225 research outputs found

    Evidence of Two Functionally Distinct Ornithine Decarboxylation Systems in Lactic Acid Bacteria

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    Biogenic amines are low-molecular-weight organic bases whose presence in food can result in health problems. The biosynthesis of biogenic amines in fermented foods mostly proceeds through amino acid decarboxylation carried out by lactic acid bacteria (LAB), but not all systems leading to biogenic amine production by LAB have been thoroughly characterized. Here, putative ornithine decarboxylation pathways consisting of a putative ornithine decarboxylase and an amino acid transporter were identified in LAB by strain collection screening and database searches. The decarboxylases were produced in heterologous hosts and purified and characterized in vitro, whereas transporters were heterologously expressed in Lactococcus lactis and functionally characterized in vivo. Amino acid decarboxylation by whole cells of the original hosts was determined as well. We concluded that two distinct types of ornithine decarboxylation systems exist in LAB. One is composed of an ornithine decarboxylase coupled to an ornithine/putrescine transmembrane exchanger. Their combined activities results in the extracellular release of putrescine. This typical amino acid decarboxylation system is present in only a few LAB strains and may contribute to metabolic energy production and/or pH homeostasis. The second system is widespread among LAB. It is composed of a decarboxylase active on ornithine and L-2,4-diaminobutyric acid (DABA) and a transporter that mediates unidirectional transport of ornithine into the cytoplasm. Diamines that result from this second system are retained within the cytosol.

    MARVEL, a Tool for Prediction of Bacteriophage Sequences in Metagenomic Bins

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    Here we present MARVEL, a tool for prediction of double-stranded DNA bacteriophage sequences in metagenomic bins. MARVEL uses a random forest machine learning approach. We trained the program on a dataset with 1,247 phage and 1,029 bacterial genomes, and tested it on a dataset with 335 bacterial and 177 phage genomes. We show that three simple genomic features extracted from contig sequences were sufficient to achieve a good performance in separating bacterial from phage sequences: gene density, strand shifts, and fraction of significant hits to a viral protein database. We compared the performance of MARVEL to that of VirSorter and VirFinder, two popular programs for predicting viral sequences. Our results show that all three programs have comparable specificity, but MARVEL achieves much better performance on the recall (sensitivity) measure. This means that MARVEL should be able to identify many more phage sequences in metagenomic bins than heretofore has been possible. In a simple test with real data, containing mostly bacterial sequences, MARVEL classified 58 out of 209 bins as phage genomes; other evidence suggests that 57 of these 58 bins are novel phage sequences. MARVEL is freely available at https://github.com/LaboratorioBioinformatica/MARVEL

    Identification by MALDI-TOF MS of Sporothrix brasiliensis isolated from a subconjunctival infiltrative lesion in an immunocompetent patient

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    Sporotrichosis is a globally distributed subcutaneous fungal infection caused by dimorphic fungi belonging to the Sporothrix species complex that affects the skin of limbs predominantly, but not exclusively. A rare case of ocular sporotrichosis in an immunocompetent Brazilian patient from the countryside of Rio de Janeiro State is reported. A 68-year-old woman presented with a subconjunctival infiltrative lesion in the right eye with pre-auricular lymphadenopathy of onset 4 months ago that evolved to suppurative nodular lesions on the eyelids. Conjunctival secretion was evaluated by histopathological examination and inoculated on Sabouraud Dextrose Agar (SDA). Histopathology showed oval bodies within giant cells and other mononucleated histiocytes. Fungus grown on SDA was identified as Sporothrix sp. by morphological observations. The isolated strain was finally identified by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) associated with an in-house database enriched with reference Sporothrix complex spectra. The strain presented a MALDI spectrum with the ion peaks of the molecular mass profile of S. brasiliensis. The patient was adequately treated with amphotericin B subsequently replaced by itraconazole. Due to scars left by the suppurative process, the patient presented poor final visual acuity. The present work presents an overview of ocular sporotrichosis and discusses the diagnostic difficulty that can lead to visual sequelae in these cases.Financial support for this work by Fundação de Amparo à Pesquisa do Rio de Janeiro [FAPERJ] (Grants: INST E-26/010.001784/2016; JCNE E-26/203.301/2017), by Conselho Nacional de Desenvolvimento Científico e Tecnológico [CNPq] (Grant Proc. 409227/2016-1). This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES). MALDI-TOF MS analyses were partially developed using equipment funded by CONICYT/Chile through the project Fondequip EQM160054 2016. The Universidad de La Frontera (Temuco, Chile) partially funded this work through the Project DIUFRO PIA19-0001. Furthermore, this study was also supported by FCT under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

    Molecular characterization of short-term primary cultures and comparison with corresponding tumor tissue of Brazilian glioblastoma patients

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    Background: Glioblastoma, the most frequent and malignant adult brain tumor, has been extensively studied. However, there is no effective treatment, and to overcome this challenging scenario, it is essential to improve preclinical biological models. This study aimed to molecularly characterize short-term glioblastoma primary cultures and to compare them with patient tumor profiles. Methods: Glioblastoma cell lines were established from Barretos Cancer Hospital patients diagnosed with glioblastoma. The cells were cultured with DMEM (+)10% FBS (+)1% PS and were molecularly characterized using array CGH (aCGH), next-generation and Sanger sequencing. Results: We established four short-term glioblastoma cultures and we found that the primary cells exhibited a diversity of chromosomal aberrations, with gain of chromosome 7 and loss of chromosomes 10, 13 and 17p being the most frequent alterations. Mutation profiling showed that hotspot TERT promoter mutations were present in 3/4 cases, followed by mutations in TP53 (2/4) and in the RB1, BRAF and PTEN (1/4) genes. A similar chromosomal and mutation pattern was observed in all short-term cultures and matched frozen tumors. Conclusions: Herein, short-term glioblastoma primary cultures were successfully characterized and had genetic make-ups that were similar to those of patient tumors, suggesting that short-term primary cultures are suitable in vitro models for studies of glioblastoma biology.Universal/CNPq (475358/2011-2-Reis RM), FAPESP (2012/19590-0-Reis RM) and the MCTI/CNPq No. 73/2013 (Reis RM) grants. Bidinotto LT was a recipient of the FAPESP fellowship (2011/08523-7 and 2012/08287-4)info:eu-repo/semantics/publishedVersio

    The TESS Triple-9 Catalog II: a new set of 999 uniformly-vetted exoplanet candidates

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    The Transiting Exoplanet Survey Satellite (TESS) mission is providing the scientific community with millions of light curves of stars spread across the whole sky. Since 2018 the telescope has detected thousands of planet candidates that need to be meticulously scrutinized before being considered amenable targets for follow-up programs. We present the second catalog of the Plant Patrol citizen science project containing 999 uniformly-vetted exoplanet candidates within the TESS ExoFOP archive. The catalog was produced by fully exploiting the power of the Citizen Science Planet Patrol project. We vetted TESS Objects of Interest (TOIs) based on the results of Discovery And Vetting of Exoplanets DAVE pipeline. We also implemented the Automatic Disposition Generator, a custom procedure aimed at generating the final classification for each TOI that was vetted by at least three vetters. The majority of the candidates in our catalog, 752752 TOIs, passed the vetting process and were labelled as planet candidates. We ruled out 142142 candidates as false positives and flagged 105105 as potential false positives. Our final dispositions and comments for all the planet candidates are provided as a publicly available supplementary table.Comment: 17 pages, 11 figures, 5 tables. Accepted for publication on MNRA

    Máquina de solda ponto

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    Este projeto consiste na restauração e aprimoramento de uma máquina de solda ponto que se encontra no galpão de mecânica do Instituto Federal Catarinense campus Blumenau. A solda ponto tem aplicação em diversas áreas, desde uso caseiro, em pequenas chapas de aço, até utilização na indústria automobilística. Tem como princípio de funcionamento a focalização de uma corrente elétrica através do eletrodo não consumível, onde o ponto entre as duas hastes aquece até fundir o material desejado. Inúmeros estudos apontam que a solda ponto pode ser considerada mais rentável para a indústria, já que não necessita de eletrodo consumível, além do fato de que a solda realizada por esse método pode ser considerada mais bonita por não ficar aparente na superfície das peças soldadas, mas sim entre ambas, formando uma espécie de sanduíche. Mediante pesquisas feitas em artigos científicos, a equipe obteve o conhecimento de materiais que seriam mais eficientes do que os já aplicados inicialmente no projeto, com essas informações, foi realizada a substituição do eletrodo da máquina, o qual era de latão, com ponto de fusão próxima aos 900°C, por um de Tungstênio, que tem um ponto de fusão mais elevado, sendo capaz de suportar o calor proporcionado pela máquina, podendo aguentar até 3,400°C, além de ser um melhor condutor, o que leva a menor perda de energia e maior facilidade no processo de soldagem. O protótipo a ser apresentado pela equipe não possui poder para atuar em uma área industrial, contudo, é capaz de realizar soldas de maneira eficiente, em menor proporção. Durante três dias, foram realizados testes no protótipo, o qual cumpriu sua função com êxito, porém, foi constatado que para ser realizada uma solda de boa qualidade, a peça de aço precisa estar devidamente reta e limpa (sem carepas de ferrugem e sem ondulações), pois, a energia transmitida pelo aparelho se concentra nas ondulações da peça, o que causa uma grande defasagem no processo de soldagem, tornando-a frágil. Pode-se concluir que a restauração e aprimoramento da máquina foi um sucesso, já que a mesma funcionou de acordo com as expectativas da equipe

    Draft genome sequence of Wickerhamomyces anomalus LBCM1105, isolated from cachaça fermentation

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    Wickerhamomyces anomalus LBCM1105 is a yeast isolated from cachaça distillery fermentation vats, notable for exceptional glycerol consumption ability. We report its draft genome with 20.5x in-depth coverage and around 90% extension and completeness. It harbors the sequences of proteins involved in glycerol transport and metabolism.The authors gratefully acknowledge Laboratorio Nacional de Ciencia e Tecnologia do Bioetanol (CTBE) and the Centro Nacional de Pesquisa em Energia e Materiais (CNPEM) for support with the sequencing of LBCM1105. This work was supported by CAPES/Brazil (PNPD 2755/2011; PCF-PVE 021/2012), by CNPq (Brazil), processes 304815/2012 (research grant) and 305135/2015-5, and by AUXPE-PVES 1801/2012 (Process 23038.015294/2016-18) from Brazilian Government and by UFOP. C.L. is supported by the strategic program UID/BIA/04050/2013 [POCI-01-0145-FEDER-007569] funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020 - Programa Operacional de Competitividade e Internacionalizacao (POCI). DMRP is a fellow from the CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico) - Brazil (310080/2018-5)
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