α-淀粉酶抑制剂生物合成途径和代谢流分析（英文）

Application of Biosynthesis Pathway Analysis and Metabolic Flux Analysis for Optimization of Fermentation of α-Amylase Inhibitor

为提高糖类的利用效率,加强糖类代谢向生成α-淀粉酶抑制剂的方向流动,提高α-淀粉酶抑制剂产量,对天蓝黄链霉菌合成α-淀粉酶抑制剂的代谢网络进行分析,找出影响α-淀粉酶抑制剂合成的代谢流量分配规律和关键节点,并且应用代谢流分析的方法研究了谷氨酸钠对α-淀粉酶抑制剂发酵中后期胞内代谢流分布的影响。结果表明:在α-淀粉酶抑制剂分批发酵过程中,未流加谷氨酸钠时合成α-淀粉酶抑制剂的代谢流量为1.84;在发酵培养基中流加谷氨酸钠使其质量浓度维持在4.0 g/L后,α-淀粉酶抑制剂生物合成的代谢流增长至3.18。因此发酵过程中流加谷氨酸钠能够改变α-淀粉酶抑制剂生物合成途径的关键节点6-磷酸葡萄糖、7-磷酸景天庚酮糖及谷氨酸的代谢流分布,提高α-淀粉酶抑制剂生物合成途径的代谢流量。

This study aimed to improve the yield ofα-amylase inhibitor and the efficiency of carbohydrate utilization duringthe fermentation of Streptomyces coelicoflavus(S.coelicoflavus).The metabolic network leading to the biosynthesis ofα-amylase inhibitor was analyzed to find out the key nodes which influenced the production ofα-amylase inhibitor.Theeffects of sodium glutamate on the metabolic flux distributions during the middle and late periods of fermentation werestudied,and metabolic flux analysis forα-amylase inhibitor production at pseudo-steady state was also conducted.Theresults showed that the metabolic flux channeled to theα-amylase inhibitor biosynthesis pathway was1.84in batchwisefermentation without the addition of sodium glutamate,while,with the addition of sodium glutamate(the concentrationwas maintain at4.0g/L),the metabolic flux was3.18,suggesting that the addition of sodium glutamate could change themetabolic flux distributions of the key nodes(glucose-6-phosphate,sedoheptulose-7-phosphate,and glutamate)and enhancethe biosynthesis ofα-amylase inhibitor.