EVIDENCE FOR A MEMBRANE-BOUND PYRROLOQUINOLINE QUINONE-LINKED GLUCOSE-DEHYDROGENASE IN ACETOBACTER-DIAZOTROPHICUS

Acetobacter diazotrophicus possesses a pyrroloquinoline quinone-linked glucose dehydrogenase (PQQ-GDH). The enzyme seemingly belongs to the type II PQQ-GDH enzymes and, at least under the culture conditions tes ted, the organism synthesizes enough PQQ to saturate the ape-enzyme. T he synthesis of this enzyme is stimulated when the organism is grown u nder N-2-fixing conditions. It is proposed that this enzyme may play a n important role in providing extra energy in N-2-fixing cells.