氮源及其补加策略对L-缬氨酸发酵的影响  

The Effect of Nitrogen Sources and Its Additional Strategies on L-valine Fermentation by Brevibacterium flavum XV0505

作　　者：冯宁[1] 白亚磊[1] 徐庆阳[1] 谢希贤[1] 陈宁[1] 

机构地区：[1]天津科技大学生物工程学院

出　　处：《食品与发酵工业》2011年第4期1-6,共6页Food and Fermentation Industries

基　　金：国家科技重大专项课题"企业新药物孵化基地建设"(2008ZX09401-05);天津市科技支撑计划重点项目(08ZCKFSH01900);天津市应用基础及前沿技术研究计划(08JCZDJC15400)

摘　　要：通过分析黄色短杆菌XV0505发酵生产L-缬氨酸的过程,得知在菌体生长期和快速产酸期氮源对L-缬氨酸发酵的影响不同。以黄色短杆菌XV0505为供试菌株,研究了不同氮源种类及不同氮源浓度对L-缬氨酸发酵过程的影响,选定了以豆饼水解液和硫酸铵为氮源,并确定了合适的初始氮源浓度。在初始氮源浓度相同的情况下,考察了间歇流加补氮策略、恒氮源浓度补氮策略和幂函数流加补氮策略对L-缬氨酸发酵的影响,研究发现,幂指数补氮策略可减少频繁的取样及铵浓度检测,在缺乏在线监测系统和反馈自控系统的情况下,将发酵体系中氮源浓度维持在合适值,既可适度促进菌体生长,又可使L-缬氨酸的产量得到进一步提高。在最优的氮源添加策略下,在30 L发酵罐发酵60 h,发酵液中L-缬氨酸可达63.17 g/L,糖酸转化率24.69%。By analyzing the L-valine fermentation process by Brevibacterium flavum XV0505, one of important factors influenced on the bacterial productivity and L-valine yield is nitrogen source and its additional strategies. The effect of nitrogen sources on the fermentation of L-valine was studied by adding different nitrogen sources with different concentrations. Therefore, soybean hydrolysates and ammonium sulfate were selected as the appropriate nitrogen source, and the best L-valine yield was obtained with the medium supplemented low initial concentration of 225 mmol/L In the case of the same initial nitrogen concentration, the effects of three nitrogen feeding strategies （intermittent nitrogen feeding, constant concentration feeding and power function feeding） on biomass, yield of L-valine, concentration of byproduct and conversion rate were studied in the 30L fermentor. The result showed that the concentration and the feed rate of nitrogen source were effectively and timely manipulated by power function feeding, while lacking of online monitoring and feedback controlled system. The yield of L-valine was further improved up to 63.17 g/L by power function feeding strategy with the conversion rate of 24.69%.

关 键 词：L.缬氨酸 氮源 补加策略 幂函数 黄色短杆菌 

分 类 号：TQ922[轻工技术与工程—发酵工程]