冷冻聚丙烯酰胺法固定化黑曲霉生产柠檬酸的研究

Production of Citric Acid by Aspergillus niger immobilized in Cryo-gel of Polyacrylamide

本文建立了冷冻聚丙烯酰胺包埋固定化微生物的方法，并用于固定化黑曲霉生产柠檬酸，与常规方法进行了比较。优化了固定化细胞生产柠檬酸的条件：蔗糖浓度１００～１４０ｇ／Ｌ，ＮＨ４Ｃｌ３．０～４．０ｇ／Ｌ初始ｐＨ３．０，培养温度３０℃。固定化细胞在半连续发酵中重复使用５批次，在连续发酵中使用３００ｈ，其余酸活性没有明显下降。

The immobilization method for microorganism entrapped in cryo-gel of polyacrylamide was developod and compared with conventional methed.Aspergillus niger cells were immobilized in cryo-gel and used for citric acid production. The fermentation conditions were optimized as follows: sucrose 100 ～140g/l, NH4Cl 3. 0～4. 0g/l ,initial pH 3.0, cultural temperature 30℃ etc.. The activity of immobilized cells decreased little after 5 batches use in semi- continuous fermentation and 300h use in continuous fermentation .