Functional characterization of a GH62 family α-L-arabinofuranosidase from Eupenicillium parvum suitable for monosaccharification of corncob arabinoxylan in combination with key enzymes

Production of xylose through enzymatic hydrolysis of glucuronoarabinoxylan from brewers’ spent grain

“…The maximum yield (63.6%) reached in this work with the assay IV (endo-xylanase GH10 + endoxylanase GH11 + α-L-arabinofuranosidase GH51 + α-glucuronidase GH67) is comparable to other arabinoxylan hydrolyzed enzymatically (Rasmussen et al 2012;Long et al 2022), but also show the necessity of supply the enzyme supplement with other accessory enzymes such as feruloyl esterase and α-l-galactosidase (Forssell et al 2008;Mccleary et al 2015;Biely et al 2016;Long et al 2022) and with other families of the α-glucuronidase such a GH115 to try increase the xylose release. Finally, due to the relevance of α-glucuronidase GH67 activity in the xylose release, it is important to probe other conditions of temperature and pH closest to the pH and temperature optima of this key enzyme.…”

“…In this work a similar pattern was obtained up to 24 h between test I (all) and IV (all-A GH43 ), but after 24 h increased xylose release in the assay IV due to the presence of one α-d-glucuronidase of the family GH67. Long et al (2022) also noted, that supplementation of the GH67 α-glucuronidase significantly enhanced (by 20-40%) the liberation of xylose from arabinoxylan of corncob during the enzyme hydrolysis (24 h), suggesting that MeGlcA substitution as an important limit factor of enzymatic saccharification remained in the substrate after the alkaline hydrogen peroxide pretreatment.…”

“…Xylooligosaccharides (XOS) are considered prebiotic compounds presenting technical and health claims (Poletto et al 2020;Swart et al 2020). Xylose derived products including xylitol, ethanol, isobutanol, lactic acid or lipid and its derivatives by biological technologies (Long et al 2022). Agricultural crop and industrial residues have been explored to obtain hemicellulose between them corncob, corn stover, wheat straw and the main byproduct of beer production known as brewers' spent grain (BSG).…”

“…Mccleary et al (2015) determined empirically an optimal enzyme mixture that contained β-xylanase (1300 U/mL), β-xylosidase (200 U/ mL), B. adolescentis α-l-arabinofuranosidase (300 U/ mL), U. maydis α-l-arabinofuranosidase (75 U/mL), and A. niger α-l-arabinofuranosidase (170 U/mL) as high purity enzymes over water-soluble wheat flour arabinoxylans (WAXs) and found a yield of 90% of l-arabinose and d-xylose release, although the addition of more enzymes did not increase the yield, suggesting the presence of other groups in the arabinoxylan, such as ferulic acid, which prevent complete hydrolysis of WAX to monosaccharides. Newly, Long et al (2022) evaluated the hydrolysis of corncob arabinoxylans with low (CAX1) or high (CAX2) branching degrees reported that a new arabinofuranosidase EpABF62A of the GH62 family combined with a GH10 xylanase, a GH43 β-D-xylosidase and a GH67 α-glucuronidase released 75.0% or 64.5% xylose from CAX1 or CAX2, respectively.…”