基于代谢流分析的L-组氨酸产生菌定向选育

Application of Metabolic Flux Analysis for Screening of L-Histidine-Producing Strains

摘要:

基于谷氨酸棒杆菌（Corynebacterium glutamicum）代谢网络和L-组氨酸合成代谢流分析，对L-组氨酸产生菌谷氨酸棒杆菌TQ2223（Phe-,Tyr-,8-AGr,SGr,CINr）进行多次硫酸二乙酯（DES）定向诱变，依次赋予其6-MPr、5-MTr、2-TAr和L-Hisase-（L-组氨酸酶缺陷）遗传标记后得到突变株TL1106(5-MTr,SGr,5-FTr,8-AGr,6-MPr,2-TAr,Hisase-)。经验证突变株TL1106可在10%葡萄糖的发酵培养基上积累L-组氨酸6.0 g/L，比出发菌株提高了2.5倍。结果表明：通过赋予目的遗传标记而改变代谢流分布，能够促进L-组氨酸的合成与积累。

Abstract:

According to the theory of metabolic flux analysis, TL1106(5-MTr,SGr,5-FTr,8-AGr,6-MPr,2-TAr, Hisase-) was obtained by diethyl sulfate (DES) mutagenesis derived from the original strain Corynebacterium glutamicum TQ2223 (Phe-,Tyr-,8-AGr,SGr,CINr). TL1106 can produce 6.0 g/L of L-Histidine in 10% glucose medium which was 2.5 times higher than that byTQ2223. Accordingly, the metabolic flux of C.glutamicum TQ2223 and its mutants TL1106 was determined, compared and analyzed in L-Histidine synthesis. Therefore, the great change of metabolic flux distribution might be caused by the introduction of genetic markers, which was useful in L-Histidine synthesis.