Hydrolysis of Steam-Pretreated Lignocellulose: Synergism and Adsorption for Cellobiohydrolase I and Endoglucanase II of Trichoderma reesei

1999 ◽  
Vol 82 (3) ◽  
pp. 243-258 ◽  
Author(s):  
Johan Karlsson ◽  
József Medve ◽  
Folke Tjerneld
Keyword(s):  
Trichoderma Reesei ◽  
Cellobiohydrolase I ◽  
Endoglucanase Ii ◽  
Hydrolysis Of

scholarly journals Hydrolyses of α- and β-cellobiosyl fluorides by cellobiohydrolases of Trichoderma reesei

1993 ◽  
Vol 291 (3) ◽  
pp. 883-888 ◽  
Author(s):  
A K Konstantinidis ◽  
I Marsden ◽  
M L Sinnott
Keyword(s):  
Trichoderma Reesei ◽  
Biological Function ◽  
Fluoride Ion ◽  
Cellobiohydrolase I ◽  
Ion Release ◽  
Cellulase Complex ◽  
Cellobiohydrolase Ii ◽  
Glycoside Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of

Cellobiohydrolase II hydrolyses alpha- and beta-D-cellobiosyl fluorides to alpha-cellobiose at comparable rates, according to Michaelis-Menten kinetics. The stereochemistry, absence of transfer products and strict hyperbolic kinetics of the hydrolysis of alpha-cellobiosyl fluoride suggest that the mechanism for the alpha-fluoride may be the enzymic counterpart of the SNi reaction observed in the trifluoroethanolysis of alpha-glucopyranosyl fluoride [Sinnott and Jencks (1980) J. Am. Chem. Soc. 102, 2026-2032]. The absolute factors by which this enzyme accelerates fluoride ion release are small and greater for the alpha-fluoride than for the beta, suggesting that its biological function may not be just glycoside hydrolysis. Cellobiohydrolase I hydrolyses only beta-cellobiosyl fluoride, which is, however, an approx. 1-3% contaminant in alpha-cellobiosyl fluoride as prepared and purified by conventional methods. Instrumental assays for the various components of the cellulase complex are discussed.

scholarly journals Enhanced Production of Trichoderma reesei Endoglucanases and Use of the New Cellulase Preparations in Producing the Stonewashed Effect on Denim Fabric

2002 ◽  
Vol 68 (8) ◽  
pp. 3956-3964 ◽  
Author(s):  
Arja Miettinen-Oinonen ◽  
Pirkko Suominen
Keyword(s):  
Trichoderma Reesei ◽  
Copy Number ◽  
Parent Strain ◽  
Expression Cassette ◽  
Coding Region ◽  
Cellobiohydrolase I ◽  
Endoglucanase Activity ◽  
Endoglucanase Ii ◽  
Enhanced Production ◽  
Denim Fabric

ABSTRACT Trichoderma reesei strains were constructed for production of elevated amounts of endoglucanase II (EGII) with or without cellobiohydrolase I (CBHI). The endoglucanase activity produced by the EGII transformants correlated with the copy number of the egl2 expression cassette. One copy of the egl2 expression cassette in which the egl2 was under the cbh1 promoter increased production of endoglucanase activity 2.3-fold, and two copies increased production about 3-fold above that of the parent strain. When the enzyme with elevated EGII content was used, an improved stonewashing effect on denim fabric was achieved. A T. reesei strain producing high amounts of EGI and -II activities without CBHI and -II was constructed by replacing the cbh2 locus with the coding region of the egl2 gene in the EGI-overproducing CBHI-negative strain. Production of endoglucanase activity by the EG-transformant strain was increased fourfold above that of the host strain. The filter paper-degrading activity of the endoglucanase-overproducing strain was lowered to below detection, presumably because of the lack of cellobiohydrolases.

Adsorption and Activity of Trichoderma reesei Cellobiohydrolase I, Endoglucanase II, and the Corresponding Core Proteins on Steam Pretreated Willow

1999 ◽  
Vol 81 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Pia Kotiranta ◽  
Johan Karlsson ◽  
Matti Siika-Aho ◽  
József Medve ◽  
Liisa Viikari ◽  
...  
Keyword(s):  
Trichoderma Reesei ◽  
Cellobiohydrolase I ◽  
Endoglucanase Ii ◽  
Core Proteins

scholarly journals Processive action of cellobiohydrolase Cel7A from Trichoderma reesei is revealed as ‘burst’ kinetics on fluorescent polymeric model substrates

2005 ◽  
Vol 385 (2) ◽  
pp. 527-535 ◽  
Author(s):  
Kalle KIPPER ◽  
Priit VÄLJAMÄE ◽  
Gunnar JOHANSSON
Keyword(s):  
Bacterial Cellulose ◽  
Trichoderma Reesei ◽  
Anthranilic Acid ◽  
Degree Of Polymerization ◽  
Cellulose Substrates ◽  
Quantitative Monitoring ◽  
End Groups ◽  
Alternative Means ◽  
Burst Kinetics ◽  
Hydrolysis Of

Reaction conditions for the reducing-end-specific derivatization of cellulose substrates with the fluorogenic compound, anthranilic acid, have been established. Hydrolysis of fluorescence-labelled celluloses by cellobiohydrolase Cel7A from Trichoderma reesei was consistent with the active-site titration kinetics (burst kinetics), which allowed the quantification of the processivity of the enzyme. The processivity values of 88±10, 42±10 and 34±2.0 cellobiose units were found for Cel7A acting on labelled bacterial cellulose, bacterial microcrystalline cellulose and endoglucanase-pretreated bacterial cellulose respectively. The anthranilic acid derivatization also provides an alternative means for estimating the average degree of polymerization of cellulose and, furthermore, allows the quantitative monitoring of the production of reducing end groups on solid cellulose on hydrolysis by cellulases. Hydrolysis of bacterial cellulose by cellulases from T. reesei revealed that, by contrast with endoglucanase Cel5A, neither cellobiohydrolases Cel7A nor Cel6A produced detectable amounts of new reducing end groups on residual cellulose.

Sign in / Sign up

Export Citation Format

Share Document