聚氨酯泡沫固定化重组枯草杆菌三段培养生产青霉素酰化酶

引　言青霉素G酰化酶 (penicillinGacylase ,EC3 5 1 11,PGA)是 β 内酰胺类抗生素工业中的关键酶之一 .目前主要采用大肠杆菌和巨大芽孢杆菌进行工业化生产 ,但由于产酶水平较低、变温发酵和需要苯乙酸诱导等缺点 ,国内外研究者尝试采用各种基因重组技术 ,以期大幅度提高产酶

PRODUCTION OF PENICILLIN G ACYLASE IN THREE-STAGE CONTINUOUS CULTIVATION SYSTEM WITH PUF IMMOBILIZED RECOMBINANT B.subtilis

Recombinant B subtilis MU108 was immobilized in PUF matrix for enhanced production of PGA The results showed that PUF matrix was suitable for partial immobilization of recombinant cells in a three phase bioreactor With immobilized bacteria, the expression of PGA and the growth of cells were compared between batch cultivation in three phase fluidized bed and continuous bioprocess in three stage cultivation system The productivity of PGA in batch cultivation was improved significantly with the increase of aeration A new three stage continuous cultivation system was designed and tested.It separated the whole process into three stages: cell growth, high temperature induction and PGA expression After the beginning of nutrient continuous feed at mid or late log phase,cell density, pH and residual glucose in the first and third stage bioreactor would be maintained steady up to 65 h Compared with those in the batch fermentation, the average productivity of PGA was improved by 190% in the three stage continuous fermentation, and the time for PGA expression was also extended from ca.10 h to ca 60h These results suggested that this new three stage cultivation technique with immobilized cells might be very efficient for large scale production of heterogeneous proteins