scholarly journals Breakdown of Corn Fiber by a Metagenomic Ferulolyl Esterase in Combination with Glycosyl Hydrolases

2021 ◽  
Vol 09 (04) ◽  
pp. 91-100
Author(s):  
Dominic W. S. Wong ◽  
Victor J. Chan ◽  
Hans Liao
Keyword(s):  
Corn Fiber ◽  
Glycosyl Hydrolases

Statistical study of mechanical properties for corn fiber with reinforced of polypropylene fiber matrix composite

2021 ◽  
Author(s):  
Sameer A. Agrawal ◽  
Ashish M. Umbarkar ◽  
Nitin P. Sherie ◽  
Ashish M. Dharme ◽  
Dharmesh Dhabliya
Keyword(s):  
Mechanical Properties ◽  
Matrix Composite ◽  
Statistical Study ◽  
Polypropylene Fiber ◽  
Corn Fiber ◽  
Fiber Matrix

scholarly journals Optimization of β-1,4-Endoxylanase Production by an Aspergillus niger Strain Growing on Wheat Straw and Application in Xylooligosaccharides Production

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2527
Author(s):  
Zahra Azzouz ◽  
Azzeddine Bettache ◽  
Nawel Boucherba ◽  
Alicia Prieto ◽  
Maria Jesus Martinez ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Wheat Straw ◽  
Plant Biomass ◽  
Residual Activity ◽  
Exchange Chromatography ◽  
Glycosyl Hydrolases ◽  
Biomass Degradation ◽  
Xylan Hydrolysis ◽  
Rsm Optimization ◽  
Single Carbon Source

Plant biomass constitutes the main source of renewable carbon on the planet. Its valorization has traditionally been focused on the use of cellulose, although hemicellulose is the second most abundant group of polysaccharides on Earth. The main enzymes involved in plant biomass degradation are glycosyl hydrolases, and filamentous fungi are good producers of these enzymes. In this study, a new strain of Aspergillus niger was used for hemicellulase production under solid-state fermentation using wheat straw as single-carbon source. Physicochemical parameters for the production of an endoxylanase were optimized by using a One-Factor-at-a-Time (OFAT) approach and response surface methodology (RSM). Maximum xylanase yield after RSM optimization was increased 3-fold, and 1.41- fold purification was achieved after ultrafiltration and ion-exchange chromatography, with about 6.2% yield. The highest activity of the purified xylanase was observed at 50 °C and pH 6. The enzyme displayed high thermal and pH stability, with more than 90% residual activity between pH 3.0–9.0 and between 30–40 °C, after 24 h of incubation, with half-lives of 30 min at 50 and 60 °C. The enzyme was mostly active against wheat arabinoxylan, and its kinetic parameters were analyzed (Km = 26.06 mg·mL−1 and Vmax = 5.647 U·mg−1). Wheat straw xylan hydrolysis with the purified β-1,4 endoxylanase showed that it was able to release xylooligosaccharides, making it suitable for different applications in food technology.

scholarly journals Determination of the Catalytic Base in Family 48 Glycosyl Hydrolases

2011 ◽  
Vol 77 (17) ◽  
pp. 6274-6276 ◽  
Author(s):  
Maxim Kostylev ◽  
David B. Wilson
Keyword(s):  
Aspartic Acid ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Thermobifida Fusca ◽  
Glycosyl Hydrolases ◽  
Content Type ◽  
Modeling Data ◽  
Partial Activity

ABSTRACTThe catalytic base in family 48 glycosyl hydrolases has not been previously established experimentally. Based on structural and modeling data published to date, we used site-directed mutagenesis and azide rescue activity assays to show definitively that the catalytic base inThermobifida fuscaCel48A is aspartic acid 225. Of the tested mutants, only Cel48A with the D225E mutation retained partial activity on soluble and insoluble substrates. In azide rescue experiments, only the D225G mutation, in the smallest residue tested, showed an increase in activity with added azide.

scholarly journals Identification of Glu-519 as the catalytic nucleophile in β-mannosidase 2A from Cellulomonas fimi

2000 ◽  
Vol 351 (3) ◽  
pp. 833-838 ◽  
Author(s):  
Dominik STOLL ◽  
Shouming HE ◽  
Stephen G. WITHERS ◽  
R. Antony J. WARREN
Keyword(s):  
Peptide Bond ◽  
Enzyme Inactivation ◽  
Ionization Mass ◽  
Glycosyl Hydrolases ◽  
Cellulomonas Fimi ◽  
Inactivation Rate Constant ◽  
Dependent Inactivation ◽  
The Difference ◽  
The Masses ◽  
Covalent Intermediate

Incubation of the β-mannosidase Man2A from Cellulomonas fimi with 2-deoxy-2-fluoro-β-d-mannosyl fluoride (2FManβF) resulted in time-dependent inactivation of the enzyme (inactivation rate constant ki = 0.57min-1, dissociation constant for the inactivator Ki = 0.41mM) through the accumulation of a covalent 2-deoxy-2-fluoro-α-d-mannosyl–β-mannosidase 2A (2FMan–Man2A) enzyme intermediate, as observed by electrospray ionization mass spectrometry. The stoichiometry of inactivation was 1:1. Removal of excess inactivator and regeneration of active enzyme by transglycosylation of the covalently attached inhibitor to gentiobiose [Glcβ(1–6)Glc] demonstrated that the covalent intermediate was catalytically competent. Comparison by MS of the peptic digests of 2FMan–Man2A with peptic digests of native Man2A revealed a peptide of m/z 1520 that was unique to 2FMan–Man2A, and one of m/z 1036.5 that was unique to a Man2A peptide. Their sequences, determined by collision-induced fragmentation, were CSEFGFQGPPTW and FGFQGPPTW, corresponding to residues 517–528 and 520–528 of Man2A respectively. The difference in mass of 483.5 between the two peptides equals the sum of the masses of the tripeptide CSE plus that of 2-fluoromannose. It was concluded that in 2FMan–Man2A, the 2-fluoromannose esterified to Glu-519 blocks hydrolysis of the Glu-519–Phe-520 peptide bond, and that Glu-519 is the catalytic nucleophile in this enzyme. This residue is conserved in all members of family 2 of the glycosyl hydrolases. This represents the first ever labelling and identification of an active-site nucleophile in a β-mannosidase.

Corn Kernel Oil and Corn Fiber Oil

2009 ◽  
pp. 409-431 ◽  
Author(s):  
Robert A. Moreau ◽  
Vijay Singh ◽  
Michael J. Powell ◽  
Kevin B. Hicks
Keyword(s):  
Corn Fiber ◽  
Corn Kernel ◽  
Kernel Oil ◽  
Fiber Oil ◽  
Corn Fiber Oil

scholarly journals Conserved Processes and Lineage-Specific Proteins in Fungal Cell Wall Evolution

2007 ◽  
Vol 6 (12) ◽  
pp. 2269-2277 ◽  
Author(s):  
Juan E. Coronado ◽  
Saad Mneimneh ◽  
Susan L. Epstein ◽  
Wei-Gang Qiu ◽  
Peter N. Lipke
Keyword(s):  
Cell Wall ◽  
Protein Function ◽  
Phosphatidyl Inositol ◽  
Low Complexity ◽  
Open Reading Frames ◽  
Specific Cell ◽  
Glycosyl Hydrolases ◽  
Fungal Cell ◽  
Structural Wall ◽  
Lineage Specificity

ABSTRACT The cell wall is a defining organelle that differentiates fungi from its sister clades in the opisthokont superkingdom. With a sensitive technique to align low-complexity protein sequences, we have identified 187 cell wall-related proteins in Saccharomyces cerevisiae and determined the presence or absence of homologs in 17 other fungal genomes. There were both conserved and lineage-specific cell wall proteins, and the degree of conservation was strongly correlated with protein function. Some functional classes were poorly conserved and lineage specific: adhesins, structural wall glycoprotein components, and unannotated open reading frames. These proteins are primarily those that are constituents of the walls themselves. On the other hand, glycosyl hydrolases and transferases, proteases, lipases, proteins in the glycosyl phosphatidyl-inositol-protein synthesis pathway, and chaperones were strongly conserved. Many of these proteins are also conserved in other eukaryotes and are associated with wall synthesis in plants. This gene conservation, along with known similarities in wall architecture, implies that the basic architecture of fungal walls is ancestral to the divergence of the ascomycetes and basidiomycetes. The contrasting lineage specificity of wall resident proteins implies diversification. Therefore, fungal cell walls consist of rapidly diversifying proteins that are assembled by the products of an ancestral and conserved set of genes.

An Improved Process for Isolation of Corn Fiber Gum

1998 ◽  
Vol 75 (4) ◽  
pp. 408-411 ◽  
Author(s):  
Landis W. Doner ◽  
Hoa K. Chau ◽  
Marshall L. Fishman ◽  
Kevin B. Hicks
Keyword(s):  
Corn Fiber
Sign in / Sign up

Export Citation Format

Share Document