Multifunctional Properties of Glycoside Hydrolase Family 43 from Paenibacillus curdlanolyticus Strain B-6 Including Exo-β-xylosidase, Endo-xylanase, and α-L-Arabinofuranosidase Activities

Abstract

The glycoside hydrolase family 43 from Paenibacillus curdlanolyticus strain B-6 (GH43B6) exhibited multifunctional properties, including exo-xylosidase, endo-xylanase, and -L-arabinofuranosidase enzymatic activities. GH43B6 released xylose as a hydrolysis product from the successive reduction of xylooligosaccharides as a result of exo-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--xylosidase activity changed to endo-xylanase activity, indicating that the enzymatic property of GH43B6 is influenced by the substituted side groups of xylan. For -L-arabinofuranosidase, arabinose was released from short-chain substrates including p-nitrophenyl--Larabinofuranoside and -L-Araf-(12)-[-L-Araf-(13)]--D-Xylp. This study reports the novel trifunctional properties of GH43B6 containing exoand endo-activity together with xylanolytic debranching enzymatic activity, which increases its potential for application in lignocellulosebased biorefineries.