HPAEC analyses of the hydrolysis products of barley β-glucan and CMC-Na.

<p>1, The hydrolysis products of CMC-Na; 2, The hydrolysis products of barley β-glucan; 3, the cellooligosaccharide standards: G1, glucose; G2, cellobiose; G3, cellotriose; G4, cellotetraose; G5, cellopentaose; G6, cellohexaose.</p

HPAEC analyses of the hydrolysis products of cellooligosaccharide.

<p>1, cellotriose; 2, cellotetraose; 3, cellopentaose; 4, cellohexaose; 5, cellooligosaccharide standards: G1, glucose; G2, cellobiose; G3, cellotriose; G4, cellotetraose; G5, cellopentaose; G6, cellohexaose.</p

A Novel GH7 Endo-β-1,4-Glucanase from <i>Neosartorya fischeri</i> P1 with Good Thermostability, Broad Substrate Specificity and Potential Application in the Brewing Industry

<div><p>An endo-β-1,4-glucanase gene, <i>cel7A</i>, was cloned from the thermophilic cellulase-producing fungus <i>Neosartorya fischeri</i> P1 and expressed in <i>Pichia pastoris</i>. The 1,410-bp full-length gene encodes a polypeptide of 469 amino acids consisting of a putative signal peptide at residues 1–20, a catalytic domain of glycoside hydrolase family 7 (GH7), a short Thr/Ser-rich linker and a family 1 carbohydrate-binding module (CBM 1). The purified recombinant Cel7A had pH and temperature optima of pH 5.0 and 60°C, respectively, and showed broad pH adaptability (pH 3.0–6.0) and excellent stability at pH3.0–8.0 and 60°C. Belonging to the group of nonspecific endoglucanases, Cel7A exhibited the highest activity on barley β-glucan (2020 ± 9 U mg^–1), moderate on lichenan and CMC-Na, and weak on laminarin, locust bean galactomannan, Avicel, and filter paper. Under simulated mashing conditions, addition of Cel7A (99 μg) reduced the mash viscosity by 9.1% and filtration time by 24.6%. These favorable enzymatic properties make Cel7A as a good candidate for applications in the brewing industry.</p></div

The effect of metal cations and reagents (5 mM) on the activity of recombinant Egl7A.

<p>^a Values represent the mean ± SD (n = 3) relative to untreated control sample</p><p>The effect of metal cations and reagents (5 mM) on the activity of recombinant Egl7A.</p

Characterization of purified recombinant Cel7A.

<p>(<b>A)</b> Effect of pH on enzyme activity assayed at 60°C. (<b>B)</b> pH stability. The enzyme activity was assayed after 1-h incubation at 37°C and different pH values. (<b>C)</b> Effect of temperature on enzyme activity at optimal pH. (<b>D)</b> Thermostability assay at 60°C and 70°C. Each value in the panel represents the means ± SD (<i>n</i> = 3).</p

SDS-PAGE analysis of purified recombinant Cel7A.

<p>Lanes: M, the molecular mass standards; 1, the deglycosylated Cel7A with Endo H treatment; 2, the purified recombinant Cel7A.</p

Application of a Novel Alkali-Tolerant Thermostable DyP-Type Peroxidase from <i>Saccharomonospora viridis</i> DSM 43017 in Biobleaching of Eucalyptus Kraft Pulp

<div><p><i>Saccharomonospora viridis</i> is a thermophilic actinomycete that may have biotechnological applications because of its dye decolorizing activity, though the enzymatic oxidative system responsible for this activity remains elusive. Bioinformatic analysis revealed a DyP-type peroxidase gene in the genome of <i>S. viridis</i> DSM 43017 with sequence similarity to peroxidase from dye-decolorizing microbes. This gene, <i>svidyp</i>, consists of 1,215 bp encoding a polypeptide of 404 amino acids. The gene encoding <i>Svi</i>DyP was cloned, heterologously expressed in <i>Escherichia coli</i>, and then purified. The recombinant protein could efficiently decolorize several triarylmethane dyes, anthraquinonic and azo dyes under neutral to alkaline conditions. The optimum pH and temperature for <i>Svi</i>DyP was pH 7.0 and 70°C, respectively. Compared with other DyP-type peroxidases, <i>Svi</i>DyP was more active at high temperatures, retaining>63% of its maximum activity at 50–80°C. It also showed broad pH adaptability (>35% activity at pH 4.0–9.0) and alkali-tolerance (>80% activity after incubation at pH 5–10 for 1 h at 37°C), and was highly thermostable (>60% activity after incubation at 70°C for 2 h at pH 7.0). <i>Svi</i>DyP had an accelerated action during the biobleaching of eucalyptus kraft pulp, resulting in a 21.8% reduction in kappa number and an increase of 2.98% (ISO) in brightness. These favorable properties make <i>Svi</i>DyP peroxidase a promising enzyme for use in the pulp and paper industries.</p></div

Physicochemical properties of enzyme-treated eucalyptus kraft pulp.

a<p>The control samples and the test samples were incubated in the selected buffer at the set temperature with and without corresponding enzyme.</p><p>Physicochemical properties of enzyme-treated eucalyptus kraft pulp.</p

Degradation circles produced by <i>Saccharomonospora viridis</i> on azure B screening plates.

<p>Degradation circles produced by <i>Saccharomonospora viridis</i> on azure B screening plates.</p

Effect of various agents on <i>Svi</i>DyP activity.

<p>UD, undetectable activity.</p><p>EDTA, ethylenediaminetetraacetic acid.</p><p>SDS, sodium dodecyl sulfate.</p><p>Effect of various agents on <i>Svi</i>DyP activity.</p