In vitro Evaluation of Feed Enzyme Compound Produced by Aspergillus sulphureus in Solid-state Fermentation

Three trials were conducted to analyze a multi-enzyme compound produced by Aspergillus sulphureus in solid-state fermentation (SSF) as a potential feed additive.The results of the first trial showed that there were at least 5 non-starch polysaccharide enzymes:xylanase,β-glucanase,pectinase,mannase and carboxy methyl cellulase (CMCase) contained in the compound.Xylanase and β-glucanase showed good activities at pH 2.5-7.0,which were in the range of 649-1046 U/g and 444-648 U/g,respectively.Pectinase showed good activity in acidic solution (pH 2.5-3.0),which ranged from 195 to 917 U/g.Mannase showed high activity of 235-298 U/g at pH 3.5-4.5 and the activity of CMCase was relatively constant at pH 2.5-7.0,which was in the range of 38.2-78.6 U/g.The second trial was aimed to test the stability of the enzymes in gastric liquor (pH 2.6) of finishing pigs and Na2HPO4-gastric liquor (pH 5.5).After 6 h incubation at 40℃ in gastric liquor,the retained activity of xylanase,β-glucanase,pectinase,mannase and CMCase was 26.3%,65.0%,71.0%,74.8% and 85.6%,respectively.While after 6 h incubation at 40℃ in Na2HPO4-gastric liquor,the retained activity of xylanase,β-glucanase,pectinase,mannase and CMCase was 87.9%,91.1%,92.3%,95.0%,and 97.5%,respectively.The third trial was carried out in a jejunum liquor (pH 5.8,200 mL),which contained 0.2 g of the multi-enzyme compound and 10 g of soybean hull or wheat bran,respectively.After 8 h incubation at 40℃,18.7% of soybean hull and 20.1% of wheat bran could be degraded to soluble saccharide,respectively.Compared with the traditional methods for feed enzyme testing which involve feeding animals for 1-3 months,enzyme assay in this way was relatively convenient.     

酸性木聚糖酶产生菌株的筛选和酶学性质分析

【目的】从自然环境筛选出可用于饲料工业加工用途的酸性木聚糖酶产生菌株。【方法】通过富集培养定向筛选技术,从土壤中分离获得18株产木聚糖酶菌株,挑选其中5株进行摇瓶发酵。对产酶最高的菌株S8-3进行初步鉴定,同时分析该菌株产生的木聚糖酶的酶学性质。【结果】经初步鉴定该菌株为黑曲霉(Aspergillus niger);该菌株发酵液的木聚糖酶活性高达628.43 U•mL-1;木聚糖酶的最适作用温度为45℃,最适pH为4.5,在70℃保温30 min后酶活力仍为60%以上,在 pH 3.0—7.0内稳定性较好。【结论】预期该菌株产的木聚糖酶具有用于饲料添加剂的潜力。     

双功能木聚糖酶研究进展

植物细胞壁的降解需要多种酶的参与协作,能够同时具有木聚糖酶、纤维素酶或其他辅酶活性的双功能酶在降低生产成本、提高催化效率等方面都具有一定的优势。随着分子生物学技术的完善,很多新的双功能酶得到分离和鉴定。以双功能木聚糖酶为主,综述了近年来在双功能木聚糖酶结构、功能及作用机理等方面的研究进展,并对其在工业生产中的应用潜力进行了探讨。     

玉米芯膳食纤维的复合酶法改性工艺优化

【目的】建立酶法提取玉米芯膳食纤维方法,优化复合酶法改性玉米芯不溶性膳食纤维（IDF）制 备可溶性膳食纤维（SDF）工艺。【方法】以玉米芯为原料,通过单因素试验优化碱性蛋白酶、α- 淀粉酶和糖 化酶预处理提取玉米芯粗膳食纤维（TDF）条件,结合正交试验优化复合酶（纤维素酶和木聚糖酶）法改性 IDF 制备 SDF 工艺。【结果】生物酶法提取玉米芯 TDF 条件：料液比 1 ∶ 10、pH 9.0、1.4% 碱性蛋白酶 50 ℃酶解 60 min;pH 6.5、0.3% 的 α- 淀粉酶和糖化酶（1 ∶ 1）、60 ℃水解 60 min,IDF 得率为 69.35%。复合酶法改 性 IDF 最佳工艺为：pH 5.0、温度 50 ℃、纤维素酶 1.2%、木聚糖酶 1.2%、酶解时间为 6 h、料液比为 1 ∶ 10, SDF 得率可达 22.16%。处理后的 SDF 持水力为 6.55 g/g,膨胀性为 6.69 mL/g,持油力为 4.65 g/g,分别比改性前 提高 40.26%、48.67%、74.16%。【结论】复合酶法改性玉米芯 IDF 制备 SDF 得率较单一纤维素酶和单一木聚糖 酶处理的 SDF 得率高,且显著提高产物 SDF 的持水力、持油力和膨胀性。     

嗜热拟青霉固体发酵产木聚糖酶的纯化和应用研究

利用一株拟青霉新种嗜热拟青霉J18,以天然农业废弃物小麦秸杆为碳源固体发酵产木聚糖酶,优化发酵条件后,产木聚糖酶水平达到16500U/g干基碳源。粗酶液经硫酸铵沉淀、凝胶过滤层析和离子交换层析3个步骤纯化,得到了电泳级纯酶。研究了该酶对馒头品质的影响,发现在面团中添加木聚糖酶能够明显改善面团的操作性能,提高馒头的比容,改善馒头的组织结构,延缓馒头的老化。     

加酶小麦日粮对猪生产性能的影响

试验选用杜×长×大三元杂交猪 64头 ,分为 8组 ,统计检验组间差异不显著。试验共分为 4个处理 ,每个处理2个重复 ,分别为正对照、负对照和处理 、 。正对照为典型玉米 -豆粕日粮 ,负对照为小麦替代日粮中 80 %的玉米 ,处理 、 分别添加 1 .5‰的溢多酶 83 8A和 0 .6‰的罗氏小麦酶 (均是木聚糖酶为主的复合酶 )。结果表明 ,试验全期日时增重 ,处理 、 分别比负对照提高 9.5 9%和 9.47% (P<0 .0 5 ) ;比正对照提高 4.0 7%和 3 .95 % (P<0 .0 5 )。小麦日粮不加酶组与玉米 -豆粕日粮相比 ,全期日增重降低 5 .0 4% (P<0 .0 5 )。添加复合酶对生长猪日增重的提高幅度大于肥育猪 ,提示阿拉伯木聚糖的抗营养作用 ,在幼龄动物表现更为明显。以经济效益来衡量 ,当小麦价格低于玉米时 ,简单用小麦代替玉米 ,添加以木聚糖酶为主的复合酶 ,可显著提高经济效益     

真菌产与细菌产木聚糖酶对黄羽肉鸡生长性能、小肠绒毛形态和血液生化指标影响的比较

本文旨在探讨2种木聚糖酶对黄羽肉鸡生长性能、消化器官发育、小肠绒毛形态和血液生化指标的影响。将1日龄健康黄羽肉鸡540羽随机分成3组,每组6个重复,每重复30羽。对照组饲喂玉米-小麦-豆粕型基础饲粮,试验A组、B组分别饲喂基础饲粮+200 g/t真菌产木聚糖酶、基础饲粮+200 g/t细菌产木聚糖酶。试验期42 d。结果显示:与对照组相比,1)试验组平均日增重显著提高(P0.05),料重比均有一定程度的降低,其中试验A组显著降低(P0.05);2)试验组血清葡萄糖含量及碱性磷酸酶和肌酸激酶活性显著提高(P0.05),血清中甘油三脂、尿素氮含量显著降低(P0.05);3)试验组腺胃和胰腺相对重量显著降低(P0.05);4)试验A组、B组空肠绒毛高度分别提高了14.81%和11.04%(P0.05),空肠绒毛高度/隐窝深度值分别提高了16.61%和12.70%(P0.05)。由此可知,在黄羽肉鸡饲粮中添加200 g/t真菌或细菌产木聚糖酶,均能改善小肠绒毛发育和机体的免疫力,提高生长性能,且2种酶之间效果差异不显著。     

木聚糖酶和葡聚糖酶对肉鸡生长性能、屠宰性能、胴体成分及血液指标的影响

文章旨在研究玉米-小麦-豆粕型日粮添加木聚糖酶和葡聚糖酶对1～42 d肉鸡生长性能、屠宰性能、胴体成分及血液指标的影响。试验选择健康、体重一致的1日龄Cobb肉仔鸡800只,随机分为2组,每组5个重复,每个重复80只。对照组饲喂玉米-小麦-豆粕型日粮,试验组饲喂基础日粮添加2000 U/g木聚糖酶+800 U/g葡聚糖酶,试验分为3个阶段,1～14 d,15～28 d和29～42 d。与对照组相比,酶制剂组显著提高了28～42 d肉鸡能量和蛋白质利用率(P <0.05),显著降低了平均日采食量、日增重和料重比(P <0.05)。对于试验全期,酶制剂组显著提高了1～42 d肉鸡能量和粗蛋白质利用率(P <0.05),同时显著降低了平均日采食量、日增重和料重比(P <0.05)。酶制剂组较对照组显著提高了肉鸡的屠宰率和腿肌率(P <0.05)。对照组与酶制剂组对肉鸡胴体干物质、脂肪和灰分含量的影响均无显著差异(P> 0.05)。日粮添加复合酶较对照组显著提高了28和42 d肉鸡血液T3的含量(P <0.05),显著降低了42 d肉鸡血液T4的含量(P <0.05),同时酶制剂组较对照组显著提高了42 d肉鸡血液葡萄糖的浓度(P <0.05)。与对照组相比,酶制剂组显著降低了28和42 d肉鸡血液尿酸含量(P <0.05),显著提高了14和42 d肉鸡血液甘油三酯含量(P <0.05)。综上所述,1～42 d肉鸡日粮添加2000 U/g木聚糖酶和800 U/g葡聚糖酶可以显著改善料肉比,提高屠宰性能,可改变血液中甲状腺激素和部分代谢物的浓度,但对胴体成分影响不大。     

Influence of partial replacement of ground wheat with whole wheat and exogenous enzyme supplementation on growth performance,nutrient digestibility and energy utilization in young broilers

This study investigated the influence of pre‐pelleting inclusion of whole wheat (WW) and exogenous enzyme supplementation on growth performance, coefficient of apparent ileal nutrient digestibility (CAID) and apparent metabolizable energy (AME) in broilers fed wheat‐based pelleted diets. A 2 × 3 factorial arrangement of treatments was used with two methods of wheat inclusion [622 g/kg ground wheat (GW) and 250 g/kg WW replaced GW (wt/wt) pre‐pelleting (PWW)] and three enzymes (xylanase, phytase and xylanase plus phytase). A total of 288, one‐day‐old male broilers (Ross 308) were individually weighed and allocated to 36 cages (8 broilers/cage), and the cages were randomly assigned to the six dietary treatments. Birds fed PWW diets gained more (p < 0.05) weight than those fed GW diets. There was no effect (p > 0.05) of WW inclusion on feed intake (FI). Phytase alone increased (p < 0.05) FI compared to xylanase or the combination. Whole wheat inclusion increased (p < 0.05) the gain‐to‐feed ratio (G:F). Feeding xylanase plus phytase and phytase‐added diets resulted in the greatest and lowest G:F, respectively, with xylanase supplemented diets being intermediate. Birds fed PWW diets had greater (p < 0.05) relative gizzard weights than those fed GW diets. There was no effect (p > 0.05) of WW inclusion on the CAID of nitrogen (N), starch and fat. Combination of xylanase and phytase resulted in greater (p < 0.05) digestibility of N, starch and fat than that of individual additions. Feeding PWW diets resulted in greater (p < 0.05) AME values than GW diets. Combination of xylanase and phytase increased (p < 0.05) the AME compared to the diets with individual additions of xylanase or phytase. The current results suggest that the influence of pre‐pelleting WW inclusion and exogenous enzymes on nutrient digestibility and broiler performance is not additive.     

利用pET-20b克隆与表达多功能半纤维素酶

将来源于嗜热厌氧乙醇菌(Thermoanaerobacter ethanolicus,JW200)的双活性阿拉伯/木糖苷酶(XarB)构建到pET-20b(+)上,得到质粒pET-20b-xarB.将来源于疏棉状嗜热丝孢菌(The rm omyces lanuginosus DSM 5826)木聚糖酶A(XynA)构建到pET-20b-xarB上,得到表达质粒pET-20b-xarB-xynA.将重组质粒pET-20b-xarB-xynA转入大肠杆菌Escherichia coli JM109(DE3)进行表达.SDS-PAGE结果显示,该重组酶的分子量为108 kDa,与理论值相符.