66 research outputs found

    Brussowvirus SW13 Requires a Cell Surface-Associated Polysaccharide To Recognize Its Streptococcus thermophilus Host

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    Four bacteriophage-insensitive mutants (BIMs) of the dairy starter bacterium Streptococcus thermophilus UCCSt50 were isolated following challenge with Brussowvirus SW13. The BIMs displayed an altered sedimentation phenotype. Whole-genome sequencing and comparative genomic analysis of the BIMs uncovered mutations within a family 2 glycosyltransferase-encoding gene (orf06955(UCCSt50)) located within the variable region of the cell wall-associated rhamnose-glucose polymer (Rgp) biosynthesis locus (designated the rgp gene cluster here). Complementation of a representative BIM, S. thermophilus B1, with native orf06955(UCCSt50) restored phage sensitivity comparable to that of the parent strain. Detailed bioinformatic analysis of the gene product of orf06955(UCCSt50) identified it as a functional homolog of the Lactococcus lactis polysaccharide pellicle (PSP) initiator WpsA. Biochemical analysis of cell wall fractions of strains UCCSt50 and B1 determined that mutations within orf06955(UCCSt50) result in the loss of the side chain decoration from the Rgp backbone structure. Furthermore, it was demonstrated that the intact Rgp structure incorporating the side chain structure is essential for phage binding through fluorescence labeling studies. Overall, this study confirms that the rgp gene cluster of S. thermophilus encodes the biosynthetic machinery for a cell surface-associated polysaccharide that is essential for binding and subsequent infection by Brussowviruses, thus enhancing our understanding of S. thermophilus phage-host dynamics.IMPORTANCE Streptococcus thermophilus is an important starter culture bacterium in global dairy fermentation processes, where it is used for the production of various cheeses and yogurt. Bacteriophage predation of the species can result in substandard product quality and, in rare cases, complete fermentation collapse. To mitigate these risks, it is necessary to understand the phage-host interaction process, which commences with the recognition of, and adsorption to, specific host-encoded cell surface receptors by bacteriophage(s). As new groups of S. thermophilus phages are being discovered, the importance of underpinning the genomic elements that specify the surface receptor(s) is apparent. Our research identifies a single gene that is critical for the biosynthesis of a saccharidic moiety required for phage adsorption to its S. thermophilus host. The acquired knowledge provides novel insights into phage-host interactions for this economically important starter species

    Novel materials for solid oxide fuel cells cathodes and oxygen separation membranes: Fundamentals of oxygen transport and performance

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    In the field of modern hydrogen energy, obtaining pure hydrogen and syngas and then being able to use them for green energy production are significant problems. Developing solid oxide fuel cells (SOFC) and catalytic membranes for oxygen separation as well as materials for these devices is one of the most likely ways to solve these problems. In this work, the authors’ recent studies in this field are reviewed; the fundamentals of developing materials for SOFC cathodes and oxygen separation membranes’ permselective layers based on research of their oxygen mobility and surface reactivity are presented. Ruddlesden – Popper phases Ln2–xCaxNiO4+δ (LnCNO) and perovskite-fluorite nanocomposites PrNi0.5Co0.5O3–δ–Ce0.9Y0.1O2–δ (PNC–YDC) were studied by isotope exchange of oxygen with C18O2 and 18O2 in flow and closed reactors. For LnCNO a high oxygen mobility was shown (D* ~ 10–7 cm2/s at 700 °C), being provided by the cooperative mechanism of oxygen migration involving both regular and highly-mobile interstitial oxygen. For PNC–YDC dominated a wide fast diffusion channel via fluorite phase and interphases due to features of the redistribution of cations resulting in superior oxygen mobility (D* ~ 10–8 cm2/s at 700 °C). After optimization of composition and nanodomain structure of these materials, as cathodes of SOFC they provided a high power density, while for asymmetric supported oxygen separation membranes – a high oxygen permeability. © 2020Support of different parts of the work by the Russian Science Foundation (Project 16-13-00112) and the budget project №AAAA-A17-117041110045-9 for Boreskov Institute of Catalysis is gratefully acknowledged. The authors from the Ural Federal University are grateful to the Government of the Russian Federation (Agreement 02.A03.21.0006, Act 211). Ce 0.9 Y 0.1 O 2–δ |Ce 0.9 Gd 0.1 O 2–δ |Ni/Zr 0.84 Y 0.16 O 2–δ anodic half-cells and Ni/Al foam substrates were kindly provided by H.C. Starck, Germany and Powder Metallurgy Institute NAN Belarus, respectively. Authors would like to appreciate International Conference on Advances in Energy Systems and Environmental Engineering (ASEE19, Wroclaw, Poland, June 9-12, 2019) Organization Committee

    Anthrax in the East Kazakhstan Region

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    Almost every year in Kazakhstan, cases of diseases of animals and people with anthrax are recorded. The incidence rate of people with anthrax in the period from 2000 to 2018 ranged from 0.01 to 0.24 per 100 thousand people. In the territory of the East Kazakhstan region, the incidence rate is higher than in the republic.Objective: a retrospective analysis of anthrax outbreaks in the East Kazakhstan region from 2000 to 2018.Methods: a retrospective analysis using statistical, cadastral data, archival funds, the results of participation in the investigation of outbreaks of infection.Results. Since 1938, cases of animal and human disease of anthrax have been recorded in East Kazakhstan. Infection of humans occurs during the slaughter of animals. In Zharma, Urjar, and Ayagozskiy areas most of all are anthrax foci of soil. In 67 % of cases, outbreaks of anthrax were recorded in these areas.Conclusion. The relative incidence rate of anthrax in people in East Kazakhstan is from 0.07 to 0.27, since 2001 it is higher than the republican indicator.In the East Kazakhstan region from 1997 to 2018, 37 people fell ill with anthrax. The form of the disease is skin, in 8.1 % secondary sepsis. In the remaining patients, the diseases were mild (70.3 %), ended in recovery. The source of human infection is mainly cattle. The isolated strains of B. anthracis have typical properties, they are included in cluster A1a, A3b (MLVA-8). The strains isolated in 2016 are similar to the strains isolated in the Almaty region (MLVA-25). Grouped with a number of European, Asian and African strains from France, Germany, Italy, Tajikistan, Pakistan, Korea and Namibia. The presence of a significant number of soil foci of anthrax in the territory of the East Kazakhstan region, not fully the implementation of veterinary and sanitary preventive measures leads to an exacerbation of the situation for anthrax

    IgTM: An algorithm to predict transmembrane domains and topology in proteins

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    <p>Abstract</p> <p>Background</p> <p>Due to their role of receptors or transporters, membrane proteins play a key role in many important biological functions. In our work we used Grammatical Inference (GI) to localize transmembrane segments. Our GI process is based specifically on the inference of Even Linear Languages.</p> <p>Results</p> <p>We obtained values close to 80% in both specificity and sensitivity. Six datasets have been used for the experiments, considering different encodings for the input sequences. An encoding that includes the topology changes in the sequence (from inside and outside the membrane to it and vice versa) allowed us to obtain the best results. This software is publicly available at: <url>http://www.dsic.upv.es/users/tlcc/bio/bio.html</url></p> <p>Conclusion</p> <p>We compared our results with other well-known methods, that obtain a slightly better precision. However, this work shows that it is possible to apply Grammatical Inference techniques in an effective way to bioinformatics problems.</p

    Morphological, Physiological and Genetic Characteristics of Populations of the Main Plague Host Rhombomys opimus Licht., 1823 in the Central Asian Desert Natural Focus of Plague

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    Revealed by morphological characters, physiological status, and genetic diversity of populations of the main plague host Rhombomys opimus Licht., 1823 in Central Asia desert natural focus is described.Differences in the skull parameters of R. opimus from different populations were revealed. It’s shown that gerbils from Moyunkum are separate autonomous populations group. Samples from Moyunkum and Mangyshlak differed from other samples. In Balkhash-Alakol depression found two regional complexes: Pre-Balkhash and Dzungarian.Study results of free amino acids level in R. opimus blood serum obtained by gas-liquid chromatography of blood sera from animals captured in different zones of Central Asian focus gave statistically significant differences. To determine genetic variability in ecological and geographical isolation of R. opimus populations the DNA was genotyped.DNA samples analysis combined the studied gerbil from the desert focus into four clusters with eighteen haplotypes. R. opimus sequence analysis taking into account data from territories of Iran, Kazakhstan and China, clustered into three large clusters. First cluster combined the sequences of Kazakhstan and China samples, while great gerbil captured in Kazakhstan is located in a separate treasure. Second and third clusters include sequences of a great gerbil captured in Iran

    Belt and Road Initiative in Central Asia: Anticipating socioecological challenges from large‐scale infrastructure in a global biodiversity hotspot

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    Until recently, China's Belt and Road Initiative (BRI) has overlooked many of the social and environmental dimensions of its projects and actions in favor of more immediate economic and sociopolitical considerations. The main focus of investments under BRI has largely been to improve transport, telecommunication, and energy infrastructures. However, in Central Asia, biodiversity is not only foundational for the livelihoods and socioeconomic wellbeing of communities, it also shapes people's culture and identities. Furthermore, ecosystem services derived from functioning landscapes bring enormous benefit for millions of people downstream through integrated and transboundary water systems. Already under pressure from climate-induced melting of glaciers, the fate of ecologically important areas is considered in light of the potential harm arising from large-scale linear infrastructure projects and related investments under China-led BRI. Following review of some of the anticipated impacts of BRI on mountain environments and societies in the region, we highlight several emerging opportunities and then offer recommendations for development programs—aiming fundamentally to enhance the sustainability of BRI investments. Leveraging new opportunities to strengthen partner countries’ priority Sustainable Development Goals and enhancing their agency in the selection of collaborations and the standards to use in environmental impact and risk assessments are recommended

    First indications on the effectiveness of the cereal seed treatment with the daRostim ® BOSTAR array against phytopathogenic bacteria and fungi in the soil

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    В рамках программы Tandem 12/ 21 проведены измерения динамики флюоресценции хлорофилла. Показано, что наболее, чем 100 опытных полей из обследованных в первую очередь Германии, на 9-11 календарной неделе активность процесса фотосинтеза (PHS) озимых зерновых с возрастанием доли (0 – 95 %) фитопатогенов снижается почти на 15 %. На полях, где семенной материал не обрабатывался препаратом daRostim ® BOSTAR, падение PHS ещё больше – до 18 %; на полях, где обработка проводилась, наблюдалось повышение PHS на 3 %. Концентрация фитопатогенов около 100 млн КОЕ/г ведёт к потере фотосинтезической активности до 15 %, в то время как инкрустация семян даёт её увеличение на 7%.Measurements of the chlorophyll fluorescence dynamics (CFD) on first about more than 100 Tandem 12/21 test areas in Germany in the 9-11 calendar week show that the photosynthesis efficiency (PHS) of winter cereals decrease with increasing proportion (0 to 95 %) of phytopathogenic bacteria and fungi in the soil almost by 15 %. On unprepared areas, the loss of PHS is even greater at -18 %; on areas treated with daRostim ® BOSTAR, a 3 % increase of PHS was observed. A concentration of phytopathogens about 100 million CFU/g results in a PHS loss of - 15 %, while after treatment with BOSTAR the photosynthesis efficiency increases by +7 %

    Glycyrrhiza uralensis Nodules: Histological and Ultrastructural Organization and Tubulin Cytoskeleton Dynamics

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    Chinese liquorice (Glycyrrhiza uralensis Fisch. ex DC.) is widely used in the food industry and as a medicine. Like other legumes, G. uralensis forms symbiotic nodules. However, the structural organization of G. uralensis nodules is poorly understood. In this study, we analyzed the histological and ultrastructural organization and dynamics of the tubulin cytoskeleton in various cells from different histological zones of indeterminate nodules formed by two strains of Mesorhizobium sp. The unusual walls of infection threads and formation of multiple symbiosomes with several swollen bacteroids were observed. A large amount of poly-&beta;-hydroxybutyrate accumulated in the bacteroids, while the vacuoles of meristematic and uninfected cells contained drop-shaped osmiophilic inclusions. Immunolocalization of the tubulin cytoskeleton and quantitative analysis of cytoskeletal elements revealed patterns of cortical microtubules in meristematic, infected and uninfected cells, and of endoplasmic microtubules associated with infection structures, typical of indeterminate nodules. The intermediate pattern of endoplasmic microtubules in infected cells was correlated with disordered arrangement of symbiosomes. Thus, analysis of the structural organization of G. uralensis nodules revealed some ancestral features more characteristic of determinate nodules, demonstrating the evolutionary closeness of G. uralensis nodulation to more ancient members of the legume family
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