Abstract:The synergetic effect of the recombinant acetylxylan esterase and xylanase from Aspergillus usamii(abbreviated as reAuAxe, reAuXyn11A, reAuXyn10A, respectively) was investigated. The fermentation of Pichia pastoris GS115/Auaxe, GS115/Auxyn11A and GS115/Auxyn10A was carried out using methanol as inducer and reAuAxe, reAuXyn11A and reAuXyn10A were successfully expressed. The amounts on the release of reducing sugar were optimized with enzyme concentration when incubated for 2 h at the optimal pH under 40 ℃ with the solid-liquid ratio of 1 g∶60 mL. A better synergistic effect was found when acetylxylan esterase and reAuXyn11A were combined. Comparing to use xylanase alone, the released reduce sugar could increase by 46% when reAuAxe and reAuXyn11A were added with a ratio of 5∶1. The removal of the O-acetyl groups from the xylose residues by acetylxylan esterase was necessary and important for the efficiency improvement of xylan hydrolysis.
