Methylglucuronoxylans (MeGX(n)) and methylglucuronoarabinoxylans (MeGAX(n)) respectively comprise most of the hemicellulose fractions in dicots and monocots and, next to cellulose, are the major resources for the production of fuels and chemicals from lignocellulosics. With either MeGX(n) or MeGAX(n) as a substrate, Bacillus subtilis 168 accumulates acidic methylglucuronoxylotriose as a limit product following the uptake and metabolism of neutral xylooligosaccharides. Secreted GH11 endoxylanase (Xyn11A), GH30 endoxylanase (Xyn30C), and GH43 arabinoxylan arabinofuranohydrolase (Axh43) respectively encoded by the xynA, xynC, and xynD genes collectively contribute to the depolymerization of MeGAX(n). Studies here demonstrate the complementary roles of these enzymes in the digestion of MeGAX(n). Coordinate expression of the xynD and xynC genes defines an operon accounting for the Axh43-catalyzed release of arabinose followed by Xyn30C and Xyn11A-catalyzed depolymerization of MeGAX(n). Both sources generate acetate and lactate as the principal fermentation products, with yields of 26 % acetate and 32 % lactate from MeGX(n) compared to 22% acetate and 21% lactate from MeGAX(n). These studies of the GH43/GH30/GH11 system in B. subtilis 168 provide a basis for the further development of B. subtilis and related species as biocatalysts for direct conversion of hemicellulose derived from energy crops as well as agricultural and forest residues to chemical feedstocks.