INFLUENCE OF DIFFERENT XYLANASES ON THE ACTIVITY OF FERULIC ACID ESTERASE ON WHEAT BRAN

The apparent specific activity of ferulic acid esterases on cell wall polysaccharide materials is enhanced by the presence of xylanases. In this paper we show that the extent of the synergy between an Aspergill us niger ferulic acid esterase (FAE-III) and various xylanases [beta-( 1,4)-D-xylan xylanohydrolases (EC 3.2.1.8)] in releasing ferulic acid from de-starched wheat bran is strongly dependent on the source of the xylanase. Differences among the xylanases are found to be due to (a) the rate of hydrolysis of wheat bran cell wall polysaccharides and (b) the size distribution and nature of the products solubilized in the h ydrolysis. In addition, analysis of the low-molecular-mass carbohydrat e products indicates that the initial rate of the hydrolysis by the xy lanase is also enhanced by the addition of the esterase, showing a rec iprocal co-operation between the enzymes.