Production of xylo-oligosaccharides (XOS) by controlled hydrolysis of xylan using immobilized xylanase from Aspergillus niger with improved properties

The production of xylo-oligosaccharides from xylan using an optimal immobilized catalyst of xylanase from Aspergillus niger is presented. The enzyme extract has several xylanases with different properties doing necessary the development of cheap and simple methods to purify them at industrial scale. The enzyme was successfully purified, immobilized and highly stabilized using a simple protocol. The principal purified xylanase was a 34 KDa protein corresponding with 50% of the endo-xylanase activity of the total strain. Among the different immobilization assayed protocols, the use of aldehyde support allowed the complete immobilization of this fraction keeping 80% of its initial catalytic activity. An optimization of this method promoted a stabilization factor of around 1100-fold more stable than soluble enzyme. The use of the optimal catalyst allowed a maximum hydrolysis degree of 73.4%. The optimization of the reaction conditions (different time and temperature) allowed producing 62% (11.93 mg/mL) of interesting xylooligo-saccharides (XOS2-XOS6) (Figure 1).