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分离自冬虫夏草可培养真菌的多样性研究 总被引:3,自引:1,他引:2
冬虫夏草是生长于青藏高原的一种名贵中药材。天然冬虫夏草及其微环境中生活着多种真菌。作者使用常规分离培养方法对冬虫夏草的真菌区系进行研究。从天然冬虫夏草的子座、菌核和菌膜3个部位共分离到572个真菌菌株,并根据形态特征将大部分菌株鉴定到37个不同的属。这些菌株经SSCP(single-strand conformation polymorphism)分析后,再根据nrDNAITS序列的相似性(以97%为阈值)共区分出92种不同的分类单元(operational taxonomic unit,OTU)。其中,属于子囊菌的菌株数及OTU数均比接合菌和担子菌多。从菌膜分离的菌株数及OTU数都明显多于子座和菌核。分离自子座的优势真菌是产黄青霉Penicillium chrysogenum,而分离自菌核和菌膜的优势真菌均为玫红假裸囊菌Pseudogymnoascus roseus。尚未最终鉴定的部分真菌可能为新的真菌物种。 相似文献
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The diminutive North American desert annual species of Ipomopsis, Section Microgilia, I. depressa and I. polycladon, agree with other members of the genus in having a flavonoid syndrome based upon 6-methoxyflavonols. Patuletin is the predominant aglycone present but traces of eupatolitin and eupalitin were detected. In I. polycladon, four glycosides of patuletin and one of eupalitin were isolated and identified. 相似文献
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Rinaudo M 《International journal of biological macromolecules》2008,43(5):444-450
This paper concerns the interaction between hyaluronan and fibrinogen as model for protein-polysaccharide interaction. From rheological investigation, it is shown that a 3D physical network is promoted by mixing the two components; the mechanism is attributed to electrostatic interactions. The influences of the molecular weight and of the hyaluronan concentration are examined; the loose interaction obtained for addition of small amount of soluble protein induces a non-Newtonian behaviour which may be in direct relation with the behaviour observed previously on synovial fluids. 相似文献
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Jerzy B. Warchoł 《Histochemistry and cell biology》1968,12(3):222-226
Summary An attempt was made to elaborate a simple method of tetrazolium reductase activity assay in biological material. The method is based on recording of changes in the amperage of threshold current, occuring in course of the reduction of tetrazolium salts. — The method could be employed by histochemists working on the reduction of tetrazolium salts. 相似文献
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Single crystals of NADPH-adrenodoxin oxidoreductase were grown in 50 mM potassium phosphate (pH 7.4) containing 5% glycerol and ammonium sulfate. The crystals are monoclinic, belong to space group P21 and have dimensions of a= 83.4 A, b = 62.6 A, c = 59.3 A, alpha = gamma = 90 degrees, and beta = 107.1 degrees. There is one molecule per asymmetric unit. 相似文献
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Jun-sheng Li Chang-rui Zhang Bin Li Feng Cao Si-qing Wang 《Inorganica chimica acta》2011,366(1):173-3639
Borazine is a promising precursor for boron nitride. A detailed investigation on the reaction of sodium borohydride and ammonium sulfate from 40 °C to 120 °C for synthesis of borazine was performed. The reaction was monitored by means of 11B nuclear magnetic resonance (11B NMR) and Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), mass spectroscopy (MS). The reaction produces mainly ammonia borane (AB), but not borazine at temperatures below 60 °C. Increases of temperature promote yield of borazine, which reaches the maximum around 110 °C. Whereas further increased temperature causes severe polymerization of borazine, and hence holds back yields of borazine. 相似文献
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The conformation of xanthan has been investigated as a function of temperature, ionic strength, and polymer concentration. A reversible transition induced by temperature is demonstrated; the melting temperature (TM) is directly correlated to the total ionic-strength and is independent of the polymer concentration. Measurements of circular dichroism show that the polysaccharide exists in a combination of only two characteristic conformations (random and ordered), regardless of the temperature and the concentrations of salt and polymer. Hydrodynamic measurements show that the hydrodynamic volume of both conformations is almost constant over the range of temperature investigated. The mechanism proposed by Morris for melting is confirmed, and a multichain process is excluded. The birefringence stability of the concentrated solutions is discussed. 相似文献
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R. Aquino I. Behar M. D'agostino F. De. Simone O. Schettino C. Pizza 《Biochemical Systematics and Ecology》1987,15(6):667-669
A new natural flavonol glycoside, isorhamnetin-3-rutinoside-4′-glucoside, together with rutin, narcissin, quercetin-3-(2G-glucosyl)-rutinoside and isorhamnetin-3-rutinoside-7-glucoside, was identified from the MeOH extract of Mercurialis annua L. The structures were established on the basis of chemical and spectral (1H and 13C NMR, FAB MS) data. 相似文献
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《Chemical Speciation and Bioavailability》2013,25(2):115-126
AbstractThe formation of micellar aggregates in the presence of calcium(II) ions in solutions containing sodium and taurodeoxycholate ions and their composition at 25°C and in 0.5 mol dm?3 N(CH3)4Cl as constant ionic medium was studied. The study was carried out by means of two different procedures. In the first one, solid calcium oxalate was equilibrated with taurodeoxycholate, sodium and hydrogen ions and the free concentration of sodium and hydrogen ions was determined. After filtration, the calcium(II) (by atomic absorption spectrophotometry) and oxalate concentration were also determined. In the second approach, hydrogen and sodium ions free concentrations were obtained by electromotive force measurements carried out in solutions containing taurodeoxycholate. The results of both procedures could be explained by assuming the presence of aggregates of different composition with the participation of sodium, calcium(II) and taurodeoxycholate ions, depending on the concentration of the reagents. Protonated species were even present in appreciable concentrations. All the found species have taurodeoxycholate aggregation numbers in multiples of three. A mechanism for the micellar aggregates containing calcium and sodium is proposed. Sodium taurodeoxycholate in the presence of calcium(II) forms larger aggregates than does taurocholate in the presence of calcium(II); the building block of the former is a trimer whereas the latter system has lower aggregation numbers and its building block is a dimer or an octamer. 相似文献
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Harold P. Klein 《Origins of life and evolution of the biosphere》1976,7(3):273-279
The Viking biological investigation will be conducted in the face of a number of constraints. Problems are created because of the inherent engineering of the instrument, communication constraints and other factors. 相似文献
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