Characterization of the Highly Efficient Acid-Stable Xylanase and β-Xylosidase System from the Fungus Byssochlamys spectabilis ATHUM 8891 (Paecilomyces variotii ATHUM 8891)

Abstract

Two novel xylanolytic enzymes, a xylanase and a β-xylosidase, were simultaneously isolated and characterized from the extracellular medium of Byssochlamys spectabilis ATHUM 8891 (anamorph Paecilomyces variotii ATHUM 8891), grown on Brewer’s Spent Grain as a sole carbon source. They represent the first pair of characterized xylanolytic enzymes of the genus Byssochlamys and the first extensively characterized xylanolytic enzymes of the family Thermoascaceae. In contrast to other xylanolytic enzymes isolated from the same family, both enzymes are characterized by exceptional thermostability and stability at low pH values, in addition to activity optima at temperatures around 65 °C and acidic pH values. Applying nano-LC-ESI-MS/MS analysis of the purified SDS-PAGE bands, we sequenced fragments of both proteins. Based on sequence-comparison methods, both proteins appeared conserved within the genus Byssochlamys. Xylanase was classified within Glycoside Hydrolase family 11 (GH 11), while β-xylosidase in Glycoside Hydrolase family 3 (GH 3). The two enzymes showed a synergistic action against xylan by rapidly transforming almost 40% of birchwood xylan to xylose. The biochemical profile of both enzymes renders them an efficient set of biocatalysts for the hydrolysis of xylan in demanding biorefinery applications.

Biochemical and Thermodynamic Studies on a Novel Thermotolerant GH10 Xylanase from Bacillus safensis

“…Endo-1,4-xylanase (xylanase) activity was determined as described previously [ 21 ]. Briefly, 50 μL of properly diluted enzyme was added to 450 μL of 20 g·L −1 oat spelt xylan (Sigma, St. Louis, MO, USA) in 50 mM citrate-phosphate buffer (pH 7.0) and placed in a thermoshaker (TS-100, BOECO, Hamburg, Germany) operating at 900 rpm and 60 °C for 15 min.…”

In Silico Phylogeny, Sequence and Structure Analyses of Fungal Thermoacidophilic GH11 Xylanases

“…For example, a recent work has shown that thermoacidophilic xylanase enzyme of Aspergillus tubingensis possessed an optimum pH and temperature of 5.0 and 50 o C, respectively (Intasit et al, 2022). In another study, Galanopoulou et al (2021) have characterized thermophilic, acid-stable xylanase from Byssochlamys spectabilis, optimally working at 65 o C and pH 3.5 (Galanopoulou et al, 2021).…”