一株产重楼皂甙内生细菌的分离与鉴定

从产自四川彭州的华重楼(Parispolyphyllavar·chinensisFranch)地下块茎中分离得到16株菌。经以薯蓣皂甙元为标准对照的薄层层析分析,表明其中编号为SNUS-1(AY842149)的菌株能分泌重楼皂甙或其类似化合物。16SrDNA序列(约1,500bp)系统发育分析表明:菌株SNUS-1与Pseudomonastolassii(AF255336)和Pseudomonastolassii(D84028)的遗传距离分别为0和0·003,在系统进化树上三者又严格聚为一族,结合形态及生理特征确定其为托氏假单孢菌(Pseudomonastolassii)。     

华重楼内生真菌聚多曲霉的促生与拮抗作用

【背景】华重楼(Paris polyphylla var. chinensis)是我国一种名贵稀缺中药材,有多种药效,由于过度采挖等原因,其野生资源现已极度匮乏。华重楼的人工栽培技术尚未成熟,生长缓慢、病害频繁发生是主要的制约因素。【目的】植物益生菌的开发是一种环保且有效的解决途径,符合生态种植的要求。【方法】通过常规方法分离鉴定内生菌,选取已报道具有促生抗病作用的菌株进行玉米种子发芽试验,无氮培养基定性检测固氮活性,平板拮抗试验检测抗菌性;高效液相色谱-质谱联用技术(Liquid Chromatography-Mass Spectrometry,LC-MS)检测其菌液的代谢成分;分光光度法检测华重楼幼苗丙二醛和叶绿素含量,LC-MS检测叶片水杨酸、茉莉酸、脱落酸、赤霉素、细胞分裂素、生长素的含量,测量华重楼地下部分生物量指标。【结果】分离得到一株菌jdqmzz-1,经rDNA ITS序列扩增比对、形态学观察、生理生化鉴定,确定为聚多曲霉(Aspergillus sydowii);其可以促进玉米种子发芽和华重楼生长,具有固氮、拮抗病原真菌尖孢镰刀菌(Fusarium oxysporum GSICC 60612)、病原细菌胡萝卜软腐果胶杆菌胡萝卜亚种(Pectobacterium carotovorum subsp. carotovorum,Pcc ATCC15713)的作用,真菌拮抗指数为42.50%,其菌液含有种类较多的促生和抑菌杀虫物质,菌液处理过的华重楼幼苗,叶片内源赤霉素和生长素含量较对照分别提高了54.1倍和2.3倍,叶绿素含量达到209.88 mg/g鲜重,较对照增加了48.80%,丙二醛含量较对照降低了15.20%;平均根数、平均根长、平均百株重较对照也有显著性(P0.01)提高。【结论】分离出的内生真菌聚多曲霉jdqmzz-1能够有效地促进华重楼的生长。     

华重楼内生菌抗菌肽的分离纯化及其特性

摘要：【目的】华重楼内生菌PCE45具有较强的抗菌活性,本文将对PCE45产生的抗菌物质进行分离纯化和性质分析报道。【方法】PCE45发酵液经硫酸铵盐析、丙酮沉淀、SephadexG75柱、DE52纤维素柱和SephadexG25凝胶柱纯化分离得到抗菌肽PCP-1。【结果】稳定性测试表明该抗菌肽对蛋白酶不敏感,对高温、强酸、强碱有较好的耐受性,可造成稻瘟病菌菌丝畸形并抑制孢子萌发。抑菌谱表明该抗菌肽对玉米弯胞病菌等真菌和大肠杆菌等细菌有较强的抑菌效果。质谱测得其分子量为1058.3D。氨基酸组成分析表明该     

一株产银杏黄酮内生真菌的初步筛选

从银杏(Ginkgo biloba L.)的根、茎、叶中共分离得到18株内生真菌,用显色反应、薄层层析(TLC)及紫外-可见分光光度法对发酵提取液进行分析并筛选得到一株产黄酮类物质的内生真菌(编号ROOT3.1),经形态学和分子生物学初步鉴定其为镰孢属黄色镰孢菌(Fusarium culmorum).对此菌株发酵液中的黄酮含量进行了测定,其含量为0.017 2 mg·mL-1.     

产薯蓣皂甙华重楼内生菌的筛选与鉴定

从华重楼(Paris polyphylla chinensis Franch)的地下块茎中分离出107株内生菌,经TLC筛选检测,菌株RZ03和RZ07可产生薯蓣皂甙。进行了形态和生理生化鉴定并将菌株的16S rDNA序列分别与用BLAST调出GenBank EMBL DDBJ中的相关序列比较,用ClustalW绘制系统发育树,RZ03与DQ019167(Exiguobac-terium acetylicum)同源性为99%,鉴定为Exiguobacterium acetylicum,RZ03、RZ07与DQ207730(Bacillus subtilis)序列同源性为99%,初步鉴定为Bacillus subtilisRZ07。     

重楼皂甙Ⅱ对狼疮性肾炎患者外周血CD4+CD25+T调节细胞表达的细胞因子的影响

目的:研究重楼皂甙Ⅱ对狼疮性肾炎患者外周血CD4+CD25+Treg分泌的细胞因子IL-10和TGF-β的影响。方法:10例健康人为正常对照组,20例LN病人随机分为四组:LN对照组(n=5)、重楼干预组1(n=5,接种细胞数为1×105/1.5ml/孔)、重楼干预组2(n=5,接种细胞数为2×105/1.5ml/孔)、重楼干预组3(n=5,接种细胞数为5×105/1.5ml/孔)。分离外周血单个核细胞,利用免疫磁珠法分离CD4+CD25+Treg。重楼干预组予重楼皂甙Ⅱ干预,正常对照组和LN对照组不予处理,各组培养72h。取各组上清,用ELISA分别检测IL-10和TGF-β的水平。结果:与正常组比较,其余各组TGF-β和IL-10的水平明显降低(P<0.01)。与LN对照组比较,重楼皂甙Ⅱ干预后各组TGF-β和IL-10的水平升高(P<0.05)。重楼干预组之间比较,重楼干预组2的TGF-β和IL-10水平较其他两组明显升高(P<0.01),而重楼干预组1和3的TGF-β和IL-10水平变化无显著性差异(P>0.05)。结论:重楼皂甙Ⅱ可上调LN患者TGF-β和IL-10的水平,上调的幅度受接种细胞数量的...     

土壤因子与华重楼生物量和药效成分含量相关性分析

为研究土壤因子对华重楼生长和药效成分积累的影响,该研究利用高效液相色谱技术(HPLC)以及相关性和多元线性回归分析方法,测定了华重楼不同产地土壤成分、样品的生物量和重楼皂苷的含量,分析了土壤因子与华重楼生物量和药效成分的相关性。结果表明:(1)不同产地土壤成分和华重楼产量及其重楼皂苷含量均有差异。(2)相关性分析显示,干重与有机质、全氮、碱解氮显著正相关,重楼皂苷Ⅰ与有机质和速效磷显著正相关,重楼皂苷Ⅱ与速效磷和速效钾显著正相关,而重楼皂苷Ⅶ与土壤各因子的相关性不显著。(3)多元线性回归分析显示,影响干重的主导因子为碱解氮,影响重楼皂苷Ⅰ的主导因子为有机质,影响重楼皂苷Ⅱ的主导因子为速效磷,而重楼皂苷Ⅱ与碱解氮呈线性负相关。综合分析认为,影响华重楼干重的土壤因子主要是碱解氮,而影响华重楼皂苷含量的土壤因子主要为有机质和速效磷,该研究结果为华重楼的人工栽培提供了理论依据。     

华重楼内生菌SS02的分离与抗菌活性的初步研究*

从华重楼(Parispolyphyllavar·ChinensisFranch)的地下块茎中分离到一株内生细菌(SS02),试验表明其发酵液对13种作物致病菌的生长有抑制作用。形态和生理生化特征表明SS02属于芽孢杆菌属(Bacillus sp·)细菌。扩增、测序得到SS02的部分16SrDNA序列,GenBank接收号AY842144。用Blastn调出与菌株16SrDNA同源的序列,用Clustalw进行多重序列对比,用Phylip按Neighbor-Joining法构建1     

产甾体皂甙华重楼内生菌的筛选与鉴定

从华重楼(Paris polyphyllavar.chinensisFranch)的地下块茎中分离筛选得到2株可能产生甾体皂甙的内生菌(SS01和SS02),薄层层析检测菌株SS01、SS02的发酵产物分别有3条和2条层析带与重楼总皂甙的层析带迁移率相当。形态和生理生化特征初步表明SS01和SS02分属于肠杆菌科(Enterobacteriaceae)和芽孢杆菌属(Bacillussp.)细菌。扩增、测序得到SS01和SS02的部分16S rDNA序列,GenBank接收号分别为AY842143和AY842144。用Blastn调出与菌株16SrDNA同源的序列,用Clustal W进行多重序列对比,用软件Phylip按Neighbor-Joining方法构建16SrDNA系统发育树。菌株SS01和SS02分别与Cedecea davisae DSM4568、Paenibacillus daejeonensis处于同一分支,相似性分别为98.9%和97.7%,将它们鉴定为Cedecea davisae SS01和Paenibacillus daejeonensis SS02。     

一株具有抗疟活性的金鸡纳树内生真菌的研究

为筛选具抗疟疾活性的的内生真菌,采用平板分离法对海南金鸡那树内生真菌进行分离纯化。利用"4日抑制疟疾"测试内生真菌发酵液的抗疟活性,采用TLC、HPLC等分析技术对内生菌发酵液等成分进行分析。从金鸡那树叶片分离到31种内生真菌,通过筛选找到了1株具有抗疟疾活性的产奎宁或奎宁类似物的内生真菌。从金鸡那树叶片中分离得到1株产奎宁的结实串孢霉属内生真菌,为奎宁的资源开发开辟了新途径。     

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.     

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     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).