Purification and characterization of a xylanase and an arabinofuranosidase from Bacillus polymyxa

Abstract

Two hemicellulases from Bacillus polymyxa were purified and characterized: a xylanase with a molecular mass of 61 kD and pl of 4.7 and an arabinofuranosidase with a molecular mass of 166 kD and pl of 4.7. The xylanase, which showed increased thermostability in the presence of MgCl2, showed a typical endo-action mode on xylans from several sources. The arabinofuranosidase was only active on (1→5)-α-l-arabinooligosaccharides but not on linear (1→5)-α-l-arabinan, arabinogalactan, and arabinoxylan. However, it was able to release arabinose from arabinoxylan when an active endoxylanase was also present in hydrolysis assays