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Characterization, gene cloning and expression of new xylanase xynb with high specific activity

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Chinese Science Bulletin 2003年第8期48卷 761-765页

作者： ZHANG Honglian, YAO Bin, WANG Yaru, ZHANG Wangzhao & YUAN Tiezheng Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China Correspondence should be addressed to Yao Bin(email: yao-bin@***) Feed Research Institute Chinese Academy of Agricultural Sciences Beijing 100081 China

Extracellular xylanase xynb from Streptomy-ces olivaceoviridis A1 has been purified and characterized. The optimal pH value and temperature of xynb for its ac-tivity are 5.2 and 60℃, respectively. The specific activity of xynb is as high as 2869.78 U/mg. Metal cations, EDTA and SDS have no effects on enzyme activity of xynb. The gene xynb coding mature protein of xynb has been cloned by PCR. The forward oligonucleotide primer used in the PCR reaction was synthesized based on the N-terminal amino acid sequence of xynb mature protein, and the reverse oligonu-cleotide primers are random oligonucleotide. The cloned gene xynb is 576 bp long and its G+C content is 64.3%. The xynb encodes 191 amino acid residues, and the putative mo-lecular weight of xynb is 20.839 kD. The xynb has been expressed in E. coli, and the expressed xylanase has normal bioactivity.

关键词：基因克隆技术基因表达木聚糖酶 xynb 比活度

具有高比活性的新木聚糖酶xynb的酶学性质研究及其编码基因的克隆和表达

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科学通报 2003年第4期48卷 364-368页

作者：张红莲姚斌王亚茹张王照袁铁铮中国农业科学院饲料研究所北京100081

纯化了橄榄绿链霉菌Al产生的胞外木聚糖酶xynb,并对其酶学性质进行了测定,xynb具有优良的酶学性质,最适pH为5.2,最适温度为60℃,比活性高达2869.78 U/mg,对金属离子及EDTA和SDS等具有较好的抗性,根据木聚糖酶成熟蛋白N端氨基酸序列测序... 详细信息

纯化了橄榄绿链霉菌Al产生的胞外木聚糖酶xynb,并对其酶学性质进行了测定,xynb具有优良的酶学性质,最适pH为5.2,最适温度为60℃,比活性高达2869.78 U/mg,对金属离子及EDTA和SDS等具有较好的抗性,根据木聚糖酶成熟蛋白N端氨基酸序列测序结果设计引物,克隆了此酶的成熟蛋白编码基因xynb,基因全长576 bp,(G+C)含量为64.3％,编码191个氦基酸,理论分子量为20.839kD,是一种新的木聚糖酶基因.构建了xynb表达载体并在大肠杆菌中得到了表达,表达产物具有正常的生物学活性.

关键词：比活性木聚糖酶 xynb 酶学性质编码基因橄榄绿链霉菌A1 基因克隆基因表达

In vitro gastrointestinal digestion study of two wheat cultivars and evaluation of xylanase supplementation

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Journal of Animal Science and Biotechnology 2015年第3期6卷 355-368页

作者： Mickael Lafond Bernard Bouza Sandrine Eyrichine Friedrich Rouffineau Luc Saulnier Thierry Giardina Estelle Bonnin Aurélie Preynat iSm2-BiosCiences UMR 7313 Aix Marseille Université Adisseo France S.A.S. Centre d'Expertise et de Recherche en Nutrition INRA UR 1268-BiopolymeresInteractions-Assemblages

Background： The filamentous fungus Talaromyces versatifis is known to improve the metabolizable energy of wheat- based poultry diets thanks to its ability to produce a pool of CAZymes and particularly endo-β（1,4）-xylanases. In order to appreciate their in vivo mode of action, the supplementation effect of two of its xylanases, XynD and xynb from families GH10 and GHll respectively, have been evaluated on two different wheat cultivars Caphorn and Isengrain, which were chosen amongst 6 varieties for their difference in non starch polysaccharides content and arabinoxylan composition. Results： Polysaccharides digestion was followed during 6 h along the digestive tract using the TNO gastrointestinal model-1, to mimic monogastric metabolism. Polysaccharide degradation appeared to occur mainly at the jejunal level and was higher with Isengrain than with Caphorn. For both cultivars, XynD and xynb supplementation increased notably the amount of reducing end sugars into the jejuno-ileal dialysates, which has been confirmed by a valuable increase of the soluble glucose into the jejunal dialysates. Conclusions： The amounts of arabinose and xylose into the dialysates and ileal deliveries increased consequently mainly for Caphorn, suggesting that XynD and xynb supplementation in wheat-based diet could alleviate the anti-nutritional effects of arabinoxylans by limiting the physical entrapment of starch and could increase the available metabolizable energy.

关键词： in vitro TNO gastrointestinal model-1 Talaromyces versatilis Wheat cultivars xynb XynD