The recombinant thermo-alkali-stable endoxylanase (Bh-xyl) of polyextremophilic bacterium Bacillus halodurans TSEV1 has been produced extracellularly using a combination of cloning strategies and physico-chemical treatment of recombinant Escherichia coli cells. Sixty percent higher secretion of recombinant xylanase has been achieved by cloning Bh-xyl in pET28a(+) and expression followed by optimization of the cultural variables (EDTA, lysozyme and temperature). The pure recombinant endoxylanase is of 42 kDa, which is active in the broad pH and temperature ranges between 7.0 and 12.0, and 30 and 100 degrees C, with optima at 9.0 and 70 degrees C. The K-m, V-max, and k(cat) values of the Bh-xyl (birchwood xylan) are 2.6 mg ml(-1), 252.3 mu mol mg(-1) min(-1) and 3.36 x10(3) min(-1), respectively. The enzyme has higher affinity for soft wood xylan than most of the xylanases from extremophilic microbes. The endoxylanase efficiently liberated xylooligosaccharides from the renewable agro-residues, which find application in functional foods as prebiotics. (C) 2014 Elsevier Ltd. All rights reserved.