Abstract
The glycoside hydrolase family 43 from Paenibacillus curdlanolyticus strain B-6 (GH43B6) exhibited multifunctional properties, including exo-beta-xylosidase, endo-xylanase, and alpha-L-arabinofuranosidase enzymatic activities. GH43B6 released xylose as a hydrolysis product from the successive reduction of xylooligosaccharides as a result of exo-beta-xylosidase activity. Moreover, GH43B6 also predominantly released xylose from low-substituted xylan derived from birchwood. However, when the highly substituted rye flour arabinoxylan was used as a substrate, exo-beta-xylosidase activity changed to endo-xylanase activity, indicating that the enzymatic property of GH43B6 is influenced by the substituted side groups of xylan. For alpha-L-arabinofuranosidase, arabinose was released from short-chain substrates including p-nitrophenyl-alpha-L-arabinofuranoside and alpha-L-Araf-(1 -> 2)-[alpha-L-Araf-(1 -> 3)]-beta-D-Xylp. This study reports the novel trifunctional properties of GH43B6 containing exo- and endo-activity together with xylanolytic debranching enzymatic activity, which increases its potential for application in lignocellulose-based biorefineries.
