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.
