Biochemical analysis of a highly specific, pH stable xylanase gene identified from a bovine rumen-derived metagenomic library
文献类型: 外文期刊
第一作者: Gong, X.
作者: Gong, X.;Gruniniger, R. J.;Forster, R. J.;Teather, R. M.;McAllister, T. A.;Gong, X.
作者机构:
关键词: Xylanase;Cow ruminal microorganisms;BAC library;Glycosyl hydrolase (GH) 10;Biobleaching
期刊名称:APPLIED MICROBIOLOGY AND BIOTECHNOLOGY ( 影响因子:4.813; 五年影响因子:4.697 )
ISSN:
年卷期:
页码:
收录情况: SCI
摘要: A metagenomic library was generated using microbial DNA extracted from the rumen contents of a grass hay-fed dairy cow using a bacterial artificial chromosome-based vector system. Functional screening of the library identified a gene encoding a potent glycoside hydrolase, xyn10N18, localised within a xylanolytic gene cluster consisting of four openreading frames (ORFs). The ORF, xyn10N18, encodes an endo-β-1,4-xylanase with a glycosyl hydrolase family 10 (GH10) catalytic domain, adopts a canonical α8/?8-fold and possesses conserved catalytic glutamate residues typical of GH10 xylanases. Xyn10N18 exhibits optimal catalytic activity at 35 °C and pH 6.5 and was highly stable to pH changes retaining at least 85 % relative catalytic activity over a broad pH range (4.0–12.0). It retained 25 % of its relative activity at both low (4 °C) and high (55 °C) temperatures, however the stability of the enzyme rapidly decreased at temperatures of>40 °C. The specific activity of Xyn10N18 is enhanced by the divalent cationsMn~(2+) and Co~(2+) and is dramatically reduced by Hg~(2+) and Cu~(2+). Interestingly, EDTA had little effect on specific activity indicating that divalent cations do not function mechanistically. The enzyme was highly specific for xylan containing substrates and showed no catalytic activity against cellulose. Analysis of the hydrolysis products indicated that Xyn10N18 was an endoxylanase. Through a combination of structural modelling and in vitro enzyme characterisation this study provides an understanding of the mechanism and the substrate specificity of this enzyme serving as a starting point for directed evolution of Xyn10N18 and subsequent downstream use in industry.
分类号: Q939.9
- 相关文献
作者其他论文 更多>>
-
Response surface optimization of the ultrasonic-assisted extraction of edible brown pigment from Macadamia shells
作者:Liu, Y. Y.;Liu, Y. J.;Gong, X.;Li, J. H.
关键词:
-
Biochemical and kinetic characterization of the multifunctional beta-glucosidase/beta-xylosidase/alpha-arabinosidase, Bgxa1
作者:Gruninger, R. J.;Gong, X.;Forster, R. J.;McAllister, T. A.;Gong, X.
关键词:Rumen;beta-Glucosidase;beta-Xylosidase;alpha-Arabinosidase;Functional metagenomics;Synergy;Glycosyl hydrolase 3;GH3
-
Wheat distillers grains in feedlot cattle diets: Feeding behavior, growth performance, carcass characteristics, and blood metabolites
作者:Yang, W. Z.;Li, Y. L.;McAllister, T. A.;Beauchemin, K. A.;Li, Y. L.;McKinnon, J. J.
关键词:beef cattle;eating behavior;growth performance;intake;wheat dried distillers grains with solubles
-
Effect of wheat distillers dried grains with solubles (DDGS) as a replacement for barley grain and barley silage on ruminal pH and fermentation in finishing beef cattle
作者:Li, Y. L.;Yang, W. Z.;He, M. L.;McAllister, T. A.;Beauchemin, K. A.
关键词:wheat DDGS;ruminal fermentation;beef cattle
-
Effect of replacing grain and silage with wheat distiller grain on intake, digestibility and urine purine derivatives in finishing beef cattle
作者:Li, Y. L.;Yang, W. Z.;McAllister, T. A.;Beauchemin, K. A.
关键词:wheat DDGS;intake;digestibility
-
Substitution of wheat dried distillers grains with solubles for barley grain or barley silage in feedlot cattle diets: Intake, digestibility, and ruminal fermentation
作者:Li, Y. L.;McAllister, T. A.;Beauchemin, K. A.;He, M. L.;Yang, W. Z.;Li, Y. L.;McKinnon, J. J.
关键词:ammonia: 7664-41-7;nutrient: nutrient;starch: 9005-25-8;ether extract;CON;total volatile fatty acid: total VFA;ruminal fermentation;feed intake;barley grain: animal feed;barley silage: animal feed;diet digestibility;diet fiber;wheat dried distillers grain soluble: animal feed
-
Enhanced Iron and Zinc Accumulation in Genetically Engineered Wheat Plants Using Sickle Alfalfa (Medicago falcata L.) Ferritin Gene
作者:Liu, D. J.;Wang, Y. B.;Guo, C. H.;Cong, Q.;Gong, X.;Liu, D. J.;Wang, Y. B.;Zhang, H. J.
关键词:sickle alfalfa;ferritin;wheat;transformation;Fe;Zn