter xylinium . C 14 studies revealed that the three compounds detected in the medium were derived from meso -erythritol. Some possible biochemical pathways by which these compounds might be synthesized are discussed. To the authors' knowledge this is the first report of the synthesis in vivo of this heptulose and of l -threitol by Acetobacter suboxydans .