Conversion of xylan by recyclable spores of Bacillus subtilis displaying thermophilic enzymes

Background: The Bacillus subtilis spore has long been used to display antigens and enzymes. Spore display can be accomplished by a recombinant and a non-recombinant approach, with the latter proved more efficient than the recombinant one. We used the non-recombinant approach to independently adsorb two thermophilic enzymes, GH10-XA, an endo-1,4-beta-xylanase (EC 3.2.1.8) from Alicyclobacillus acidocaldarius, and GH3-XT, a beta-xylosidase (EC 3.2.1.37) from Thermotoga thermarum. These enzymes catalyze, respectively, the endohydrolysis of (1-4)-beta-D-xylosidic linkages of xylans and the hydrolysis of (1-4)-beta-D-xylans to remove successive D-xylose residues from the non-reducing termini.