Transformation of xylan into value-added biocommodities using Thermobacillus composti GH10 xylanase

Carbohydr Polym. 2020 Nov 1:247:116714. doi: 10.1016/j.carbpol.2020.116714. Epub 2020 Jul 3.

Abstract

Enzymatic transformation of xylans into renewable fuels and value-added products is mediated by xylanases. Here we describe the biochemical and X-ray structural characterization of Thermobacillus composti GH10 xylanase (TcXyn10A) at 2.1 Å resolution aiming to unravel details of its recognition of glucurono- and arabinoxylan at a molecular level. TcXyn10A improves the efficiency of pretreated lignocellulosic biomass hydrolysis by a commercial enzyme cocktail causing a 15.35 % increase in xylose release and 4.38 % glucose release after 24 h of reaction. The enzyme releases predominantly xylobiose and xylotriose, as well as MeGlcA3 × 3 (from beechwood glucuronoxylan) and a range of decorated xylooligosaccharides (XOS) from rye arabinoxylan, with Ara2 × 2 being the major product. The enzyme liberates XOS with the yields of 29.09 % for beechwood glucuronoxylan and 16.98 % for rye arabinoxylan. Finally, TcXyn10A has a high thermal stability, halotolerance, and resistance to ethanol, biochemical properties that can be desirable for a number of industrial applications.

Keywords: Bioconversion; Cleavage pattern; Crystallographic structure; Prebiotics; Xylan.

MeSH terms

  • Bacillales / enzymology*
  • Endo-1,4-beta Xylanases / metabolism*
  • Hydrolysis
  • Substrate Specificity
  • Xylans / chemistry*
  • Xylans / metabolism

Substances

  • Xylans
  • glucuronoxylan
  • arabinoxylan
  • Endo-1,4-beta Xylanases

Supplementary concepts

  • Thermobacillus composti