Growth of G. oxydans strains with glucose (275 mM; 50 g liter−1). Cultivation was carried out in duplicate (points in the graph represent averages) in bioreactors (Dasgip, Juelich, Germany) under pH and aeration control (15% dissolved oxygen). •, G. oxydans N44-1 pBBR1MCS4; ▴, G. oxydans N44-1 mgdH::kan pBBR1MCS4; squares, G. oxydans N44-1 ΔmgdH sgdH::kan pBBR1MCS4, with 15% dissolved oxygen (▪) and with 30% dissolved oxygen (□).