重组大肠杆菌产普鲁兰酶发酵条件优化  

Optimization of fermentation conditions for pullulanase production by recombinant Escherichia coli

作　　者：王小兰[1] 穆晓清[1,2] 徐岩 聂尧[1,2] 

机构地区：[1]江南大学生物工程学院,江苏无锡214122 [2]江南大学工业生物技术教育部重点实验室,江苏无锡214122 [3]中国食品科技与技术重点实验室,江苏无锡214122

出　　处：《食品与发酵工业》2015年第7期24-28,共5页Food and Fermentation Industries

基　　金：国家重点基础研究发展(973)计划项目(2011CB710800);国家高技术研究发展(863)计划项目(2012AA022207);高等学校学科创新引智计划项目(111计划;111-2-06);国家自然科学基金(21176103);高端外国专家项目(GDW20133200113)

摘　　要：在7L发酵罐规模，利用自诱导培养方式，对重组大肠杆菌产普鲁兰酶发酵条件进行优化研究，主要考察了发酵过程中控制溶解氧浓度、pH和采用补料策略对菌体生长和普鲁兰酶表达的影响。结果表明，最佳发酵培养条件：溶氧浓度维持在20％-30％；pH保持在7．60；第9h时，以0．8g／（L·h）的速度流加甘油；在20h，以0．2g／（L·h）的速度流加乳糖。此条件下，重组菌的细胞浓度OD600nm从12．58上升到42．25，提高了3．36倍；普鲁兰酶酶活力从356U／ml上升到1200U／ml，提高了3．37倍。By using auto-induction system, the fermentation conditions including oxygen and pH were controlled in a 7-L batch system, and then fed-batch fermentations were carried out using glycerol as a carbon source and lactose as inducer so as to discuss the effects on fermentation by different feeding modes. The optimum conditions were found to be as follows ： the dissolved oxygen concentration was maintained at 20% - 30% , the culture pH was kept at 7.60, and glycerol was added by the rate of 0.8 g/（ L · h） at 9h, lactose was added by the velocity of 0.2 g/（ L · h） at 20 h. Using the optimal conditions, concentration of ceils and activity of pullulanase were increased from 12.58 to 42.25 and from 356 U/mL to 1200 U/mL respectively, which were 3.36 and 3.37 times of those in fed-batch fermentation.

关 键 词：普鲁兰酶 发酵优化 分批补料发酵 恒速流加 自诱导培养 DO—stat 

分 类 号：TQ925[轻工技术与工程—发酵工程]