Polyol Dehydrogenases of Gluconobacter Oxydans.

The secondary hydroxyl group involved in the oxidation, and the cis-vicinal secondary hydroxyl group, must have a D configuration jvith respect to t,he primary alcohol group adjacent to the site of oxidation. This specific mode of otida,tion facilitated the synthesis of several new ketoses. In a series of papers, Hudson and Richtmyer and their a.ssociates described the microbiological synthesis of several new heptuloses (448), and the oxidation of n-cry&on-gala&o-octitol to an octulose (9). Several w-deoxysugar alcohols, which do not possess the Bertrand-Hudson configuration, are nevertheless oxidized by growing cultures of Gluconobacter ox@ans (suboxydans) ATCC 621 (10, 11). By considering t,he CH&HOHgroup as a substituted -CH,OH group, the Bertrand-Hudson rule was extended to predict the action of the organism upon w-deoxysugar alcohols (10). Virtually no attention has been paid to the enzymology of polyol oxidations by acetic acid bacteria. According to Arcus and Edson (la), glycerol-grown G. oxydans (suboxydans) produces two types of mannitol dehydrogenase of low specificity. One is a particulate, cytochrome-linked system that oxidizes polyols with the Bertrand-Hudson configuration. The second dehydrogenase is a soluble, nicotinamide adenine dinucleotide-linked enzyme with broad specificity. Cummins (13) reported on an NAD-linked sorbitol dehydrogenase in G. oxydans ATTC 621 which oxidized sorbitol to o-fructose. However, sorbitol was also oxidized by an NADP-linked enzyme to L-sorbose. Bygrave and Shaw (14) partially purified an NADP-linked D-