溶氧对巨大芽孢杆菌发酵亚硝酸还原酶的影响

Effect of dissolved oxygen on nitrite reductase fermentation by Bacillus megaterium MPF-906

通过振荡间歇静置培养,研究不同静置时间对巨大芽孢杆菌发酵生产亚硝酸还原酶(nitrite reductase,NiR)的影响,并在适宜间歇静置条件下,分析细胞生长、基质消耗与NiR酶量的关系。结果表明,在发酵前12h每2h振荡培养间歇60min静置培养的条件下,20h发酵时所得亚硝酸盐还原酶的酶活最高;在每2h振荡培养间歇60min静置培养的条件下,周期为20h的该菌的发酵特性研究表明,菌体的细胞生长量及发酵液中的亚硝酸盐消耗量和葡萄糖消耗量均同步低于一直振荡培养的对照组,但发酵20h后所得亚硝酸还原酶的酶活为98.7U/mL,比一直振荡培养的对照组的酶活高出103.4%。

Bacillus megaterium MPF-906 was cultivated by shaking culture with static intervals. The effects of different static intervals on nitrite reductase （NiR） production were investigated. The relationship between the growth of B. megaterinm MPF-906, the consumption of substrate and the activity of nitrite reductase was analyzed. The results showed that when there was a 60min static interval following every 2h shaking in the initial 12h of fermentation, the highest NiR activity was appeared at 20h. Under above conditions, the biomass of B. rnegaterium MPF-906, the degradation of nitrite and the consumption of glucose were all lower than control under shaking flask cultivation, but the NiR activity at 20h was 98.7U/ml and 103.4% higher than control.