Trichoderma reesei

About: Trichoderma reesei is a research topic. Over the lifetime, 3832 publications have been published within this topic receiving 152877 citations. The topic is also known as: Trichoderma reesi.

Sporotrichum thermophile Growth, Cellulose Degradation, and Cellulase Activity.

Abstract: The activity of components of the extracellular cellulase system of the thermophilic fungus Sporotrichum thermophile showed appreciable differences between strains; ..beta..-glucosidase was the most variable component. Although its endoglucanase and exoglucanase activities were markedly lower, S. thermophile degraded cellulose faster than Trichoderma reesei. The production of ..beta..-glucosidase lagged behind that of endoglucanase and exoglucanase. The latter activities were produced during active growth. When growth was inhibited by cycloheximide treatment, the hydrolysis of cellulose was lower than in the control in spite of the presence of both endoglucanase and exoglucanase activities in the culture medium. Degradation of cellulose was a growth-associated process, with cellulase preparations hydrolyzing cellulose only to a limited extent. The growth rate and cell density of S. thermophile were similar in media containing cellulose or glucose. A distinctive feature of fungal development in media incorporating cellulose or lactose (inducers of cellulase activity) was the rapid differentiation of reproductive units and autolysis of hyphal cells to liberate propagules which were capable of renewing growth immediately.

Enzymatic kinetic of cellulose hydrolysis: inhibition by ethanol and cellobiose.

Abstract: The ethanol effect on the Trichoderma reesei cellulases was studied to quantify and clarify this inhibition type. To determine inhibition parameters of crude cellulase and purified exoglucanase Cel7A, integrated Michaelis-Menten equations were used assuming the presence of two inhibitors: cellobiose as the reaction product and ethanol as a possible bioproduct of cellulose fermentation.

Cellobiohydrolase from Trichoderma reesei

Abstract: A 1,4-beta-D-glucan cellobiohydrolase (EC 3.2.1.91) was purified from the culture liquid of Trichoderma reesei by using biospecific sorption on amorphous cellulose and immunoaffinity chromatography. A single protein band in polyacrylamide-gel electrophoresis and one arc in immunoelectrophoresis corresponded to the enzyme activity. The Mr was 65 000. The pI was 4.2-3.6. The purified enzyme contained about 10% hexose. The enzyme differs from previously described cellobiohydrolases in being more effective in the hydrolysis of cellulose.

The endo-1,4-beta-glucanase I from Trichoderma reesei. Action on beta-1,4-oligomers and polymers derived from D-glucose and D-xylose

Abstract: The reaction mechanism of the non-specific endo-1,4-beta-glucanase from Trichoderma reesei QM 9414 (endoglucanase I) was investigated using both reducing-end3H-labelled and universally 14C-labelled cellooligosaccharides, as well as reducing-end3H-labelled xylooligosaccharides. The bond cleavage frequencies of cellooligosaccharides proved to be dependent upon the substrate concentration, especially in the case of cellotriose. In addition to simple hydrolytic cleavage, the enzyme catalyzes reactions along alternative pathways, including transglycosylations leading to products larger than the substrate. Some of these pathways were shown to be reversible. During cellotriose or cellopentaose degradation, substrate resynthesis was demonstrated by incorporation of added radioactive D-glucose or cellobiose. The endoglucanase I is active on xylan and xylooligosaccharides, but less than on soluble cellulose derivatives (e.g. hydroxyethylcellulose) and cellooligosaccharides. The fact that for these different types of substrates the same active site is operative is proven by the ability of the enzyme to utilize cellooligosaccharides and xylooligosaccharides as both glycosyl donors and acceptors. The mixed substrate reactions lead to products composed of D-glucosyl and D-xylosyl residues. The kinetic parameters for cellooligosaccharide degradation can be used for the description of an extended substrate binding site. Of the four putative glycosyl subsites, -II and +II show the highest affinities, 16.7 kJ.mol-1 and 7.1 kJ.mol-1, respectively.