Abstract:

Production of lipase by Rhizopus arrhizus was studied in a rotating biological contactor（RBC）with polyurethane foam（PUF），as a porous biomass support，attached on both sides of the RBC disks.The effects of aeration rate，rotating rate of discs，volume of broth and the number of discs on the lipase activity were studied in the 6 L RBC，and the optimum fermentation condition was as follows：4 L·min^-1 aeration rate，100 r·min^-1 rotating rate，3.5 L medium with three discs in 6 L RBC.Repeated batch fermentation by immobilized mycelium was tested and it was found that immobilized cells showed high stability for repeated use.Five repeated batches could be carried out in 6 L RBC and the lipase productivity increased from 3125 U·h^-1 in batch fermentation to 9512 U·h^-1 in repeated batch fermentation，which was 3 times as high as that in batch fermentation.

Key words:

转盘反应器, 重复批次发酵, 脂肪酶, 根霉

摘要： 以聚氨酯海绵为载体将根霉固定于转盘表面，利用转盘反应器实现脂肪酶的固定化发酵。考察了通气量、转速、装液量及转盘个数等操作参数对发酵过程的影响，得到了优化的反应操作条件，即通气量4 L·min^-1,转速100 r·min^-1，装液量3.5L，采用三个转盘。在上述条件下进行重复批次实验，可重复5批次, 单位时间产率10931.1 U·h^-1, 是批次反应的3.5倍。固定化细胞连续发酵,大大缩短了发酵的时间, 酶的平均活力和时间产率获得大幅提高。

关键词:

转盘反应器, 重复批次发酵, 脂肪酶, 根霉