60Co辐射诱变对巴氏蘑菇(姬松茸)子实体多糖组分与结构变化的影响

巴氏蘑菇(姬松茸)原菌株J1和辐射突变株J3子实体粗多糖经水提、醇沉、Sevage法去除蛋白,透析得精多糖ABJ-1和ABJ-3;经紫外扫描和凝胶色谱法检测表明,ABJ-1和ABJ-3均具有较高的纯度。以苯酚-硫酸法测得了ABJ-1和ABJ-3的糖含量分别为47%和76.68%,凯氏定氮法测定其含氮量分别为5.77%和21%。,以凝胶过滤法测定了其分子量均在4万左右。完全酸水解后气相色谱分析显示ABJ-1含有甘露糖、葡萄糖、半乳糖等单糖,ABJ-3含有大量的甘露糖及少量的葡萄糖等单糖。红外光谱和Smith降解后气相色谱分析显示ABJ-1和ABJ-3糖基连接键均以a,1-4糖苷键为主。     

60Co辐射诱变对巴氏蘑菇(姬松茸)子实体多糖组分与结构变化的影响

巴氏蘑菇(姬松茸)原菌株J1和辐射突变株J3子实体粗多糖经水提、醇沉、Sevage法去除蛋白,透析得精多糖ABJ-1和ABJ-3;经紫外扫描和凝胶色谱法检测表明,ABJ-1和ABJ-3均具有较高的纯度。以苯酚-硫酸法测得了ABJ-1和ABJ-3的糖含量分别为47%和76.68%,凯氏定氮法测定其含氮量分别为5.77%和21%。,以凝胶过滤法测定了其分子量均在4万左右。完全酸水解后气相色谱分析显示ABJ-1含有甘露糖、葡萄糖、半乳糖等单糖,ABJ-3含有大量的甘露糖及少量的葡萄糖等单糖。红外光谱和Smith降解后气相色谱分析显示ABJ-1和ABJ-3糖基连接键均以a,1-4糖苷键为主。     

两种灵芝孢子粉多糖的分离纯化和结构

本文采用水提醇沉法从灵芝孢子粉中提取其粗多糖,经Sepharose CL-6B凝胶柱层析分离得两种主要成分LBPI和LBPII,经高效液相色谱鉴定,均为高均一性成分,分子量分别为9.17×10 ⁴和1.86×10 ⁴;经酸水解、乙酰化和气相色谱分析,确定LBPI的单糖组成为甘露糖、半乳糖和葡萄糖,LBPII的单糖组成为鼠李糖、甘露糖、半乳糖和葡萄糖;通过高碘酸氧化、甲基化和GC-MS进行结构分析,确定LBPI中葡萄糖残基连接方式为1→、1→4,6和1→3,6连接,半乳糖残基为1→6连接,甘露糖残基为1→3,6连接,LBPII中鼠李糖残基连接方式为1→连接,葡萄糖残基为1→、1→4、1→6、1→4,6和1→3,6连接,半乳糖残基为1→6连接,甘露糖残基为1→2,3,6连接。综上,两种多糖LBPI和LBPII均为多分支的中型杂多糖,但两者的单糖组成和连接方式存在差异,这两种多糖成分均为首次报道,可望为灵芝孢子粉的成分、活性研究和资源开发提供理论依据。     

猪肚菇多糖WPG1的相对分子质量测定及原子力显微镜观测

热水提取猪肚菇粗多糖中的酸性多糖WPG1,经凝胶纯化后用高效液相色谱（HPLC）测定其相对分子质量,用气相色谱对其单糖组成进行分析,用原子力显微镜（AFM）对其形态结构进行观测。结果表明：酸性多糖WPG1经SephacrylS-300凝胶层析纯化后得到WPG1-1和WPG1-2这2个组分; 经HPLC分析可知WPG1-1与WPG1-2均为单一组分,其相对分子质量分别为1.7×106和1.6×104; WPG1-1与WPG1-2的单糖组成主要是糖醛酸、甘露糖、葡萄糖和半乳糖; 原子力显微镜观测图分析表明WPG1-1为网链状聚集体结构,WPG1-2呈梭状聚集体,两者均非单链存在。     

当归多糖的分离、纯化及单糖成分分析

选取当归为原料,采用水提醇沉法进行多糖提取,经Savage法结合木瓜蛋白酶法脱蛋白,H2O2脱色,透析,DEAE-52纤维素柱分离得到5个级分。经紫外光谱法与葡聚糖凝胶-100(SephadexG-100)凝胶柱层析法鉴定5种成分均为单一成分;通过红外光谱法、薄层色谱法、气相色谱-质谱联用(GC-MS)法分析该五种成分,5级多糖成分均为果胶类多糖;WASP-1可能是吡喃环当归多糖复合物;WASP-2为β-型吡喃环当归多糖复合物;WASP-3既是β-型吡喃环当归多糖复合物,又是α-型D-吡喃环当归多糖复合物;WASP-4为吡喃环当归多糖复合物;WASP-5为β-型当归多糖复合物,可能含有吡喃环;经GC-MS鉴定,WASP-1、WASP-2及WASP-3中单糖组成为山梨糖、阿拉伯糖、葡萄糖、半乳糖;WASP-4中单糖组成为葡萄糖与半乳糖;WASP-5中仅含葡萄糖。     

夏枯草多糖的分离、纯化及结构初步分析

采用100℃热水提取,得到夏枯草粗多糖。经阴离子交换柱层析、凝胶过滤柱层析对粗多糖进行纯化分级,通过高效凝胶过滤色谱测得了其主要组分PLS3的重均分子量为8.3×10-5Da。对PLS3进行了红外分析,测定了其初步结构;并分别以气相色谱和柱前衍生化高效液相色谱法测定了粗多糖和PLS3的单糖组成,发现两者所含单糖种类一致,都为半乳糖、葡萄糖、甘露糖、木糖、阿拉伯糖、鼠李糖,但两种物质的单糖组成相对摩尔百分比有所差异。     

宁夏中宁地区灵武长枣果实多糖的单糖成分GC-MS分析

研究宁夏中宁地区灵武长枣果实多糖的单糖成分,为不同地区灵武长枣的开发利用提供试验依据。以不同发育时期中宁产灵武长枣果实为试验材料,采用热水浸提法和气相色谱-质谱联用法(GC-MS)等,探讨不同发育时期果实多糖含量变化规律及其单糖组成成分。结果表明,不同发育时期中宁产灵武长枣果实粗多糖得率分别为:膨大前期0.43%、快速膨大期0.527%、着色期0.80%和完熟期0.618%;果实粗多糖经DEAE-52均得到Ju-0、Ju-1、Ju-2、Ju-3 4个多糖级分,其中Ju-2含量为最高,表明果实多糖的主要形式为酸性多糖;不同发育时期果实各精制多糖总共含有阿拉伯糖、鼠李糖、核糖、岩藻糖、木糖、甘露糖、半乳糖、葡萄糖、葡萄糖醛酸、半乳糖醛酸10种单糖,不含果糖,以阿拉伯糖、半乳糖、核糖、鼠李糖、糖醛酸含量较高,岩藻糖、葡萄糖含量次之,木糖、甘露糖含量较低,但其含量各组分有差异。精制多糖含量随着果实的发育进程总体呈现上升趋势;不同发育时期中宁产灵武长枣果实各精制多糖中单糖组成及含量各不相同。     

金樱子多糖单糖组成的TMS柱前衍生化/GC-MS研究

探讨金樱子多糖的含量及其单糖组成,为金樱子质量评价及临床用药提供参考依据。本文采用水提-醇沉法获得金樱子多糖,以葡萄糖为标准品,蒽酮-硫酸比色法测定多糖含量;多糖酸解后经三甲基硅烷(TMS)衍生化,以标准品单糖为对照,采用气-质联用法(GC-MS)测定多糖的单糖组成。结果表明,本实验条件下,测得金樱子多糖提取得率为29.38%;金樱子多糖中单糖由阿拉伯糖、鼠李糖、木糖、甘露糖、半乳糖、葡萄糖、果糖组成,其中葡萄糖、甘露糖、果糖和半乳糖在金樱子多糖中占比较大,分别为65.03%、7.36%、16.11%及8.87%。     

两个赤芝子实体多糖的理化特性分析及结构鉴定

赤芝子实体多糖P32A分子量为506,322,P32B分子量为287,389,两种多糖均以己糖为主构成。P32A由鼠李糖、木糖、甘露糖和葡萄糖组成,四种单糖的摩尔比为：4．3：2．6：6．3：11．4;P32B亦由鼠李糖、木糖、甘露糖和葡萄糖组成,摩尔比为：1．2：1．0：2．1：9．2。该结果显示,P32A与P32B具有较类似的糖组成,且都以葡萄糖和甘露糖为主要单糖组分。根据^13C NMR和甲基化的结果分析知P32A可能含有l→4连接的葡萄糖构成的主链,非还原末端均由葡萄糖构成,此外P32A中还有l,4-连接的甘露糖和l,3—连接的鼠李糖。P32B可能以l→3连接形成主链,部分l,3-连接葡萄糖的6位有分支,该多糖也含有由葡萄糖构成的非还原末端,与P32A类似,P32B中还含有l,4-连接的甘露糖,不同的是不含l,3—连接的鼠李糖。     

画眉草多糖提取及其保湿性能研究

本文以脱脂画眉草为原料,用纤维素酶超声辅助法提取多糖;经脱蛋白、脱色、DEAE-纤维素分离纯化,得到3种多糖TPS1、TPS2、TPS3,提取率分别为0.42％、0.66％、0.54％.通过高效凝胶渗透色谱(HPGPC)分析,3种多糖的分子量分别为7886 Da、8467 Da、6366 Da;高效离子色谱(HPIC)测得TPS1组成单糖为果糖,TPS2、TPS3组成单糖为阿拉伯糖、半乳糖、葡萄糖、木糖、甘露糖、果糖、核糖和一种未知糖.对多糖TPS2的保湿和吸湿性研究结果表明TPS2的保湿和吸湿能力均优于常用保湿剂甘油、聚乙二醇400、1,3-丁二醇、壳聚糖.     

水稻条斑病细菌hrp基因诱导表达系统的建立

水稻条斑病细菌(Xanthomonas oryzae pv.oryzicola,Xooc)决定在非寄主植物上激发过敏反应(hypersensitive response)和在寄主水稻上具致病性(pathogenicity)的hrp基因簇是诱导表达的。为研究hrp基因的功能,利用hpa1和hrpX基因的启动子与gfp基因进行融合,构建了hrp基因诱导表达系统。绿色荧光蛋白表达揭示,Xooc的hrp基因在营养丰富的NB培养基上不能有效表达,在hrp诱导培养基XOM3上可有效表达。以hrpX和hrpG突变体为参照,RT-PCR研究结果提示,Xooc野生型菌株hpa1基因在NB上不能有效表达,在XOM3培养基上可有效表达。相应地,hrpX突变体中hpa1基因不能被诱导表达,而在hrpG突变体中hpa1基因转录表达水平低于野生菌。研究结果还证实,水稻悬浮细胞能高效诱导Xooc的hrp基因表达。Xooc hrp基因诱导表达系统的建立为研究hrp基因功能、发掘T3SS效应分子以及开展Xooc致病性研究奠定了基础。     

Non-specificity of a colorimetric method for the estimation of N-acetyl-d-glucosamine

The colorimetric method of Reissig et al. for the estimation of N-acetylamino sugars, is often used as a specific method for the quantification of the N-acetyl-d-glucosamine. Although this assay is more sensitive to the monomer, it recognizes all soluble N-acetyl-d-glucosamine oligomers. This result is very important because this method is extensively used in biology for the estimation of chitinolytic activity.     

转Cry1Ac/1Ab基因棉花对异色瓢虫生长发育及其捕食功能的影响

【目的】为探究转Cry1Ac/1Ab基因棉花对异色瓢虫生长发育及其捕食功能的影响。【方法】以转Cry1Ac/1Ab基因棉与其亲本常规棉为实验材料,利用取食不同棉花品种叶片的棉铃虫饲喂异色瓢虫幼虫。【结果】与常规亲本棉相比,取食饲喂转基因棉花叶片的初孵棉铃虫幼虫的异色瓢虫幼虫从1龄发育至化蛹期时间延长0.77 d,但差异不显著;除1龄幼虫体重增加(0.0773 mg)外,其余各龄期幼虫体重均有所下降,但差异均不显著;异色瓢虫1、2、3、4龄幼虫对初孵棉铃虫捕食量均随棉铃虫密度的增加而增加,捕食功能反应均符合HollingⅡ圆盘方程。【结论】转Cry1Ac/1Ab基因棉花对异色瓢虫生长发育无显著影响,饲喂取食转Cry1Ac/1Ab基因棉花的棉铃虫对异色瓢虫捕食功能无显著差异。     

Location of the ompT gene relative to that of appY on the physical map of the Escherichia coli chromosome

Results concerning the precise location of the ompT gene (encoding the outer membrane protease OmpT) on the Escherichia coli chromosome were obtained which disagree with published restriction sites in the gene. It is shown that the gene, together with appY, is present on a 3.075 PstI fragment, encompassing positions 596–598 of the E. coli physical map.     

Phylogeographic patterns in Leccinum sect. Scabra and the status of the arctic-alpine species L. rotundifoliae

We investigated inter- and intraspecific phylogenetic relationships in the ectomycorrhizal fungal genus Leccinum section Scabra. Species of this section are exclusively associated with Betula and occur throughout the Northern Hemisphere. We compared the phylogenetic relationships of arctic, alpine, boreal and temperate accessions of section Scabra based on DNA sequences of the single-copy nuclear gene Gapdh and the multiple-copy nuclear region 5.8S-ITS2. Exclusively arctic lineages were not detected in species that occur both in arctic-alpine or boreal regions, except in L. rotundifoliae that was restricted to cold climates. L. scabrum and L. holopus showed an intercontinental phylogeographic pattern, and L. variicolor showed a pattern unrelated to geographical distribution. Molecular clock estimates indicated that L. rotundifoliae is as old as other species in section Scabra. Individual gene trees suggest that interspecific hybridisation occurred several times in the evolution of section Scabra.     

Autonomy of the wingless mutation in Drosophila melanogaster

Summary T(Y;2) translocations were used to cytologically localise the wingless locus of Drosophila melanogaster. We found that an existing T(Y;2), which is an insertion of a segment of 2L into the Y chromosome, has wg ⁺ within this insert. This Y chromosome was used to generate an attached XY chromosome containing wg ⁺. The mutation claret-nondisjunctional (ca ^nd) was used to induce the loss of this XY chromosome and thus generate gynandromorphs with wg ¹/wg ¹ male tissue and wg ⁺/wg ¹/wg ¹ female tissue. Analysis of these gynanders demonstrated that a genotypically wingless mutant hemithorax is usually also phenotypically mutant in these half body mosaics; thus wg ¹ is discautonomous. This observation is of interest as it is known that wg is not cell autonomous.     

The phylogenetic placement of the Leucogastrales, including Mycolevis siccigleba (Cribbeaceae), in the Albatrellaceae using morphological and molecular data

The morphology of many hypogeous fungi converges on a homogeneous reduced form, suggesting that disparate lineages are subject to a uniform selection pressure. The primary goal of this study was to evaluate the morphology and infer the phylogeny of the Leucogastrales with Mycolevis siccigleba using a Bayesian methodology. A comprehensive morphological assessment was used for an a priori phylogenetic inference to guide the sequencing effort. All structures except spore ornamentation pointed to the Albatrellaceae as the most likely sister taxon. Polyporoletus sublividus, a close relative of Albatrellus, produces ornamented basidiospores with a similar structure to M. siccigleba basidiospores. The ITS from 30 taxa was used for the molecular phylogenetic analysis. P. sublividus was found sister to Mycolevis. Leucophleps spinispora and L. magnata formed a group sister to the Polyporoletus/Mycolevis group, whereas Leucogaster was polyphyletic with respect to the core of the Leucogastrales and sister to A. caeruleoporus. This relationship was expected as previously undescribed chlamydospores produced by members of Albatrellus had a similar morphology to the basidiospores of L. rubescens.     

Molecular phylogeny of the Acre clade (Crassulaceae): Dealing with the lack of definitions for Echeveria and Sedum

The phylogenetic relationships within many clades of the Crassulaceae are still uncertain, therefore in this study attention was focused on the “Acre clade”, a group comprised of approximately 526 species in eight genera that include many Asian and Mediterranean species of Sedum and the majority of the American genera (Echeveria, Graptopetalum, Lenophyllum, Pachyphytum, Villadia, and Thompsonella). Parsimony and Bayesian analyses were conducted with 133 species based on nuclear (ETS, ITS) and chloroplast DNA regions (rpS16, matK). Our analyses retrieved four major clades within the Acre clade. Two of these were in a grade and corresponded to Asian species of Sedum, the rest corresponded to a European–Macaronesian group and to an American group. The American group included all taxa that were formerly placed in the Echeverioideae and the majority of the American Sedoideae. Our analyses support the monophyly of three genera – Lenophyllum, Thompsonella, and Pachyphytum; however, the relationships among Echeveria, Sedum and the various segregates of Sedum are largely unresolved. Our analyses represents the first broad phylogenetic framework for Acre clade, but further studies are necessary on the groups poorly represented here, such as the European and Asian species of Sedum and the Central and South American species of Echeveria.     

Cloning of the cysB gene of Erwinia carotovora subsp. carotovora, and the identification of its product

Summary The suicide vector pJB4JI was used to generate a range of Tn5-induced mutants of Erwinia carotovora subsp. carotovora (Ecc). One mutant, HC500, was a cysteine auxotroph which had a non-pectolytic, non-cellulolytic, non-proteolytic phenotype when grown under sulphate-limitation. The cysteine lesion of HC500 was shown to be analogous to the cysB mutation of Escherichia coli. The Ecc-cysB ⁺ gene product was identified as a protein of M_r 36000.