丝素作为固定化酶载体的研究进展与应用

本文详细描述了制备丝素固定化酶的各种方法，如包埋法、戊二醛共价交联法以及膜状、粉状、线状三种形状的固定化酶的制作；并就固定化葡萄糖氧化酶、过氧化物酶、脲酶、脂肪酶、果胶酶、过氧化氢酶、糖化酶、超氧化物歧化酶、青霉素酰化酶、木瓜蛋白酶、苯丙氨酸裂解酶、β-葡萄糖苷酶等的研究进展与应用进行了介绍和评价。     

菌藻固定化技术及其在养殖污水处理中的应用进展

传统养殖污水的处理方法主要以悬浮态活性污泥法为主,随着微生物固定化技术的发展,逐步改进了活性污泥法中水力停留时间长、抗冲击负荷差等弊端,但出水氮、磷和重金属的含量依然过高。随着新型菌、藻固定化技术的发展,功能藻类的加入解决了此类问题。本文就菌藻固定化技术进行综述,着重介绍最新的菌藻固定化技术及其特点、配伍反应器种类及其在养殖污水中的应用效果,并分析该技术存在的问题和研究方向,以期为菌藻固定化技术在养殖污水治理上的应用提供参考。     

鹅源草酸青霉产果胶酶对肉鸡消化生理影响的研究

本文旨在研究鹅源草酸青霉产果胶酶对肉鸡消化生理的影响.选用1日龄健康肉雏鸡240只,随机分成4组,每组4个重复,每个重复15只.对照组饲喂基础日粮,3个试验组分别饲喂在基础日粮中添加0.249%果胶酶、0.168%纤维素酶和0.15%复合酶(果胶酶:纤维素酶=1:1)的试验日粮,并观测28日龄和49日龄肉鸡的肠道消化酶活性、49日龄肉鸡的肠道组织形态.结果表明,28日龄时,果胶酶组十二指肠、胰腺的淀粉酶、脂肪酶、胰蛋白酶活性以及空肠的脂肪酶活性均显著高于对照组(P<0.05),胃蛋白酶活性极显著高于对照组(P<0.01);49日龄时,果胶酶组胰腺的淀粉酶、脂肪酶、胰蛋白酶活性,十二指肠的淀粉酶、胰蛋白酶活性,空肠的脂肪酶活性以及胃蛋白酶活性均显著高于对照组(P<0.05).与对照组相比,果胶酶组空肠的绒毛高度显著提高(P<0.05),肠壁厚度显著降低(P<0.05).此外,复合酶组的部分肠道消化酶活性和空肠的绒毛高度显著或极显著高于果胶酶组和纤维素酶组(P<0.05或P<0.01).由此可知:果胶酶可提高肉鸡肠道消化酶活性,改善空肠组织形态;与纤维素酶配合应用对肠道消化酶活性、空肠组织形态的影响更为显著.     

香菇木屑菌糖中5种饲用添加酶活性的测定与分析

对香菇木屑菌糠中的纤维素酶、木聚糖酶、α-半乳糖苷酶、果胶酶、蛋白酶的活性进行研究.结果表明,纤维素酶和木聚糖酶的活性分别为16.56 IU和13.86 IU,α-半乳糖苷酶和果胶酶的活性较低,蛋白酶则没有活性.     

添加复合酶对玉米-豆粕-青干草型底物短期静态人工瘤胃发酵的影响

本研究采用短期静态人工瘤胃发酵的体外培养法,研究了8种复合酶对玉米-豆粕-青干草型底物瘤胃发酵的影响.复合酶由纤维素酶、木聚糖酶、酸性蛋白酶、中性蛋白酶和果胶酶组成.结果表明:添加复合酶可以改变瘤胃发酵模式,提高饲料的消化率;各组复合酶处理的产气量、氨态氮浓度、VFA浓度与对照组相比有所增加(P<0.05).根据发酵参数判断,最佳复合酶中纤维素酶、木聚糖酶、酸性蛋白酶、中性蛋白酶、果胶酶和稻壳粉(载体)所占比例分别为20%、5%、5%、2%、2%和66%.     

头孢菌素合成酶无载体固定化工艺研究

本实验对头孢菌素合成酶无载体固定化工艺进行研究。本实验对头孢菌素合成酶交联聚集体制备的固定化温度、固定化时间、固定化PH进行考察。最佳制备条件为固定化温度为5摄氏度、固定化时间90分钟、固定化PH为7.头孢菌素合成酶转化试验转化收率为73.2%。     

壳聚糖固化绿色木霉A1O产纤维素酶的研究

用壳聚糖作为载体、戊二醛作为交联剂来固定化木霉A10产纤维素酶.试验发现交联剂的最佳交联浓度为5％.通过L9 (34)正交试验,结果显示用该方案来固定化木霉A10号产纤维素酶是可行的,并且固定化效率最高为69.12％,最佳条件为固定化pH值为8、物料比为1:0.03、处理时间为12h.固定化后,酶对热的稳定性明显提高;...     

鹅源草酸青霉所产果胶酶对肉鸡生长性能及血液生化指标的影响

为了研究鹅源草酸青霉所产果胶酶在肉鸡日粮中的添加效果与使用方法,本试验分成4组,第4组为对照组,其余3组为试验组,分别在基础日粮的基础上添加0.249%果胶酶、0.168%纤维素酶、0.150%复合酶,测定试验肉鸡的生产性能和血液生化指标.结果表明,果胶酶组各期的平均日增重、体重均比对照组显著增加(P<0.05),料重比均显著降低(P<0.05);各期的尿酸、尿素氮比对照组显著降低(P<0.05),49日龄血糖显著提高(P<0.05).此外,与果胶酶组和纤维素酶组相比,复合酶组各期生产性能显著提高;28日龄尿素氮显著降低(P<0.05),谷丙转氨酶显著提高(P<0.05),49日龄血糖、总胆固醇显著提高(P<0.05),尿素氮显著降低(P<0.05),49日龄尿酸比纤维素酶组显著降低(P<0.05).由此可知:果胶酶对肉鸡生长性能和血液生化指标影响显著;果胶酶与纤维素酶配合应用效果更好.     

饲料及饲用酶制剂中果胶酶活力的测定

饲用酶制剂作为饲料添加剂在饲料中的应用越来越广泛。果胶酶制剂作为一种重要的添加剂还没有国家标准和测定方法标准。酶活力的测定主要有还原法、色原底物法、粘度法等 (冯涛 ,2 0 0 3)。其中还原法中的 3、5 -二硝基水杨酸(DNS)比色法 (简称DNS法 )作为动物体外测定酶活力的方法具有操作简便 ,对试剂、仪器等条件要求不高等优点 ,该方法是利用果胶酶在一定温度、时间和pH值条件下水解果胶 ,释放出的还原性半乳糖醛酸与 3、5 -二硝基水杨酸发生显色反应 ,水解生成半乳糖醛酸的量与吸光度成正比 ,即与果胶酶活力成正比 ,用分光光度法进…     

果胶酶对肉仔鸡生长性能及屠体性状的影响

试验选用 1日龄商品艾维茵肉仔鸡 4 32只。完全随机分为 2 4圈 ,每圈 18只 ,地面平养 5 4天。试验分为 4个处理 ,每个处理 6圈 ,分别饲喂 4种不同的日粮 ,即对照组 (基础日粮组 )、添加金霉素 5 0mg/kg日粮组、添加果胶酶 5 0 0mg/kg日粮组、添加果胶酶 10 0 0mg/kg日粮组。试验结果表明 ,果胶酶在肉仔鸡饲养前 2 1日龄的促生长效果显著 ,平均日增重 (ADG)和平均日采食量 (ADFI)均比对照组有显著增加 (P <0 .0 5 ) ,饲料转化率显著提高 (P <0 .0 5 ) ,与抗生素效果相当 ;2 1～ 4 2日龄时仅 5 0 0mg/kg果胶酶组出现ADFI比对照组显著增加 (P <0 .0 5 ) ,但饲料转化率较其它各组显著降低 (P <0 .0 5 )。 4 2～ 5 4日龄时 5 0 0mg/kg果胶酶组ADG显著高于抗生素组 (P <0 .0 5 ) ,饲料转化率显著提高 (P <0 .0 5 )。饲养全期 ,添加抗生素或果胶酶组ADG与对照组差异显著 (P <0 .0 5 ) ,ADFI仅5 0 0mg/kg果胶酶组与对照组有显著差异 (P <0 .0 5 )。     

从脱脂米糠中提取蛋白质和植酸的研究

以脱脂米糠为原料,研究果胶酶、纤维素酶、木瓜蛋白酶在超声辅助下对米糠蛋白和植酸同时提取的影响,探讨了该方法的最佳工艺条件。实验结果表明:在弱酸性条件下,采用先超声后纤维素酶和木瓜蛋白酶复合作用的方法可使提取的植酸量高于传统酸法,提取的蛋白质优于碱法。最佳工艺条件为:超声时间30 min,料液比1:10,蛋白提取量为1.804 3 g,植酸提取量为1.430 5 g。     

果胶酶对鹅净蛋白利用率及氨基酸消化率的影响

为了研究日粮中添加不同水平的果胶酶对鹅干物质消化率、净蛋白利用率（NPU）和氨基酸消化率的影响,选取24只24月龄的健康五龙鹅,随机分为4组,日粮中果胶酶添加水平分别为0％、0．1％、0．2％、0．3％,采用全收粪法进行代谢试验。结果表明：在代谢能（ME）和粗蛋白（CP）摄入量基本一致的条件下,随着果胶酶添加水平的提高,0．2％添加组粪中的氨态氮（NH3-N）浓度最低,为1．20mg／kg,与其他组相比差异显著或极显著（P〈0．01或P〈0．01）;甘氨酸表观消化率偏低,但是,组间差异不显著,其它各种氨基酸表观消化率（AAAD）均较高（72．19％～94．27％）,说明日粮中添加适量的果胶酶制剂能够有效地提高鹅对营养物质的消化吸收率。     

绿色饲料添加剂——果胶酶的研究

果胶酶是降解饲料抗营养因子——果胶的有效酶,它作为一种绿色饲料添加剂在畜牧业生产中的应用越来越广泛。文章针对这一现状,主要对果胶酶的性质、分类、作用机理作一阐述,并对其研究前景进行简要概括。     

饲料级果胶酶对肉仔鸡生长性能的影响

试验旨在研究日粮中添加饲料级果胶酶对肉仔鸡生长性能的影响。选择体重、健康状况基本一致的AA肉仔鸡240只,随机等分为试验组与对照组2个组,每组设3个重复,每重复40只,分成2个处理组,试验组饲喂在基础日粮中添加0.01％含6000U/g 的饲料级果胶酶的日粮,进行为期35d的试验。结果表明,与对照组相比,试验组日增重提高9.51％（P〈0.05）;料重比降低7.06％（P〈0.05）;死淘率降低11.00％（P〈0.05）。说明在日粮中添加饲料级果胶酶可显著提高肉仔鸡的生长性能。     

用果胶酶澄清桑椹果汁的工艺研究

用果胶酶对桑椹果汁进行了澄清工艺的试验。结果表明 ,在果胶酶的最小用量为 0 15mL/L、温度 4 0～6 0℃、pH 3～ 4的工艺条件下澄清的桑椹果汁 ,透光率达 95 %以上 ,可溶性固形物含量基本不变。     

产果胶酶枯草芽孢杆菌的鉴定、发酵条件优化及产物酶学性质的研究

以果胶为唯一碳源筛选到1株产果胶酶的菌株JLSP-13,通过菌落形态观察、生理生化指标试验和16SrDNA保守序列分析,鉴定JLSP-13为枯草芽孢杆菌,命名为Bacillus subtilis JLSP-13。采用响应面法(RSM)优化其产酶条件,并系统研究产物酶学性质。结果表明:B.subtilis JLSP-13的最佳发酵时间为25.02 h,添加可溶性淀粉和果胶的最佳浓度分为0.61%和0.042%,B.subtilis JLSP-13果胶酶(BpgA)活性最大预测值达38.8 U/mL,验证值为37.6 U/mL,是基础培养基的2.6倍。BpgA的最适温度为60℃,Tm为82.9℃,其热稳定性较好;最适pH为6.0,在pH 6.0～8.0范围内较稳定;Km和Vmax分别为5.128 mg/mL、12.92 mg(/mL.min),BpgA能快速降低果胶底物的黏度。     

Effect of enzymes of microbial origin on in vitro digestibilities of dry matter and crude protein in soybean meal

The effects of supplementation with cellulase, xylanase, pectinase, hemicellulase, glucanase, phytase and protease of microbial origin on digestibility of crude protein (CP) and dry matter (DM) of soybean meal in vitro were examined in the present study. Changes in viscosity during in vitro digestion were also examined as an index of carbohydrate digestibility. Hemicellulase and all enzyme combinations without protease showed significant improvement of CP digestibility. Cellulase, xylanase, phytase and glucanase tended to improve CP digestibility. Dry matter digestibility was improved significantly by pectinase and all enzyme combinations. Cellulase and phytase tended to improve DM digestibility. Crude protein and DM digestibilities were the highest when all the enzymes except protease were added. Protease, cellulase, pectinase, xylanase, glucanase and hemicellulase significantly reduced viscosity, while phytase had no effect on viscosity. Viscosity was increased unexpectedly when all the enzymes were added. These results strongly suggest that a combination of carbohydrases improves the CP and DM digestibility of soybean meal while protease inhibits the actions of these enzymes. The present study also suggests that viscosity is not always a good index of digestibility. Moreover, excluding the protease from commercial crude enzyme preparations may improve digestibility.     

缫丝废水发酵产果胶酶的条件优化研究

果胶酶制剂能够有效地提高饲养动物对营养物质的消化吸收率,是一种绿色饲料添加剂。缫丝废水是缫丝厂的主要排放物,是一种无毒、含氮和磷较高的有机废水。本研究以前期选育所得高产果胶酶菌株沙福芽孢杆菌(Bacillus safensis)G7-7作为试验菌株,利用缫丝废水为主要发酵原料,对产果胶酶条件进行优化。通过单因素试验和正交试验得出该菌株的最佳产酶条件为:以5%蚕沙为产酶诱导物,发酵液蔗糖添加量1.1%,接种量16%,发酵液初始pH 9.5,36℃发酵84 h。在此条件下菌株的产果胶酶能力可达到21.84 U/mL,是优化前12.39 U/mL的1.76倍,其中发酵液蔗糖添加量对产果胶酶影响达到显著水平。     

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.     

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, b-glucanase, pectinase, mannase and carboxy methyl cellulase (CMCase) contained in the compound. Xylanase and b-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°C in gastric liquor, the retained activity of xylanase, b-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°C in Na₂HPO₄-gastric liquor, the retained activity of xylanase, b-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, 200mL), 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°C, 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.