26 research outputs found

    Production of Brazilian human norovirus VLPs and comparison of purification methods

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    Noroviruses (NVs) are responsible for most cases of human nonbacterial gastroenteritis worldwide. Some parameters for the purification of NV virus-like particles (VLPs) such as ease of production and yield were studied for future development of vaccines and diagnostic tools. In this study, VLPs were produced by the expression of the VP1 and VP2 gene cassette of the Brazilian NV isolate, and two purification methods were compared: cesium chloride (CsCl) gradient centrifugation and ion-exchange chromatography (IEC). IEC produced more and purer VLPs of NV compared to CsCl gradient centrifugation

    Production of enzymes for the diagnosis of CoVid-19

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    Os coronavírus representam um grupo de vírus cujos genomas são baseados em RNA fita simples de sentido positivo (+)ssRNA sendo causadores de diversas infecções respiratórias em humanos, incluindo a COVID-19. O diagnóstico rápido e preciso deste vírus é fundamental para nortear o tratamento da doença. Atualmente, os mais importantes testes de diagnóstico deste vírus são baseadas em imunoensaios (ELISA) ou em testes moleculares (PCR). Por se tratar de um genoma de RNA, a detecção do coronavírus se dá pela RT-PCR que envolve o uso de duas enzimas: transcriptase reversa e Taq DNA polimerase

    Bioprospecting microbial diversity for lignin valorization : dry and wet screening methods

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    Lignin is an abundant cell wall component, and it has been used mainly for generating steam and electricity. Nevertheless, lignin valorization, i.e. the conversion of lignin into high value-added fuels, chemicals, or materials, is crucial for the full implementation of cost-effective lignocellulosic biorefineries. From this perspective, rapid screening methods are crucial for time- and resource-efficient development of novel microbial strains and enzymes with applications in the lignin biorefinery. The present review gives an overview of recent developments and applications of a vast arsenal of activity and sequence-based methodologies for uncovering novel microbial strains with ligninolytic potential, novel enzymes for lignin depolymerization and for unraveling the main metabolic routes during growth on lignin. Finally, perspectives on the use of each of the presented methods and their respective advantages and disadvantages are discussed

    Analysis of the Transcriptome in Aspergillus tamarii During Enzymatic Degradation of Sugarcane Bagasse

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    The production of bioethanol from non-food agricultural residues represents an alternative energy source to fossil fuels for incorporation into the world's economy. Within the context of bioconversion of plant biomass into renewable energy using improved enzymatic cocktails, Illumina RNA-seq transcriptome profiling was conducted on a strain of Aspergillus tamarii, efficient in biomass polysaccharide degradation, in order to identify genes encoding proteins involved in plant biomass saccharification. Enzyme production and gene expression was compared following growth in liquid and semi-solid culture with steam-exploded sugarcane bagasse (SB) (1% w/v) and glucose (1% w/v) employed as contrasting sole carbon sources. Enzyme production following growth in liquid minimum medium supplemented with SB resulted in 0.626 and 0.711 UI.mL−1 xylanases after 24 and 48 h incubation, respectively. Transcriptome profiling revealed expression of over 7120 genes, with groups of genes modulated according to solid or semi-solid culture, as well as according to carbon source. Gene ontology analysis of genes expressed following SB hydrolysis revealed enrichment in xyloglucan metabolic process and xylan, pectin and glucan catabolic process, indicating up-regulation of genes involved in xylanase secretion. According to carbohydrate-active enzyme (CAZy) classification, 209 CAZyme-encoding genes were identified with significant differential expression on liquid or semi-solid SB, in comparison to equivalent growth on glucose as carbon source. Up-regulated CAZyme-encoding genes related to cellulases (CelA, CelB, CelC, CelD) and hemicellulases (XynG1, XynG2, XynF1, XylA, AxeA, arabinofuranosidase) showed up to a 10-fold log2FoldChange in expression levels. Five genes from the AA9 (GH61) family, related to lytic polysaccharide monooxygenase (LPMO), were also identified with significant expression up-regulation. The transcription factor gene XlnR, involved in induction of hemicellulases, showed up-regulation on liquid and semi-solid SB culture. Similarly, the gene ClrA, responsible for regulation of cellulases, showed increased expression on liquid SB culture. Over 150 potential transporter genes were also identified with increased expression on liquid and semi-solid SB culture. This first comprehensive analysis of the transcriptome of A. tamarii contributes to our understanding of genes and regulatory systems involved in cellulose and hemicellulose degradation in this fungus, offering potential for application in improved enzymatic cocktail development for plant biomass degradation in biorefinery applications

    Trichoderma harzianum expressed sequence tags for identification of genes with putative roles in mycoparasitism against Fusarium solani

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    The plant pathogen Fusarium solani causes a disease root rot of common bean (Phaseolus vulgaris) resulting in great losses of yield in irrigated areas of the Southeast and Midwest regions of Brazil. Species of the genus Trichoderma have been used in the biological control of this pathogen as an alternative to chemical control. To gain new insights into the biocontrol mechanism used by Trichoderma harzianum against the phytopathogenic fungus, Fusarium solani, we performed a transcriptome analysis using expressed sequence tags (ESTs) and quantitative real-time PCR (RT-qPCR) approaches. A cDNA library from T. harzianum mycelium (isolate ALL42) grown on cell walls of F. solani (CWFS) was constructed and analyzed. A total of 2927 high quality sequences were selected from 3845 and 37.7% were identified as unique genes. The Gene Ontology analysis revealed that the majority of the annotated genes are involved in metabolic processes (80.9%), followed by cellular process (73.7%). We tested twenty genes that encode proteins with potential role in biological control. RT-qPCR analysis showed that none of these genes were expressed when T. harzianum was challenged with itself. These genes showed different patterns of expression during in vitro interaction between T. harzianum and F. solani. (C) 2012 Elsevier Inc. All rights reserved.FINEPFINEPNational Council for Scientific and Technological Development (CNPq) (FINEP/CT-AGRO/Acao) [01.07.0551.00, 0845/07]National Council for Scientific and Technological Development (CNPq) (FINEP/CTAGRO/Acao)FAPEGOFAPEGOCNPqCNP

    Identification of mycoparasitism-related genes against the phytopathogen Sclerotinia sclerotiorum through transcriptome and expression profile analysis in Trichoderma harzianum

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    Submitted by Luciana Ferreira ([email protected]) on 2018-08-23T13:09:52Z No. of bitstreams: 2 Artigo - Andrei Stecca Steindorff - 2014.pdf: 1683612 bytes, checksum: 2dfecb540a7b68095f55a7b617efe882 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2018-08-24T12:22:04Z (GMT) No. of bitstreams: 2 Artigo - Andrei Stecca Steindorff - 2014.pdf: 1683612 bytes, checksum: 2dfecb540a7b68095f55a7b617efe882 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2018-08-24T12:22:05Z (GMT). No. of bitstreams: 2 Artigo - Andrei Stecca Steindorff - 2014.pdf: 1683612 bytes, checksum: 2dfecb540a7b68095f55a7b617efe882 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014Background: The species of T. harzianum are well known for their biocontrol activity against plant pathogens. However, few studies have been conducted to further our understanding of its role as a biological control agent against S. sclerotiorum, a pathogen involved in several crop diseases around the world. In this study, we have used RNA-seq and quantitative real-time PCR (RT-qPCR) techniques in order to explore changes in T. harzianum gene expression during growth on cell wall of S. sclerotiorum (SSCW) or glucose. RT-qPCR was also used to examine genes potentially involved in biocontrol, during confrontation between T. harzianum and S. sclerotiorum. Results: Data obtained from six RNA-seq libraries were aligned onto the T. harzianum CBS 226.95 reference genome and compared after annotation using the Blast2GO suite. A total of 297 differentially expressed genes were found in mycelia grown for 12, 24 and 36 h under the two different conditions: supplemented with glucose or SSCW. Functional annotation of these genes identified diverse biological processes and molecular functions required during T. harzianum growth on SSCW or glucose. We identified various genes of biotechnological value encoding proteins with functions such as transporters, hydrolytic activity, adherence, appressorium development and pathogenesis. To validate the expression profile, RT-qPCR was performed using 20 randomly chosen genes. RT-qPCR expression profiles were in complete agreement with the RNA-Seq data for 17 of the genes evaluated. The other three showed differences at one or two growth times. During the confrontation assay, some genes were up-regulated during and after contact, as shown in the presence of SSCW which is commonly used as a model to mimic this interaction. Conclusions: The present study is the first initiative to use RNA-seq for identification of differentially expressed genes in T. harzianum strain TR274, in response to the phytopathogenic fungus S. sclerotiorum. It provides insights into the mechanisms of gene expression involved in mycoparasitism of T. harzianum against S.sclerotiorum. The RNA-seq data presented will facilitate improvement of the annotation of gene models in the draft T. harzianum genome and provide important information regarding the transcriptome during this interaction
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