基础疫苗学会议报告

<正>(接上期)(b)aroA突变种,它是芳香族代谢的营养缺陷型,(c)cya一arp突变种‘它存生长中需要高水平的CAMP其它型的肠侵人性载休菌株是与侵人的志贺氏福氏痢疾杆菌质粒相结合的大肠杆菌K-12杂交株,这个杂交株可以传递己在大肠杆菌载体中克隆化的任何抗原。是否已开发出最佳肠侵入细菌载体菌株     

林可霉素产生菌无活性突变株的选育

1引言 本文介绍了盐酸林可霉素产生菌无活性突变株的选育和原生质体融合的方法以及实验结果,运用uv、uv+Licl、DES、NTG等方法,对60#菌种进行诱变获得了无活性突变株.运用诱变方法获得了带稳定抗SM标记的菌株914#,将914#和8811#进行原生质体融合,获得了遗传性稳定的融合子.     

紫外线诱变提高细菌产纤维素酶活力的研究

从南京红山动物园土样及食草动物的粪便中分离出14种产纤维素酶菌株,其中F1表现出较高的酶活力.以F1为出发菌株,通过紫外线诱变处理,采用透明圈法初筛和摇瓶培养复筛,获得了10株高产纤维素酶的突变株Q1～Q10.经紫外线诱变处理的Q3突变株产酶活力最高,与出发菌株相比酶活力提高了15.8倍.     

磷细菌突变株生理特性的研究

本文对经过筛选培育出的一株解磷能力较强的磷细菌突变株Ｄ０１７Ｐ的生理特性进行了研究。其中,最佳氮源为麦麸汁,与出发菌株所用马铃薯汁相比,生物量增加９．８倍,解磷能力提高７１．４％,最佳碳源为蔗糖,与出发菌株所用碳源葡萄糖比较,解磷能力提高２８．８％,金属离子,培养温度,ｐＨ,气／液比等也对突变株的生长有一定影响,其结果可作为选定工业化条件的参考。     

抗药性基因突变筛选高产菌株

本文通过洁霉素对盐酸林可霉素产生菌 98-1菌株孢子的致死浓度测定 ,采用诱变剂EMS的四种不同诱变剂量对菌株孢子进行诱变处理 ,诱变处理的孢子涂布在含洁霉素 ( 2 0 0 0 0ug/ml)的高氏平板上 ,获得了大量的洁霉素抗性基因突变株 ,然后从 90 0株洁霉素抗性基因突变株中通过初筛获得高于诱变出发菌株产素能力的菌株 5 6株 ,再进一步通过摇瓶复筛 ,并结合菌丝生长及摇瓶代谢情况 ,获得优于出发菌株的诱变菌株 4株。将这 4个菌株连同出发菌株连续三批次进行摇瓶发酵 ,结果 4个突变株的产素能力 (产量 )及摇瓶代谢和菌丝生长情况均优于出发菌株 ,试验筛选出最优菌株 0 2 -0 3 -40 2。将 0 2 -0 3 -40 2进行罐上发酵生产试验 ,结果试验罐比对照罐平均效价提高 1 7.5 6% ,平均产量提高 1 9.3 4%。本文建立了林可霉素高产菌株的洁霉素抗性基因突变诱变快速高效的筛选方法     

海葵附生油脂降解菌的分离鉴定及生长条件优化

采用油脂中性红平板筛选法,从太平洋绿侧花海葵体腔中分离筛选到一株具有油脂降解能力的菌株XZL-13,依据菌株的形态特征、生理生化特性及分子生物学特征对其归属进行了鉴定,并采用分光光度法探究了该菌株的最适生长条件,研究了该菌株在最适生长条件下的生长曲线及以不同油脂作为唯一碳源的生长情况。结果表明,筛选获得的油脂降解菌XZL-13为蒙氏假单胞菌(Pseudomonas monteilii);最适生长条件为:初始pH值7.5、初始盐度2.0g·L~(-1)、培养温度25℃,在此条件下培养7h,菌落总数达到最大;油脂降解菌XZL-13在以玉米油、花生油或芝麻油为唯一碳源的培养基中生长情况较好。     

2,2-二甲基环丙腈水合酶产生菌的氮离子注入选育及突变株产酶条件研究

离子注入技术被广泛应用于微生物的品种改良.利用N 离子注入法对本实验室筛选并保藏的产2,2-二甲基环丙腈水合酶菌种Pseudomonas sp.ZJUT0509进行选育,以提高2,2-二甲基环丙甲酰胺的产量,为进一步的手性拆分提供更多的原料.结果表明,氮离子注入诱变Pseudomonas sp.ZJUT0509的存活率曲线符合离子注入诱变的"马鞍型"特征曲线.通过离子注入获得的突变株的腈水合酶活性有显著提高,其中突变株F60-4的酶活达30.1 U·mL-1,约为原始菌株的9倍.对突变株F60-4进行产酶条件的优化考察,获得了培养条件.F60-4菌株产酶的最佳碳源是葡萄糖(2 g·L-1),最佳氮源是酵母粉(10 g·L-1),最适初始pH值为6.5,最适发酵温度为20℃,最佳诱导剂为1.0g·L-1的己内酰胺.与原始菌株Pseudomonas sp.ZJUT0509相比,突变株F60-4对有机氮源的利用率更高.最佳诱导剂由己内酰胺代替了原来的2,2-二甲基环丙甲腈,使实验操作简便.突变株F60-4的发酵周期为36 h,比原始菌株缩短了12 h.     

高酒精耐受性产酒酵母菌的选育

从某高粱酿酒厂的酒糟中分离到．1株耐受19％酒精的具有产酒精能力的酵母菌,标记为S17,初步鉴定其属于酒香酵母属（Brettanomyces）。对菌株S17进行紫外诱变以提升其耐酒精的能力。结果表明,菌株S17经紫外线照射120s,筛选得到一株可以耐受20％酒精的正突变株,相比原始菌株的酒精耐受力提高了1％。     

FlcA在巴西固氮螺菌Sp7中对细菌细胞壁厚度的影响

目的评价Flc A在巴西固氮螺菌Sp7对细菌细胞壁厚度的影响。方法将野生型巴西固氮螺菌Sp7、flc A敲除株Sp7-flc AΔ及Tn5插入突变株Sp72001,分别在NB培养基及营养缺乏的絮凝培养基中培养,于透射电镜下观察细胞形态,测量细胞壁厚度,检测不同营养条件下Flc A对细菌外观和细胞壁厚度的影响。结果野生型巴西固氮螺菌Sp7、flc A敲除株Sp7-flc AΔ及Tn5插入突变株Sp72001在NB培养基中的细胞壁厚度的中位数分别为(34.13±12.47)、(29.94±9.25)、(34.90±14.88)nm,差异无统计学意义(P>0.05);而在絮凝培养基中培养的细胞壁厚度分别为(75.03±17.67)、(27.00±12.17)、(42.22±15.54)nm,两两比较,差异均有统计学意义(P<0.001);同时,每种菌株用两种不同培养基培养的细胞壁厚度差异有统计学意义(P<0.05)。结论在絮凝条件下,敲除flc A的细菌细胞壁比野生型菌株的细胞壁明显变薄,Flc A可能参与了细菌细胞壁的发育。     

金矿土壤重金属耐受菌的筛选鉴定及性能研究

从蒙古国Zaamar金矿土壤中筛选到6株重金属耐受菌株,将其命名为菌株Z1、Z1a、Z2b、Z31、Z62、Z8,对其进行了鉴定和去除重金属性能考察。结果表明,其中5株菌(Z1、Z1a、Z2b、Z62、Z8)均为芽孢杆菌属;对重金属耐受性测试发现,对Pb~(2+)耐受性最好的菌株是Z1a、Z2b、Z62、Z8,耐受浓度均达到8mmol·L~(-1);对Ni~(2+)耐受性最好的是Z1a、Z2b,耐受浓度达到7mmol·L~(-1);对Zn~(2+)耐受性最好的菌株是Z1,耐受浓度达到8mmol·L~(-1);对Co~(2+)耐受性最好的菌株是Z2b,耐受浓度达到9mmol·L~(-1);对Cu~(2+)耐受性最好的菌株是Z1,耐受浓度达到2mmol·L~(-1);菌株Z31对重金属耐受性不明显。性能测试发现,菌株Z1对Cu~(2+)去除能力最强,溶液中Cu~(2+)去除率达18.38%;菌株Z1a对Ni~(2+)去除能力最强,溶液中Ni~(2+)去除率达13.02%;菌株Z2b对Co~(2+)去除能力最强,溶液中Co~(2+)去除率达到17.76%;菌株Z62对Pb~(2+)去除能力最强,溶液中Pb~(2+)去除率达12.96%;6株菌均对Zn~(2+)没有去除能力。     

Intimin及其受体Tir在致病性大肠杆菌致细胞线粒体功能障碍中的作用

目的探讨致病性大肠杆菌(Enteropathogenic Escherichia coli,EPEC)外膜蛋白Intimin及其受体Tir在EPEC致HeLa细胞线粒体功能障碍中的作用。方法将EPEC外膜蛋白Intimin及其受体Tir删除株、相应质粒互补株或染色体互补株感染HeLa细胞,用线粒体膜电位(Mitochondria membrane potential,MMP)检测试剂JC-1染色细胞线粒体,通过多功能酶标仪检测MMP水平,Western blot检测Intimin的表达及Tir的转位。结果与野生型菌株相比,Eae删除株和Tir删除株感染细胞的MMP功能显著减弱(P<0.05),Eae删除株功能能被质粒表达相应蛋白所互补,Tir删除株不能被质粒表达Tir互补,但可被染色质表达野生型Tir或TirY474S互补,而染色质TirS434A突变株不能引起明显的MMP下降。结论 Intimin和Tir是参与线粒体功能障碍的重要分子;TirS434在线粒体功能障碍中起重要作用。     

Nodulation of electrodeposited copper due to suspended particulate

Cathode nodulation was studied by electrodepositing copper at 38 mA cm^?2 from acid sulphate baths which contained 0.5 g dm^?3 of various suspended particulate. The conductive particulates, such as copper and graphite, produced dense nodulation at temperatures of 50° C and less. Antimony and silver powders caused pitting as well as nodulation. Non-conducting powders such as lead sulphate, lead dioxide, and gypsum produced no nodulation, and correspondingly were occluded only to a very small extent. Once formed, the nodules occluded very large concentrations of any particulate present. The nodulation decreased markedly with an increase in temperature, particularly from 50° to 70° C. With increasing Cu²⁺ ion concentration, the nodulation decreased nominally. These effects and characteristics of the nodulated deposits are discussed.     

Effect of N3 modifications on the affinity of spin label ç for abasic sites in duplex DNA

Noncovalent site‐directed spin labeling (NC‐SDSL) of abasic sites in duplex DNAs with the spin label ç , a cytosine analogue, is a promising approach for spin‐labeling nucleic acids for EPR spectroscopy. In an attempt to increase the affinity of ç for abasic sites, several N3 derivatives were prepared, and their binding affinities were determined by EPR spectroscopy. Most of the N3 substituents had a detrimental effect on binding. The triazole‐linked polyethylene‐glycol derivative ( 12 a ) showed a 15‐fold decrease in affinity, whereas the binding affinities of ethyl azido ( 8 b ) and hydroxyl ( 8 c ) derivatives were five‐ to sixfold lower. The spin‐labeled nucleoside Ç showed only a twofold decrease, thus binding better than 8 c , even though it contains the larger 2′‐deoxyribose substituent at N3 instead of a 2‐hydroxyethyl group. N3 derivatives that contained the basic ethyl amino ( 9 ) or ethyl guanidino ( 10 ) substituents had both higher binding affinity and solubility, attributed to their cationic charge at neutral pH. Compounds 9 and 10 are promising candidates for NC‐SDSL of nucleic acids, for distance measurements by pulsed EPR spectroscopy.     

Integrated Proteomics and Metabolomics Analysis of Nitrogen System Regulation on Soybean Plant Nodulation and Nitrogen Fixation

The specific mechanisms by which nitrogen affects nodulation and nitrogen fixation in leguminous crops are still unclear. To study the relationship between nitrogen, nodulation and nitrogen fixation in soybeans, dual-root soybean plants with unilateral nodulation were prepared by grafting. At the third trifoliate leaf (V3) to fourth trifoliate leaf (V4) growth stages (for 5 days), nitrogen nutrient solution was added to the non-nodulated side, while nitrogen-free nutrient solution was added to the nodulated side. The experiment was designed to study the effects of exogenous nitrogen on proteins and metabolites in root nodules and provide a theoretical reference for analyzing the physiological mechanisms of the interaction between nitrogen application and nitrogen fixation in soybean root nodules. Compared with no nitrogen treatment, exogenous nitrogen regulated the metabolic pathways of starch and sucrose metabolism, organic acid metabolism, nitrogen metabolism, and amino acid metabolism, among others. Additionally, exogenous nitrogen promoted the synthesis of signaling molecules, including putrescine, nitric oxide, and asparagine in root nodules, and inhibited the transformation of sucrose to malic acid; consequently, the rhizobia lacked energy for nitrogen fixation. In addition, exogenous nitrogen reduced cell wall synthesis in the root nodules, thus inhibiting root nodule growth and nitrogen fixation.     

Nitriles in organic synthesis: The Reaction of Cinnamonitriles with cyclohexanone and acetylacetone

The reaction of 1 a , b with cyclohexanone afforded hexahydronaphthalene derivatives ( 3 a , b ). In contrast to the behaviour of 1 a , b , cyclohexanone reacts with 4a – c to yield the propenylidenecyclohexanone derivatives ( 5a – c ). The reaction of 1a with acetylacetone gives 4H-pyran 6 and a 1:2-adduct 8 a . On treatment of 8 a with sodium metal in the presence of dioxane, the pyrano [2, 3-b]pyridine ( 9a ) was obtained. When 1 b , c reacted with acetylacetone, the only isolable products were 8 b , c . Reaction of 4a with acetylacetone gives acyclic compound 10 . This on treatment with basic reagents, gives the pyran derivative ( 13 ).     

Catalytic Asymmetric Conjugate Addition of Mercaptans to β‐Substituted‐β‐Trifluoromethyl Oxazolidinone Enoates: Access to Chiral Trifluoromethylated Tertiary Thioethers and Thiols

The first asymmetric conjugate addition of mercaptans to β‐substituted‐β‐trifluoromethyl oxazolidinone enoates has been developed. The opposite enantiomers of adducts, containing a trifluoromethylated hetero‐quaternary stereogenic centers, could be obtained by utilizing two pseudo‐enantiomeric Cinchona alkaloid‐derived tertiary amine/squaramides as catalysts. Potassium dihydrogen phosphate was found to accelerate the reaction rate without compromising the enantioselective excess. A variety of chiral trifluoromethylated tertiary thioethers and thiols were readily prepared with excellent enantioselectivity.

     

α-Substituierte Phosphonate. 37. α-Pyrrolomethanphosphonsäurederivate und N-Vinylpyrrole

α-Substituted Phosphonates. 37. Derivatives of α-Pyrrolomethanephosphonic Acid and N-Vinylpyrroles Diethyl α-aminomethanephosphonate 5a and its α-aryl derivatives 5b–d react with 2,5-diethoxytetrahydrofuran 1 to give diethyl α-pyrrolomethanephosphonate 9a and the α-aryl derivatives 9b–d , respectively. The pyrrolo derivatives 9 can be converted into the lithium salts 15 and 16 , respectively, which with carbonyl compounds undergo the HORNER reaction yielding E/Z-mixtures of N-vinylpyrroles 18 . In certain cases the intermediate of the HORNER reaction, the β-hydroxyphosphonate 17 , can be isolated. The pyrrolo-analogue of stilbene, 18a , is formed only as E-isomer. On treating the lithium salts 15 and 16 with 9 or with alkyl halides α-C-alkylated pyrrolo-phosphonates 22 and 23 , respectively, are obtained.     

Folgeprodukte halogenierter Aldehyde. XVII. Reaktionen des N-(1,2,2,2-Tetrachlorethyl)-trichloracetaldimins mit Alkoholen und Mercaptanen

Derivatives of Halogenated Aldehydes. XVII. Reactions of N-(1,2,2,2-Tetrachloroethyl)trichloroacetaldimine with Alcohols and Thioalcohols Reactions of N-(1,2,2,2-tetrachloroethyl)trichloroacetaldimine 1 with methanol lead to 1,2,2,2-tetrachloroethyl-(2,2,2-trichloro-1-methoxyethyl)amine 2a , N-(2,2,2-trichloro-1-methoxyethyl)trichloroacetaldimine 3a and bis-(2,2,2-trichloro-1-methoxyethyl)amine 5 . After the reaction of the aldimine 1 with ethanol or propanol only the N-(1-alkoxy-2,2,2,-trichloroethyl)trichloroacetaldimines 3b, c are isolated; with thioalcohols only the N-(1-alkylthio-2,2,2-trichloroethyl)-trichloroacetaldimines 4a–c are obtained. The aldimines 3a–c and 4b, c are decomposed on treatment with hydrochloric acid and an excess of an alcohol or thioalcohol to yield the amine hydrochlorides 6a–c, 7b, c , which are transformed into the amines 8a–c and 9b, c . From these amines the derivatives 10–15 are prepared.     

应用光敏生物素标记探针检测杂交瘤细胞中小鼠白血病病毒

采用BamHⅠ酶切和琼脂糖凝胶电泳技术，从重组质粒pSF11中回收5kb小鼠白血病病毒（MuLv）DNA片段，用光敏生物素标记制备DNA探针，采用斑点杂交法检测杂交癌细胞，McAb纯品以及SP2／0细胞中的MuLv。结果表明，此探针特异性好，灵敏度可达25pg。在检测的13株杂交瘤细胞和2株SP2／0细胞中分别有5株和1株为MuLv阳性，在McAb纯品中未查出MuLv。