排序方式: 共有59条查询结果,搜索用时 15 毫秒
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放线菌BOS-009的分离、拮抗活性及鉴定 总被引:3,自引:0,他引:3
对从长白山不同海拔环境中分离筛选出可以产生抗菌活性物质的BOS-009放线菌菌株进行了研究,测定了该菌的抗菌谱,发现该菌株对多种植物病原性真菌及细菌有拮抗作用.通过形态特征、培养特征观察,生理生化特性及抑菌谱等系列比较.发现该菌株与链霉菌属的除虫链霉菌(Streptomyces avermitilis)的特征基本相符;通过16s rDAN序列比对,发现该菌株16s rDAN与除虫链霉菌的16s rDAN同源性达99%.根据多项分类原则和系统进化树的构建分析,将该菌株暂归入除虫链霉菌类. 相似文献
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放线菌YIM31249发酵液萃取物的抗菌活性初步研究 总被引:6,自引:0,他引:6
从云南洱源采集的土壤样品中分离到一株放线菌YIM31249,进行摇瓶发酵,然后用乙酸乙酯萃取发酵液,对萃取物进行体外抗菌实验。试验表明:对大肠杆菌和金黄色葡萄球菌的最低抑菌浓度(HIC)为0.24mg/mL,最低杀菌浓度(MBC)为1.88mg/mL;对灰霉和黑曲霉的MIC和MBC均为0.022mg/mL。因此,放线菌YIM31249菌发酵液中具有天然抗菌活性物质,且抗菌作用明显,有较广的抗菌谱。 相似文献
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An Improved Technique for the Rapid Chemical Characterisation of Bacterial Terpene Cyclases 下载免费PDF全文
Dr. Jeroen S. Dickschat Dr. Khomaizon A. K. Pahirulzaman Patrick Rabe Tim A. Klapschinski 《Chembiochem : a European journal of chemical biology》2014,15(6):810-814
A derivative of the pET28c(+) expression vector was constructed. It contains a yeast replication system (2μ origin of replication) and a yeast selectable marker (URA3), and can be used for gene cloning in yeast by efficient homologous recombination, and for heterologous expression in E. coli. The vector was used for the expression and chemical characterisation of three bacterial terpene cyclases. 相似文献
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A rapid quantification method for bacteria in activated sludge has been developed, based on fluorescence in situ hybridization (FISH) and epifluorescence microscopy. Samples are hybridized on slides and analyzed by direct microscopic observation. Abundance categories were designed based on digital images of the target organisms. These rating systems were developed for the filamentous bacteria Microthrix parvicella and for different morphotypes of nocardioform actinomycetes, but can easily be adapted to other types of microorganisms. Due to the quantification by direct microscopic observation, this method is suitable for samples that are difficult to be processed by semi-automated image analysis techniques, such as samples containing fluorescent debris, cells of different fluorescence intensities and target organisms that need partial enzymatic digestion prior to FISH. In contrast to commonly used rating systems consisting of photographs, the newly developed categories allow to quantitatively compare results of different categories and different organisms. The uncertainties of the results were calculated by a non-parametric bootstrap procedure; a thorough uncertainty analysis was performed including sample variability and operator subjectivity. 相似文献
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用平皿自然沉降法于2006年至2007年间分别对舟山市市区5个测定点作了12次空气微生物测定,调查了舟山市区主要功能区(居民区、沿海区、公园区、校园区、交通区)大气中细菌、放线菌和真菌类的数量变化动态。结果表明:全年空气中细菌的数量均远远高于真菌及放线菌的数量,真菌和放线菌数量变化相一致,其中真菌数略高于放线菌数量。细菌总数在冬季达到最高值,春季下降,至夏季最低与秋季基本持平;真菌与放线菌数量在春季达到最高峰,夏季急剧下降,秋季达最低,显示出舟山市空气微生物含量变化不全同于我国一些内陆城市的海岛特征。 相似文献
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Background: The plant-growth-promoting rhizobacterium Tsukamurella tyrosinosolvens is a rare strain ofactinomycete, in order to recognize and expand the ecological functions of rare actinomycetes. Methods: In thisexperiment, we studied the effect of Tsukamurella tyrosinosolvens P9 on the drought resistance of peanut byinoculating peanut seedlings in pots and measuring the growth and physiological indicators of peanut under droughtstress and re-watering conditions. Results: The results showed that during drought stress, the relative water content ofthe soil and leaves, chlorophyll content, and stomatal length, width, and aperture were significantly decreased whilethe levels of malondialdehyde (MDA), H2O2 and stomatal density were significantly increased. Peanut growth wasalso inhibited. However, inoculation with the P9 strain significantly promoted the growth of peanut under droughtstress as plant height, fresh weight, root length and root weight were significantly higher compared with theuninoculated drought stress group. In addition, in P9-inoculated plants, the water and chlorophyll contents weresignificantly higher and the activities of the antioxidant enzymes CAT and SOD were significantly increased (exceptduring the six days of drought treatment). While the stomatal length, width, and aperture were improved, the levelsof MDA and H2O2 were significantly decreased. NBT staining showed that inoculation with P9 reduced O2−accumulation under stress. After re-watering, the physiological indexes of inoculated plants recovered more quicklyand grew better. Conclusions: The results showed that T. tyrosinosolvens P9 enhanced drought resistance andimproves peanut growth by increasing leaf water content, increasing photosynthesis, regulating stomatal closure, andimproving antioxidant enzyme activity. 相似文献
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Dr. Emilianne M. Limbrick Audrey E. Yñigez-Gutierrez Callie C. Dulin Dagmara K. Derewacz Dr. Jeffrey M. Spraggins Dr. Kathryn M. McCulloch Prof. T. M. Iverson Prof. Brian O. Bachmann 《Chembiochem : a European journal of chemical biology》2020,21(23):3349-3358
Everninomicins are orthoester oligosaccharide antibiotics with potent activity against multidrug-resistant bacterial pathogens. Everninomicins act by disrupting ribosomal assembly in a distinct region in comparison to clinically prescribed drugs. We employed microporous intergeneric conjugation with Escherichia coli to manipulate Micromonospora for targeted gene-replacement studies of multiple putative methyltransferases across the octasaccharide scaffold of everninomicin effecting the A1, C, F, and H rings. Analyses of gene-replacement and genetic complementation mutants established the mutability of the everninomicin scaffold through the generation of 12 previously unreported analogues and, together with previous results, permitted assignment of the ten methyltransferases required for everninomicin biosynthesis. The in vitro activity of A1- and H-ring-modifying methyltransferases demonstrated the ability to catalyze late-stage modification of the scaffold on an A1-ring phenol and H-ring C-4’ hydroxy moiety. Together these results establish the potential of the everninomicin scaffold for modification through mutagenesis and in vitro modification of advanced biosynthetic intermediates. 相似文献
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为研究湖北咸宁浓香型黄鹤楼酒霉菌和放线菌的类型和特点,采用不同的培养基,对夏季和冬季车间样品微生物进行分离纯化及形态鉴别。结果表明,夏季车间空气中分离到15株霉菌,大曲中10株霉菌(104~105 CFU/g),窖泥中1株霉菌和1株放线菌(102~103 CFU/g)。冬季车间空气中分离到9株霉菌,大曲中9株霉菌(104~105 CFU/g),窖泥中7株霉菌(103~104 CFU/g);窖泥霉菌菌落的气丝少,形态与空气及大曲中的主要霉菌差异显著。比较冬季和夏季样品,仅从冬季大曲的曲心和曲皮中分离到青霉,从夏季底泥中分离到一株放线菌,冬季的空气霉菌少于夏季,而冬季窖泥中的霉菌多于夏季。 相似文献