基于pH的反馈补料方法在谷氨酸发酵中的应用

Application of a pH feedback-controlled substrate feeding method in glutamic acid fermentation

摘要:

为简化谷氨酸发酵补料工艺，提出了一种新型的基于pH的补料方式。考察谷氨酸发酵过程中氨消耗量 (x) 和糖消耗量 (y) 发现，两者之间存在较好的线性关系 (y=7.4744x，R2=0.9989)，以此为pH反馈补料工艺中补料液中葡萄糖与氨的混合比例，能较好地将谷氨酸发酵过程中葡萄糖浓度稳定在12~21 g/L。比较恒定葡萄糖浓度补料工艺与pH反馈补料工艺发现，采用pH反馈补料工艺进行发酵，葡萄糖转化率、谷氨酸产酸速率分别提高了9.06％和17.5％左右，同时发酵周期缩短2 h以上。

关键词:谷氨酸发酵，pH反馈补料，葡萄糖浓度

Abstract:

A novel method based on pH value was proposed to simplify the substrate feeding method for glutamic acid fermentation. The linear relationship between the consumption amounts of ammonia (x) and that of glucose (y) was established (y=7.4744x, R2=0.9989) which could be used as the ratio of the amount of ammonia and that of glucose in the feeding broth. Thus the concentration of glucose could be controlled through the adjustment of pH automatically. In the glutamic acid fermentation using the pH feedback-controlled glucose feeding method, the glucose concentration in fermentation broth was maintained between 12 and 21 g/L. Compare with the constant glucose concentration feeding method, the glucose conversion rate and glutamic acid productivity increased by 9.06% and 17.5% respectively, when the pH feedback-controlled glucose feeding method was employed, and fermentation period was shorten above 2 h.

Key words:glutamic acid fermentation, pH feedback-controlled substrate feeding method, glucose concentration