【摘要】 本研究采用的基因工程菌为酵母Y33::YFD71-3,其基因型为α,his,leu,ade,suc,摇瓶培养时心钠素的表达水平为1—2mg/L。在含有葡萄糖、YNB以及不同量腺嘌呤、组氨酸和亮氨酸的YG培养基中作摇瓶培养,当细胞的生长由腺嘌呤限制时,蛋白的分泌有明显增加,在YG培养基中加入5g/L的CAA后腺嘌呤成为限制性基质,培养基中腺嘌呤、YNB和亮氨酸用量对心钠素的表达有很大影响。在5L反应器中进行补料分批培养,流加葡萄糖、YNB、CAA、腺嘌呤、组氨酸和亮氨酸,心钠素的最高浓度达到24.8mg/L。更多还原

【Abstract】 The genotype of the recombinant yeast strain Y33::YFD71-3 used in this study was a, his, leu. ade and suc. Preliminary batch cultures in shake flasks showed the expression level of atrial natriuretic pepticle (ANP) was 1-2 mg/L. Shake flask cultures were carried out in YG media which contained glucose, yeast nitrogen base (YNB), and different amounts of adenine, histidine and leucine. When cell growth was limited by adenine, protein secreted from Y33:: YFD71-3 cells was increased obviously. Adenine became the limilting substrate when the YG medium was supplemented with 5g/L of casamino acid (CAA) and the tevel of ANP expression was influenced by the concentrations of adenine, YNB and leucine in the medium. In fed batch cultures carried out in a RIBE-5 fermenter, the cultures were fed with glucose and a mixture of YNB, CAA, adenine, histidine and leucine to improve cell growth and ANP expression, and the maximum ANP concentration in the culture reached 24. 8mg/L.更多还原