Navegando por Autor "Pylro, Victor Satler"
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Item Anatomical characterisation of mycorrhizal fungi in neotropical orchids.(2013) Pylro, Victor Satler; Nogueira, Ricardo Eustáquio; Lanna, Maria Célia da SilvaThe mycorrhizas are fungi associations considered to be a requirement for the survival of orchids that live naturally in ecosystems, since this group of plants depends on the fungi to germinate, as well as for their establishment. The knowledge of mycorrhizical fungi biodiversity of Brazilian orchids and characteristics of this interaction are of great importance for further reintroduction programs, conservation and handling of these vegetal species. Thus, in this work, we present the anatomical characterisation of mycorrhizas in Neotropical orchids by using a simple staining method. Moreover, unusual hyphae colonisation was also observed.Item Aumento da disponibilidade de N via deposição atmosférica e fenologia reprodutiva de Habenaria caldensis Kraenzl. (Orchidaceae) no Parque Estadual do Itacolomi (PEIT) – MG, Brasil.(2011) Pylro, Victor Satler; Cruz, Eduardo dos Santos; Duarte, Gabriela Frois; Kozovits, Alessandra RodriguesAo lado do aumento da concentração de CO2, a deposição atmosférica de N é atualmente considerada um dos mais importantes fatores de alteração do funcionamento dos ecossistemas nativos, tendo já provocado drásticas mudanças na composição florística e na ciclagem de nutrientes no hemisfério norte. Entretanto, em sistemas tropicais e subtropicais, pouco se sabe sobre os efeitos do enriquecimento de N via deposição atmosférica, sobre o seu funcionamento. A compreensão da amplitude e da direção das respostas de orquídeas ao aumento da concentração de N disponível pode ajudar a alimentar modelos de dinâmica de populações rupícolas em resposta às mudanças globais. Avaliamos as respostas de floração e frutificação em plantas de Habenaria caldensis Kraenzl. (Orchidaceae), espécie de ampla distribuição em Minas Gerais, em consequência do aumento da disponibilidade de N por meio de fertilizações com nitrato de amônio, in situ, por aspersão. Em resposta à adição de N, a antese foi adiantada em cerca de 15 dias em relação aos indivíduos do grupo controle. Pelos resultados obtidos, o aumento da disponibilidade de N via deposição atmosférica pode afetar em curto prazo a ecologia de orquídeas e possivelmente outras plantas de campos rupestres alterando seus padrões fenológicos e alométricos. Em médio e longo prazos, tais modificações podem ter relevante impacto sobre a dinâmica de populações e comunidades desse tipo vegetacional.Item Brazilian microbiome project : revealing the unexplored microbial diversity-challenges and prospects.(2014) Pylro, Victor Satler; Roesch, Luiz Fernando Wurdig; Ortega, José Miguel; Amaral, Alexandre Morais do; Tótola, Marcos Rogério; Hirsch, Penny Ruth; Rosado, Alexandre Soares; Góes Neto, Aristóteles; Silva, Artur Luiz da Costa da; Rosa, Carlos Augusto; Morais, Daniel Kumazawa; Andreote, Fernando Dini; Duarte, Gabriela Frois; Melo, Itamar Soares de; Seldin, Lucy; Lambais, Márcio Rodrigues; Hungria, Mariangela; Peixoto, Raquel Silva; Kruger, Ricardo Henrique; Tsai, Siu Mui; Azevedo, Vasco Ariston de CarvalhoThe Brazilian Microbiome Project (BMP) aims to assemble a Brazilian Metagenomic Consortium/Database. At present, many metagenomic projects underway in Brazil are widely known. Our goal in this initiative is to co-ordinate and standardize these together with new projects to come. It is estimated that Brazil hosts approximately 20 % of the entire world’s macroorganism biological diversity. It is 1 of the 17 countries that share nearly 70 % of the world’s catalogued animal and plant species, and is recognized as one of the most megadiverse countries. At the end of 2012, Brazil has joined GBIF (Global Biodiversity Information Facility), as associated member, to improve the access to the Brazilian biodiversity data in a free and open way. This was an important step toward increasing international collaboration and clearly shows the commitment of the Brazilian government in directing national policies toward sustainable development. Despite its importance, the Brazilian microbial diversity is still considered to be largely unknown, and it is clear that to maintain ecosystem dynamics and to sustainably manage land use, it is crucial to understand the biological and functional diversity of the system. This is the first attempt to collect and collate information about Brazilian microbial genetic and functional diversity in a systematic and holistic manner. The success of the BMP depends on a massive collaborative effort of both the Brazilian and international scientific communities, and therefore, we invite all colleagues to participate in this project.Item Characterization of bacterial strains capable of desulphurisation in soil and sediment samples from Antarctica.(2010) Boniek, Douglas; Silva, Débora Regina Figueiredo; Pylro, Victor Satler; Duarte, Gabriela FroisThe presence of sulphur in fossil fuels and the natural environment justifies the study of sulphur-utilising bacterial species and genes involved in the biodesulphurisation process. Technology has been developed based on the natural ability of microorganisms to remove sulphur from polycyclic aromatic hydrocarbon chains. This biotechnology aims to minimise the emission of sulphur oxides into the atmosphere during combustion and prevent the formation of acid rain. In this study, the isolation and characterization of desulphurising microorganisms in rhizosphere and bulk soil samples from Antarctica that were either contaminated with oil or uncontaminated was described. The growth of selected isolates and their capacity to utilise sulphur based on the formation of the terminal product of desulphurisation via the 4S pathway, 2-hydroxybiphenyl, was analysed. DNA was extracted from the isolates and BOX-PCR and DNA sequencing were performed to obtain a genomic diversity profile of cultivable desulphurising bacterial species. Fifty isolates were obtained showing the ability of utilising dibenzothiophene as a substrate and sulphur source for maintenance and growth when plated on selective media. However, only seven genetically diverse isolates tested positive for sulphur removal using the Gibbs assay. DNA sequencing revealed that these isolates were related to the genera Acinetobacter and Pseudomonas.Item Detection of horizontal gene transfers from phylogenetic comparisons.(2012) Pylro, Victor Satler; Vespoli, Luciano de Souza; Duarte, Gabriela Frois; Yotoko, Karla Suemy ClementeBacterial phylogenies have become one of the most important challenges for microbial ecology. This field started in the mid-1970s with the aim of using the sequence of the small subunit ribosomal RNA (16S) tool to infer bacterial phylogenies. Phylogenetic hypotheses based on other sequences usually give conflicting topologies that reveal different evolutionary histories, which in some cases may be the result of horizontal gene transfer events. Currently, one of the major goals of molecular biology is to understand the role that horizontal gene transfer plays in species adaptation and evolution. In this work, we compared the phylogenetic tree based on 16S with the tree based on dszC, a gene involved in the cleavage of carbon-sulfur bonds. Bacteria of several genera perform this survival task when living in environments lacking free mineral sulfur. The biochemical pathway of the desulphurization process was extensively studied due to its economic importance, since this step is expensive and indispensable in fuel production. Our results clearly show that horizontal gene transfer events could be detected using common phylogenetic methods with gene sequences obtained from public sequence databases.Item Diversidade e aplicação de fungos micorrizicos arbusculares em complexo ferruginoso, no Quadrilátero Ferrífero, Minas Gerais.(2014) Lima, Laís Luana de; Kozovits, Alessandra Rodrigues; Pylro, Victor Satler; Kozovits, Alessandra Rodrigues; Silva, Danielle Karla Alves da; Pagano, Marcela CláudiaComplexos ferruginosos, comumente conhecidos como vegetação de canga, apresentam elevada importância ambiental devido à alta biodiversidade, endemismo e heterogeneidade de habitats. Entretanto, esses se encontram ameaçados por atividades antrópicas, sendo a mineração a mais impactante. Os fungos micorrízicos arbusculares (FMAs) tem um importante papel na regulação dos ecossistemas devido à associação com a maioria das plantas e sua influencia na biodiversidade e produtividade vegetal. Esse estudo foi conduzido com o objetivo de acessar a diversidade taxonômica, estrutura da comunidade de FMA, relacionando com as condições edáficas do solo, em formações vegetacionais sobre diferentes tipos de canga, na Serra da Brígida em Ouro Preto (MG), onde distribuem-se habitats de campos ferruginosos predominantemente campestres e, formação florestal considerada estacional semidecidual. Acaulospora e Glomus foram os gêneros mais representativos em abundância e número de espécies. As variáveis edáficas mensuradas foram capazes de separar as duas áreas e explicar aproximadamente 50% da variação total dos dados, sendo o pH a variável mais influente. Além disso, foi verificado que as comunidades dos dois ambientes são diferentes entre si, e respondem a sazonalidade. Posteriormente foi testado o feito da inoculação de FMAs, no crescimento e ganho de biomassa de plântulas de Periandra mediterranea, uma espécie nativa de campos ferruginosos em laterita exposta após mineração de bauxita. Testamos a hipótese que as plântulas inoculadas com espécie de FMA nativa seriam favorecidas em ganho de biomassa vegetal e taxa de sobrevivencia. Diante dos resultados obtidos, conclui-se que a P. mediterranea tolera as condições adversas do substrato com 100% de sobrevivência das plântulas em todos os tratamentos. Maiores ganhos em biomassa vegetal foram observados no tratamento com a espécie de FMA nativa, sugerindo que esta espécie é uma boa candidata para ser utilizada em projetos de recuperação de áreas degradadas por mineração de bauxita.Item A step forward to empower global microbiome research through local leadership.(2016) Pylro, Victor Satler; Tsai, Siu Mui; Rodrigues, Jorge Luiz Mazza; Andreote, Fernando Dini; Roesch, Luiz Fernando Wurdig; Duarte, Gabriela FroisObtaining the full microbial potential to benefit local communities and citizens, as well as ongoing conservation efforts, is a major challenge for Brazil and other developing countries. We propose policies and priorities for organizing microbiome studies locally and worldwide, aiming for a comprehensive catalogue of microbiomes, as recently urged.Item The role of mycorrhization helper bacteria in the establishment and action of ectomycorrhizae associations.(2010) Rigamonte, Tatiana Alves; Pylro, Victor Satler; Duarte, Gabriela FroisMore than 95 % short roots of most terrestrial plants are colonized by mycorrhizal fungi as soon as they emerge in the upper soil profiles. The establishment of mycorrhizal association involves profound morphological and physiological changes in root and fungus. It is affected by other rhizospheric microorganisms, specifically by the bacteria. Bacteria may have developed mechanisms of selective interaction with surrounding microorganisms, with neutral or positive effects on mycorrhizal associations, but negative effect on root pathogens in general. Because of the beneficial effect of bacteria on mycorrhizae, the concept of Mycorrhization Helper Bacteria (MHB) was created. Five main actions of MHB on mycorrhizae were proposed: in the receptivity of root to the mycobiont, in root-fungus recognition, in fungal growth, in the modification of rhizospheric soil and in the germination of fungal propagules. MHB appear to develop a gradation of specificity for the mycobiont, but little or no specificity for the host plant in symbiosis. One of the main groups of MHB is the fluorescent Pseudomonas, well represented in diversity and cell density studies of mycorrhizal associations. This review covers the activity of MHB in the establishment of ectomycorrhizae, taking as model the effects of Pseudomonas sp. described in scientific literature.