沼气料液对木聚糖酶活性的影响

在木聚糖酶反应体系中添加不同比例的沼气料液,研究了沼气料液对绿色木霉Trichoderma viride YNUCC0183、疏棉状嗜热丝孢菌Thermomyces lanuginosus YNUCC4154、放线菌Streptomyces sp.YNUCC0233和5株兼性厌氧细菌来源的木聚糖酶活性的影响.结果表明,沼气料液对不同来源的木聚糖酶均有抑制作用,绿色木霉Trichoderma viride YNUCC0183和兼性厌氧细菌B5-3来源的木聚糖酶所能耐受的料液比率最高,达37.5%(V/V), 适合用于沼气原料的预处理提高沼气得率.     

新型酶制剂在肉用小鸡日粮中的应用

传统的酶制剂仅含有蛋白酶和脂肪酸等，这些酶一般辅助消化道的内源酶的消化降解，在体内内源酶充足时．添加的意义不太大。近年来．芬兰等国家通过基因编码再进行克隆等先进的高科技生物技术，已开发并商业化生产饲料使用的阿拉伯木聚糖酶、a一葡聚糖酶等新型饲料复合酶制剂。常规饲用谷物，尤其是麦类及其糠教副产品，在不同程度上含有阿拉伯木聚糖（戊聚糖）、R一葡聚糖，这两种水溶性非淀粉多糖（NSP）是谷物的重要抗营养因子．是细胞壁的成分。NSP不能被猪与禽等单胃动物的内源酶所消化分解．引起抗营养效应（Friesen等1992）。这…     

The influence of native and modified arabinoxylan preparations on baking properties of rye flour

Water soluble arabinoxylans, especially of rye origin, are known to considerably improve quality of bread. The aim of the current research was to check the changes in properties of rye dough and bread after the addition of different arabinoxylan preparations. Structure forming properties of these additives were given by the application of hydrolysis, and cross-linking, which influenced molar mass and reactivity of arabinoxylans.     

碱性蛋白酶和木聚糖酶对玉米-豆粕型日粮干物质和粗蛋白质的体外酶解效果研究

本试验旨在通过透析袋体外酶解法研究碱性蛋白酶和木聚糖酶对玉米-豆粕型日粮还原糖生成量、干物质和粗蛋白质体外酶解效果的影响。试验采用单因子试验设计,碱性蛋白酶的添加浓度分别为20、40、60、80、100 U/g,木聚糖酶的添加浓度分别为10、20、30、40、50 U/g,每个添加水平分别设5个重复。结果表明:碱性蛋白酶添加浓度由20 U/g提高至100 U/g时,可显著提高日粮还原糖生成量和干物质酶解效率(二次,P<0.05);木聚糖酶添加浓度由10 U/g提高至50 U/g时,显著提高日粮干物质酶解效率(二次,P<0.05)。以干物质消化率为评价指标时,根据二次曲线方程计算得出碱性蛋白酶和木聚糖酶的适宜添加浓度分别为65 U/g和33 U/g。     

Impact of variable corn nutrient content,AME prediction,and xylanase inclusion on growth performance

An experiment was conducted to investigate the effect of corn apparent metabolizable energy (AME) value, on broiler performance associated with geographical location (source), xylanase inclusion, and formulation. A 3 (corn source) × 2 (formulation; adjusted or non-adjusted value) × 2 (xylanase inclusion, 0 vs 16,000 BXU/kg) factorial randomized complete block desig study was conducted which included 10 replicates of 20 male broilers per replicate for a 42 d experiment. In the non-adjusted corn diets, each dietary treatment contained the same percentage of each corn source while the adjusted corn diets formulated based on a corn near-infrared (NIR) nutrient analysis and AME prediction equation (AB Vista, Marlborough, UK). In all cases, the predicted AME of the corns was lower than the NRC (1994) AME value, resulting in additional fat inclusion. The dietary program consisted of 3 dietary phases; starter (d 1 to 18), grower (d 19 to 33), and finisher (d 34 to 42) with growth performance monitored at feed changes. Xylanase increased (p < 0.05) starter feed consumption and d 18 body weight (BW) (2.1%), and an increase in BW (4.6%) was observed using the predicted AME values. Corn source continued to impact broiler performance throughout the remainder of the trial as corn source A consistently outperformed (p < 0.05) corn source C with increased BW and reduced mortality corrected FCR. Dietary adjustment with AME predicted values for each corn source consistently improved (p < 0.05) growth performance. Corn source A had the highest average BW with a 2.9% increase (p < 0.05) over corn source C. Early feed conversion rate (FCR) was improved (p < 0.05) with the predicted AME value diet-fed broilers, decreasing FCR by 3%. Multiple significant interactions were observed between the corn source and the adjustment method. For example, with d 42 FCR, using the predicted AME value adjustment had an impact of 9 and 10 points for corn source B and C, respectively, but only 2 for corn source A. This experiment demonstrates the impact of variable corn nutrient content and the potential improvement when using NIR technology for ingredient nutrient specifications.     

日粮添加木聚糖酶对肉鸡十二指肠及空肠SSmRNA表达的研究

小麦日粮中添加以木聚糖酶为主的复合酶可以提高鸡的表观代谢能和养分消化率，降低食糜粘度，钝化或消除阿拉伯木聚糖的抗营养作用。因此，木聚糖酶已广泛地应用于以小麦为基础日粮的肉鸡生产。     

高产木聚糖酶的紫色红曲霉菌株筛选及酶学性质研究

[目的]筛选紫色红曲霉木聚糖酶,并研究其酶学性质。[方法]采用平板筛选和固体培养方法获得了产木聚糖酶较高的紫红曲霉（Monascus pupureus）533。采用50%~70%硫酸铵盐析、Sephadex G-25凝胶层析、DEAE Sepharose fast flow阴离子交换层析和SephacrylS-200凝胶层析进行纯化。最后,研究温度、pH、金属离子和化学物质对酶活性的影响。[结果]经分离纯化后得到相对分子质量约为46.0 kD的木聚糖酶。木聚糖酶最适反应温度为47℃;最适反应pH为5.5,pH稳定范围为4.5~5.5;Ca2＋、Fe2＋、Na＋和Tween 80对酶活力有激活作用;Mn2＋、Tris、EDTA、尿素和SDS对酶活力有抑制作用;Cu2＋和K＋对酶活力影响不大。[结论]该研究筛选到1株高产木聚糖酶的紫色红曲菌株,扩大了产木聚糖酶的菌株范围。     

木聚糖酶基因xynA在大肠杆菌中的表达研究

通过引物拼接的方式合成采用大肠杆菌优势密码子的疏棉状嗜热丝孢菌木聚糖酶基因xynA,插入到热激质粒pHsh和质粒pET-20b中构建重组质粒pHsh-xynA和pET-20b-xynA,再转入大肠杆菌JM109表达。经热激和IPTG诱导后,木聚糖酶在重组菌中获得特异性表达,产物以胞内可溶性蛋白和包涵体形式存在。重组菌pET-20b-xynA在16℃下表达量最大,胞内酶活达42.13 U/ml,重组菌pHsh-xynA在42℃下胞内酶活最大,为35.06 U/ml。与质粒pHsh相比,pET-20b质粒更有利于重组木聚糖酶的表达。     

壳聚糖固定化木聚糖酶的工艺研究

先对影响固定化木聚糖酶效果的几个单因素如壳聚糖质量浓度、戊二醛体积分数、给酶量等指标进行测定,然后采用L9(43)正交试验设计法对壳聚糖作为载体固定化木聚糖酶的工艺进行优化.单因素试验结果表明,当壳聚糖质量浓度为50和60 g/L时,其固定化酶活力较高;而交联剂戊二醛为60 mL/L时,所形成的载体与酶结含量达最大;将...     

不同微生物酶对牛粪堆肥腐熟的影响

[目的]研究牛粪堆肥复合酶的最佳配比。[方法]以种子发芽指数（GI）作为牛粪堆肥腐熟度的指标,采用正交试验,研究纤维素酶、葡聚糖酶、木聚糖酶、蛋白酶等对牛粪堆肥的腐熟作用。[结果]在牛粪堆肥物种添加0.8%纤维素酶,在第15天时GI值达110.08%;在牛粪堆肥物种添加1.0%葡聚糖酶,第15天时GI值达103.68%。在正交试验中,酶总量增加,GI值降低,堆制15 d时的GI值最高,为73.47%。[结论]最佳配伍方案为0.7%葡聚糖酶＋0.9%纤维素酶＋0.3%木聚糖酶＋0.1%蛋白酶。