海藻酸钙固定赤霉菌菌丝产素的研究

Study on Gibberellin Production by Immobilized Gibberella fujikuroi in Calcium Alginate

将赤霉菌丝固定在海藻酸钙微球中进行连续发酵,考察产赤霉素情况。对海藻酸钠和钙盐浓度固定赤霉菌菌丝的微球稳定性进行初步研究,讨论了固定不同菌龄的赤霉菌微球在不同葡萄糖浓度下的产素能力及菌丝生长能力。实验表明:菌丝微球较稳定的固定条件是菌丝8 g/L、海藻酸钠浓度3 g/L和钙离子浓度3 mol/L;摇瓶发酵72 h,90 h的菌丝微球中菌丝营养生长基本停止,当培养液葡萄糖浓度为2 g/L时,赤霉素终浓度为1 145.5μg/ml,比生产速率为4.61×10-3/h;在该条件下固定菌丝球的床层式连续发酵,赤霉素比生产速率为4.82×10-3/h,是相应分批发酵过程中最大赤霉素生产速率的1.87倍。

In order to investigate gibberellin-producing capacity in the continuous fermentation,the cells of Gibberella fujikuroi were immobilized in the form of Ca2＋-alginate beads.The conditions for immobilization were investigated.Then,the growing capacity and production potential were discussed in the immobilization beads containing different age mycelium at a different concentration of glucose.The experimental results showed that the optimal immobilization condition was 3 g/L sodium alginate and 8 g/L cell in the presence of 3mol/L CaCl2.The maximum specific gibberellin-produced rate was 4.61×10-3/h as the culture condition was Ca2＋-alginate beads immobilized 90 h age hypha and 2 g/L glucose concentration in shake-flask cultures,while the mycelium growth basically stopped in immobilized beads.In this condition,the specific production rate of gibberellic acid was 4.82×10-3/h in a continuous fixed-bed bioreactor by immobilized mycelium of Gibberella fujikuroi,was 1.87 times than the maximum specific production rate in the batch fermentation.