芹菜夜蛾NPV离体复制的研究

芹菜夜蛾ＮＰＶ能够在小菜蛾细胞系中有效地复制增殖。受感染细胞呈典型细胞病理变化。病毒在细胞核中复制装配,病毒感染率为８５％,多角体产量为５８８×１０^６ＰＩＢｓ／ｍｌ。病毒增殖动力学显示,病毒感染细胞７２ｈ,胞外病毒达最大滴度,ＴＣＩＤ_５０值为１．９×１０^８ＴＣＩＤ５０／ｍｌ。     

电脉冲法转化苏云金芽孢杆菌BMB171的研究

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（ＯＤ_６５０ｎｍ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     

嗜热脂肪芽孢杆菌质粒DNA的高压电穿孔转化研究*

采用高压电穿孔法将穿梭质粒导入了嗜热脂肪芽胞杆菌（Ｂａｃｉｌｌｕｓ　ｓｔｅａｒｏｔｈｅｒｍｏｐｈｉｌｕｓ）Ｋ１０４１和Ｔ５２１菌株。以对数生长后期的菌体制备Ｋ１０４１转化细胞,以ＬＢ平板上于５０℃培养的过夜菌制备Ｔ５２１转化细胞,细胞密度为５～７×１０^９细胞／ｍＬ。电击条件如下：电容２５μＦ,电场强度１０．０ＫＶ／ｃｍ,脉冲控制器设定２００。 Ｋ１０４１和 Ｔ５２１最高转化效率分别达２．０１×１０⁴和１．１９ ×１０²转化子／     

高活性反硝化颗粒污泥的研究

以上流式厌氧污泥床（ＵＡＳＢ）反应器中的反硝化颗粒污泥为样品,研究了颗粒污泥的基本特性。测定出颗粒污泥中的优势无机元素为Ｃａ、Ｐ．颗粒表面以球菌和短杆菌为主。反硝化菌是颗拉中的优势菌群,数量可达６．５ｘ１０^８－１．５ｘ１０^１０个／ｍｌ颗粒污泥。初步鉴定了两株脱氮菌Ｍｉｃｒｏｃｏｃｃｕｓｓｐ．ｓｔｒａｉｎＮ_１和ＰｓｅｕｄｏｍｏｎａｓａｅｒｕｇｉｎｏｓａｓｔｒａｉｎＮ_２．     

一株产虾青素的黄杆菌CF-60的研究

从土壤中分离到一株黄杆菌（Ｆｌａｖｏｂａｃｔｅｒｉｕｍｓｐｐ）Ｃ_Ｆ－６０,该菌的生长需Ｍｇ^２＋存在,ＭｇＳＯ_４·７Ｈ_２Ｏ的最适浓度为０．２％;蛋白胨是该菌株生长的最好氮源,它不能利用无机氮。种龄超过９６ｈ的菌体不能在新鲜培养基中生长。经５４ｈ的２Ｌ恒化器发酵,生物量达６．８ｇ／Ｌ,色素产量为１０．６ｍｇ／Ｌ。该菌产生的类胡萝卜素成分简单,主要成分的含量为９０．３％,该成分经初步鉴定是分子结构中含有羰基和羟     

柏毛虫核型多角体病毒的分离及应用后效观察

从柏毛虫（ＤｅｎｄｒｏｌｉｍｕｓｓｕｆｆｕｓｃｕｓＬａｊｏｎｑｕｉｅｒｅ）幼虫尸中分离到一株核型多角体病毒,其多角体平面图像为三、四边形和近圆形,直径１．２－２．５μｍ,病毒粒子杆状,大小约７５×５２０ｎｍ。室内试验表明此株病毒对三龄寄主幼虫的ＬＣ_５０为５１８８个多角体／ｍｌ。野外防治效果可达８０％以上,好于化学农药甲基１６０５和辛硫磷等,并有持久的后效作用。该病毒对经济昆虫家蚕、柞蚕和天敌昆虫七星瓢虫无致病作用。     

少动鞘脂单胞菌S1胞外多糖发酵工艺条件研究

研究了摇瓶培养条件下少动鞘脂单胞菌引的胞外多糖的发酵工艺。Ｓ１菌的发酵产胶可采用二步发酵法：第一阶段,培养基成分为：蔗糖１０ｇ,ＮＨ_４ＮＯ_３　０．５ｇ,ＫＨ_２ＯＰ_４　０．５ｇ,ＭｎＳＯ_４　０．３ｇ,ＭｇＳＯ_４　０．１ｇ,吐温８０ ０．０２ｇ溶于蒸馏水并定容至１０００ｍＬ,ｐＨ７．２±０．１,温度３３℃～３５℃,高溶氧。第二阶段,发酵 １０～１２ｈ后,补加蔗糖４０ｇ／Ｌ,温度     

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

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     

芽孢杆菌M_(50)产生β甘露聚糖酶的条件研究

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。Ｆｅ^３＋ 、Ａｌ^３＋ 、ＥＤＴＡ、Ｈｇ^２＋ 对酶有抑制作用,而Ｂａ^２＋ 、Ｍｎ^２＋ 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。     

N+离子注入热带假丝酵母对长链二元酸产量的影响*

用热带假丝酵母（Ｃａｎｄｉｄａ ｔｒｏｐｉｃａｌｉｓ）ＳＣＢ４１２作为出发菌株,经能量５０ＫｅＶ、剂量１× １０^１１～５ ×１０^１５ ｉｏｎｓ／ｃｍ^２的Ｎ^＋离子注入诱变处理,以产生可遗传的诱变。 Ｎ^＋离子注入后,存活率与剂量呈指数衰减关系：ｌｏｇ（存活率％）＝ ８．２３－ ０．６０４ × ｌｏｇ（剂量）,在培养过程中可观察到酵母菌菌落和细胞形态均发生了变化。经筛选,获得了一株能够利用     

广东省烟草花叶病病原病毒的鉴定

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)。     

Influenza Hemagglutinin and Neuraminidase Membrane Glycoproteins

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.     

Construction of an infectious cDNA clone of Tembusu virus isolated from breeder Peking ducks

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,     

Towards a coherent nomenclature of plant viruses

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-     

芝麻病毒病病原研究——Ⅰ.芝麻矮化坏死病害的鉴定

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。     

Epidemiologic interference of virus populations

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     

Occurrence and distribution of viruses infecting potato in Russia

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.     

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

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。