Catalyzes an exceptionally high rate of oxidation of a wide range of aldose sugars, including D-glucose, galactose, arabinose and xylose, and also the disaccharides lactose, cellobiose and maltose. A + D-glucose = AH2 + D-glucono-1,5-lactone Monomer. Acinetobacter calcoaceticus contains two different PQQ dependent enzymes with GDH activity. GDH-A prefers 2-deoxyglucose as substrate, the specific substrates for GDH-B are disaccharides. Belongs to the bacterial PQQ dehydrogenase family.