【摘要】 对产青霉素G酰化酶的温度诱导型重组枯草芽孢杆菌发酵条件进行了研究。结果表明,培养基的最佳氮源和碳源组成为:35gL-1牛肉膏、3gL-1葡萄糖和6gL-1淀粉;最佳诱导时机是细胞对数生长的中后期,诱导前应将pH调节至中性;最佳诱导条件为升高温度至50℃并维持4min;随后将温度降低到34℃进行重组蛋白的表达。在上述条件下,PGA的表达水平可以达到5.8UmL-1。SDS-PAGE电泳分析表明该重组菌能够将绝大部分表达的PGA分泌到细胞外,而且表达的PGA蛋白占有高比例(90%)。更多还原

【Abstract】 The fermentation conditions for penicillin G acylase production with a temperature-inducible recombinant Bacillus subtilis were studied. The medium should contain 35gL-1 of beaf extract, 3 gL-1 of glucose and 6gL-1 of starsh. The temperature inducing should be carried out at the late stage of exponential growth phase and the pH should be regulated to 7.0. The optimal inducing temperature is 50 oC and should last for 4 minutes. After inducing, the temperature should be lowered to 34oC and continuously cultured for another 7 hours. With the optimal conditions, the PGA activity as high as 5.8UmL-1 was reached. From SDS-PAGE analyses, the recombinant Bacillus subtilis MU 103 can secrete almost all of the expressed PGA into the medium, and more than 90% of total proteins in the supernatant is recombinant PGA.更多还原