A novel glycoside hydrolase 43-like enzyme from <i>Clostridium boliviensis</i> is an endo-xylanase and a candidate for xylooligosaccharide production from different xylan substrates

Abstract

The genome of <i>Clostridium boliviensis</i> strain E-1 encodes a number of hypothetical enzymes, annotated as glycoside hydrolase-like but not classified in the Carbohydrate Active Enzyme Database (CAZy). A novel thermostable GH43-like enzyme is here characterized as an endo-β-xylanase of interest in the production of prebiotic xylooligosaccharides (XOs) from different xylan sources. <i>CbE1</i>Xyn43-l is a two-domain enzyme composed of a catalytic GH43-l domain and a CBM6 domain, producing xylotriose as main XO product. The enzyme has homologs in many related <i>Clostridium</i> strains which may indicate a similar function and be a previously unknown type of endo-xylanase in this evolutionary lineage of microorganisms.