RELEASE OF FERULIC ACID FROM WHEAT BRAN BY A FERULIC ACID ESTERASE (FAE-III) FROM ASPERGILLUS-NIGER

Ferulic acid was efficiently released from a wheat bran preparation by a ferulic acid esterase from Aspergillus niger (FAE-III) when incubat ed together with a Trichoderma viride xylanase (a maximum of 95% total ferulic acid released after 5 h incubation). FAE-III by itself could release ferulic acid but at a level almost 24-fold lower than that obt ained in the presence of the xylanase (2 U). Release of ferulic acid w as proportional to the FAE-III concentration between 0.1 U and 1.3 U, but the presence of low levels of xylanase (0.1 U) increased the amoun t of ferulic acid released 6-fold. Total sugar release was not influen ced by the action of FAE-III on the wheat bran, but the rate of releas e of the apparent end-products of xylanase action (xylose and xylobios e) was elevated by the presence of the esterase. The results show that FAE-III and the xylanase act together to break down feruloylated plan t cell-wall polysaccharides to give a high yield of ferulic acid.