Non-coordinated synthesis of glucose dehydrogenase and its prosthetic group PQQ inAcinetobacterandPseudomonasspecies

Abstract

Abstract The activity of pyrrolo-quinoline quinone (PQQ)-dependent glucose dehydrogenase (GDH) was determined in Acinetobacter and Pseudomonas species, grown under different conditions. In Acinetobacter lwoffi which, in contrast to Acinetobacter calcoaceticus , is unable to oxidize glucose to gluconic acid, the absence of GDH activity was not due to the absence of GDH protein (apoenzyme) but to the absence of its prosthetic group, PQQ. GDH activity could be restored by addition of PQQ to cell suspensions. Taxonomic implication of these results are discussed. Pseudomonas aeruginosa , strain PAO1 is known to contain active GDH when grown aerobically on glucose, but to lack this activity when grown anaerobically with nitrate. Also in this organism the absence of active GDH was due to lack of PQQ synthesis under these conditions, since GDH activity could be reconstituted by addition of PQQ to cell-free extracts. Similar observations were made with cultures of Pseudomonas acidovorans and Rhodopseudomonas sphaeroides , indicating that control of GDH activity by PQQ synthesis maybe widespread among bacteria.