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Lars Rutqvist 《Acta veterinaria Scandinavica》1969,10(3):234
Mycelial filtrates from Aspergillus fumigatus (AF) hydrolyzed protein substrate buffered at various pH values. Using casein as substrate there were distinct activity optima at pH 2.9, pH 6.2, and pH 10, with maximum activity at pH 6.2. Using haemoglobin as substrate there were activity optima at pH 3.6, pH. 4.6, and pH 10, with the biggest activity peak at pH 4.6.The pH stability at 4°G of the caseinase activity at pH 6.2 and pH 10 was strongest at pH 4, common to both, whereas the caseinase activity at pH 2.9 showed maximum pH stability at pH 6—7.The casein hydrolyzing activity at pH 2.9, pH 6.2, and pH 10 showed different optimum incubation temperatures and irregular heat inactivation.Normal rabbit serum inhibited the caseinase activity at pH 2.9 and pH 6.2 to some extent. The caseinase activity at pH 10 was almost completely inhibited. Antiserum against mycelial filtrate showed no definite inhibition beyond that exerted by normal serum.Following electrophoresis of antiserum, the presence of specific neutralizing antibodies against the casein precipitating enzyme of mycelial filtrate from AF could be established. Investigations of 14 AF strains showed immunological uniformity with respect to the casein precipitating enzyme. 相似文献
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Mycelial filtrates from Aspergillus fumigatus (AF), shown to possess haemolytic, toxic, casein precipitating, and protein hydrolyzing activity, hydrolyzed poly-L-lysine and poly-L-glutamine in the pH range 4.6—5.3. Incipient activity against poly-L-lysin was observed at pH 9. Owing to spontaneous hydrolysis of the polyamino acid at pH > 10, no activity optimum could be traced.Gel filtration of mycelial filtrate on Sephadex G-75 or G-100 columns offered no definite information whether the protein hydrolyzing activity, using haemoglobin as substrate, at the optimum pH values, 2.9, 4.6 and 10, shows the activity of a single enzyme with more than 1 pH optimum or of more than 1 enzyme active at different pH values. Certain results of the investigations seem to indicate that the protein hydrolyzing activity at pH 2.9 was not caused by enzymes identical with the enzyme (s) causing the protein hydrolyzing activity at pH 4.6 or pH 10.Casein precipitating and protein hydrolyzing activity occurred, following gel filtration on a Sephadex G-100 column, in identical fractions whereas neither haemolysin nor toxin could be found in samples of 0.5 ml fraction solution from any of the fractions after filtration on Sephadex G-75 or G-100 columns.By using antiserum to a crude filtrate from a homologous AF strain it could be shown, applying immuno-electrophoresis, that dialyzed mycelial filtrate contained 8 precipitating antigens whereas proteinase purified by gel filtration and displaying protein hydrolyzing activity at pH 2.9, pH 4.6 and pH 10 contained 4 such antigens. 相似文献
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甘肃高山细毛羊在品种育成后的30多年里坚持育种方向,加强选种选配,提高品种质量。现对育成的几个新品系进行系统回顾和生产性能分析,总结育种取得的经验,旨在为设计和合理制定育种规划提供参考。 相似文献
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本研究比较了9株鸡新城疫不同弱毒株的毒力和免疫原性。结果显示,新城疫弱毒耐热B株、V4株、Ulster 2C株基本不致死鸡胚,ICPI为0,MDT/MLD大于150h;Hitchner B1株及F株7/10鸡胚致死,死胚胎儿有明显充血、出血病痕,120h活胚明显萎缩,ICPI为0.213~0.238,MDT约为120h;La Sota株、Clone30株、N79株及VG/GA株120h内鸡胚全部死亡,死胚胎儿有明显充血、出血病痕,ICPI为0.3~0.4,MDT约为103~109h。9株NDV的IVPI均为0对鸡只不致病,但免疫原性有所不同,NDVB株免疫原性较好,全部保护,NDVF株最弱。 相似文献
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近年来,蚕品种秋丰×白玉有不少改良品系,为摸清秋丰×白玉各品系之间的异同,根据省农业厅蚕种公司的部署,在德清县进行了秋丰×白玉各原种品系及其一代杂交种的比较试验,现将试验结果报告如下。 相似文献
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Serological Comparison of Hemagglutinating Encephalomyelitis Viruses Isolated from Different Outbreaks 下载免费PDF全文
Examination by the HI test of 20 representative HEV isolates reveals that only one of them, HEV-18 differs quantitatively from the others. The difference is confirmed qualitatively by the SN test. Both the HI and SN tests demonstrated that all the other HE viruses, though isolated from oubreaks of disease in widely separated areas of Canada over a period of eight years, represent a single strain. 相似文献
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欧洲肉鸽不同品系生产性能测定 总被引:1,自引:0,他引:1
选取成年欧洲肉鸽高产系(1系)、兼用系(2系)、快大系(3系)各30对,测量体尺、屠宰性能测定;统计生产群繁殖性能,分析欧洲肉鸽不同品系的生产性能,明确各系的品系特征。结果表明,欧洲肉鸽引入中国以来,历经多年的饲养与选育,2系体躯更长,3系胸部宽大,1系体型最小。欧洲肉鸽胸肌为球型,双胸肌性状明显,胸肌率达到了30%以上。欧洲肉鸽产肉性能非常好,屠宰率在87%左右、全净膛率在75%左右。1系繁殖性能优良,年产蛋窝数达到了9.68窝。3系不论是成年鸽还是乳鸽体重最大,乳鸽28日龄体重达到了601.27g。2系兼顾了繁殖性能和产肉能力。1系高产、2系兼用、3系快大,各系特征明显。 相似文献
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R. B. Truscott 《Canadian journal of veterinary research》1973,37(4):375-381
A toxin which is lethal for two week old chicks has been recovered from strains of Escherichia coli O78:K80 of bovine and avian origin and from avian isolates of serogroups O2, O45 and O109. The toxin is heat-labile, antigenic, high in protein, inactivated by pronase, trypsin, amylase, and pancreatic lipase. The toxin may be precipitated by ammonium sulfate or TCA treatment from the supernatant obtained by repeated centrifugation of sonicated cells. Considerable purification has been obtained by column chromatography using Sepharose 6B. 相似文献
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部分省市猪群猪流感的血清学调查及猪流感病毒的分离与鉴定 总被引:59,自引:9,他引:59
对黑龙江、吉林、辽宁、安徽、山东、内蒙、河南、河北、江苏、安徽、浙江、湖北、福建、广东、海南、上海等省、市猪群进行了猪流感的血清学和病原学调查研究。从 130 6份猪鼻棉拭子样品和死亡猪肺、气管样品中分离到 39株H3N2亚型猪流感病毒 ,12株 H1亚型猪流感病毒及其它亚型猪流感病毒 ,病毒粒子在透射电镜下呈现典型的正粘病毒特征 ,有囊膜和纤突 ,多为椭圆形、圆形、或杆形 ,直径约 80~ 12 0 nm。对 1997- 2 0 0 1年 3895份猪血清的血清学调查结果表明 ,近年中国多个地区猪群存在抗SWTN77(H1)、SWCO77(H3)、DKAT6 9(H1)、TKUK6 3(H3)流感病毒抗体 ;1998年来自河北的猪血清中抗 SWTN77阳性率高达 33.3% ;1999年来自内蒙的猪血清中抗 TKUK6 3和SWCO77阳性率分别为 13.3%和 2 6 .7% ;2 0 0 0- 2 0 0 1年调查的所有省市的猪群中均存在抗SWCO77抗体 ,阳性率从 3.2 %~ 10 0 %。说明近年我国猪群中 H3亚型猪流感的污染相当普遍 相似文献
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