pH调控方式和温度对透明质酸发酵过程的影响

Effects of pH Control Modes on Hyaluronic Acid Fermentation Process

摘要:

本文以一株产透明质酸（hyaluronic acid, HA）的兽疫链球菌为研究对象，在5.00 L发酵罐和250 mL摇瓶中考察了温度和pH对HA发酵过程中菌体生长、HA产量、HA分子量大小以及分布的影响。结果显示，当pH为7.00时适合菌体生长，而在产物合成阶段更高的pH条件8.00下HA比生成速率更高。据此，设计了分段和周期性改变发酵过程pH的调控模式，研究表明：分段pH调控方式与pH为7.00时相比HA浓度没有提高，但是pH在7.00和8.00之间进行的分段调节时分子量提高了10.60%，同时显著降低了多分散系数，另外在pH在7.00和8.00之间进行的分段调节的同时在33 ℃的培养温度下收获时HA分子量提高了18.70%，而为后续工业化生产分子量更为集中的HA，同时降低不同分子量HA分离成本提供了方向。

Abstract:

In this work, the microorganism concentration, HA yield, HA molecular weight and molecular weight distribution of hyaluronic acid (HA) wereanalyzed at different pH and temperature in 5 L bioreactor and 250 mL shake flask. It was found that the best pH for bacteria growth and HA production was 7.00, but under HA synthesis stage, HA generation rate was higher at higher pH condition 8.00. Two regulation styles, the periodic control mode and subsection control mode were designed. The results were as follows: the periodic control mode had no effect to HA yield and HA molecular weight, subsection control mode had no effect to HA yield, but could impove the molecular weight by 10.60% and significantly reduced the dispersion coefficient, and at periodic control mode when culture temperature was 33 ℃，HA molecular weight when harvested was 18.70% higher than temperature 37 ℃. These results could provide directions for subsequent industrialization production molecular weight concentrated HA and reducing the separation cost of HA with different molecular weights.