To optimize the expression of type A ferulic acid esterase (FaeA) from Aspergillus niger in Pichia pastoris X-33 using codon optimization. Recombinant FaeA was purified from the fermentation broth, with the maximum specific activity of 48.4 +/- 0.1 U mg(-1). Adding it during mashing process for beer brewing raised the filtration rate by 14.5% while the turbidity and viscosity declined by 22 and 6.9%, respectively. Addition of FaeA increased the concentrations of free ferulic acid (FA) and arabinoxylan (AX) in the wort, while the polymeric arabinoxylans content declined significantly. Recombinant FaeA was capable to prevent the oxidative gelation of PAX formation by breaking the cross-linking of FA among AX chains and improve the filtration performance of wort.