Fermentation of lactic acid with Rhizopus arrhizus in a stirred tank reactor with a periodical bleed and feed operation

摘要: Semicontinuous fungal fermentation of lactic acid (LA) by Rhizopus arrhizus was performed using a periodical bleed and feed (PBF) operation in stirred tank bioreactor with volume 4.5 dm3. LA productivity up to 2.91 kg m−3 h−1 yield 75.3% were achieved. Using PBF cycles, prolonged 240 h an average 2.31 total 67.3% at mean pH 5.30. The most effective production required filamentous morphology the biomass. When such changed pellets biomass growth stopped, decreased 1.63 62.6%. successfully maintained for 152 when inoculation spores. CaCO3 initially used neutralisation did not dissolve well since it entrapped It replaced 25% ammonia. Long-time below 5 productivity. Accumulating fermenter increase With rate, increased. on-line extraction or pertraction trialkylamines demands value 4. This can be achieved short time interruption end each cycle without decrease after restoration optimal value.