在线推定和控制葡萄糖浓度改善谷氨酸发酵性能

谷氨酸发酵过程一般需要定时、人工分批式地添加葡萄糖。该流加操作方式会引起发酵罐内葡萄糖浓度的剧烈波动, 不利于高效、稳定的谷氨酸生产。谷氨酸发酵具有显著的非增殖耦联特征, 产酸期葡萄糖耗量与氨水耗量存在非常明显的关联性。通过在线计量氨水耗量推定糖耗以及葡萄糖浓度, 可比较准确地将谷氨酸发酵产酸期的糖浓度控制在预先设定的水平。当糖浓度控制在5 g/L~10 g/L的低水平时, 最终谷氨酸浓度可以达到80 g/L的较高水平, 高糖浓度下的渗透压效应有望得到缓解, 有利于发酵生产的稳定。

On-line Glucose Concentration Prediction and Control for Improving Glutamate Fermentation Performance

In industrial glutamate fermentation, intermitted feeding glucose with the help of off-line glucose measurement is generally necessary. This kind of feeding strategy could cause large variations in glucose concentration so that it is not favorable for the achievement of efficient and stable glutamate fermentation. Glutamate fermentation is characterized with typical non-growth association behavior, and during glutamate production phase glucose consumption is closely correlated with ammonia consumption. In this study, glucose concentration was controlled at various pre-determined levels by predicting glucose consumption amount and thus its concentration with the aid of on-line monitoring ammonia consumption. When glucose concentration was controlled around a lower level of 5 g/L~10 g/L, the final glutamate concentration could reach a relatively higher level of 80 g/L. In this way, the huge osmotic stress change due to the large glucose concentration variation with the intermitted feeding method could be avoided and the glutamate fermentation performance enhancement be expected.