Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: KEGG:D03434 (Cellulase)
 512 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cellulase [EC 3.2.1.4] component was purified from a crude cellulase preparation of Trichoderma viride (Meicelase) by consecutive column chromatography procedures, and was designated as cellulase III. The enzyme was homogeneous on polyacrylamide gel disc electrophoresis. The molecular weight of the enzyme was estimated to be about 45,000 by gel filtration. The optimum pH and temperature of the enzyme were pH 4.5-5.0 and 50 degrees, respectively. The enzyme was stable over the range of pH 4.5-7.5 at 4 degrees for 24 hr, and retained 40% of the original carboxymethylcellulose-saccharifying activity after heating at 100 degrees for 10 min. The enzyme was completely inactivated by 1 mM Hg2+, and partially by 1 mM Ag+ and Cu2+. The enzyme was characterized as a less-random type cellulase on the basis of its action on carboxymethylcellulose. The enzyme split cellohexaose, retaining the beta-configuration of the anomeric carbon atoms in the hydrolysis products. The Km values of cellulase III for cellooligosaccharides decreased in parallel with increase of the chain length of the substrates, while Vmax values showed a tendency to increase. The enzyme produced predominantly cellobiose and glucose from various cellulosic substrates as well as from higher cellooligosaccharides. Cellulase III preferentially attacked the aglycone linkage of p-nitrophenyl beta-D-cellobioside. The enzyme was found to catalyze the rapid synthesis of cellotetraose from cellobiose (condensation action).
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PMID:Enzymatic studies on a cellulase system of Trichoderma viride. IV. Purification and properties of a less-random type cellulase. 1 53

Cellulase produced by Trichoderma viride acted on carboxymethyl cellulose with a Km of 4.9 g substrate per litre, showing a pH optimum at 4.5 and a temperature optimum at 55 degrees C. Ag+, Hg2+, Zn2+, Cu2+ and N3- were inhibitory..
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PMID:Properties of cellulase from Trichoderma viride. 3 94

Studies were conducted to evaluate the effects of cellulase from Trichoderma viride in a diet for broilers containing high levels of wheat bran. Broiler-type, mixed-sex chicks were fed from 3 to 8 weeks of age. Wheat bran was added at 0, 10, and 20% levels. A fourth group received the 20% wheat bran plus the cellulase enzyme added at the level of .008%. A portion of the chicks was used in a digestibility study with chromic oxide as an indicator. The summarized data showed that cellulose treatment had a significant effect on reducing feed consumption (P less than .01) and an apparent effect in improving feed-to-gain ratio. Cellulase supplementation significantly improved the digestibility of cell wall components (P less than .01). Calcium, phosphorus, iron, zinc, and copper associated with cell walls were solubilized by cellulase. Iron balance was negative in the groups without cellulase; however, iron, which is bound by the bran, apparently was made available for absorption by cellulase.
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PMID:Effects of cellulase from Trichoderma viride on nutrient utilization by broilers. 299 59

Sodium phosphate buffer was used to extract cellulases from the plant solids fraction of rumen contents. The mixed cellulase preparation had maximal activity at pH 6.9 and 49 degrees C. The V(max) and the apparent K(m) for wheaten hay cellulose were 19.8 glucose units/min and 6.35 mg/ml, respectively, and for microcrystalline cellulose (Sigmacell) at the same enzyme concentration, they were 33 glucose units/min and 27.5 mg/ml, respectively. For these assays a glucose unit was defined as nanomoles of glucose plus twice the nanomoles of cellobiose. Consideration of thermodynamic and kinetic data suggested that the hydrolysis of a relatively labile arabino-xylan comprising 3% of the wheaten hay cellulose was dependent on prior removal of the protecting beta-1,4-glucose chains at the outer surface of the cellulose preparation. Sequential removal of structural polysaccharides from the plant cell wall rendered the latter more susceptible to cellulase activity. Cellulase activity was stimulated by increasing the concentration of phosphate from 5 to 50 mM. The stimulation was magnified in the presence of cell-free rumen fluid. Cellulase activity was not stimulated by calcium, magnesium, iron, zinc, manganese, copper, or cobalt ions and was unaffected by the chelators ethylenediaminetetraacetic acid and ethyleneglycol-bis (beta-aminoethyl ether)-N,N'-tetraacetic acid. O-phenanthroline inhibited activity by 30 to 50%, but this may have been due to nonchelate properties. Anaerobic conditions or thiol protective agents were not essential for either the activity or stability of the cellulases during assay. An ultrafiltrable inhibitor of cellulase activity was detected in cell-free rumen fluid.
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PMID:Factors affecting the activity of cellulases isolated from the rumen digesta of sheep. 1634 26

Enzyme extracts of cellulase [filter paper cellulase (FPase) and carboxymethyl cellulase (CMCase)], chitinase, and chitosanase produced by Aspergillus niger NRRL-567 were evaluated. The interactive effects of initial moisture and different inducers for FP cellulase and CMCase production were optimized using response surface methodology. Higher enzyme activities [FPase 79.24+/- 4.22 IU/gram fermented substrate (gfs) and CMCase 124.04+/-7.78 IU/gfs] were achieved after 48 h fermentation in solid-state medium containing apple pomace supplemented with rice husk [1&percnt; (w/w)] under optimized conditions [pH 4.5, moisture 55% (v/w), and inducers veratryl alcohol (2 mM/kg), copper sulfate (1.5 mM/kg), and lactose 2% (w/w)] (p<0.05). Koji fermentation in trays was carried out and higher enzyme activities (FPase 96.67+/-4.18 IU/gfs and CMCase 146.50+/-11.92 IU/gfs) were achieved. The nonspecific chitinase and chitosanase activities of cellulase enzyme extract were analyzed using chitin and chitosan substrates with different physicochemical characteristics, such as degree of deacetylation, molecular weight, and viscosity. Higher chitinase and chitosanase activities of 70.28+/-3.34 IU/gfs and 60.18+/-3.82 to 64.20+/-4.12 IU/gfs, respectively, were achieved. Moreover, the enzyme was stable and retained 92-94% activity even after one month. Cellulase enzyme extract obtained from A. niger with chitinolytic and chitosanolytic activities could be potentially used for making low-molecular-weight chitin and chitosan oligomers, having promising applications in biomedicine, pharmaceuticals, food, and agricultural industries, and in biocontrol formulations.
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PMID:Chitinolytic and chitosanolytic activities from crude cellulase extract produced by A. niger grown on apple pomace through Koji fermentation. 2221 Jun 19