Feruloyl esterases (FAEs) act synergistically with xylanases to hydrolyze ester-linked ferulic (FA) and diferulic (diFA) acid from cell wall material and therefore play a major role in the degradation of plant biomass. The potential applications of these enzymes with reference to agriculture. food and pharmaceutical industries, are discussed in this review. FAE activities produced by different microorganisms are compared for both submerged and solid state fermentations. In addition, their physicochemical properties and molecular biology are presented. (c) 2007 Elsevier Ltd. All rights reserved.