Acinetobacter calcoaceticus, which is unable to grow in the presence of glucose because it lacks hexokinase and gluconokinase activities, grows well in the presence of permeable intermediates of the tricarboxylic acid cycle. However, addition of glucose led to increased rates of growth with other carbon sources, although it is unable to grow in the presence of glucose as the sole carbon source. This species possesses pyrrolo-quinoline quinone-dependent glucose dehydrogenase on the outside of the membrane, and through coupling with this emzyme, ATP was synthesized in the presence of glucose. The newly biosynthesized ATP with the addition of glucose led to increases in the initial rate of the active transport system and the growth rate of the cells. The supplemental energy due to glucose oxidation may be obtained through a cytochrome-linked reaction with the glucose dehydrogenase.