保加利亚乳杆菌微胶囊化工艺研究

目的制备保加利亚乳杆菌微胶囊,提高菌株的酸、热耐受性及降低菌体的分离成本。方法以保加利亚乳杆菌(Lactobacillus bulgaricus)为研究对象,海藻酸钠(SA)为壳材、CaCl2为固化剂,制备保加利亚乳杆菌微胶囊;包埋率、颗粒平均化程度、机械强度等为考核指标,研究保加利亚乳杆菌微胶囊化的工艺。结果当海藻酸钠浓度为0.75%、CaCl2浓度为3%、电压为600V、泵速为1.96mL/min、震动频率为80Hz时,微胶囊化包埋效果最佳,经固定化后的菌微胶囊保持了良好的保加利亚乳杆菌的活性,微囊化保加利亚乳杆菌经过2次连续发酵后的产酸量分别达到59.4g/L和55.8g/L。结论本研究为工业化生产乳酸提供了一条具有经济价值的途径。

Microencapsulation of Lactobacillus bulgaricus

Abstract: Objective To prepare Lactobacillus bulgaricus microcapsules, improve the bacterial tolerance to acid and heat, and reduce the cost of separation of the bacteria. Methods Lactobacillus bulgaricus was used as the research subject, with sodium alginate as the shell material and CaCl2 as the fixative agent. The conditions of microencapsulation were optimized by analyzing the embedding rate, the degree of grain uniformity and the mechanical strength. Results The optimal microencapsulation was achieved when the concentration of sodium alginate was 0.75% and that of CaCl2 was 3%, the voltage was 600 V, the pump speed was 1.96 mL/min, and the vibration frequency was 80 Hz. The immobilized bacterial microcapsules maintained the activity of Lactobacillus bulgaricus, and the acid productivity of the microencapsulated Lactobacillus bulgaricus reached up to 59.4 g/L and 55.8 g/L, respectively, upon two consecutive fermentations. Conclusion This result may provide an economic way for industrialized production of lactic acid.