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电脉冲法转化苏云金芽孢杆菌BMB171的研究 总被引:3,自引:0,他引:3
研究了用电脉冲法转化苏云金芽孢杆菌受体菌BMB171的优化条件以及由转化导入的几类cry基因在BMB171中的表达效果。结果表明,采用SG溶液作电脉冲缓冲液,用10.okV/cm的脉冲场强和1次电脉冲(4.6ms)以及采用对数前期(OD650nm为0.2~0.3)收获的受体菌,可以达到最高转化频率,其中用pHT3101电转化 BMB171的最高频率达 8×107转化子/μg DNA。转化频率随质粒pHT3101浓度的增加,在54.69pg/mL至3.50μg/mL范围内 相似文献
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一种改进的阴茎电刺激采精法和猕猴藏酋猴及熊猴的采精及其精液特征的初步研究 总被引:6,自引:2,他引:4
本文报道了一种改进的阴茎电刺激采精法,用脱脂棉和铝箔作为电极,以避免直接用金属电极可能对阴茎的损伤,并运用这一方法对猕猴(Macacamulatta)、藏酋猴(M.thibetana)和熊猴(M.assamensis)进行了电刺激采精及其精液特征研究。电刺激采精模式为连续刺激和间断刺激方式。在采精过程中没有发生阴茎损伤。对初次接受电刺激采精的动物以间断刺激模式效果较好。猕猴、藏酋猴和熊猴的射精体积分别为2.0±0.1、6.3±1.1和3.2±0.6ml;液化体积分别为0.7±0.6、2.1±0.4和1.7±0.3ml;精子浓度分别为12.6±1.2×10~8、45.6±5.6×10~8和11.5±0.9×10~8/ml。3种动物精液的液化率分别为:猕猴36.2±0.9%,藏酋猴34.0±1.4%;熊猴51.8±1.2%。3种动物的精子总数与射精体积和凝块体积没有相关性(r~2=0.079;0.016;0.094和r~2=0.064;0.020;0.072)。上述结果表明:1)改进的阴茎电刺激采精法适用于猕猴,特别是阴茎表面较为粗糙的藏酋猴和熊猴;2)藏酋猴的射精体积和精子总数是迄今已报道的非人灵长类中最大的,可能 相似文献
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芽孢杆菌M_(50)产生β甘露聚糖酶的条件研究 总被引:3,自引:0,他引:3
从土壤中分离到9 株产生β甘露聚糖酶的芽孢杆菌( Bacillus sp .) 。Bacillussp . M50250m L三角瓶摇瓶培养试验,以4 % 的魔芋粉为碳源,1-0 % ( NH4)2SO4 为氮源,0-35 %Na2CO3 ,30 ~34 ℃培养60h 产酶达到高峰。酶活力为180 ~200u/m L。100L 罐发酵,在30 ~32 ℃,1∶0 .75vvm 通气量,200r/min 条件下,发酵液酶活力高达330u/m L。酶的最适反应温度和pH 分别为50 ℃和6-0 ,低于50 ℃,pH5 .0 ~7 .0 酶稳定。Fe3+ 、Al3+ 、EDTA、Hg2+ 对酶有抑制作用,而Ba2+ 、Mn2+ 对酶有激活作用。发酵粗酶液对苎麻精干麻精练,显示对精干麻的半纤维素残胶具有降解作用。 相似文献
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广东省烟草花叶病病原病毒的鉴定 总被引:2,自引:0,他引:2
烟草花叶病是广东省产烟区的主要病害之一。我们在南雄等八个县进行调查,1983年至1984年的一般发病率为2~20%。根据血清学反应、病毒粒体形态、鉴别寄主反应及寄主范围、媒介昆虫种类、物理性质、交互保护反应等各项检验结果,鉴定广东省烟草花叶病病原是:三个黄瓜花叶病毒可能株系(普通株系CMV-C,烟草坏死株系CMV-TN,烟草黄色坏死株系(CMV-TYN),烟草花叶病毒(TMV),马铃薯病毒Y(PVY),烟草脉带花叶病毒(TVBMV)和烟草褪绿斑驳病毒(TCMV)(暂定)。 相似文献
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Influenza Hemagglutinin and Neuraminidase Membrane Glycoproteins 总被引:2,自引:0,他引:2
Considerable progress has been made toward understanding the structural basis of the interaction of the two major surface glycoproteins of influenza A virus with their common ligand/substrate: carbohydrate chains terminating in sialic acid. The specificity of virus attachment to target cells is mediated by hemagglutinin, which acquires characteristic changes in its receptor-binding site to switch its host from avian species to humans. Anti-influenza drugs mimic the natural sialic acid substrate of the virus neuraminidase enzyme but utilize the much tighter binding of the drugs for efficacy. Resistance to one of the two main antiviral drugs is differentially acquired by the two distinct subsets of neuraminidase as a consequence of structural differences in the enzyme active site between the two phylogenetic groups. 相似文献
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正Dear Editor,Since April 2010,an outbreak of a new disease has elicited symptoms of high fever,loss of appetite,and reduction in egg production in layer ducks in eastern China;this phenomenon has now spread throughout China(Cao et al.,2011;Su et al.,2011).The causative agent of the disease was identified as Tembusu virus(TMUV),which was classified into the genus Flavivirus, 相似文献
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Muhammad Ali 《中国病毒学》2016,31(3):197-198
正The International Committee on Taxonomy of Viruses(ICTV)has the decree to set the rules for the classification and naming of viruses.The species is the lowest level considered in the taxonomic hierarchy.In general,virus species are named according to the structure"isolation hostsymptomsand the word‘virus’".A typical example is Tobacco mosaic virus[Genus:To- 相似文献
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K. Dietz 《Journal of mathematical biology》1979,8(3):291-300
Summary There are a few simulation studies for interference models in the literature but the present paper discusses an analytical model for the competition of two interfering virus populations in a community. The mathematical model consist of eight coupled differential equations which have up to four equilibrium points. Criteria for local stability are given.This paper has been read at the workshop on Nonlinear Models in Biology and Medicine, 23rd Biometric Colloquium, German Region of the Biometric Society, Nuremberg, March 1977 相似文献
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芝麻病毒病病原研究——Ⅰ.芝麻矮化坏死病害的鉴定 总被引:1,自引:0,他引:1
在湖北武昌芝麻上分离到的矮化坏死分离物(DNe-I)侵染芝麻引起严重矮化,叶片皱缩坏死。它能够摩擦接种侵染7科14种植物。在苋色藜、千日红上引起局部坏死斑,侵染油菜和百日菊引起系统花叶和黄化。DNe-I能够被桃蚜、花生蚜以非持久性方式进行传播。病毒体外稳定性状:存活期4天,钝化温度60~65℃,稀释限点4×10~(-4)。提纯病毒为线状粒体,长度为770nm。病毒外壳蛋自为单一亚基组成,分子量为30,700±600D。制备抗血清微量沉淀法测定其效价为1:256。在油菜病组织中,观察到风轮状及长直片层叠聚体类型的胞质内含体。在血清学性质上,该分离物与芜菁花叶病毒密切相关,与花生轻斑驳病毒和花生斑驳病毒弱相关,与大豆花叶病毒和西瓜花叶病毒不相关。基于上述性质,DNe-I被鉴定为芜菁花叶病毒。这是国内芜菁花叶病毒自然侵染芝麻的首次报道。 相似文献
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H. Yanagisawa Y. Matsushita A. Khiutti N. Mironenko Y. Ohto O. Afanasenko 《Letters in applied microbiology》2021,73(1):64-72
Potato viral disease has been a major problem in potato production worldwide including Russia. Here, we detected Potato Virus M (PVM), P (PVP), S (PVS), Y (PVY), and X (PVX) and Potato Leaf Roll Virus (PLRV) by RT-PCR on potato leaves and tubers from the Northwestern (NW), Volga (VF), and Far Eastern (FE) federal districts of Russia. Each sample was co-infected with up to five viruses. RT-PCR disclosed all six viruses in NW, three in VF, and five in FE. Phylogenetic analyses of PVM and PVS strains resolved all PVM isolates in Group O (ordinary) and all PVS isolates in Group O. Seven PVY strains were detected, and they included only recombinants. PVY recombinants were thus the dominant potato virus strains in Russia, although they widely varied among the regions. Our research provides insights into the geographical distribution and genetic variability of potato viruses in Russia. 相似文献
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小麦土传病毒在感病小麦细胞中的分布及小麦梭条斑花叶病毒RNA组分 总被引:2,自引:0,他引:2
陈剑平 《Virologica Sinica》1993,8(2):181-184
四川雅安、陕西长安的土传小麦病毒病由小麦梭条斑花叶病毒(WSSMV)引起,而浙江安吉、新昌、江苏宜兴的病害则由WSSMV和土传小麦花叶病毒(SBWMV)所致。WSSMV和SBWMV可以同时复合侵染同一株小麦,但在病细胞中二者彼此独立分布。我国WSSMV RNA有2个基因组,分子量分别为2.6×10~6和1.5×10~6,与日本小麦黄花叶病毒(WYMV)一致。 相似文献