High efficiency co-production of ferulic acid and xylooligosaccharides from wheat bran by recombinant xylanase and feruloyl esterase

The enzymatic hydrolysis of lignocellulosic biomass has been studied for years, but this hydrolysis has been minimally used in the industry due to its high costs and low conversion yields. In the work reported here, ferulic acid (FA) and xylooligosaccharides (XOS) were generated from wheat bran at high yields based on the synergistic action of two xylan-degrading enzymes, xylanase (AnXyn11A) and feruloyl esterase (AnFaeA), Which were cloned from Aspergillus niger BE-2 and heterologously expressed at high levels in Pichia pastoris. AnXyn11A exhibited a maximal activity of 240 U mL(-1) at pH 5.0 and 60 degrees C and less thermostability above 50 degrees C. AnFaeA showed a maximal activity of 21 U mL(-1) at pH 5.0 and 45 degrees C and high thermostability below 55 degrees C. The ratio of FA released from destarched wheat bran (DSWB) under the synergistic action of AnXyn11A and AnFaeA increased to 70% in comparison with that of the individual enzyme acting alone (only 16.8% of FA was released). Moreover, at the optimum level of enzyme addition, the XOS yield was double that under the single enzyme action. (C) 2017 Elsevier B.V. All rights reserved.