Showing papers on "Xylanase published in 1980"

Polysaccharide-degrading enzymes of Botrytis allii and Sclerotium cepivorum. Enzyme production in culture and the effect of the enzyme on isolated onion cell walls

Abstract: Botrytis allii and Sclerotium cepivorum were grown on liquid media with purified onion cell walls as the sole or major carbon source respectively Polysaccharide-degrading activity determined at daily intervals for 10 days after inoculation increased over the course of the experiment For both fungi, degrading activity against sodium polypectate was the highest at all times Xylan, galactan and citrus pectin-degrading activities appeared at similar rates to each other with some variation in relative amounts from the two fungi Carboxymethyl cellulase activity increased markedly after 6 days and activity against araban remained relatively low Cell walls were incubated with enzyme preparations and the release of total carbohydrate and of individual sugars was measured Cell wall carbohydrate was solubilized by enzyme preparations in amounts which increased with the age of the culture The pattern of release of the individual sugars showed two groups, one containing uronic acid, galactose, rhamnose and arabinose and the second xylosem glucose, fucose and mannose The release of the first group was related to polygalacturonase activity and the second to the cellulase and possibly xylanase activities These findings emphasize the importance of polygalacturonase activity in the solubilization of onion cell walls by both fungi

Detection and assay of xylanolytic enzymes in a Cellulomonas isolate

Abstract: The accuracy of xylanase assay was tested and improved. The assay was used to monitor xylanase production by a Cellulomonas isolate and to demonstrate that this activity is distinct from the organism's β-xylosidase activity.

High Cellobiase and Xylanase Production by Sclerotium rolfsii UV-8 Mutant in Submerged Culture.

Abstract: Sclerotium rolfsii UV-8 mutant secretes high levels of cellobiase and xylanase in addition to having high cellulase production The apparent K(m) and V(max) of cellobiase (grown in NM-2 + 2% corn steep liquor medium) with cellobiose as a substrate were 56 mM and 222 mumol of glucose liberated per min per ml of culture filtrate, respectively The addition of 2% corn steep liquor to NM-2 medium increased endo-beta-glucanase, cellobiase, and xylanase yields by approximately 15-fold

Influence of compound fertilizer and cupric sulfate on soil enzymes and CO2-evolution

Abstract: 1. Compound fertilization inhibits the enzymatic activities of the hydrolytic decomposition of litter. 2. In the nursery soil examined urease and xylanase activities had been distinctly reduced after six weeks, whereas cellulase and invertase activities had scarcely been affected after this period. 3. Through compound fertilization the enzymatic activities of intracellular dehydrogenases increased by the same amount as the microbial biomass. 4. It was proved that, in the case of litter decomposition, extracellular biochemical activity was not at all bound to be in direct relation to the microbial biomass, but that it is closely connected to the decomposible organic matter. 5. An additional treatment of the soil with cupric sulfate brought a toxic effect. Dehydrogenase activity was inhibited by a further 72%, urease and xylanase activities by 30%. Invertase activity was only reduced by 15% and cellulase activity by 10%. 6. The present studies make it possible to understand the complicated interaction between soil microorganisms and the plant, point to the inhibition of litter decomposition by chemical soil treatments (fertilization, addition of a heavy metal) and suggest the competition for nutrients between the plant and the soil microflora. 7. A new method for the determination of invertase activity in soils was developed.

Kinetic Studies on Xylanase Induction by β-Xyloside in Streptomyces sp.

Abstract: Xylanase induction by β-xyloside was investigated in non-growing conditions using non-induced mycelia of Streptomyces sp. No. 3137 harvested from glucose medium. The mycelia started to produce xylanase without lag time when β-xyloside was added. The rate of xylanase synthesis was dependent on the concentration of β-xyloside added to the inducing culture medium. The induction constants of various β-xylosides were calculated from the Lineweaver-Burk plots; those of methyl-, isopropyl-, butyl- and ethylencyanohydrin-β-d-xylosides were 10.53 mm, 3.83 mm, 0.55mm and 0.25 mm, respectively. Some α-xylosides repressed xylanase synthesis. The rate of xylanase synthesis decreased suddenly after the addition of α-xyloside. The inhibition constants of methyl-, ethyl- and isopropyl-α-d-xylosides were 8.80 mm, 12.50 mm and 33.33 mm, respectively. The xylanase induction was also repressed by glucose. However, this repression was completely restored after consuming additional glucose.

Enzymatic activities in coniferous leaf litter.

Abstract: Assays for measuring the activities of cellulase, xylanase, mannase, amylase, ..beta..-glucosidase, invertase, and protease employing buffered suspensions of ground coniferous and deciduous leaf litter exhibited zero-order kinetics. Only a small percentage of the whole-litter activities of invertase, ..beta..-glucosidase, and protease were extractable into 0.05M potassium acetate, pH 5.0; however, extractable activities of cellulase and xylanase represented from 39 to 174% of the whole-litter activities indicating their soluble exocellar nature. Extractable protease and amylase activities were best correlated with the average daily rates of CO/sub 2/ evolution in a group of 90 leaf litter samples equally representing 18 coniferous species. Enzymatic activities were readily detectable in extracts of all samples but classification of the samples by species provided little differentiation in the distribution of either enzymatic activities or rates of CO/sub 2/ evolution. Mannase, cellulase, and xylanase activities were well-correlated with each other in all samples. Assays attempting to measure a pool of readily-metabolizable substances in litter by extractable reducing substances, ninhydrin-positive substances, glucose, and phenolics failed to show correlation coefficients >0.41 with rates of CO/sub 2/ evolution. Addition of D-(+)-catechin to litter extracts, up to levels equivalent to those observed in the group of samples, did not inhibit any carbohydrasemore » thus suggesting the lack of inhibition of litter-decomposing enzymes by the concentrations of phenolics present in these coniferous leaf litters.« less

Enzymatic treatment of waterrinsoluble substrate

Abstract: PURPOSE:To improve the efficiency of the enzymatic treatment of a water-insoluble substrate, by treating the substrate with an enzyme in the presence of a protein other than the enzyme. CONSTITUTION:A water-insoluble substrate is treated with an enzyme in the presence of a protein other than said enzyme. The protein is, e.g. a water-soluble protein such as bovine serum albumin, egg albumin, etc. The water-insoluble substrate adsorbs a part of the protein. The water-insoluble substrate for the enzymatic reaction, is e.g. cellulose such as hemicellulose flour, filter paper, saw dust, etc., xylane such as of a bark, cottonseed hulls, etc. The combination of the water- insoluble substrate and the enzyme is, e.g. cellulose with cellulase, xylan with xylanase, inulin with inulase, etc.

Chemical experimentation under extreme conditions

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