Endo-xylanases play a key role in the hydrolysis of xylan and recently they have attracted much attention due to their potential applications on the biofuel and paper industries. We isolated a Pseudozyma brasiliensis sp. nov. strain from the intestinal tract of Chrysomelidae larvae that parasitize sugarcane roots. This basidiomycetous yeast produces a xylanase designated PbXynA which was purified and characterized. The molecular weight of PbXynA is 24 kDa, it belongs to the GH11 family and its optimum pH and optimum temperature are 4.0 and 55 C, respectively. PbXynA has as secondary structure predominantly beta-sheets and sigmoidal kinetic behavior with elevated speed conversion from substrate-to-products (V-max = 2792.0 mu mol product/min/mg protein). It is highly activated by bivalent cations such as Ca2+, however in the presence of Cu2+ xylanase activity was inhibited. It has a high specific activity and produces xylooligosaccharides that have a variety of industrial applications, indicating PbXynA has a great biotechnological potential. (C) 2013 Elsevier Ltd. All rights reserved.