scholarly journals Synergistic Cellulose Hydrolysis Dominated by a Multi-Modular Processive Endoglucanase from Clostridium cellulosi

2016 ◽  
Vol 7 ◽  
Author(s):  
Min Yang ◽  
Kun-Di Zhang ◽  
Pei-Yu Zhang ◽  
Xia Zhou ◽  
Xiao-Qing Ma ◽  
...  
Keyword(s):  
Cellulose Hydrolysis ◽  
Processive Endoglucanase

scholarly journals Processive Endoglucanase Active in Crystalline Cellulose Hydrolysis by the Brown Rot Basidiomycete Gloeophyllum trabeum

2005 ◽  
Vol 71 (5) ◽  
pp. 2412-2417 ◽  
Author(s):  
Roni Cohen ◽  
Melissa R. Suzuki ◽  
Kenneth E. Hammel
Keyword(s):  
Extracellular Enzymes ◽  
Reducing Sugars ◽  
Soluble Sugars ◽  
Brown Rot ◽  
Cellulose Hydrolysis ◽  
Major Product ◽  
Crystalline Cellulose ◽  
Gloeophyllum Trabeum ◽  
Processive Endoglucanase ◽  
Brown Rot Fungus

ABSTRACT Brown rot basidiomycetes have long been thought to lack the processive cellulases that release soluble sugars from crystalline cellulose. On the other hand, these fungi remove all of the cellulose, both crystalline and amorphous, from wood when they degrade it. To resolve this discrepancy, we grew Gloeophyllum trabeum on microcrystalline cellulose (Avicel) and purified the major glycosylhydrolases it produced. The most abundant extracellular enzymes in these cultures were a 42-kDa endoglucanase (Cel5A), a 39-kDa xylanase (Xyn10A), and a 28-kDa endoglucanase (Cel12A). Cel5A had significant Avicelase activity—4.5 nmol glucose equivalents released/min/mg protein. It is a processive endoglucanase, because it hydrolyzed Avicel to cellobiose as the major product while introducing only a small proportion of reducing sugars into the remaining, insoluble substrate. Therefore, since G. trabeum is already known to produce a β-glucosidase, it is now clear that this brown rot fungus produces enzymes capable of yielding assimilable glucose from crystalline cellulose.

scholarly journals Processivity, Substrate Binding, and Mechanism of Cellulose Hydrolysis by Thermobifida fusca Cel9A

2007 ◽  
Vol 73 (10) ◽  
pp. 3165-3172 ◽  
Author(s):  
Yongchao Li ◽  
Diana C. Irwin ◽  
David B. Wilson
Keyword(s):  
Catalytic Domain ◽  
Cellulose Hydrolysis ◽  
Site Directed Mutagenesis ◽  
Crystalline Cellulose ◽  
Thermobifida Fusca ◽  
Processive Endoglucanase ◽  
Cellulose Binding ◽  
Increased Activity ◽  
Catalytic Cleft ◽  
Conserved Residue

ABSTRACT Thermobifida fusca Cel9A-90 is a processive endoglucanase consisting of a family 9 catalytic domain (CD), a family 3c cellulose binding module (CBM3c), a fibronectin III-like domain, and a family 2 CBM. This enzyme has the highest activity of any individual T. fusca enzyme on crystalline substrates, particularly bacterial cellulose (BC). Mutations were introduced into the CD or the CBM3c of Cel9A-68 using site-directed mutagenesis. The mutant enzymes were expressed in Escherichia coli; purified; and tested for activity on four substrates, ligand binding, and processivity. The results show that H125 and Y206 play an important role in activity by forming a hydrogen bonding network with the catalytic base, D58; another important supporting residue, D55; and Glc(−1) O1. R378, a residue interacting with Glc(+1), plays an important role in processivity. Several enzymes with mutations in the subsites Glc(−2) to Glc(−4) had less than 15% activity on BC and markedly reduced processivity. Mutant enzymes with severalfold-higher activity on carboxymethyl cellulose (CMC) were found in the subsites from Glc(−2) to Glc(−4). The CBM3c mutant enzymes, Y520A, R557A/E559A, and R563A, had decreased activity on BC but had wild-type or improved processivity. Mutation of D513, a conserved residue at the end of the CBM, increased activity on crystalline cellulose. Previous work showed that deletion of the CBM3c abolished crystalline activity and processivity. This study shows that it is residues in the catalytic cleft that control processivity while the CBM3c is important for loose binding of the enzyme to the crystalline cellulose substrate.

Effect of Rhodococcus sp. pretreatment on cellulose hydrolysis of corn stalk

2020 ◽  
pp. 1-7
Author(s):  
Pan Hu ◽  
Huanan Li ◽  
Wenjing Xiao ◽  
Xiaohang Xie ◽  
Yuxian Yang ◽  
...  
Keyword(s):  
Cellulose Hydrolysis ◽  
Corn Stalk ◽  
Hydrolysis Of ◽  
Rhodococcus Sp

Rational Design of Solid-Acid Catalysts for Cellulose Hydrolysis Using Colloidal Theory

2021 ◽  
Author(s):  
Ziyang Zhang ◽  
Geoffrey A Tompsett ◽  
Christopher Lambert ◽  
Sergio Granados-Focil ◽  
Michael T. Timko
Keyword(s):  
Rational Design ◽  
Solid Acid ◽  
Molecular Level ◽  
Cellulose Hydrolysis ◽  
Solid Acid Catalysts ◽  
Acid Catalysts

Solid-acid catalysts functionalized with catalytic groups have attracted intense interests for hydrolyzing cellulose into fermentable compounds. However, the solid-acid catalysts design has been guided by molecular level of interactions and...

Cellulase-Inspired Solid Acids for Cellulose Hydrolysis: Structural Explanations for High Catalytic Activity

ACS Catalysis ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 1464-1468 ◽  
Author(s):  
Maksim Tyufekchiev ◽  
Pu Duan ◽  
Klaus Schmidt-Rohr ◽  
Sergio Granados Focil ◽  
Michael T. Timko ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Cellulose Hydrolysis ◽  
Solid Acids ◽  
High Catalytic Activity

HaloTag mediated artificial cellulosome assembly on a rolling circle amplification DNA template for efficient cellulose hydrolysis

2016 ◽  
Vol 52 (40) ◽  
pp. 6701-6704 ◽  
Author(s):  
Qing Sun ◽  
Wilfred Chen
Keyword(s):  
Rolling Circle Amplification ◽  
Cellulose Hydrolysis ◽  
The Self ◽  
Rolling Circle ◽  
Dna Template ◽  
Dna Scaffold

We report here the generation of artificial cellulosomes onto a DNA scaffold using the self-labeling HaloTag for DNA conjugation. Rolling circle amplification multiplexing templates were used to increase the complexity of this system with higher efficiency observed.

P. vortex-mediated strategies for polysaccharides decomposition

TECHNOLOGY ◽  
2015 ◽  
Vol 03 (02n03) ◽  
pp. 80-83
Author(s):  
Mark Polikovsky ◽  
Eshel Ben-Jacob ◽  
Alin Finkelshtein
Keyword(s):  
Degradation Products ◽  
Cellulose Degradation ◽  
Cellulose Hydrolysis ◽  
Industrial Applications ◽  
Biofuel Production ◽  
E Coli ◽  
Novel Approach ◽  
Textile Manufacture ◽  
Hydrolysis Of Cellulose ◽  
The Relationship

Cellulose hydrolysis has many industrial applications such as biofuel production, food, paper and textile manufacture. Here, we present a novel approach to cellulose hydrolysis using a consortium of motile bacteria, Paenibacillus vortex, that can swarm on solid medium carrying a non-motile recombinant E. coli cargo strain expressing the β-glucosidase and cellulase genes that facilitate the hydrolysis of cellulose. These two species cooperate; the relationship is mutually beneficial: the E. coli is dispersed over long distances, while the P. vortex bacteria gain from the supply of cellulose degradation products. This enables the use of such consortia in this area of biotechnology.

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