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Xylanase
About: Xylanase is a research topic. Over the lifetime, 7099 publications have been published within this topic receiving 163793 citations.
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TL;DR: In conclusion, xylanase supplementation improved growth performance, enhanced intestinal enzyme activities and influenced the balance of intestinal microflora of juvenile Jian carp.
Abstract: A total of 900 juvenile Jian carp (Cyprinus carpio var. Jian) (7.99 ± 0.02 g) were fed diets containing graded levels of xylanase at 220 (unsupplemented control), 650, 1070, 1480, 1810 and 2470 U kg−1 diet for 10 weeks to investigate the effects of xylanase levels on growth performance, intestinal enzyme activities and microflora. The per cent weight gain, feed efficiency, protein efficiency ratio, protein production value, lipid production value, ash production value, calcium production value and phosphorus retention ratio were significantly improved with increasing levels of xylanase up to a point, and thereafter declined (P < 0.05). The activities of trypsin, chymotrypsin, lipase and amylase in the hepatopancreas and intestine, activities of alkaline phosphatase, Na+, K+-ATPase, creatine kinase and γ-glutamyl transpeptidase in three intestinal segments were improved by dietary xylanase (P < 0.05). The amounts of Lactobacillus, Escherichia coli and Aeromonas were significantly affected by dietary xylanase levels (P < 0.05). In conclusion, xylanase supplementation improved growth performance, enhanced intestinal enzyme activities and influenced the balance of intestinal microflora of juvenile Jian carp. The optimal level of xylanase in juvenile Jian carp (7.99–99.16 g) based on PWG was 1259 U kg−1 diet by the quadratic regression analysis.
72 citations
TL;DR: A minor xylanase, named XYN IV, was purified from the cellulolytic system of the fungus Trichoderma reesei Rut C30, and showed clear homology with xylanases classified in glycoside hydrolase family 30, which also includes glucanases and mannanases.
Abstract: A minor xylanase, named XYN IV, was purified from the cellulolytic system of the fungus Trichoderma reesei Rut C30. The enzyme was discovered on the basis of its ability to attack aldotetraohexenuronic acid (HexA-2Xyl-4Xyl-4Xyl, HexA(3)Xyl(3)), releasing the reducing-end xylose residue. XYN IV exhibited catalytic properties incompatible with previously described endo-β-1,4-xylanases of this fungus, XYN I, XYN II and XYN III, and the xylan-hydrolyzing endo-β-1,4-glucanase EG I. XYN IV was able to degrade several different β-1,4-xylans, but was inactive on β-1,4-mannans and β-1,4-glucans. It showed both exo-and endo-xylanase activity. Rhodymenan, a linear soluble β-1,3-β-1,4-xylan, was as the best substrate. Linear xylooligosaccharides were attacked exclusively at the first glycosidic linkage from the reducing end. The gene xyn4, encoding XYN IV, was also isolated. It showed clear homology with xylanases classified in glycoside hydrolase family 30, which also includes glucanases and mannanases. The xyn4 gene was expressed slightly when grown on xylose and xylitol, clearly on arabinose, arabitol, sophorose, xylobiose, xylan and cellulose, but not on glucose or sorbitol, resembling induction of other xylanolytic enzymes from T. reesei. A recombinant enzyme prepared in a Pichia pastoris expression system exhibited identical catalytic properties to the enzyme isolated from the T. reesei culture medium. The physiological role of this unique enzyme remains unknown, but it may involve liberation of xylose from the reducing end of branched oligosaccharides that are resistant toward β-xylosidase and other types of endoxylanases. In terms of its catalytic properties, XYN IV differs from bacterial GH family 30 glucuronoxylanases that recognize 4-O-methyl-D-glucuronic acid (MeGlcA) substituents as substrate specificity determinants.
72 citations
TL;DR: The isolated endo-1,4-beta-xylanase was a true xylanase without cellulase activity and possessed extensive identity with a proposed amino-terminal consensus sequence of xylanases from bacteria.
Abstract: An endo-1,4-beta-xylanase (1,4-beta-D-xylan xylanohydrolase, EC 3.2.1.8) has been isolated from a commercial preparation of Trichoderma viride. The molecular weight was 22,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the pI value was 9.3. The xylanase was a true xylanase without cellulase activity. When the N-terminal amino acid sequence of the first 50 residues was compared with that of a xylanase from Schizophyllum commune, strong evidence for homology was found, with more than 50% amino acid identity. T. viride xylanase also possessed extensive identity with a proposed amino-terminal consensus sequence of xylanases from bacteria.
71 citations
TL;DR: The XynD gene, encoding the sole P. funiculosum GH10 xylanase described so far, was cloned into the pPICZαA vector and expressed in methylotrophe yeast Pichia pastoris, in order to compare the results obtained with the GH11 xylanases data.
Abstract: Background
The filamentous fungus Penicillium funiculosum produces a range of glycoside hydrolases (GH). The XynD gene, encoding the sole P. funiculosum GH10 xylanase described so far, was cloned into the pPICZαA vector and expressed in methylotrophe yeast Pichia pastoris, in order to compare the results obtained with the P. funiculosum GH11 xylanases data.
71 citations
TL;DR: Proteomic analyses and enzymology studies are combined to show that sequential and submerged cultivation methods differently influence both titers and secretion profile of key enzymes required for the hydrolysis of sugarcane bagasse.
71 citations