309 research outputs found

    Inhibition of Fungi and Gram-Negative Bacteria by Bacteriocin BacTN635 Produced by Lactobacillus plantarum sp. TN635

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    The aim of this study was to evaluate 54 lactic acid bacteria (LAB) strains isolated from meat, fermented vegetables and dairy products for their capacity to produce antimicrobial activities against several bacteria and fungi. The strain designed TN635 has been selected for advanced studies. The supernatant culture of this strain inhibits the growth of all tested pathogenic including the four Gram-negative bacteria (Salmonella enterica ATCC43972, Pseudomonas aeruginosa ATCC 49189, Hafnia sp. and Serratia sp.) and the pathogenic fungus Candida tropicalis R2 CIP203. Based on the nucleotide sequence of the 16S rRNA gene of the strain TN635 (1,540 pb accession no FN252881) and the phylogenetic analysis, we propose the assignment of our new isolate bacterium as Lactobacillus plantarum sp. TN635 strain. Its antimicrobial compound was determined as a proteinaceous substance, stable to heat and to treatment with surfactants and organic solvents. Highest antimicrobial activity was found between pH 3 and 11 with an optimum at pH = 7. The BacTN635 was purified to homogeneity by a four-step protocol involving ammonium sulfate precipitation, centrifugal microconcentrators with a 10-kDa membrane cutoff, gel filtration Sephadex G-25, and C18 reverse-phase HPLC. SDS-PAGE analysis of the purified BacTN635, revealed a single band with an estimated molecular mass of approximately 4 kDa. The maximum bacteriocin production (5,000 AU/ml) was recorded after a 16-h incubation in Man, Rogosa, and Sharpe (MRS) medium at 30 °C. The mode of action of the partial purified BacTN635 was identified as bactericidal against Listeria ivanovii BUG 496 and as fungistatic against C. tropicalis R2 CIP203

    Interplay of Sugar, Light and Gibberellins in Expression of Rosa hybrida Vacuolar Invertase 1 Regulation

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    Our previous findings showed that the expression of the Rosa hybrida vacuolar invertase 1 gene (RhVI1) was tightly correlated with the ability of buds to grow out and was under sugar, gibberellin and light control. Here, we aimed to provide an insight into the mechanistic basis of this regulation. In situ hybridization showed that RhVI1 expression was localized in epidermal cells of young leaves of bursting buds. We then isolated a 895 bp fragment of the promoter of RhVI1. In silico analysis identified putative cis-elements involved in the response to sugars, light and gibberellins on its proximal part (595 bp). To carry out functional analysis of the RhVI1 promoter in a homologous system, we developed a direct method for stable transformation of rose cells. 5′ deletions of the proximal promoter fused to the uidA reporter gene were inserted into the rose cell genome to study the cell’s response to exogenous and endogenous stimuli. Deletion analysis revealed that the 468 bp promoter fragment is sufficient to trigger reporter gene activity in response to light, sugars and gibberellins. This region confers sucrose- and fructose-, but not glucose-, responsive activation in the dark. Inversely, the –595 to –468 bp region that carries the sugar-repressive element (SRE) is required to down-regulate the RhVI1 promoter in response to sucrose and fructose in the dark. We also demonstrate that sugar/light and gibberellin/light act synergistically to up-regulate β-glucuronidase (GUS) activity sharply under the control of the 595 bp pRhVI1 region. These results reveal that the 127 bp promoter fragment located between –595 and –468 bp is critical for light and sugar and light and gibberellins to act synergistically

    Emerging properties of financial time series in the “Game of Life”

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    We explore the spatial complexity of Conway’s “Game of Life,” a prototypical cellular automaton by means of a geometrical procedure generating a two-dimensional random walk from a bidimensional lattice with periodical boundaries. The one-dimensional projection of this process is analyzed and it turns out that some of its statistical properties resemble the so-called stylized facts observed in financial time series. The scope and meaning of this result are discussed from the viewpoint of complex systems. In particular, we stress how the supposed peculiarities of financial time series are, often, overrated in their importance

    Apium plants: Beyond simple food and phytopharmacological applications

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    Apium plants belong to the Apiaceae family and are included among plants that have been in use in traditional medicine for thousands of years worldwide, including in the Mediterranean, as well as the tropical and subtropical regions of Asia and Africa. Some highlighted medical benefits include prevention of coronary and vascular diseases. Their phytochemical constituents consist of bergapten, flavonoids, glycosides, furanocoumarins, furocoumarin, limonene, psoralen, xanthotoxin, and selinene. Some of their pharmacological properties include anticancer, antioxidant, antimicrobial, antifungal, nematocidal, anti-rheumatism, antiasthma, anti-bronchitis, hepatoprotective, appetizer, anticonvulsant, antispasmodic, breast milk inducer, anti-jaundice, antihypertensive, anti-dysmenorrhea, prevention of cardiovascular diseases, and spermatogenesis induction. The present review summarizes data on ecology, botany, cultivation, habitat, medicinal use, phytochemical composition, preclinical and clinical pharmacological efficacy of Apium plants and provides future direction on how to take full advantage of Apium plants for the optimal benefit to mankind.N. Martins would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the strategic project ref. UID/BIM/04293/2013 and “NORTE2020-Northern Regional Operational Program” (NORTE-01-0145-FEDER-000012)

    Drop impact behaviour on alternately hydrophobic and hydrophilic layered bead packs

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    A high level of water repellency in soils has an impact on soil hydrology, plant growth and soil erosion. Studies have been performed previously on model soils; consisting of close packed layers of glass spheres (140–400 μm in diameter), to mimic the behaviour of rain water on water repellent soils. In this study measurements were performed on multi-layered bead packs, to assess the interaction of water drops impacting layers consisting of different hydrophobic and hydrophilic layers. A high speed video camera was used to record the impact behaviour of water droplets on the bead packs focussing on the spreading of the droplet and the subsequent rebound behaviour of the droplet. Observations were made from the videos of the liquid marble effect on the droplet, whereby hydrophobic particles form a coating around the droplet, and how it differed depending on the arrangement of hydrophobic and hydrophilic layers within the bead pack. The droplet release height was varied in order to establish a relationship between impact velocity and the degree to which liquid marbling occurs, with higher impact speeds leading to a greater degree of liquid marbling. Measurements were also made to find the transition speeds between the three rebound conditions; rebound, pinning and fragmentation, showing an overall decrease in pinning velocity as the bead size increased

    KSR2 mutations are associated with obesity, insulin resistance, and impaired cellular fuel oxidation.

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    Kinase suppressor of Ras 2 (KSR2) is an intracellular scaffolding protein involved in multiple signaling pathways. Targeted deletion of Ksr2 leads to obesity in mice, suggesting a role in energy homeostasis. We explored the role of KSR2 in humans by sequencing 2,101 individuals with severe early-onset obesity and 1,536 controls. We identified multiple rare variants in KSR2 that disrupt signaling through the Raf-MEKERK pathway and impair cellular fatty acid oxidation and glucose oxidation in transfected cells; effects that can be ameliorated by the commonly prescribed antidiabetic drug, metformin. Mutation carriers exhibit hyperphagia in childhood, low heart rate, reduced basal metabolic rate and severe insulin resistance. These data establish KSR2 as an important regulator of energy intake, energy expenditure, and substrate utilization in humans. Modulation of KSR2-mediated effects may represent a novel therapeutic strategy for obesity and type 2 diabetes.This work was supported by the Wellcome Trust (098497/Z/12/Z; 077016/Z/05/Z; 096106/Z/11/Z) (ISF and LRP), Medical Research Council (MC_U106179471) (NW), NIHR Cambridge Biomedical Research Centre (ISF, IB and SOR), and European Research Council (ISF). This study makes use of data generated by the UK10K Consortium (WT091310). A full list of the investigators who contributed to the generation of the data is available from http://www.UK10K.org.This is the final published version. It first appeared at http://www.cell.com/abstract/S0092-8674%2813%2901276-2

    Thermococcus kodakarensis encodes three MCM homologs but only one is essential

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    The minichromosome maintenance (MCM) complex is thought to function as the replicative helicase in archaea and eukaryotes. In eukaryotes, this complex is an assembly of six different but related polypeptides (MCM2-7) but, in most archaea, one MCM protein assembles to form a homohexameric complex. Atypically, the Thermococcus kodakarensis genome encodes three archaeal MCM homologs, here designated MCM1-3, although MCM1 and MCM2 are unusual in having long and unique N-terminal extensions. The results reported establish that MCM2 and MCM3 assemble into homohexamers and exhibit DNA binding, helicase and ATPase activities in vitro typical of archaeal MCMs. In contrast, MCM1 does not form homohexamers and although MCM1 binds DNA and has ATPase activity, it has only minimal helicase activity in vitro. Removal of the N-terminal extension had no detectable effects on MCM1 but increased the helicase activity of MCM2. A T. kodakarensis strain with the genes TK0096 (MCM1) and TK1361 (MCM2) deleted has been constructed that exhibits no detectable defects in growth or viability, but all attempts to delete TK1620 (MCM3) have been unsuccessful arguing that that MCM3 is essential and is likely the replicative helicase in T. kodakarensis. The origins and possible function(s) of the three MCM proteins are discussed

    Rare Variant Analysis of Human and Rodent Obesity Genes in Individuals with Severe Childhood Obesity

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    A. Palotie on työryhmän UK10K Consortium jäsen.Obesity is a genetically heterogeneous disorder. Using targeted and whole-exome sequencing, we studied 32 human and 87 rodent obesity genes in 2,548 severely obese children and 1,117 controls. We identified 52 variants contributing to obesity in 2% of cases including multiple novel variants in GNAS, which were sometimes found with accelerated growth rather than short stature as described previously. Nominally significant associations were found for rare functional variants in BBS1, BBS9, GNAS, MKKS, CLOCK and ANGPTL6. The p.S284X variant in ANGPTL6 drives the association signal (rs201622589, MAF similar to 0.1%, odds ratio = 10.13, p-value = 0.042) and results in complete loss of secretion in cells. Further analysis including additional case-control studies and population controls (N = 260,642) did not support association of this variant with obesity (odds ratio = 2.34, p-value = 2.59 x 10(-3)), highlighting the challenges of testing rare variant associations and the need for very large sample sizes. Further validation in cohorts with severe obesity and engineering the variants in model organisms will be needed to explore whether human variants in ANGPTL6 and other genes that lead to obesity when deleted in mice, do contribute to obesity. Such studies may yield druggable targets for weight loss therapies.Peer reviewe
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