固定化醋酸杆菌发酵特性的研究

Study on the Fermentation Characteristics of Immobilized Acetobacteria As. 1.41

采用海藻酸钠包埋法制备固定化醋酸杆菌。摇瓶实验的产酸速率可达0.82克醋酸/升·时。连续14批次的发酵实验表明,固定化细胞活性稳定,凝胶颗粒强度无变化,适于连续化生产。用2～4％海藻酸钠固定的醋酸杆菌,在使用过程中,存在明显的细胞泄漏现象,高产酸速率是固定化细胞和游离细胞共同作用的结果。在本实验条件下,总产酸速率与固定化细胞的投入量成正比。用改变凝胶颗粒直径和改变包埋的细胞浓度的方法考察了固定化醋酸杆菌发酵过程中的内扩散效应,减小颗粒直径可提高包埋法制备的固定化细胞的表观活性。

Acetobacteria As. 1.41 was entrapped with alginate and its acetic acid-producing rate in shaking flask cultures reached 0.82g/h·l. 14 batches of fermentation performed continuously showed that, the bioactivities of the immobilized cells and the mechanical strength of the gel grains were constant, therefore it could be used in a continuous production. During the fermentations with the immobilized Acetobacteria, which was entrapped with 2 - 4 % alginate, an obvious cell leakage was observed. High acetic acid-producing rate was contributed to the metabolism of both immobilized cells and free cells. Under our experimental conditions the total acid production rate was proportional to the amount of immobilized cells used. The inner diffusion effect in a fermentation process with immobilized acetoba-cteria was studied by changing the diameter of gel grain or the entrapped cell concentration. The apparent activity of immobilized cells increased with decreasing of the diameter of gel grains.