Fig. 1

Diagram of integrated system for foam-control and repeated fed-batch fermentation (a). During the fermentation, foam formed in the head space of bioreactor and streamed into collecting container (b) under the driving force of air flow. The circular ring (c) with some ⌀1 mm micropores could break the foam into liquid. After breaking, little residual foam and broth were pumped back into the bioreactor by peristaltic pump