The nature and mode of action of the cellulolytic component C1 of <i>Trichoderma koningii</i> on native cellulose

Halliwell, G.; Griffin, Michael D. W.

doi:10.1042/bj1350587

Cited by 157 publications

(58 citation statements)

References 12 publications

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“…This is probably because of the previous lack of a suitable system for visualizing cellulase action and the failure to exploit high-resolution electron microscopic techniques. Cellulase studies to date have characterized the chemical composition of cellulase enzymes, the specificities of their reactions, and certain aspects of their kinetics (3)(4)(5)(6)(7)(8)(9)(10); however, biochemical studies are not able to monitor the morphological changes that occur in the cellulose substrate during the process of hydrolysis.…”

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confidence: 99%

Enzymatic hydrolysis of cellulose: Visual characterization of the process

White

Brown

1981

Proc. Natl. Acad. Sci. U.S.A.

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Cellulose from the Gram-neative bacterium Acetobacter xylinum has been used as a model substrate for visualizing the action of cellulase enzymes from the fungus Trichoderma reesei. High-resolution electron microscopy reveals that A. xylinum normally produces a ribbon of cellulose that is a composite of bundles of crystalline microfibrils. Visual patterns of the process of cellulose degradation have been established. Enzymes are initially observed bound to the cellulose ribbon. Within 10 min, the ribbon is split along its long axis into bundles of microfibrils which are subsequently thinned until they are completely dissolved within 30 min. Incubations with purified components of the cellulase enzyme system produced less dramatic changes in ribbon structure. Purified 1,4-(-D-glucan cellobiohydrolase I (D) (EC 3.2.1.91) produced no visible change in cellulose structure. Purified endo-1,4-l-D-glucanase IV (EC 3.2.1.4) produced some splaying of ribbons into microfibril bundles. In both cases, whole ribbons were present even after 60 min of incubation, visually confirming the synergistic mode of action of these enzymes.Considering the abundance of cellulose, the decomposition of cellulose is perhaps one of the most common natural degradative processes. The importance of understanding this reaction becomes apparent when one considers the potential exploitation of cellulose as a renewable energy resource through its conversion to ethanol (1), the importance of cellulose degradation in nutrient cycling, and the possible role of cellulase action in the fundamentals of plant cell growth and development (2). Although the action of cellulases has been extensively studied in biochemical terms, little is known about the interaction of cellulase enzymes with its cellulose substrate at the macromolecular level. This is probably because of the previous lack of a suitable system for visualizing cellulase action and the failure to exploit high-resolution electron microscopic techniques. Cellulase studies to date have characterized the chemical composition of cellulase enzymes, the specificities of their reactions, and certain aspects of their kinetics (3-10); however, biochemical studies are not able to monitor the morphological changes that occur in the cellulose substrate during the process of hydrolysis.The trivial name cellulase actually refers to a system of three different enzymes whose combined actions lead to the efficient degradation of cellulose. In a currently accepted scheme of cellulase action (4, 11, 12), endo-1,4-,&D-glucanase (EC 3.2.1.4) (endoglucanase) randomly cleaves internal glucosidic bonds within an unbroken glucan chain. The newly created nonreducing chain end then becomes the substrate for 1,4-f3-D-glucan cellobiohydrolase (EC 3.2.1.91) (cellobiohydrolase), which cleaves cellobiose dimers from the glucan chain and releases them into solution. The hydrolysis of cellulose into the glucose end product is completed by /3glucosidase (EC 3.2.1.21), which splits cellobiose into glucose monomers. The crea...

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confidence: 99%

Enzymatic hydrolysis of cellulose: Visual characterization of the process

White

Brown

1981

Proc. Natl. Acad. Sci. U.S.A.

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“…It allows a determination of [17] from a one point measurement of viscosity: =log[ij] + c X Using relationships (3) and (4), it can be noticed that: ( 9 ) (10) Standard errors are indicated. The difference between CO and CE is without significance.…”

Section: Resultsmentioning

confidence: 99%

“…As clearly indicated by its common name, cellulase has to hydrolyse cellulose:, the enzyme system hydrolysing HEC or CMC is in fact a HECase or CMCase. Such a statement is important because a true cellulase can be free of CMCase (2,9) or a CMCase can act as a xylanase, then as a hemicellulase (22). This indicates that the results obtained with CMC or HEC must not only be necessarily related to the physiological concept of cellulose, but also to hemicellulose, etc.…”

Section: Discussionmentioning

confidence: 99%

Viscosimetric determination of cellulase activity: critical analyses

Guignard

Pilet

1976

Plant and Cell Physiology

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“…The intrinsic reaction kinetics of enzymatic cellulose hydrolysis is also subjected to mediation by a host of factors like inhibitory effects of reaction intermediates and enzyme adsorption. The soluble products such as cellobiose and glucose have been reported to be the inhibitors of the cellulase complex (Howell and Stuck, 1975;Katz and Reese, 1968;Ghose, 1977;Nisizawa, 1973), individual enzyme endoglucanase components (Halliwell and Griffin, 1973;Ladisch et al, 1980), cellobiohydrolase (Hsu et al, 1980) and β-glucosidase (Wood and Mc Care, 1975;Gong et al, 1997). In recent years, the potential of using microorganisms as biotechnological sources of industrially relevant enzymes has stimulated interest in the exploration of extracellular enzymatic activity in several microorganisms (Akpan et al, 1999;Abu et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

Testing Carboxymethyl Cellulase Activity Secreted by Trichophyton Terrestre in Carboxymethyl Cellulose Solution

Lone¹,

Sahay²,

Ravinder³

2014

American Journal of Microbiology

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The techniques employed for bioconversion of cellulosic biomass to simple sugars by cellulases have a great industrial brunt. Cold-adapted microorganisms are potential resource of cold-active carboxymethyl cellulases secluded from the cold regions. In this study, Trichophyton terrestre-a rare fungal species in Indian soils, isolated from the rhizosphere of Juglans regia L. during winter season was subjugated for the production and commotion of an enzyme carboxymethyl cellulase in carboxymethyl cellulose solution by DNS method at an ample range of temperatures, using Lineweaver-Burk plot which offers a practical graphical method for the analysis of Michealis-Menten equation, to establish the imperative terms in enzyme kinetics as K m and V max . The enzyme kinetic parameters like maximum activity (V max ), K m and turnover number were recorded at varying concentrations of CMC and different temperatures (4°C and 50°C). The enzyme was found to be tolerant and stable at two varying temperatures which enables this fungal species to survive in the extreme environmental conditions of northern India. Such property of carboxymethyl cellulase enzyme has extensive range of applications and the potential to open new application fields in the areas of industrial processes.

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The nature and mode of action of the cellulolytic component C1 of Trichoderma koningii on native cellulose

Cited by 157 publications

References 12 publications

Enzymatic hydrolysis of cellulose: Visual characterization of the process

Enzymatic hydrolysis of cellulose: Visual characterization of the process

Viscosimetric determination of cellulase activity: critical analyses

Testing Carboxymethyl Cellulase Activity Secreted by Trichophyton Terrestre in Carboxymethyl Cellulose Solution

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