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[摘要]
为了提高苯丙氨酸解氨酶的产量和活力,对高效表达圆红冬孢酵母苯丙氨酸解氨酶基因的重组大肠杆菌JM109进行培养,优化了发酵培养基成分、培养条件以及发酵工艺,结果表明,最佳葡萄糖浓度为20 g/L,碳氮比为7.86,添加5 g/L酵母粉和蛋白胨有利于菌体产酶,最佳发酵液初始pH为7.5,接种量为10%。通过以上优化,重组大肠杆菌培养18 h时酶活可达到70 U/g(DCW),酶活比原工艺提高了1.6倍。
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[Abstract]
In order to improve the yield and activity of phenylalanine ammonia lyase (PAL) produced by recombinant E. coli strain, the culture conditions of recombinant E .coli strain carrying PAL gene of Rhodotorula toruloides was studied and optimized. The results showed that the optimal original glucose concentration, C/N ratio, the inoculation size and the initial pH value, fermentation time were 20 g/L, 7.86, 10%, 7.5 and 18 h, respectively. It was also found that the PAL activity was significantly improved by adding 5 g/L peptone and 5g/L yeast powder in fermentation medium. Under the optimized conditions, the PAL activity reached 70 U/g (DCW), which is 1.6 times higher than that under original fermentation conditions.
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