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21.
Giuliana Catara Immacolata Fiume Filippo Iuliano Giovanna Maria Giuseppe Ruggiero 《Biocatalysis and Biotransformation》2013,31(5):358-370
A new serine-carboxyl proteinase, called kumamolisin-ac, was purified from the thermoacidophilic bacterium Alicyclobacillus acidocaldarius. The enzyme is a monomeric protein of 45?kDa, active over a wide temperature range (5.0–70°C) and extremely acidic pHs (1.0–4.0), showing maximal proteolytic activity at pH?2.0 and 60°C. Interestingly, kumamolisin-ac displayed a significant proteolytic activity even at 5°C, thus suggesting a sort of cold-adaptation for this enzyme. The protease was remarkably stable at high temperatures (t1/2 at 80°C, 10?h, pH?2.0) and over a broad range of pH (2.0–7.0). Substrate analysis indicated that kumamolisin-ac was active on a variety of macromolecular substrates, such as haemoglobin, hide powder azure, and azocoll. In particular, a high specific activity was detected towards collagen. The corresponding gene was cloned, expressed and the recombinant protease, was found to be homologous to proteases of the ‘S53’ family. From the high identity with kumamolisin and kumamolisin-As, known as collagenolytic proteases, kumamolisin-ac can be considered as the third collagenolytic affiliate within the ‘S53’ family. Cleavage specificity investigation of kumamolisin-ac revealed a unique primary cleavage site in bovine insulin B-chain, whereas a broad specificity was detected using bovine α-globin as substrate. Thus, kumamolisin-ac could represent an attractive candidate for industrial-scale biopeptide production under thermoacidophilic conditions. 相似文献
22.
Abstract The distribution of macrophytic plant communities, defined by phytosociological numerical methods, in the irrigation system of the Lower river Po Plane was correlated with water characteristich. Water samples were collected periodically within phytocoena well-characterized from the phytosociological viewpoint. Nymphaeid-dominated communities (all. Nymphaeion) usually occur in deeper waters than elodeid- myriophyllid-, and ceratophyllid-dominated vegetation types (all. Potamogetonion). Hydrochemically, all of the studied waterbodies can be classified as rich in electrolytes and in bicarbonates. The distribution of phytocoena reflects a gradient in nutrient content: the Nymphoidetum peltatae characterizes waters moderately rich; the Myriophyllum spicatum community and the Trapetum natantis fairly rich; the Potamogetonetum pectinati and the Ceratophyllum demersum community very rich in nutrients. 相似文献
23.
Abstract Soil microfungi in homogeneous areas of three plant communities of North Italy.—The soil microfungi associated with three different community types in Prealpine region of North Italy were investigated. Frequency values for the taxonomic entities isolated were calculated, based on occurrence at sampling sites, in each community. Most of the entities were quantitatively rare. The microfungal communities associated with Acer pseudoplatanus and Fraxinus excelsior, with Ostrya carpinifolia and with Fagus sylvatica appeared to be a distinctive group, even if many of them contained a substantial number of species wich are common with other vegetation types. 相似文献
24.
Within an integrated management plan for contaminated site remediation at a given territorial scale, the performance of treatability tests could be useful and/or expressly requested by the control authority on a site-specific basis to evaluate the overall feasibility of a given remedial option. The thermal desorption process appears to be a favorable treatment technology for organic contaminants. In this context, a particular lab-scale, indirectly heated desorber for treatability tests was originally developed and first applied to natural soils with different textures (silty sand, loam, silt clay, and clayey silt) that were “ad hoc” highly contaminated with diesel oil at various desorption process conditions (heating temperature in the range of 300–390°C, and reactor retention time in the range of 40–120 min). The Italian soil threshold level for heavy hydrocarbons (C > 12) of 50 mg kg?1 (dry matter) was assumed to be the successful goal of the treatability studies. In addition to the individuation of the favorable desorption process conditions for each soil, also in terms of a composite evaluation of heating temperature and retention time, the comparative experimental results provided useful indications of the possible influence of soil texture, the reduction of initial soil organic matter, and the evaluation of kinetic rate constants. 相似文献
25.
Eugin Destici Edwin H. Jacobs Filippo Tamanini Maarten Loos Gijsbertus T. J. van der Horst Ma?gorzata Oklejewicz 《PloS one》2013,8(12)
The mammalian circadian system is composed of a light-entrainable central clock in the suprachiasmatic nuclei (SCN) of the brain and peripheral clocks in virtually any other tissue. It allows the organism to optimally adjust metabolic, physiological and behavioral functions to the physiological needs it will have at specific time of the day. According to the resonance theory, such rhythms are only advantageous to an organism when in tune with the environment, which is illustrated by the adverse health effects originating from chronic circadian disruption by jetlag and shift work. Using short-period Cry1 and long-period Cry2 deficient mice as models for morningness and eveningness, respectively, we explored the effect of chronotype on the phase relationship between the central SCN clock and peripheral clocks in other organs. Whereas the behavioral activity patterns and circadian gene expression in the SCN of light-entrained Cry1-/- and Cry2-/- mice largely overlapped with that of wild type mice, expression of clock and clock controlled genes in liver, kidney, small intestine, and skin was shown to be markedly phase-advanced or phase-delayed, respectively. Likewise, circadian rhythms in urinary corticosterone were shown to display a significantly altered phase relationship similar to that of gene expression in peripheral tissues. We show that the daily dissonance between peripheral clocks and the environment did not affect the lifespan of Cry1-/- or Cry2-/- mice. Nonetheless, the phase-shifted peripheral clocks in light-entrained mice with morningness and eveningness-like phenotypes may have implications for personalized preventive and therapeutic (i.e. chronomodulation-based) health care for people with early and late chronotypes. 相似文献
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27.
Luigi Ornano Alessandro Venditti Mauro Ballero Cinzia Sanna Luana Quassinti Massimo Bramucci Giulio Lupidi Fabrizio Papa Sauro Vittori Filippo Maggi Armanodoriano Bianco 《化学与生物多样性》2013,10(8):1464-1474
The essential oils of Artemisia arborescens growing in Sardinia (Italy), collected during three plant growth stages, i.e., from the vegetative stage to post‐blooming time, were characterized. Moreover, the in vitro antiproliferative and antioxidant activities of the oil isolated from aerial parts collected in February were evaluated. The essential oils belonged to the β‐thujone/chamazulene chemotype, notably with the highest amount of chamazulene (ca. 52%) ever detected up to now in the genus Artemisia and, in general, in essential oils. Quantitative variations in the oil composition were observed as the plant passes from the vegetative to the blooming stage. The oil was tested for its potential tumor cell growth‐inhibitory effect on T98G, MDA‐MB 435S, A375, and HCT116 human cell lines, using the MTT (=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) assay. The highest activity was observed on A375 and HCT116 cell lines, with IC50 values of 14 μg/ml. Moreover, the in vitro antioxidant and free radical‐scavenging assays revealed the oil to be an effective scavenger of the ABTS radical cation, with an activity comparable to that of Trolox®. These results support the use of A. arborescens oil for the treatment of inflamed skin conditions. Finally, the composition of the polar fraction of the A. arborescens aerial parts was also examined, and the main component detected was 5‐O‐caffeoylquinic acid, which was identified for the first time in this plant. 相似文献
28.
Mariarosaria Calvello Silvia Tabano Patrizia Colapietro Silvia Maitz Alessandra Pansa Claudia Augello Faustina Lalatta Barbara Gentilin Filippo Spreafico Luciano Calzari Daniela Perotti Lidia Larizza Silvia Russo Angelo Selicorni Silvia M Sirchia Monica Miozzo 《Epigenetics》2013,8(10):1053-1060
Beckwith-Wiedemann syndrome (BWS) is a rare disorder characterized by overgrowth and predisposition to embryonal tumors. BWS is caused by various epigenetic and/or genetic alterations that dysregulate the imprinted genes on chromosome region 11p15.5. Molecular analysis is required to reinforce the clinical diagnosis of BWS and to identify BWS patients with cancer susceptibility. This is particularly crucial prenatally because most signs of BWS cannot be recognized in utero. We established a reliable molecular assay by pyrosequencing to quantitatively evaluate the methylation profiles of ICR1 and ICR2. We explored epigenotype-phenotype correlations in 19 patients that fulfilled the clinical diagnostic criteria for BWS, 22 patients with suspected BWS, and three fetuses with omphalocele. Abnormal methylation was observed in one prenatal case and 19 postnatal cases, including seven suspected BWS. Seven cases showed ICR1 hypermethylation, five cases showed ICR2 hypomethylation, and eight cases showed abnormal methylation of ICR1 and ICR2 indicating paternal uniparental disomy (UPD). More cases of ICR1 alterations and UPD were found than expected. This is likely due to the sensitivity of this approach, which can detect slight deviations in methylation from normal levels. There was a significant correlation (p < 0.001) between the percentage of ICR1 methylation and BWS features: severe hypermethylation (range: 75–86%) was associated with macroglossia, macrosomia, and visceromegaly, whereas mild hypermethylation (range: 55–59%) was associated with umbilical hernia and diastasis recti. Evaluation of ICR1 and ICR2 methylation by pyrosequencing in BWS can improve epigenotype-phenotype correlations, detection of methylation alterations in suspected cases, and identification of UPD. 相似文献
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30.
The coalescent with recombination is a fundamental model to describe the genealogical history of DNA sequence samples from recombining organisms. Considering recombination as a process which acts along genomes and which creates sequence segments with shared ancestry, we study the influence of single recombination events upon tree characteristics of the coalescent. We focus on properties such as tree height and tree balance and quantify analytically the changes in these quantities incurred by recombination in terms of probability distributions. We find that changes in tree topology are often relatively mild under conditions of neutral evolution, while changes in tree height are on average quite large. Our results add to a quantitative understanding of the spatial coalescent and provide the neutral reference to which the impact by other evolutionary scenarios, for instance tree distortion by selective sweeps, can be compared. 相似文献