pH及通气量对法夫酵母生物量以及所产<sup>6</sup>G-果糖基转移酶活性的影响

pH及通气量对法夫酵母生物量以及所产⁶G-果糖基转移酶活性的影响

摘要: 实验分别考察了5L发酵罐中恒定pH7.0、8.0、9.0和发酵前期每隔4h、发酵后期每隔12h改变pH的梯度控制方法以及不同通气量对法夫酵母发酵过程中生物量以及所产6G-果糖基转移酶活性的影响,结果表明,恒定的pH7.0和通气量5L/min最有利于细胞生长,得到最大生物量（干重）分别为11.6和11.8g/L。恒定的pH8.0和通气量8L/min最有利于酶活性,得到最高酶活性都为0.32mol/L/min,综合考虑生物量以及酶活性,最终确定优化后的发酵条件是控制发酵过程pH为8.0,通气量为8L/min,发酵以后在72h得到最大生物量为11.20g/L,最高酶活为0.32mol/L/min。

Abstract: The effect of initial culture pH and controlled pH ranging from 7. 0 to 9. 0 and VC (ventilatory capacity) ranging from 5 to 12L/min on biomass and 6G-fructofuranosidase activity by Xanthophyllomyces dendrorhous which were using in the free-whole-cell biotransformation were investigated in batch fermentation. An optimal pH of 7. 0 and VC of 5L/min were obtained for cell growth, cell density was 11. 6g/L and 11. 8g/L, respectively, and an optimal pH of 8. 0 and VC of 8L/min were obtained for 6G-fructofuranosidase activity, both of them were 0. 32mol/L/min. Comprehensive consideration of the cell density and 6G-fructofuranosidase activity, the final optimal pH and VC for fermentation was 8. 0 and 8L/min, respectively.