High-level Expression of Phenylalanine Ammonia-lyase in Lactococcus lactis via Synthesized Sequence Based on Bias Codons

To construct a safer and more efficient gene engineering Lactococcus lactis for expressing phenylalanine ammonia lyase (PAL) which will benefit PKU therapy. A PAL cDNA of Parsly and a synthesized PAL sequence based on Lactococcus lactis bias codons (palart) were recombined into two Lactococcus lactis NICE systems. The activities of the expressed PALs were detected, and the effect of Lactococcus lactis bias codons on the expression of exterior protein was analyzed. The results showed that the expression level of PAL was increased by using bias codons in the two Lactococcus lactis NICE systems, through which several safer and more efficient strains of the gene engineering Lactococcus lactis were obtained.