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对5株克雷伯氏肺炎杆菌(包括两株乳酸途径被敲除的工程菌株)发酵生产2,3-丁二醇能力进行了比较,其中K.pneumonia HR521 LDH(乳酸合成途径中ldhA基因被敲除)具有最佳的发酵性能。通过正交试验优化了其发酵培养基的主要组分,优化后的培养基组成为:葡萄糖90 g/L,(NH4)2HPO4 3 g/L,玉米浆(CLSP)6 g/L,乙酸钠5 g/L,KCl 0.4 g/L,MgSO4 0.1 g/L,FeSO4.7H2O 0.02 g/L,MnSO4 0.01 g/L。在优化后的发酵培养基中进行摇瓶发酵,24 h发酵乙偶姻和2,3-丁二醇的终浓度为37.46 g/L,比未优化前增加了10 g/L,2,3-丁二醇得率达到了理论得率的90.53%,生产强度1.56 g/(L.h),检测不到副产物乳酸的生成,利于后提取工艺的进行和工业生产的应用。
Five strains of Klebsiella pneumoniae (including two engineering strains knocked out by the lactic acid pathway) were fermented to produce 2,3-butanediol, of which K. pneumonia HR521 LDH (the ldhA gene in the lactic acid synthesis pathway was Knockout) has the best fermentation performance. The main components of the fermentation medium were optimized by orthogonal test. The optimal culture medium consisted of glucose 90 g / L, (NH4) 2HPO4 3 g / L, corn syrup 6 g / L, sodium acetate 5 g / L, KCl 0.4 g / L, MgSO4 0.1 g / L, FeSO4.7H2O 0.02 g / L and MnSO4 0.01 g / L. Shaking flask fermentation was carried out in the optimized fermentation medium. The final concentration of acetoin and 2,3-butanediol after fermentation for 24 h was 37.46 g / L, increased by 10 g / L compared with that before optimization, - Butanediol has reached the theoretical yield of 90.53%, production strength of 1.56 g / (Lh), the formation of lactic acid can not be detected by-product, which is conducive to the extraction process and industrial applications.