Codon optimization of Aspergillus niger feruloyl esterase and its expression in Pichia pastoris

To enhance the expression level of recombinant feruloyl esterase in Pichia pastoris, the Aspergillus niger feruloyl esterase (AnFaeA) gene was optimized based on the codon usage bias of P. pastoris and synthesized. The synthetic AnFaeAsyn was inserted into the pPICZαA and then integrated into P. pastoris X33. SDS-PAGE analysis of recombinant feruloyl esterase displayed a single protein band with an apparent molecular mass of 40.0 kDa. Western blot analysis confirmed that the expressed protein was the target protein. Furthermore, we showed that codon optimization increased enzyme yield for about 6.4-fold (35.12 U/mL vs 5.51 U/mL) in shake flask cultivation, compared to the non-codon-optimized control. Taken together, this study showed that the yield of feruloyl esterase could be increased by codon optimization.