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1.
以PEG600、Tween-20、L—Met三种非离子表面活性剂分别处理摇瓶发酵0h和50h的泰乐菌素产生菌——弗氏链霉菌,考察其对泰乐菌素的效价和组分转化的影响,从而为提高泰乐菌素的产量和质量提供基础。结果表明,PEG600、Tween-20两种非离子表面活性剂均能促进泰乐菌素效价的提高,但会降低泰乐菌素组分A的含量;L-Met可抑制泰乐菌素效价的提高,但会促进A组分含量的提高。  相似文献   

2.
泰乐菌素的药用性能及促生长作用   总被引:1,自引:0,他引:1  
泰乐菌素(Tylosin)是我国“九·五”规划新引进的国家级新兽药 ,它是由弗氏链霉菌分泌的一种大环内酯类抗生素 ,其中含有4种具有生物活性的成分 ,以泰乐菌素A的活性最高。根据英国药典(兽药)1993年版 ,泰乐菌素成品中应含有A组分80%以上。1理化性质泰乐菌素为白色至浅黄色粉末 ,无臭、味苦。在0.1mol/LHCl溶液中 ,在290nm处具有最强吸收峰 ,可采用分光光度法直接测定。光照对泰乐菌素生物效价无明显变化 ,但组分降低 ;加热情况下生物学效价略有下降 ;水溶液中生物学效价稳定 ;具有吸湿性 ,但吸湿后生…  相似文献   

3.
为提高弗氏链霉菌对泰乐菌素的产素能力,构建了弗氏链霉菌双拷贝串联基因tylF、tylE和tylCV基因工程菌。本研究以弗氏链霉菌作为出发菌株,并以其全基因组DNA为模板分别扩增tylF和tylE以及tylCV基因、以质粒pSET152为模板扩增强启动子基因permE,采用重叠延伸PCR技术和EcoRV、XbaI双酶切结合的连接方法,构建弗氏链霉菌表达载体pSET152-permE-tylF-tylE-tylCV,并转化至大肠杆菌ET12567,利用大肠-链霉菌属间接合转移技术获得工程菌株。研究结果表明,工程菌株摇瓶效价(14580 u/mL)比出发菌株(11318 u/mL)提高了29%;液相色谱结果显示,工程菌株的泰乐菌素A和泰乐菌素C相对峰面积显著(P≤0.05)高于出发菌株。增加弗氏链霉菌tylF、tylE和tylCV的拷贝数可有效提高泰乐菌素的产量,以及优化组分,为泰乐菌素生产菌的遗传改造提供参考。  相似文献   

4.
泰乐菌素是中国养殖业广泛使用的抗菌促生长类兽用抗生素之一,它进入畜禽体后,其原形和代谢产物会随畜禽粪尿进入环境,与环境微生物产生互作效应,由此本文首先介绍了环境介质中泰乐菌素残留现状,然后综述了泰乐菌素与土壤微生物的互作效应。目前畜禽生产中使用的泰乐菌素是泰乐菌素A、B、C和D的混合物,其中泰乐菌素A占80%以上,因此泰乐菌素A也是泰乐菌素在环境中残留的主要形式,但在不同环境条件下,泰乐菌素A可转化为泰乐菌素B、C和D,而且已有研究表明在畜禽粪便、污水、土壤及水体等环境介质中均检测到泰乐菌素A及其代谢产物的残留。土壤中残留的泰乐菌素可与微生物产生互作效应,即一方面泰乐菌素可影响土壤中微生物的数量、群落结构和功能;另一方面土壤微生物在受到泰乐菌素胁迫时会产生和传播耐药基因以及可降解泰乐菌素微生物等。笔者还对今后该领域的研究进行了展望。  相似文献   

5.
浊度法测定酒石酸泰乐菌素可溶性粉效价研究   总被引:1,自引:0,他引:1  
目的:建立浊度法测定酒石酸泰乐菌素可溶性粉效价的方法。方法:以金黄色葡萄球菌为试验菌,抗生素检定培养基Ⅲ号为试验用培养基,制备菌悬液。采用浊度法和管碟法对酒石酸泰乐菌素可溶性粉的效价测定进行比较,并对浊度法进行方法学验证。结果:用浊度法测定酒石酸泰乐菌素可溶性粉的效价,泰乐菌素的浓度范围在0.6-2.0 u/mL之间,其浓度对数与吸收度有良好的线性关系,相关系数r=0.999 0,平均回收率为100.3%,RSD为0.91%;用浊度法与管碟法测定结果无明显差异,方法学验证表明,浊度法测定酒石酸泰乐菌素可溶性粉效价的方法可行。结论:本方法具有可信限率低、灵敏度高、精密度高、快速简便等优点,可用于泰乐菌素及其制剂的效价测定。  相似文献   

6.
为了选育出泰乐菌素高产菌株,以弗氏链霉菌(Streptomyces fradiae)TL-15028菌株作为出发菌株,利用化学诱变、物理诱变以及复合诱变的方法对菌株进行诱变处理,比较不同诱变方法的诱变效果,通过诱变筛选出1株遗传稳定性好、且具有泰乐菌素和豆油抗性的菌株TLEU-1503,其发酵效价比出发菌株提高了36.5%,达到14124μg/m L,对泰乐菌素高效生产、品质提升具有重要意义。  相似文献   

7.
为了选育出泰乐菌素高产菌株,以弗氏链霉菌(Streptomyces fradiae)TL-15028菌株作为出发菌株,利用化学诱变、物理诱变以及复合诱变的方法对菌株进行诱变处理,比较不同诱变方法的诱变效果,通过诱变筛选出1株遗传稳定性好、且具有泰乐菌素和豆油抗性的菌株TLEU-1503,其发酵效价比出发菌株提高了36.5%,达到14124μg/m L,对泰乐菌素高效生产、品质提升具有重要意义。  相似文献   

8.
李乐菌素从开发生产至现今,已有近50年的历史,但整个国际市场的消耗量呈逐年上升趋势,全世界每年用量约2500吨,我国每年从美、意进口约200吨。在日本50%以上的猪饲料中添加泰乐菌素,能有效地抗痢疾弧菌,促进生长发育;对肉鸡的促生长能提高饲料报酬6%,提高增重15%;在兽医临床上,其对支原体的极度敏感性能被很好地应用。可以说,泰乐菌素和工业化的畜禽饲养是分不开的.给全球养殖业带来的效益是无可估量的。一.泰乐菌素的组成、结构泰乐菌素为纯天然抗生素,由弗氏链霉菌分泌。主要由4种具有生物活性的组分A、…  相似文献   

9.
泰乐菌素发酵过程中,PH值的控制及豆油的补加量对组份的转化存在显著影响。研究结果表明,在转化阶段当PH值控制在适当范围内,对不菌素效价影响不大,但可大大提高泰乐菌素A的含量;同时在发酵中期及转化前这一阶段补加适量豆油,不仅可使效价逐步提高,还中明显促进大菌C向泰乐菌素A的转化。  相似文献   

10.
目的:验证比浊法测定泰乐菌素效价方法的可行性。方法:应用比浊法测定泰乐菌素效价,并对微生物比浊法、管碟法测定泰乐菌素效价的结果进行评价。结果:比浊法、管碟法效价测定结果一致。结论:比浊法具有简便、精确、快速的特点,可用于泰乐菌素及其制剂含量的测定。  相似文献   

11.
As there is no statistical evidence that saddle fit influences the load exerted on a horse's back, this study was performed to assess the hypothesis that the width of the tree significantly alters the pressure distribution on the back beneath the saddle. Nineteen sound horses were ridden at walk and trot on a treadmill with three saddles differing only in tree width. Kinetic data were recorded by a sensor mat. A minimum of 14 motion cycles were used in each trial. The saddles were classified into four groups depending on fit. For each horse, the saddle with the lowest overall force (LOF) was determined. Saddles were classified as "too-narrow" if they were one size (2 cm) narrower than the LOF saddle, and "too-wide" if they were one size (2 cm) wider than the LOF saddle. Saddles two sizes wider than LOF saddles were classified as "very-wide". In the group of narrow saddles, the pressure in the caudal third (walk 0.63 N/cm(2)+/-0.10; trot 1.08 N/cm(2)+/-0.26) was significantly higher compared to the LOF saddles (walk 0.50 N/cm(2)+/-0.09; trot 0.86 N/cm(2)+/-0.28). In the middle transversal third, the pressure of the wide saddles (walk 0.73 N/cm(2)+/-0.06; trot 1.52 N/cm(2)+/-0.19) and very-wide saddles (walk 0.77 N/cm(2)+/-0.06; trot 1.57 N/cm(2)+/-0.19) was significantly higher compared to LOF saddles (walk 0.65 N/cm(2)+/-0.10/ 0.63 N/cm(2)+/-0.11; trot 1.33 N/cm(2)+/-0.22/1.27 N/cm(2)+/-0.20). This study demonstrates that the load under poorly fitting saddles is distributed over a smaller area than under properly fitting saddles, leading to potentially harmful pressures peaks.  相似文献   

12.
Complications in late gestation are challenging problems for the equine clinician and are causes of considerable distress to owners. Health problems in a pregnant mare in each stage of gestation can adversely affect the pregnancy. It is important to obtain a thorough history and perform a detailed and systematic examination of the pregnant mare so that the mare may be classified as normal or high-risk. However, even after a thorough examination, practitioners may face problems with the interpretation and assessment of risk. Normal mares should foal in the stable or pasture. Mares classified as having a high-risk pregnancy need to be monitored precisely for signs of oncoming foaling with attendance of trained personnel when labour begins. A valuable method for monitoring of the high-risk mare is assessing fetoplacental well-being. Fetoplacental well-being is most accurately assessed with ultrasonography as well as several available hormone profiles. We are proposing our scoring system of the mare's health, which may be useful in the assessment of risk during pregnancy and help clinicians to decide whether sending the mare to the clinic is reasonable or unnecessary.  相似文献   

13.
顾问刘中一张德邻宋瑞祥聂振邦张子仪戎易王维四会长白美清国务院原副秘书长、第四届理事会会长常务副会长(8人,以姓氏笔划为序)刘永好新希望集团董事长、第四届理事会副会长刘汉元通威股份有限公司董事长、第四届理事会副会长陈丹广东恒兴集团股份有限公司董事长、第四届理事会副会长张延喜农业部原副部长、第四届理事会副会长吴明夏湖南正虹科技发展股份有限公司董事长、第四届理事会副会长陶一山唐人神集团股份有限公司董事长、第四届理事会副会长温鹏程广东温氏食品集团有限公司董事长、第四届理事会副会长谭竹洲原化学工业部副部长、第…  相似文献   

14.
The understanding and application of genetics have grown extremely quickly since it has become possible to sequence the whole genome of an organism. The human genome sequence was completed in 2001 and that of the horse in 2007. The significance of this is that it makes it more feasible to explain how both genetically simple and complex traits are transmitted from one generation to the next and, therefore, to make informed breeding decisions, modify how horses are managed and trained to minimise the risk of disease and injury, and improve methods of prevention, diagnosis and treatment of many conditions. The science of genetics/genomics will continue to grow internationally, limited only by the funds available. The application of the science to man, horses and other species raises very complex moral and commercial issues. Thoroughbred breeders are perceived by some as resistant to change, but their apparent intransigence is often based on a genuine concern for the integrity of the breed. By taking control of the application of the advances in genetics, the Thoroughbred industry potentially has the opportunity to improve both the health and performance of Thoroughbreds. If, however, the science is applied in an uncoordinated manner, driven by commercial interests with no underlying concern for the horses themselves, there is a very real risk that breeders, the Thoroughbred breed and individual horses will all suffer as a consequence.  相似文献   

15.
为了找出支配鸡胆囊交感节后神经元的分布规律,选用体重1.5 kg~2.5 kg的成年母鸡6只,将CT-HRP溶液注入胆囊壁,动物存活3 d~4 d后,经左心室灌流固定,取内脏神经节、肾上腺神经节以及双侧胸、腰和荐段交感干神经节,制成50 μm的连续冰冻切片,TMB法呈色反应,置明视野显微镜下观片统计.结果发现,支配鸡胆囊的交感传出神经元胞体位于内脏神经节(占41.1%)、肾上腺神经节(占40.5%)和T2~T7交感干神经节(占18.4%),在交感干神经节中标记细胞的峰值位于T5、T6交感干神经节.所有的标记细胞以位于右侧的占优势.  相似文献   

16.
赵云翔  赵蕊  张恒  郭金彪 《养猪》2022,(1):52-55
试验以深圳某集团销售外三元商品猪为研究对象,分析了商品猪不同胴体性能对分割销售效益的影响.结果表明,销售完成率与胴体背膘厚呈正相关,不同背膘厚的销售完成率差异极显著(P<0.01);销售完成率与胴体重呈正相关,不同胴体重的销售完成率差异显著(P<0.05);销售毛利率与胴体背膘厚呈正相关,不同背膘厚的销售毛利率差异极显...  相似文献   

17.
犊牛腹泻与肠道菌群的变化   总被引:1,自引:0,他引:1  
本文检测腹泻犊牛的直肠内8种主要正常菌群的变化,并与健康犊牛进行对比。结果发现,犊牛腹泻时,大肠杆菌、双岐杆菌和乳杆菌变化较大,而其它菌群变化较小。腹泻或将腹泻时,大肠杆菌数增加,双岐杆菌和乳杆菌数下降。腹泻康复或即将康复时,大肠杆菌减少,双岐杆菌、乳杆菌数增加。  相似文献   

18.
19.
试验选择陕北白绒山羊繁育中心羊场的成年健康母羊(怀孕前期)16只,育成母羊13只,育成公羊13只,空腹称重。测定每只羊1d的采食量,计算其摄入的营养成分含量,并与原苏联绒用山羊饲养标准比较,进行饲养水平评价。结果显示,与饲养标准比较,陕北白绒山羊繁育中心羊场的育成母羊代谢能高2.68MJ,粗蛋白低59.29g,钙低3.00g,磷低1.52g;育成公羊代谢能高3.47MJ,粗蛋白低81.92g,钙低4.42g,磷低2.62g;成年母羊代谢能高2.51MJ,粗蛋白低91.33g,钙低3.09g,磷低1.93g。结合羊的体况综合评价饲养水平基本合理,但尚需要按饲养标准增加粗蛋白、钙、磷等营养物质的供给量。  相似文献   

20.
对致死后的野生雄性猪獾作全身骨骼系统观察测定,共拍摄照片6幅,查明猪獾全身共有252共骨头,另有4块喉软骨,长约4.3cm,略弯圆柱状阴茎骨,16对肋软骨,上下各1对犬齿,较发达,分别长1.4cm,1.3cm,发现猪獾善于穴居或栖居,行动迟缓的骨骼特征:(1)胸椎发达,颈椎,腰椎较发达;(2)胸骨的前端愈合完全,后端膨大突出:(3)前肢短,有29.5cm,后肢长,有33.4cm,均有强大锐利的脚爪;(4)尾椎较长,全长16.9cm。  相似文献   

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