一种快速提取大质粒的方法

本文介绍一种快速提取大质粒的方法。应用该方法,对含有pTA1,R68.45,RP(?)Tn501,pUB307,RP_4,pJRD215和pTr30质粒的多能硫杆菌(Thiabacillus versius)、氧化硫硫杆菌(Thiobacillus thiooxidans)和大肠杆菌(Escherichia coli)进行了质粒提取。结果表明,该方法提取的质粒条带清晰,分辨率高,而且重复性好。     

菌根真菌一新种一石斛小菇

从云南省野生铁皮石斛(Dendrobium candidum wall. Ex Lindl.)根中分离出一菌根真菌,经系统形态学研究后,将其鉴定为小菇属(Mycena)一新种：石斛小菇(Mycenadendrobii)。标本保藏在中国科学院微生物研究所菌物标本室(HMAS)。用石斛小菇伴播12种兰科植物种子,实验结果表明该真菌对天麻(Gastrodia elata)和密花石斛(Dendrobum densiflorum)种子萌发有明显促进作用。     

福建锈菌初步名录

本文报告福建省的锈菌29属150种,它们包括无柄锈科(MeLampsoraceae)11属36种,柄锈科(Pucciniaceae)15属98种以及半知锈(Uredinales Imperfecti)3属16种;其中无柄锈科的拟夏孢锈属(Uredinopsis)、明痂锈属(Hyalopsora)、膨痂锈属(Puccini-astrum)、栅锈属(Melampsora)、赭痂锈属(Ochropsora)、两型锈属(Pucciniostele)和柱锈属(Cronartium),柄锈科的不眠多胞锈属(Kuehneola)、不休白双胞锈属(Leucotelium)、戟孢锈属(Hamaspora)、多胞锈属(Phragmidium)、伞锈属(Ravenelia)、不眠单胞锈属(Maravalia)和鞘柄锈属(Coleopuccinia)以及半知锈的夏孢锈属(Uredo)在福建首次发现。文中对每个种列出学名、寄主、采集地及标本号。某些种附加了讨论。所有标本保藏在中国科学院微生物研究所真菌标本室。     

核酸酶BN及SN基因的克隆和序列分析

分别从解淀粉芽孢杆菌(Bacillus amyloliquefaciens)和金黄色葡萄球菌(Staphylococcus aurcus)中提取染色体DNA,经HindⅢ酶解后PCR扩增获得Barnase(核酸酶BN)基因和Staphylococcal Nuclease(核酸酶SN)基因,并克隆到质粒pGEMTZ-f(+)上。序列分析表明,核酸酶BN的核苷酸序列与已发表的序列有99.3%的同源性,而与据此推测的氨基酸序列完全一致。核酸酶SN基因的核苷酸序列与已发表     

芽孢杆菌原生质体作为质粒DNA转化的受体

枯草芽孢杆菌(Bacillus subtilis) B3F 7658,短小芽孢杆菌(B. pumilus) AS 1.940,巨大芽孢杆菌(B．Megaterium) AS 1.941,和多粘芽孢杆菌(B. polymyxa) AS 1.878等菌株,既不能作为染色体DNA的转化受体,也不能作为质粒DNA的转化受体。用不同量的溶菌酶处理这些菌株形成原生质体,然后加pUB110质粒DNA,经聚乙二醇6000(PEG)诱导,在含新霉素(400μg／ml)的DM-3再生培养基上恢复细胞壁,培养48小时后,转化子数为1.0 x 103一4.6×105／μg DNA。若同时用PEG和Ca2+ 离子诱导,转化子数可提高2—3倍。质粒pUBll0用EcoRI酶切后,转化子数大大下降(2.0×102转化子／μg DNA)。Eco RI酶切后,用T4连接酶连成环状,转化子数有所增加(1．7×103转化子／μg DNA)。     

抑菌试验用于测定T-2毒素

本文从镰刀菌中提取T-2毒素,对不同的酵母菌进行抑菌试验,结果证明红酵母属(Rho-dotorula)的三个种,即红酵母(R.glutrnis)、深红酵母(R.ruber)和小红酵母(R.minuta)对T-2毒素最敏感,被定为测毒敏感菌。将抑菌试验与家兔皮肤反应试验、豌豆发芽抑制试验进行对比,结果有部分重合,但不能相互取代。由于抑菌试验具有快速、简便、准确的优点,可做为测定T-2毒素的方法之一。     

克鲁斯假丝酵母及其近似种的脉冲电泳核型分析

用钳位均匀电场脉冲电泳(CHEF)系统分析了克鲁斯假丝酵母(Candida krusei),郎比可假丝酵母(C. lambica)和粗状假丝酵母(C. valiad)的模式菌株的电泳核型,发现这三种表型相似的假丝酵母却具有互不相同的染色体DNA分子带型,为其分类学研究提供了可靠的鉴别依据。在常规分类学研究的基础上,测定了AS 2.75(原定种名为(C. incospicua),AS2.1182(原定种名为 C. lambica)和AS 2.1772(未定种)等三株假丝酵母的G+C含量和脉冲电泳核型。通过对已报道的C. inconspicu的G+C含量及上述三种假丝酵母模式菌株的脉冲电泳核型的比较分析证明,AS 2.75和AS 2.1772为粗状假丝酵母(C. valida),AS 2.1182为克鲁斯假丝酵母(C. krusei)。     

我国13种天南星科作物上的芋花叶病毒

用直接负染和免疫电镜方法从我国浙江省(杭州、奉化、温州等地)、上海、北京、福建、湖南等地的13种天南星科大田作物:芋(Colocasia esadenta)、魔芋(Amorphophallus sinesis)、药用植物:半夏(Pinellia ternata)、掌叶半夏(P. cordata)、盾叶半夏(P. pedatisecta)以及观赏植物:马蹄莲(Zantedeschia aethiopica)、海芋(Alocasia macrorrhiza)、象耳芋(Colocasia gigantea)、台果芋(Syngonium podophygum)、黄金葛(Scindapsus aureus)、广东万年青(Aglaonema modestum)、花叶芋(Caladium bicolar)、剑叶喜林芋(Philodendium oxycadium)上均检测到芋花叶病毒(Dasheen mosaicvirus, DMV)。在免疫吸附-免疫修饰电镜水平上,该病毒与DMV抗血清和PVY抗血清均有强阳性反应。在人工接种条件下,DMV各分离物均不侵染烟草等非天南星科供试植物,但接种天南星科指示植物Philodendr…     

降解直链烷基苯磺酸钠真菌的分离鉴定及其降解特性

从直链烷基苯磺酸钠(LAS)污染土壤中分离到12株能降解LAS的真菌。经鉴定,它们分属于青霉属(Prnicillium)、曲霉属(Aspergillus)、帚霉属(Scopulariopsis)和头孢霉属(Cephalosporium)。研究了Aspergillus f-11降解LAS酶活诱导生成的条件及降解LAS的特点。还利用液相色谱对真菌和细菌降解LAS的产物进行了比较。     

贵州灵芝科III．

本文继续报道贵州灵芝科(Ganodermataceae)3种,其中灵芝属(Ganoderma Karst.)2种,即新种镇宁灵芝(Ganoderma zhenningense He)和热带灵芝(Ganoderma troplcum(Jungh．)Bres．);网孢芝属(Humphreya Steyaert)1种,即咖啡网孢芝[Humphreya coffe-atum (Berk.)Steyaert]。以上引证标本全部保藏在贵州科学院生物研究所真菌标本室。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.