Characterization of a new α-L: -arabinofuranosidase from Penicillium sp. LYG 0704, and their application in lignocelluloses degradation.

A gene (arf) encoding an α-L: -arabinofuranosidase (ARF) that hydrolyzes arabinose substituted on xylan was isolated from Penicillium sp. The gene was predicted to encode 339 amino acid residues showing 71-75% homology to GH family 54. E. coli expressed ARF showed optimal activity at 50°C and pH 5-6 on wheat arabinoxylan. The hydrolysis activities on oat spelt xylan by ARF and xylanase were 1.67-fold higher than that of xylanase alone. The synergistic effects of ARF and commercial enzymes (xylanase and cellulase) on popping-pretreated rice straw were 1.15-1.51-fold higher amounts of sugars released in the [ARF + xylanase + cellulase] mixture than in the mixtures [ARF + xylanase], [ARF + cellulase], and [xylanase + cellulase]. Moreover, the liberation of arabinose by ARF was enhanced 2.1-2.9-fold in a reaction with xylanase and cellulase as compared with [xylanase + cellulase] and ARF alone.