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黄霉素产生菌BBG1213的发酵工艺优化 总被引:1,自引:0,他引:1
对黄霉素产生菌Streptomyces bambergiensis1213培养基配方、种子培养时间及摇瓶装液量等培养条件进行优化,结果表明:当发酵培养基配方为:玉米淀粉3.5%、玉米浆0.6%、酵母粉1.0%、蛋白胨0.3%、黄豆饼粉2.5%、(NH4)2SO40.13%、K2HPO40.03%,BBG1213产抗水平最高;种子培养时间36h为宜;摇瓶装液量30ml,发酵周期86h-89h最佳。采用双碟法,建立了发酵液中黄霉素含量测定方法。 相似文献
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黄霉素高产菌株的选育 总被引:2,自引:0,他引:2
目的:为了获得黄霉素高产菌株。方法:进行了一系列的诱变筛选。以加纳链霉菌(Streptomyces ghanaesis)SgWE-11为出发菌株,采用紫外线诱变,以其自身代谢物黄霉素作为筛选因子。结果:获得一株遗传稳定且黄霉素发酵效价比出发菌株高出170.25%的菌株。对该菌株采用亚硝酸诱变,并以链霉素作为筛选因子时得到一株效价值为875u/mL的高产菌株SgWE-25,比出发菌株SgWE-11提高了4.4倍。传代结果表明,在传代的同时结合自然分离,可以保持稳定的产抗特性。 相似文献
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利用基因芯片可以得到不同基因在不同生命过程中的表达,因此在医学诊断与病变分析中受到重视,并开始大量应用.经测定发现,不同基因在病变过程的不同阶段中的表达是不相同的,由此可以得到在病变过程的不同基因的表达特征.在本文中,我们给出了乳腺癌在转移过程中的基因表达特征的聚类分析法分析,并改进了k-means聚类算法,使之具有自动搜索聚类数的功能,并且有助于改善k-means算法的聚类结果陷入局部最小值的状况.通过对平均聚类误差指标的比较,kr—means要优于k-means算法.本文所得到的结果可供乳腺癌诊断与病变分析参考,同时可以应用于小型基因检测芯片的制备,也可以用于构建基因网络调控图. 相似文献
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以福建近海出现过的13属23种石首鱼(Sciaenidae)作为分类单元(OperationalTaxonomic Units)及其量化数据取值依据,选取39个特征指标,采用系统聚类分析法(HierarchicalCluster)对其进行数值分类,得出了福建近海石首鱼类的聚类分类结果.结果表明:聚类分析法的分类结果与传统的形态分类结果基本吻合,可将福建近海出现过的石首鱼类分成13类(属).证明了朱元鼎教授等对我国石首鱼类的分类是比较科学、合理的.研究结果支持把鮸状黄姑鱼(Nibea.miichthioides)归到黄鳍牙鱼(鱼或)属(Chrysochir),这一点与传统的形态分类法观点不同.另外,本研究结果对大头白姑鱼(Argyrosomus macrocephalus)和勒氏短须石首鱼(Umbrina.russelli)的分类存有分歧,并提出了一些具有参考价值和值得重视的观点,有待将来进一步的探讨. 相似文献
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星座图聚类分析在小麦品种资源分类中的应用 总被引:1,自引:0,他引:1
根据星座图聚类分析的原理和方法,对濮阳市农科所从各地引进的20个小麦品种进行分析,分成3类,分析结果与田间表现相吻合。为育种者进行亲本选择和小麦品种资源分类提供了依据。 相似文献
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David B. Hedrick Tom White James B. Guckert William J. Jewell David C. White 《Journal of industrial microbiology & biotechnology》1992,9(3-4):193-199
Summary An anaerobic phase-separation biomass reactor was established on cellulose with the hydrolysis and fermentation steps occurring in the first stage, and acetogenesis and methanogenesis in the second stage. Based upon lipid biomarker analysis, eubacterial and eukaryotic cells accounted for approximately 6% of the volatile solids of the first stage and 17% of the second, while methanogens were approximately 1% of the volatile solids in the first stage and 9% of the second. Clustering the polar lipid fatty acids into groups based upon their distributions between the two stages of the reactor clarified the differences in community structure caused by phase-separated operation. Although inoculated from the same source, the two stages maintained very different microbial communities. Signature fatty acids known as indicators of unbalanced growth in eubacteria were significantly higher in the first stage of the reactor. 相似文献
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中国葡萄属植物形态学聚类分组研究 总被引:2,自引:1,他引:2
对《中国葡萄志》描述的38个中国葡萄属野生种和1个栽培种,按照《葡萄种质资源描述规范和数据标准》的要求,对18个描述符用代码数量化并进行聚类分析,根据形态特征的相似程度,将我国葡萄属野生种和欧亚种划分为8个组和5个亚组。第1组包含毛葡萄、腺枝葡萄、龙泉葡萄、美丽葡萄和庐山葡萄,第2组包含麦黄葡萄和小叶葡萄,第3组包含5个亚组21个种类,其中亚组1包含山葡萄、陕西葡萄、浙江蘡薁、蘡薁和湖北葡萄,亚组2包含绵毛葡萄和勐海葡萄,亚组3包含小果葡萄、云南葡萄和葛藟葡萄,亚组4包含毛脉葡萄、华东葡萄、武汉葡萄和井冈葡萄,亚组5包含刺葡萄、秋葡萄、桦叶葡萄、网脉葡萄、蒙自葡萄、凤庆葡萄和河口葡萄,第4组仅包含欧洲葡萄,第5组包含温州葡萄、红叶葡萄、复叶葡萄、乳源葡萄和狭叶葡萄,第6组包含东南葡萄、罗城葡萄和闽赣葡萄,第7组仅包含菱叶葡萄,第8组仅包含鸡足葡萄一个种。 相似文献
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根据星座图聚类分析的原理和方法,对濮阳市农科所从各地引进的20个小麦品种进行分析,分成3类,分析结果与田间表现相吻合。为育种者进行亲本选择和小麦品种资源分类提供了依据。 相似文献
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D. Pangallo K. Chovanov H. Drahovska F. De Leo C. Urzì 《International biodeterioration & biodegradation》2009,63(7):868-872
The aim of this work was the evaluation of fluorescence ITS-PCR (f-ITS) as a molecular tool to analyze the microbial community involved in the biodeterioration of cultural heritage surfaces. As a case study we analyzed by f-ITS ninety-two bacterial strains isolated from a medieval fresco and the surrounding air environment. The internal transcribed spacer between the 16S and 23S rRNA genes was amplified, and then the fluorescently labeled PCR products were separated by capillary electrophoresis. Bacterial strains were identified by 16S rDNA sequencing. The f-ITS electropherograms showed different profiles coherent with the affiliation of the strains at the genus and species levels. Among the isolates obtained from the fresco surface, those belonging to the genus Bacillus were the most prevailing exhibiting 8 different f-ITS profiles. The airborne bacilli exhibited only 2 of these 8 profiles. Staphylococcus were mostly isolated from air and produced 4 different profiles. Pseudomonas isolates presented 3 different profiles, and one of them was typical of Pseudomonas putida. Members of the other genera produced their distinctive profiles. Our results show that f-ITS is a promising molecular tool for the rapid selection and clustering of strains isolated from different sources. 相似文献
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Hierarchical cluster analysis as a tool to manage variation in germplasm collections 总被引:1,自引:0,他引:1
J. P. Peeters J. A. Martinelli 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,78(1):42-48
Summary The potential of using hierarchical cluster analysis to classify entries from a germplasm collection according to their degree of similarity was assessed. Results suggest that similarity is generally greatest among individual entries by country of origin and that hierarchical cluster analysis could be used as a tool to classify entries from germplasm collections according to their respective gene pools, even when no passport data are available. Based on this technique, it is also shown that the segregative potential of entries can be estimated. 相似文献
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Numerical classification methods can simulate strategies of intuitive classifications. This paper considers two different intuitive syntaxonomic schemes suggested for stagnant eutrophic fresh-water communities with a view to identifying which among the commonest numerical methods of classification fits the two intuitive schemes best. Comparison of classifications using an information function and discriminant analysis revealed that the different numerical methods simulate different intuitive schemes, but the results of the numerical classifications are always judged superior. Two new syntaxonomic schemes optimizing the sharpness between the syntaxa are proposed. 相似文献