NH_4^+浓度对黄色短杆菌XV0505发酵生产L-缬氨酸的影响  

Effect of NH_4^+ concentration 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,天津300457

出　　处：《生物加工过程》2011年第2期12-17,共6页Chinese Journal of Bioprocess Engineering

基　　金：国家科技重大专项课题资助项目(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：以L-缬氨酸(L-Val)生产菌黄色短杆菌XV0505为供试菌株,以(NH4)2SO4为唯一添加N源,考察不同NH 4+浓度对发酵过程中菌体干质量、L-Val产量和葡萄糖消耗速率以及菌体内代谢流量的影响。研究表明:NH 4+浓度过高或不足都会影响发酵水平,降低L-Val的产量。合适的初始NH4+浓度为225 mmol/L,产酸期NH4+维持浓度为35 mmol/L时,有利菌体产酸。在此NH4+浓度下,在30 L发酵罐发酵60 h,发酵液中菌体生物量和L-Val质量浓度分别可达22.35和59.12 g/L。The ammonium sulfate was selected as the only feeding nitrogen source in the L-valine fermentation process by Brevibacterium flavum XV0505.Effects of different NH＋4 concentrations on biomass,yield of L-valine,glucose consumption rate and the metabolic flux were studied in a 30 L fermentor.Results showed that excessive or insufficient concentrations of NH＋4 would adversely affect the yield of L-valine and bacterial growth.Therefore,the appropriate additive dosage of NH＋4（225 mmol/L） was determined,and L-valine production was increased by keeping low NH＋4 concentration（35 mmol/L） in the synthesis period of L-valine.With the optimum additional dosage of NH＋4,the yields of L-valine and DCW were up to 59.12 and 22.35 g/L（60 h） in the 30 L fermentor.

关 键 词：黄色短杆菌 代谢流 NH4+ L-缬氨酸 

分 类 号：Q93[生物学—微生物学]