植物乳杆菌透性化细胞催化生产低聚半乳糖的工艺优化  

Optimization of galactooligosaccharides production by permeabilized Lactobacillus plantarum cells as catalyst

作　　者：魏春[1] 孔令民[1] 刘利峰[1] 

机构地区：[1]浙江工业大学生物工程学院,浙江杭州310014

出　　处：《发酵科技通讯》2016年第1期18-22,共5页Bulletin of Fermentation Science and Technology

基　　金：浙江省自然科学基金项目(LY12B06010)

摘　　要：以乳糖为底物,利用含β-半乳糖苷酶的植物乳杆菌透性化细胞催化生产低聚半乳糖(GOS)。在5 L发酵罐上进行了以乳糖为碳源的植物乳杆菌WZ011的厌氧培养,β-半乳糖苷酶产量在发酵14 h时达到最大值5 U/m L。收获的植物乳杆菌菌体用于透性化全细胞催化生产GOS的研究。比较了乙醇、Tween 80、SDS、DMSO、丙酮这五种渗透剂对胞内β-半乳糖苷酶酶活的影响。结果表明以40%乙醇作为渗透剂处理最为有效,β-半乳糖苷酶胞内酶活可达500 U/g(细胞干重DCW)。进一步对40%乙醇渗透处理后整细胞催化生产GOS的工艺条件进行了研究,结果表明乳糖浓度、初始p H、温度和反应时间对GOS合成均有显著影响。在乳糖质量浓度为400 g/L,初始p H为7.0,温度50℃及反应进行10 h的条件下,GOS产量达到最大值32%(质量分数)。Galactooligosaccharides（GOS） could be synthesized from lactose by whole cells of permeabilized LactobaciUus plantarum containing [5-galactosidase. Lactobacillus plantarum WZ011 was anaerobically cultured in 5 L fermentor with lactose as carbon source. The β-galactosidase production reached 5 U/mL after 14 h of fermentation. The harvested cells were used for GOS synthesis after permeabilization. The effect of five permeability reagents including ethanol, Tween 80, SDS, DMSO and acetone on the intracellular β-galaetosidase activity was compared. The results indicated that permeabilization with 40% ethanol was most effective and the intraeellular β-galaetosidase activity was 500 U/g （dried cell weight, DCW）. The reaction conditions of GOS synthesis with the whole cells permeabilized by 40% ethanol were further examined. The results indicated that lactose concentration, initial pH, temperature and reaction time all influenced the GOS synthesis significantly. GOS was obtained in 32% yield under the conditions of lactose concentration 400 z/L. DH 7.0. 50 ~C and reaction time 10 h.

关 键 词：植物乳杆菌 Β-半乳糖苷酶 低聚半乳糖 透性化细胞 

分 类 号：TQ92[轻工技术与工程—发酵工程]