O-2 UPTAKE DURING SOLID-STATE FERMENTATION IN A ROTATING DRUM BIOREACTOR

The maximum O-2 uptake by Rhizopus oligosporus grown in a 200 litre ro tating drum bioreactor at 0.5 rpm ranged from 6.7 to 7.6 mmol per min per kg initial dry substrate (IDS), for runs done with 4 baffles each 17 cm wide, and 12 baffles each 5 cm wide. Without baffles, the maximu m O-2 uptake rate at 5 rpm was 6.9 mmol/(min.kg IDS), compared to 5.1 mmol/(min.kg IDS) obtained at 0.5 rpm. Therefore O-2 supply is adequat e in rotating drum bioreactors as long as slumping flow regimes of the substrate bed are avoided.