title: Release of ferulic acid from oat hulls by Aspergillus ferulic acid esterase and trichoderma xylanase.
abstract: Oat hulls, an agricultural byproduct, contain a relatively high amount of ferulic acid (FA; 4-hydroxy-3-methoxycinnamic acid), which is believed to be inhibitory to oat hull biodegradability by rumen microorganisms. In this paper, Aspergillus ferulic acid esterase (FAE) was investigated for its ability to release FA from oat hulls. The objectives were to determine the effects of particle size of oat hulls (ground to pass through 1 mm and 250 microm screens and a 100 microm sieve) on release of FA by FAE both in the presence and in the absence of Trichoderma xylanase. The results show that the release of FA by FAE was dependent upon the particle size of oat hulls (< or = 250 microm). In the absence of Trichoderma xylanase, little FA was released by FAE. In the presence of Trichoderma xylanase, there was a significant release of FA by FAE, indicating a synergistic interaction between FAE and Trichoderma xylanase on release of FA from oat hulls. These results indicate that FAE is able to break the ester linkage between FA and the attached sugar, releasing FA from oat hulls. This may leave the remainder of the polysaccharides open for further hydrolytic attack by rumen microorganisms. It is likely that removing FA from oat hulls could improve rumen biodegradability, thus improving the nutritional value of oat hulls.
authors.affiliation: College of Agriculture, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan S7N5A8, Canada. yupe@sask.usask.ca
authors.forename: Peiqiang
authors.initials: P
authors.lastname: Yu
authors.forename: David D
authors.initials: DD
authors.lastname: Maenz
authors.forename: John J
authors.initials: JJ
authors.lastname: McKinnon
authors.forename: Vern J
authors.initials: VJ
authors.lastname: Racz
authors.forename: David A
authors.initials: DA
authors.lastname: Christensen
mesh_terms: D001230:Aspergillus / Q000201:enzymology*; D018554:Avena / Q000737:chemistry / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D003373:Coumaric Acids / Q000032:analysis / Q000378:metabolism*; D004043:Dietary Fiber / Q000032:analysis; D004044:Dietary Proteins / Q000032:analysis; D010316:Particle Size; D014242:Trichoderma / Q000201:enzymology*; D043325:Xylan Endo-1,3-beta-Xylosidase; D014995:Xylosidases / Q000378:metabolism*
chemical_list: D003373:Coumaric Acids; D004043:Dietary Fiber; D004044:Dietary Proteins; C004999:ferulic acid; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase; D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase