固态发酵复合酶培养条件的优化及工艺研究

根据猪的消化生理特点和饲喂饲料,确定猪用复合酶以酸性蛋白酶、木聚糖酶为主,兼有纤维素酶,并采用单因素搜索试验对培养基组成、培养条件进行优化。试验确定的最佳培养基组成为:麸皮60g,纤维素粉40g,豆粕10g,(NH4)2SO42g,MgSO40.05g,K2HPO40.1g。最佳培养条件为:接种量w(曲种)=0.3%,每克原料含3×105个孢子,培养温度30～35℃和适宜的培养时间,在此条件下,所产酶活力分别为:纤维素酶8597U/g,木聚糖酶5054U/g,酸性蛋白酶861U/g。     

发酵花生壳粉生产复合酶的初步研究

从实验室保藏的菌株中选取了一株能发酵花生壳粉产酸性蛋白酶的菌株黑曲霉HKS-07,并通过诱变得到高产菌株UV11,对培养基组成及培养条件进行了优化研究试验。结果表明,菌株UV11在m(麸皮):m(花生壳粉)为6:4、豆粕10%、(NH4)2SO42%、MgSO4·7H2O0.05%、K2HPO40.1%的培养基质上,加水比1:1.1,接种量为105~106个/g,置28～30℃下培养24～30h,产酶量为酸性蛋白酶1226U/g、纤维素酶7996U/g、木聚糖酶3192U/g、糖化酶1080U/g,热稳定性好,具有良好的应用前景。     

饲用复合酶固体发酵工业化生产

宇佐美曲霉YW-38是一株高产饲用复合酶的生产菌株。在20m3自动固体发酵罐内32～35℃间断通风发酵64h,YW-38产酸性蛋白酶、木聚糖酶、β-葡聚糖酶、纤维素酶、β-甘露聚糖酶、果胶酶和淀粉酶等复合酶系,其中:酸性蛋白酶和木聚糖酶活力分别为15200和1200U/g。本试验研究了YW-38菌株的工业化生产的最佳培养基配方和发酵工艺条件。发酵培养基组成为:麸皮800kg,豆饼粉200kg,(NH4)2SO420kg,KH2PO45kg,水分55%～58%,pH值6.2～6.5,发酵过程中补加2次无菌水,每次200kg。     

响应面分析法优化酸性蛋白酶固态发酵培养基的研究

用响应面分析法(采用中心组合一致精度的设计)对影响土曲霉产酸性蛋白酶固态发酵培养基的4个主要影响因素(麸皮与豆粕比例、硫酸铵、硝酸钠、磷酸二氢钾)进行了优化,考察了各因素及其交互作用对酸性蛋白酶酶活的影响。用SAS9.1.3软件模拟二次多项式回归预测模型并建立了影响因素与响应值(酸性蛋白酶酶活)之间的函数关系,即回归方程,找到了各因素的最佳水平,即麸皮与豆粕比例为1:0.20、硫酸铵为1.9%、硝酸钠为0.97%、磷酸二氢钾为3.3%,此时酸性蛋白酶酶活为9326U/g。通过验证试验,5次重复试验的平均值为9327U/g,与模型预测值基本一致。     

白酒酒糟制备多酶益生菌饲料发酵工艺研究

选择产甘露聚糖酶枯草芽孢杆菌L-1、产植酸酶枯草芽孢杆菌L-2、产木聚糖酶YB-5、乳酸片球菌Rp作为制备多酶益生菌饲料的生产菌种。通过单因素和正交试验最终确定最佳底物干基组分为36%白酒酒糟、26%玉米粉、28%麸皮、8%豆粕,料水比10.8,装填量20 g/250 ml。结果表明:多酶益生菌饲料中益生菌活菌数为(1.97±0.09)×10~(11)cfu/g,甘露聚糖酶酶活(11.62±0.26)U/g、木聚糖酶酶活(15.30±0.36)U/g、植酸酶酶活(16.37±0.16)U/g、蛋白酶酶活(15.27±0.16)U/g以及淀粉酶酶活(19.37±0.33)U/g。     

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。     

黑曲霉ASP-12固态发酵木聚糖酶培养条件研究

通过三角瓶和托盘固态发酵对黑曲霉ASP-12产木聚糖酶的各种环境因素进行了研究。结果表明,培养基的初始pH值为4.5￣5.0,发酵温度为28￣32℃,托盘发酵起始水分应控制在60%￣65%,三角瓶的水分为55%左右,接种量为1%(v/m,109个/ml),培养48h,可以达到最高酶活。对发酵过程酶活的变化趋势研究发现,高峰分别出现在32h和48h,且48h高于32h时的木聚糖酶酶活。正交试验结果显示培养基最优配方为:玉米芯5%、K2HPO40.2%、豆粕2%、麸皮95%。     

小麦型饲粮中添加酸性木聚糖酶对肉鸡消化道食糜黏度的影响

本试验旨在对比研究酸性和中性木聚糖酶的酶学性质及其在小麦型饲粮中的降黏效果。饲养试验检测2种木聚糖酶（酸性和中性木聚糖酶）对胃肠液的耐受性;pH 3.5条件下测试2种木聚糖酶的相对活性;选用木聚糖纯品和谷物检测2种木聚糖酶的降黏效果;选取512只1日龄的817白羽肉公鸡,随机分为4组（每组8个重复,每个重复16只）,对照组饲喂小麦型基础饲粮,试验组在小麦型基础饲粮中分别添加4 U/g中性木聚糖酶、2和4 U/g酸性木聚糖酶,试验期42 d。结果显示：1）相比中性木聚糖酶,酸性木聚糖酶对肉鸡胃肠液有更好的耐受性。2）在pH 3.5条件下,酸性木聚糖酶的相对活性比中性木聚糖酶高64.1%。3）对于高黏（黑麦）阿拉伯木聚糖,相比中性木聚糖酶,酸性木聚糖酶的降黏效果提升了42.9%。4）在小麦型饲粮中添加木聚糖酶提高了肉鸡的生长性能,其中4 U/g酸性木聚糖酶对生长性能的提高效果优于4 U/g中性木聚糖酶。5）对于饲喂小麦型饲粮的肉鸡,4 U/g酸性木聚糖酶组粗蛋白质表观消化率分别比2 U/g酸性木聚糖酶组、4 U/g中性木聚糖酶组和对照组提高了3.5%(P<0.05)、7.4%(P&l...     

芽孢杆菌木聚糖酶固体发酵工艺研究

利用固体发酵对实验室筛选的芽孢杆菌021产木聚糖酶的培养基和发酵工艺进行研究。结果表明,以麸皮和黄豆饼粉(9:1)为主要基质,4%麦芽糖、4%硝酸铵有助于产酶。最佳发酵条件为:含水量65%、起始pH值8.0、发酵温度为37℃、接种量8%、250ml三角瓶装料20g、培养36h。在最佳发酵条件下,木聚糖酶酶活可达3.25U/g。     

培养条件对黑曲霉产酶的影响

在玉米秸秆粉和麸皮组成的培养基上对黑曲霉进行固体培养,研究不同秸秆粉∶麸皮配比及不同营养液和不同培养时间对黑曲霉产纤维素酶和木聚糖酶的影响。结果表明,不同培养条件对黑曲霉产滤纸酶和木聚糖酶都有影响,黑曲霉产滤纸酶的最优培养条件组合为麸皮∶秸秆粉1∶4、Mandel营养液、培养96h,所得酶活力为15.136U/g,比实验最低组的酶活提高了4.32倍;产木聚糖酶的最优培养条件组合为麸皮∶秸秆粉3∶1、NaNO3、培养96h,所得酶活为282.702U/g,比实验最低组的酶活提高了34.2%。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.