用于固定化米根霉发酵生产L-乳酸的转盘反应器及其放大

利用米根霉菌丝体发达且易于吸附在固体表面的特性,将其固定化于转盘表面,利用转盘反应器实现L 乳酸的固定化发酵。考察了固定化过程中的底物浓度、产物浓度和溶解氧浓度的变化规律。在此基础上,进一步研究了8L反应器的通气量、装液量及转盘转速等操作参数对发酵过程的影响,得到了优化的反应器操作条件。最后,利用自制的1m3反应器考察了转盘反应器固定化发酵的可行性,得到了比较满意的结果,证实该反应器具有良好的工业应用前景。     

ETHANOL FERMENTATION OF MIXED GLUCOSE AND XYLOSE BY PICHIA STIPITIS

Pichia stipitis CBS 5773 yeast cells were used to ferment the mixed substrates consisted of glucose andxylose to produce ethanol.The effects of aeration rate,initial substrate concentration and pH on substrateutilization and ethanol yield were evaluated.During batch fermentation,the oscillation phenomena in cell growthwere observed at low aeration rate,whereas the diauxic growth at high aeration rate.The substrate utilizationratio and ethanol yield reached 95％ and 0.46g/g respectively under appropriate operation conditions.Amodified unstructural model was proposed to simulate the diauxic cell growth,substrate consumption andproduct formation.