【摘要】 对一株产气气杆菌产普鲁兰酶的发酵培养基进行了优化,确定了该菌株的最适发酵培养基配方为(g/L):玉米淀粉15,豆饼粉10,CH3COONH4 8,K2HPO4.3H2O 0.5,MgSO4.7H2O 0.5,KCl 0.5,FeSO4.7H2O 0.05.采用该培养基在5.L发酵罐水平发酵55.h,普鲁兰酶活力达到54.64.U/mL.研究了不同铵盐形式对该菌株产普鲁兰酶的影响,结果发现:以CH3COONH4为无机氮源,该菌株产普鲁兰酶活力高,且该酶绝大部分能分泌至胞外.而以NH4Cl,NH4NO3及(NH4)2SO4为无机氮源,该菌产普鲁兰酶活力较低,且为胞内酶.更多还原

【Abstract】 The fermentation medium for producing pullulanase by Aerobacter aerogenes was studied.The fermentation medium consists of(g/L):15 corn starch,10 bean powder,8 CH3COONH4,0.5 K2HPO4.3H2O,0.5 MgSO4.7H2O,0.5 KCl,0.05 FeSO4.7H2O.The experiment was also carried out in a 5 L fermentor.The effects of different kinds of ammonium salt on activity of pullulanase were studied.The results show that the pullulanase is secreted into the growth medium and perform the highest activity when CH3COONH4 is used as nitrogen.However,pullulanase is not secreted into the growth medium and the strain has low-yield production in the presence of NH4Cl,NH4NO3 and(NH4)2SO4.更多还原