黑木耳电泳核型分析

采用等高锁状均质电场（ＣＨＥＦ）凝胶电泳技术,对黑木耳（Ａｕｒｉｃｕｌａｒｉａ ａｕｒｉｃｕｌａ）电泳核型进行分析,以酿酒酵母（Ｓａｃｃｈａｒｏｍｙｃｅｓ ｃｅｒｅｖｉｓｉａｅ）菌株ＹＰＨ７５５和粟酒裂殖酵母（Ｓｃｈｉｚｏｓａｃｃｈａｒｏｍｙｃｅｓ ｐｏｍｂｅ）菌株ＡＳ２．２１４的染色体ＤＮＡ大小作为分子量标记,估计黑木耳基因组中至少包含９条ＤＮＡ分子量在８５０ｋｂ至５８００ｋｂ之间的染色体,     

脉冲电泳核型分析在酿酒酵母菌分类学研究中的应用

根据酵母属（ Ｓａｃｃｈａｒｏｍｙｃｅｓ Ｍｅｙｅｎ ｅｘ Ｒｅｅｓｓ） 分类学研究最新进展,核实并更新了保藏于中国普通微生物菌种保藏中心的该属菌株的种类归属。在形态和生理生化性状,包括对６ 种糖的发酵能力、对１８ 种碳源和３ 种氮源化合物的同化能力、在无维生素培养基中和３７ ℃下的生长情况、对放线菌素酮的抗性等常规分类学研究的基础上,对部分疑难菌株进行了脉冲电泳核型比较分析。酿酒酵母（ Ｓａｃｃｈａｒｏｍｙｃｅｓｃｅｒｅｖｉｓｉａｅ） 、贝酵母（ Ｓ．Ｂａｙａｎｕｓ） 和巴氏酵母（ Ｓ．Ｐａｓｔｏｒｉａｎｕｓ） 三者与少孢酵母（ Ｓ．Ｅｘｉｇｕｕｓ） 在电泳核型上具有明显的差异,主要表现在前三者染色体ＤＮＡ 分子的大小范围均为２２５ ～２２００ ｋｂ ,而Ｓ．Ｅｘｉｇｕｕｓ 缺少小于３６５ ｋｂ 的染色体ＤＮＡ 分子。Ｓ．Ｃｅｒｅｖｉｓｉａｅ 的模式和权威菌株具有１２ ～１４ 条染色体ＤＮＡ 带;Ｓ．Ｂａｙａｎｕｓ 和Ｓ．Ｐａｓｔｏｒｉａｎｕｓ 的模式菌株均有１７ 条带,但在带型上存在一定差异。原归于Ｓ．Ｃｅｒｅｖｉｓｉａｅ 的株菌ＡＳ２－１００ 具有１６ 条带,与Ｓ．Ｃｅｒｅｖｉｓｉａｅ 区别明显而与Ｓ．…     

一种新的脉冲电泳分子量标记*

在脉冲电泳（ｐｕｌｓｅｄ－ｆｉｅｌｄ　ｇｅｌ　ｅｌｃｔｒｏｐｈｏｒｅｓｉｓ,ＰＦＧＥ）研究中,经常使用的分子量标记有啤酒酵母（Ｓａｃｃｈａｒｏｍｙｃｅｓ　ｃｅｒｅｖｅｓｌａｅ）和粟酒裂殖酵母（Ｓｃｈｉｚｏｓａｃｃｈａｒｏｍｙｃｅｓ　ｐｏｍｂｅ）的染色体完整ＤＮＡ。其中,啤酒酵母（如菌株ＹＮＮ２９５）有１６条染色体,分子量变化范围为０．２５Ｍｂ～２．２Ｍｂ（ＭｃＣｌｕｓｋｅｙｅｌａｌ,１９９０）,适于作为小于２．２Ｍｂ的染色体ＤＮＡ的分子量标记;粟酒裂殖酵母（如菌株９７２ｈ－）有３条染色体,分子量…     

用做标记的两种酵母菌完整染色体DNA的简化制备法

已知分子量大小的染色体ＤＮＡ分子标记是脉冲电泳研究中用以估算样本染色体ＤＮＡ分子大小必不可少的参照物。对用做标记的啤酒酵母（Ｓａｃｈａｒｏｍｙｃｅｓｃｅｒｅｖｉｓｉａｅ）和粟酒裂殖酵母（Ｓｃｈｉｚｏｓａｃｈａｒｏｍｙｃｅｓｐｏｍｂｅ）完整染色体ＤＮＡ几种制备方法的比较研究以及改进研究表明,液氮冷冻研磨法,凝胶包埋法以及凝胶包埋破壁法效果均很好,都得到大量染色体ＤＮＡ,且彼此间无明显差异。表明液氮冷冻研磨法和凝胶包埋法制备上述两种酵母菌染色体ＤＮＡ分子标记是两种理想的方法,可完全取代凝胶包埋破壁法,即缩短处理时间又降低成本。此外,相同的电泳样本块在不同的电泳条件下,所得结果有一定的差异,表明电泳条件是影响电泳结果的一个重要因素     

表型相似的热带假丝酵母和麦芽糖假丝酵母在脉冲电泳核型上的差异

热带假丝酵母Ｃａｎｄｉｄａ ｔｒｏｐｉｃａｌｉｓ （Ｃａｓｔｅｌｌａｎｉ ）Ｂｅｒｋｈｏｕｔ和麦芽糖假丝酵母Ｃ． ｍａｌｔｏｓａＫｏｍａｇａｔａ, Ｎａｋａｓｅ ＆ Ｋａｔｓｕｙａ是两种可利用烃类作为碳和能量来源的酵母菌,前者还是一种条件致病菌,可引起系统感染。这两种假丝酵母菌在形态和生理生化性状上非常相似,用常规分类方法不易准确地鉴别。本研究对Ｃ． Ｔｒｏｐｉｃａｌｉｓ和Ｃ ｍａｌｔｏｓａ的模式菌株以及中国普通微生物菌种保藏中心（ＣＧＭＣＣ）保藏的归于这两个种名下的其它菌株进行了脉冲电泳核型比较分析。发现这两个表型相似的种具有明显不同的染色体ＤＮＡ分子带型,而同一种内的不同菌株却具有相同或相似的分子核型。Ｃ．Ｔｒｏｐｉｃａｌｉｓ的特异染色体ＤＮＡ分子带谱为２条８．５—１．２ Ｍｂ的带, ４条２．３－３．４ Ｍｂ的带。 Ｃ ｍａｌｔｏｓａ的特异带谱为： ３～４条分子量在１．１－１．３Ｍｂ范围内的带, １条约为２．２Ｍｂ的带以及２－３条大小为３．２－３．５Ｍｂ的带。 Ｃ ｔｒｏｐｉｃａｌｉｓ与Ｃ ｍａｌｔｏｓａ在染色体ＤＮＡ分子带型上的差异与二者在可溶性淀粉的同化能力和４０℃下的生长能力上的差异具有明显的相关性…     

多菌种混合发酵无醇饮料的研究*

以大麦芽、大麦和大米为主料,优质红茶为辅料,依据微生物生理代谢与生态的基本原理,选择了三个菌种混合发酵,开发了一种新型发酵无醇饮料。采用的三个菌种是：酵母菌（Ｓａｃｃｈａｒｏｍｙｃｅｓｃｅｒｉｖｉｓｉａｅ）,嗜酸乳酸菌（Ｌａｃｔｏｂａｃｉｌｌｕｓａｃｉｄｏｐｈｉｌｕｓ）,弱氧化醋酸单胞菌（Ａｃｅｔｏｍｏｎａｓｓｕｂｏｘｙｄａｎｓ）。将上述菌种按一定比例（１：１：２）接种,接种总量为发酵基质的１０％,控制发酵温度２０－２５℃,发酵时间５天,即可制成风格独特、口味纯正     

L-山梨糖脱氢酶的纯化及性质的研究

从５Ｌ罐发酵Ｌ－山梨糖的Ｇｌｕｃｏｎｏｂａｃｔｅｒ　ＳＣＢ３２９和Ｂａｃｉｌｌｕｓ　ｔｈｕｒｉｎｇｉｅｎｓｉｓ　ＳＣＢ９３３混合菌株中差速离心收集ＳＣＢ３２９菌体,破碎,离心获得无细胞抽提液,硫酸铵分级沉淀蛋白后依次经ＤＥＡＥＣｅｌｌｕｌｏｓｅ ５２和Ｑ Ｓｅｐｈａｒｏｓｅ ＦＦ柱层析分离得到了Ｌ－山梨糖脱氢酶（ＳＤＨ）,它能将Ｌ－山梨糖脱氢氧化为Ｌ－山梨酮,ＳＤＳ－ＰＡＧＥ电泳测得分子量约为６０ＫＤ。动力学性研究表明它为一个典型的Ｍｉｃｈａｅｌｉｓ－Ｍｅｎｔｅｎ氏酶,对Ｌ－山     

酵母属间原生质体融合改进菌株木糖发酵性能

通过单倍体分离和紫外诱变,获得了１４株树干毕赤酵母（Ｐｉｃｈｉａｓｔｉｐｉｔｉｓ）７１２４和酿酒酵母（Ｓａｃｈａｒｏｍｙｃｅｓｃｅｒｅｖｉｓｉａｅ）１３００的营养缺陷型突变株。用聚乙二醇（ＰＥＧ）和电诱导融合及致死融合等方法,实现了树干毕赤酵母和酿酒酵母的属间原生质体融合。融合子能发酵木糖产生酒精,其厌氧发酵木糖和木糖葡萄糖混合液的能力明显优于亲株,耐酒精的性能也比亲株树干毕赤酵母７１２４有所提高。融合子经ＤＮＡ含量、细胞体积测定和稳定性能实验证明为稳定融合子。     

酿酒酵母耐热相关基因DNA片断的初探

对模板ＤＮＡ,Ｍｇ＾２＋的浓度以及ＰＣＲ反应程序等因素进行了研究,得出了对酿酒酵母（Ｓａｃｃｈａｒｏｍｙｃｅｓ ｃｅｒｅｖｉｓｉａｅ）进行随机护增多态性ＤＮＡ（ＲＡＰＤ）分析的优化条件。在此基因上对酿酒酵母耐高温菌株ＨＵ－ＴＹ－１及原始出发菌株ＬＫ的基因组ＤＮＡ进行ＲＡＰＤ分析,结果表明：两菌株间确实存在着扩增带型上的差异,而这些差异可能与菌株的耐高温性状有关。从而为今后通过四分子分析寻找与耐热相     

拮抗菌BS—98分泌抗菌蛋白的条件及其发酵液特性

由本室分离得到一株强烈抑制芦笋茎枯病等植物病原真菌的拮抗菌ＢＳ—９８菌株（Ｂａｃｉｌｌｕｓｓｕｂｔｉｌｉｓ）。用环柱法检测该菌株的抗菌活性表明,该菌株除抑制芦笋茎枯病菌ＰｈｏｍａａｓｐａｒａｇｉＳａｃｃ外,对小麦赤霉病菌（Ｆｕｓａｒｉｕｍｇｒａｍｉｎｅａｒｕｍ）,棉花枯萎病菌（Ｆｕｓａｒｉｕｍｏｘｙｓｐｏｒｕｍｆｓｐ．Ｖａｓｉｎｆｅｃｔｕｍ）、棉花黄萎病菌（Ｖｅｒｔｉｃｉｌｌｕｍａｌｂｏ—ａｔｒｕｍ）、黄瓜灰霉病菌（Ｂｏｔｒｙｔｉ     

三种被孢霉的电泳核型分析

利用等强度均一电场（Ｃｏｎｔｏｕｒ－ｃｌａｍｐｅｄ　Ｈｏｍｏｇｅｎｅｏｕｓ　Ｅｌｅｃｔｒｉｃ　Ｆｉｅｌｄ,ＣＨＥＦ）凝胶电泳技术比较了三种被孢霉菌株及两株诱变菌株的电泳核型。结果显示深黄被孢霉ＡＳ３．３４１０（Ｍｏｒｔｉｅｒｅｌｌａ　ｉｓａｂｅｌｌｉｎａ　ＡＳ３．３４１０）及其诱变株Ｍ(６－２２)、ＭＨ(２３)具有相同的染色体ＤＮＡ分子的数目和大小,而与拉曼被抱霉ＡＳ３．３４１３（Ｍ．ｒａｍａｎｎｉａｎａ　ＡＳ３．３４１３）和葡酒色被孢霉ＡＳ３．３４１４（Ｍｖｉｎａｃｅａ　ＡＳ３．３４１４）显示出明显的差异。三种被抱霉明显的染色体带数分别为１５条,１０条和１１条,分离的染色体ＤＮＡ大小范围大约为３９０ｋｂ－２６６０Ｋｂ,基因组大小分别约为２１６４０Ｋｂ、１５０４０Ｋｂ、１９６７０Ｋｂ。     

Staphylococcal enterotoxin B gene is associated with a discrete genetic element.

The chromosomal location of the enterotoxin B gene in Staphylococcus aureus is unknown. Southern hybridization analysis of the chromosomal DNA from several enterotoxin B (SEB)-producing strains has shown that at least 26.8 kilobases (kb) of DNA is associated with the enterotoxin B gene (entB). We have found that one end of the entB element is located approximately 1.5 kb downstream of the entB gene. The chromosomal region adjacent to this end of the entB element was found to be homologous in several SEB-producing (SEB+) and SEB-nonproducing (SEB-) S. aureus strains. The chromosomes of all the SEB+ strains studied were homologous for at least 24 kb upstream of the entB gene. Some naturally occurring SEB- strains lacked the entire entB element, while others showed variable homology to the region upstream of the entB gene. These data suggest that the entB gene is part of a discrete genetic element that is at least 26.8 kb in size.     

Genome size and restriction fragment length polymorphism analysis of Vibrio cholerae strains belonging to different serovars and biotypes

Abstract The genome size of Vibrio cholerae has been determined by pulsed field gel electrophoresis following digestion of chromosomal DNA with endonucleases. The genome size of all the classical strains examined was about 3000 kb and that of El Tor biotype was 2500 kb. The Not I and S fi I digestion patterns of the genomes of several V. cholerae straimns belonging to different serovars and biotypes showed distinct restriction fragment length polymorphism (RFLP). RFLP analysis together with the genome size can be used to differentiate strains of different serovars and biotypes of V. cholerae .     

Karyotypes of Pneumocystis carinii from Korean rats.

Molecular karyotyping was applied to Pneumocystis carinii(Pc) from two strains of experimental rats, Sprague Dawley(SD) and Fisher(F), in Korea. Field inversion gel electrophoresis and contour clamped homogeneous electric field electrophoresis resolved 15 chromosomal bands from the Pc. The size of the bands was estimated 270kb to 684kb from SD rats, and 273kb to 713 kb from F rats. The bands of 283 kb from SD rats and of 273 kb from F rats stained more brightly suggesting duplicated bands. Total number of chromosomes was at least 16, and total genomic size was estimated 7 x 10(6) bp. All of the bands from F rats hybridized to the probe of repeated DNA sequences of Pc and the band of 448 kb size was proved to contain rDNA sequences, but Pc. chromosome bands from SD rats showed no reactions to the probes. The 2 different karyotypes of P. carinii from 2 strains of rats were maintained consistently for 2 years.     

Plasmid analysis and cloning of the dichloromethane-utilization genes of Methylobacterium sp. DM4

The dichloromethane (DCM)-utilizing facultative methylotroph Methylobacterium sp. DM4 was shown to contain three plasmids with approximate size of 120 kb, 40 kb and 8 kb. Curing experiments suggested that the DCM-utilization character was correlated with the possession of an intact 120 kb plasmid. The DCM-utilization genes were cloned on the broad-host-range vector pVK100. Plasmid pME1510, a recombinant plasmid carrying a 21 kb HindIII fragment complemented DCM-utilization-negative derivatives of Methylobacterium sp. DM4 and conferred the DCM-utilization-positive phenotype to a number of Gram-negative methylotrophic bacteria. In Southern hybridization experiments with pMe1510 as a probe, chromosomal DNA from Methylobacterium sp. DM4 gave definite signals while purified plasmid DNA did not. Plasmid pME1510 did not hybridize with total DNA from a cured DCM-non-utilizing derivative of Methylobacterium sp. DM4. It is concluded that the DCM-utilization genes are located on the chromosome or on a megaplasmid. Curing procedures thus led to the formation of a chromosomal or megaplasmid deletion larger than 21 kb and covering the DCM-utilization genes or to the loss of an undetected megaplasmid.     

Physical map of the genome of Acholeplasma oculi ISM1499 and construction of a Tn4001 derivative for macrorestriction chromosomal mapping.

A physical chromosomal map of Acholeplasma oculi ISM1499 was constructed by using field inversion gel electrophoresis. To assist in the ordering of the chromosomal fragments, a modified transposon, Tn4001.1064, was constructed. It was also used to rescue mycoplasmal chromosomal sequences adjacent to transposon insertion sites in a one-step cloning procedure. The total size of the A. oculi ISM1499 genome was estimated to be 1,633 kb. The restriction enzyme sites for ApaI, BssHII, EagI, and SmaI were positioned on the map along with several transposon insertion sites.     

粟酒裂殖酵母染色体DNA的脉冲电泳分析

采用等高锁状均质电场（CHEF）凝胶电泳技术,对来自中国微生物菌种保藏委员会普通微生物中心的粟酒裂殖酵母（Schizosaccharomycespombe）菌株AS2.214进行染色体DNA分析。CHEF电泳结果显示菌株AS2.214的4条染色体DNA的分子大小分别约为5900kb、3200kb、2500kb和550kb,基因组大小约为12000kb。供试菌株AS2.214第Ⅰ条染色体DNA为5900kb与已研究报道的菌株972h和HM248（5700kb）的基本一致,第Ⅱ条染色体DNA（3200kb）和第皿条染色体DNA（2500kb）,分别较上述2个菌株约小1400kb和1000kb,第Ⅳ条染色体DNA的分子大小与部分非整倍体菌株HM248的极微染色体Ch16DNA相近（500kb）。研究结果表明粟酒裂殖酵母菌株间染色体DNA长度存在显著差异,菌株AS2.214可能是三倍体减数分裂所产生的稳定的部分非整倍体。     

Chromosome-size variation in Giardia lamblia: the role of rDNA repeats.

Giardia lamblia trophozoites contain at least five sets of chromosomes that have been categorized by chromosome-specific probes. Pulsed field separations of G. lamblia chromosomes also demonstrated minor bands in some isolates which stained less intensely with ethidium than the major chromosomal bands. Two of the minor bands of the E11 clone of the ISR isolate, MBa and MBb, were similar to each other and to chromosomal band I by hybridization to total chromosomal DNA and by hybridization of specific probes. In order to determine the extent of this similarity, I have developed a panel of probes for many of the Pacl restriction fragments and have shown that most of the Pacl and Notl fragments found in MBa are also present in MBb. The differences are found in both telomeric regions. At one end, MBb contains a 300 kb region not found in MBa. At the other end of MBb is a 160 kb region containing the rDNA repeats which is bounded on one end by the telomeric repeat and on the other by sites for multiple enzymes that do not digest the rDNA repeats. The corresponding region of MBa is 23 kb in size. The size difference is consistent with the eightfold greater number of rDNA repeats in MBb than MBa and suggests that 30% of the size difference is accounted for by different numbers of copies of the rDNA repeat. MBa of another ISR clone (ISR G5) is 150 kb larger in size than MBa of ISR E11. The data suggest that MBa and MBb are homologous chromosomes of different sizes and that a portion of the size difference is accounted for by different copy numbers of the rDNA repeat.