松乳菇Lactarius deliciosus与红汁乳菇L. hatsudake子实体内可培养细菌多样性的研究

分离松乳菇Lactarius deliciosus与红汁乳菇L.hatsudake子实体内可培养的细菌,进行分类鉴定,为后期细菌与乳菇的相互作用研究奠定基础。利用传统平板法分离培养乳菇子实体内的细菌,进行16S r DNA片段的扩增和测序及系统发育树的构建和物种多样性分析。从松乳菇中获得66株细菌,红汁乳菇中获得48株细菌。松乳菇子实体内细菌隶属于3个门6个属10个种,其中变形菌门的γ-变型菌纲为优势类群,占细菌总数的77.28%,β-变形菌纲的Pandoraea和拟杆菌门的金黄杆菌属Chryseobacterium分别占细菌总数的12.12%和10.6%。红汁乳菇子实体内共分离、鉴定出细菌3个门7个属7个种,其中变形菌门中的γ-变型菌纲为优势类群,占细菌总数的77.09%,厚壁菌门的芽胞杆菌属Bacillus和拟杆菌门的金黄杆菌属Chryseobacterium分别占细菌总数的14.58%和8.33%。松乳菇与红汁乳菇子实体内存在一定种类和数量的细菌,其中荧光假单胞菌Psedomonas fluorescens和美洲爱文氏菌Ewingella americana为优势细菌。     

印度块菌-云南松菌根际土壤细菌的种群组成和群落结构

以印度块菌-云南松菌根际土壤细菌为研究对象,研究其种群组成和结构特征。(1)稀释平板法分离得到印度块菌-云南松菌根际土壤细菌的纯培养菌株,对菌株的16S rRNA序列测序分析,对测序的菌株数量和得到的OTUs数量绘制物种累积曲线,当物种累积曲线趋于平缓时,对OTUs进行系统发育分析,揭示可培养细菌的种群组成和结构特征。(2)对印度块菌-云南松菌根际土壤细菌16S rRNA基因的V3—V4区进行高通量测序,分析全部细菌类群的种群组成和结构特征。(1)分离得到菌根际可培养细菌793株,分属于3个属的61个OTUs,其中假单胞菌属(Pseudomonas)序列占总序列的86%,不动杆菌属(Acinetobacter)序列占总序列的9.8%,链霉菌属(Streptomyces)序列占总序列的6.5%。假单胞菌是印度块菌-云南松菌根际土壤可培养细菌的绝对优势类群。(2)高通量测序得到菌根际细菌序列8937条,分属于20个门、198属、2073个OTUs。隶属于变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和酸杆菌门(Acidobacteria)的OTUs占总OTUs的65.9%,变形菌门、放线菌门和酸杆菌门细菌是印度块菌-云南松菌根际土壤细菌的优势细菌。隶属于黄杆菌属(Flavobacterium)、根瘤菌属(Rhizobium)和假黄色单胞菌属(Pseudoxanthomona)的OTUs占总OTUs的33%,黄杆菌属、根瘤菌属和假黄色单胞菌属细菌是印度块菌-云南松菌根际土壤细菌的优势属。印度块菌-云南松菌根际土壤可培养细菌多样性较低,假单胞菌属细菌占据绝对优势地位。印度块菌-云南松菌根际土壤细菌类群具有较高的多样性,物种种类丰富,优势菌群集中。     

泥浸汁对太湖沉积物中的好氧可培养细菌多样性的影响

【目的】研究添加泥浸汁与否对太湖沉积物中可培养细菌的影响。【方法】采用R2A培养基和添加泥浸汁R2A培养基对沉积物中细菌进行分离培养,16S r RNA基因系统发育分析比较种群结构。【结果】培养基中添加泥浸汁,可使可培养细菌的种类数量增加到1.6倍。16S r RNA基因序列分析表明,培养的优势细菌类群存在明显差别。R2A培养基上生长的细菌主要为厚壁菌门(52%)、放线菌门(24%)、变形菌门(20%)和拟杆菌门(4%),其中大部分细菌与芽孢杆菌属、假单胞菌属、节杆菌属等关系密切;而添加泥浸汁的R2A培养基上生长的细菌则主要为变形菌门(40%)、放线菌门(35%)、厚壁菌门(22.5%)和拟杆菌门(2.5%),与鞘脂单胞菌属、芽孢杆菌属、副球菌属、节杆菌属等关系密切。【结论】添加泥浸汁原始营养因子可提高沉积物中可培养细菌的多样性,提高菌种可培养效率。     

伊犁河流域春季可培养细菌多样性及其胞外酶检测

利用可培养法对新疆伊犁河流域水体和沉积物中细菌多样性进行分析，以期初步阐明流域河流可培养细菌群落结构。采用5种琼脂培养基分离纯化可培养细菌，依据其16S rRNA基因序列进行系统发育分析，并运用平板法对纯化菌株的胞外酶产生情况进行检测。序列分析结果表明，225株细菌分别属于变形菌门γ亚群(Gamma-pseudomonadota, 56.44%)、放线菌门(Actinomycetota, 18.22%)、厚壁菌门(Firmicutes, 14.22%)、变形菌门α亚群(Alpha-pseudomonadota, 4.89%)、变形菌门β亚群(Beta-pseudomonadota, 4%)、拟杆菌门(Bacteroidota, 0.44%)和异常球菌-栖热菌门(Deinococcota, 0.44%)等7个大的系统发育类群，41个属84个种。其中假单胞菌属(Pseudomonas,42.22%)、不动杆菌属(Acinetobacter,9.33%)和芽胞杆菌属(Bacillus,9.33%)为优势菌属。菌种分布结果显示，伊犁河流域主要支流和干流中可培养细菌地域分布性强。分离菌株产胞外酶...     

杭州市西湖景区春季空气细菌多样性特征

选取了杭州市西湖景区4个典型样点,利用高通量测序方法研究了其空气细菌多样性特征。结果表明,在细菌门水平上,各样点优势细菌为变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes),其总相对含量在断桥残雪(MSBB)、柳浪闻莺(OSW)、宝石流霞(PSHFRC)和三潭印月(TPMM)分别为88.31%、86.03%、85.06%和89.28%,且不同样点优势菌群存在一定的差异,OSW和TPMM厚壁菌门分别占9.65%和11.6%,拟杆菌门分别占6.86%和5.55%,MSBB和PSHFRC拟杆菌门分别占7.31%和7.86%,厚壁菌门分别占7.09%和5.32%。在细菌属水平上,各样点优势菌属及含量差异显著,MSBB、TPMM、OSW和PSHFRC相对含量最高的菌属分别为马赛菌属(Massilia)、两面神菌属(Janibacter)、鞘氨醇单胞菌属(Sphingomonas)和甲基杆菌属(Methylobacterium),分别占6.22%、6.45%、6.05%和11.5%,各样点相对含量高于2%的细菌属有鞘氨醇单胞菌属、甲基杆菌属、薄层菌属(Hymenobacter)和异常球菌属(Deinococcus),这些菌属是西湖景区各样点共有的优势菌群;通过空气细菌OTU及多样性分析可知,MSBB空气细菌丰富度较高,均匀度较低,而PSHFRC丰富度较低,均匀度较高。杭州西湖景区不同样点空气细菌群落特征差异显著,且其丰富度和均匀度明显不同。     

冷箭竹根际土壤中可培养细菌的多样性

为了解冷箭竹(Bashania fangiana)根际土壤中可培养细菌的多样性,2006年5月从四川卧龙自然保护区冷箭竹根际土壤中共分离出50株具不同菌落形态的细菌.16S rDNA序列分析结果表明:50株菌分属于10个属26个种.27株属于变形菌门γ亚群(Gammaproteobaeteria)(42.3%)、9株属于厚壁菌门(Firmicutes)(26.9%)、4株属于放线菌门(Actinobacteria)(15.4%)、6株属于变形菌门β亚群(Betaproteobacteria)(7.7%)、3株属于变形菌门α亚群(Alphaproteobacteria)(3.9%),1株与土地杆菌属(Pedobacter)关系密切.假单胞菌属(Pseudomonas)和芽孢杆菌属(Bacillus)为优势菌属.2株菌为可能的新种或属.研究表明冷箭竹根际土壤中含有较为丰富的微生物多样性.     

降雨对秦皇岛西浴场细菌总数和可培养菌群组成的影响

【目的】研究降雨条件对浴场细菌总数和优势菌群组成的影响。【方法】2014年8月强降雨前后采集秦皇岛西浴场3个站位的海水样品,采用荧光显微镜计数法和平板计数法分别对细菌总数和可培养细菌总数进行计数;对群落结构组成进行分析,并对可培养细菌进行鉴定。【结果】雨前3个站位细菌总数和可培养细菌总数平均值分别为5.6×10~9 CFU/L和8.3×10~7 CFU/L,雨后分别为9.2×109 CFU/L和2.1×10~8 CFU/L。在可培养菌群中,变形菌门(Proteobacteria,雨前占80%,雨后占73%)是主要的微生物类群,其次为拟杆菌门(Bacteroides,雨前占12%,雨后占13%)、厚壁菌门(Firmicutes,雨前占7%,雨后占11%)等;肠杆菌属(Enterobacter spp.,21株)、海杆菌属(Marinobacter spp.,13株)、弓形菌属(Arcobacter spp.,13株)、假单胞菌属(Pseudomonas spp.,10株)、芽孢杆菌属(Bacillus spp.,10株)和弧菌属(Vibrio spp.,6株)为雨前可培养细菌优势属,而雨后可培养细菌优势属为肠杆菌属(22株)、海杆菌属(21株)、芽孢杆菌属(14株)、不动杆菌属(Acinetobacter spp.,11株)、假单胞菌属(9株)和弓形菌属(5株)等。【结论】降雨对细菌总数有显著的影响,同时降雨后浴场微生物群落结构发生了改变。     

南极中山站长城站土壤及海洋沉积物可培养细菌多样性

南极地区具有气候酷寒干燥、强紫外(UV)辐射和季节性光照与温度波动等恶劣的极端环境条件,孕育了大量微生物资源和潜在新物种。为了挖掘南极不同生境样品蕴含的微生物菌种资源,更好地认识和探索南极地区微生物资源多样性,利用低温寡营养富集结合梯度稀释涂布的方法,对南极长城站、中山站土壤和近海表层沉积物3个生境的样品进行细菌分离和16S rRNA基因序列相似性分析以确定南极细菌分类学地位。结果表明,共获得482株纯培养细菌,有54个属,142个种,分布于变形菌门(Proteobacteria,42%),放线菌门(Actinobacteria,40%),厚壁菌门(Firmicutes,12%),拟杆菌门(Bacteroidetes,4%)和异常球菌-栖热菌门(Deinococcus-Thermus,1%)。优势属为嗜冷杆菌属(Psychrobacter,12%)、假单胞属(Pseudomonas,10%)和节杆菌属(Arthrobacter,9%)。不同生境样品中纯培养细菌多样性存在较大差异。中山站干燥土壤样品中放线菌门比例明显高于变形菌门,有13个特有属,嗜冷杆菌属(Psychrobacter)、红球菌属(Rhodococcus)为优势菌;长城站近岸砂土样品中变形菌门菌株最多,拟杆菌门比例高于中山站样品,有高比例的假单胞菌,分离到12个特有属;近海沉积物样品细菌群落结构最简单,分离到9个特有属。经16S rRNA基因序列对比发现,有7株菌为潜在新种。     

春兰根中可分泌吲哚乙酸的内生细菌多样性

植物内生细菌可通过分泌吲哚乙酸(Indole-3-aceticacid,IAA)等方式促进植物生长。本研究以温室盆栽春兰(Cymbidium goeringii)为材料,采用分离培养方法对春兰根中可分泌IAA的内生细菌多样性进行了研究。从春兰根组织中共分离纯化得到了256株内生细菌,其中57株具有分泌IAA的能力,占总菌数的22.3%。根据ARDRA(amplified ribosomal DNA restriction analysis)及16SrDNA系统发育分析结果,将57株内生细菌划分为25个组,分属于6大类群,分别为变形菌门的α-变形菌纲(35.1%)、γ-变形菌纲(14.0%)和β-变形菌纲(8.8%)、厚壁菌门(33.3%)、放线菌门(7.0%)及拟杆菌门(1.8%)。其中变形菌门的α-变形菌纲和厚壁菌门为优势类群,类芽孢杆菌属(Paenibacillus)为优势菌属,且为高产IAA的主体菌属。另外,测序结果显示有4个菌株的序列与已知细菌的最高序列相似性低于97.0%,可能为潜在的新种或新属。研究结果表明春兰根中分泌IAA的内生细菌具有丰富的多样性。这一结果可为研究和开发植物促生细菌提供基础资料...     

圈养大熊猫粪便中微生物多样性的研究

本试验采集了5只圈养成年大熊猫的新鲜粪便,用高通量测序技术,研究了大熊猫粪便中细菌和古菌的结构和组成。试验结果表明:圈养成年大熊猫粪便细菌主要由变形菌门Proteobacteria(74.45%)、厚壁菌门Firmicutes(15.66%)、拟杆菌门Bacteroidetes(4.34%)、蓝藻门Cyanophyta/色球藻纲Chroococcophyceae(4.01%)等组成,其中变形菌门主要以埃希氏杆菌属Esherichia/志贺氏菌属Shigella(49.84%)为主;厚壁菌门主要以梭菌属Clostridium(4.65%)为主;拟杆菌门主要以稳杆菌属Empedobacter(3.51%)为主;蓝藻门全部为未分类的色球藻纲(4.01%)。古菌主要由泉古菌门Crenarchaeota(55.99%)和广古菌门Euryarchaeota(42.33%)组成,其中优势古菌是热变形菌纲Thermoprotei(55.99%)中未分类的属和产甲烷菌属Methanogenium(24.70%)。     

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.     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.