The effect of an oligosaccharide reducing-end xylanase, BhRex8A, on the synergistic degradation of xylan backbones by an optimised xylanolytic enzyme cocktail

Publication date: Available online 19 December 2018Source: Enzyme and Microbial TechnologyAuthor(s): Samkelo Malgas, Brett. I. PletschkeAbstractXylan, the most abundant hemicellulose in lignocellulosic biomass, requires a consortium of xylanolytic enzymes to achieve its complete de-polymerisation. As global interest in using xylan containing lignocellulosic feedstocks for biofuel production increases, an accompanying knowledge on how to efficiently depolymerize these feedstocks into fermentable sugars is required. Since it has been observed that the same enzyme [i.e. an enzyme with the same EC (Enzyme Commission) classification] from different GH families can display different substrate specificities and properties, we evaluated GH10 (XT6) and 11 (Xyn2 A) xylanase performance alone, and in combination, during xylan depolymerisation. Synergistic enhancement with respect to reducing sugar release was observed when Xyn2 A at 75% loading was supplemented with 25% loading of XT6 for both beechwood glucuronoxylan (1.14-fold improvement) and wheat arabinoxylan (1.1-fold improvement) degradation. Following this, the optimized xylanase mixture was dosed with an oligosaccharide reducing-end xylanase (Rex8A) from either Bifidobacterium adolescentis or Bacillus halodurans for further synergistic enhancement. Dosing 75% of the xylanase mixture (Xyn2 A:XT6 at 75:25%) with 25% loading of Rex8A led to an enhancement of reducing sugar (up to 1.1-fold improvement) and xylose release (up...
Source: Enzyme and Microbial Technology - Category: Biotechnology Source Type: research