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Registros recuperados: 24 | |
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Chagas Junior, Aloisio Freitas; Universidade Federal do Tocantins; Oliveira, Luiz Antonio de; Intituto Nacional de Pesquisas da Amazônia; Oliveira, Arlem Nascimento de; Universidade Federal do Amazonas, Manaus; Willerding, André Luiz; Centro de Biotecnologia da Amazônia. |
Em solos com baixa disponibilidade de fósforo, como os de terra firme da Amazônia, a habilidade de estirpes de rizóbio de solubilizar compostos de fosfato inorgânico é extremamente importante. Assim, o objetivo deste trabalho foi determinar a capacidade de solubilização de fosfato de cálcio (P-Ca) e fosfato de alumínio (P-Al) de isolados de rizóbio de solos na Amazônia em laboratório e a eficiência simbiótica dos isolados em aumentar os conteúdos de N e P em caupi. Os isolados de rizóbio foram avaliados em meios específicos para solubilização desses fosfatos por um período de 15 dias, obtendo-se os seus índices de solubilização (I.S.). Dos 205 isolados avaliados, 68 solubilizaram P-Ca, 47 solubilizaram P-Al e 32 solubilizaram tanto P–Ca quanto P–Al. Entre... |
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Palavras-chave: 5.01.02.04-4 Fósforo; Amazônia; Ecologia microbiana Microbiologia e bioquímica do solo Phosphorus; Amazon; Microbial ecology. |
Ano: 2010 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/3185 |
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Reij,Martine W.; van Schothorst,Michiel. |
Although numerous papers on Microbiological Risk Assessment (MRA) of food products have been published, a number of issues related to it remain unresolved. This paper explains the role of Microbiological Risk Assessment in the context of Risk Analysis as outlined by Codex Alimentarius. It reviews some representative work in the area, with particular emphasis on the objectives, outputs and conclusions of the studies, and on how researchers propose using the resulting Risk Estimate for decision making. Several problems and sources of confusion concerning MRA are identified, such as terminology, the application of Risk Estimates to establish Food Safety Objectives and microbiological criteria for foods, lack of data, and the difference between Risk Assessment... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Risk assessment; Food microbiology; Microbial ecology; Codex Alimentarius. |
Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822000000100002 |
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Lima,Felipe Rezende; Ferreira,Almir José; Menezes,Cristine Gobbo; Miranda,Vitor Fernandes Oliveira; Dourado,Manuella Nóbrega; Araújo,Welington Luiz. |
ABSTRACT Carnivorous plant species, such as Utricularia spp., capture and digest prey. This digestion can occur through the secretion of plant digestive enzymes and/or by bacterial digestive enzymes. To comprehend the physiological mechanisms of carnivorous plants, it is essential to understand the microbial diversity related to these plants. Therefore, in the present study, we isolated and classified bacteria from different organs of Utricularia breviscapa (stolons and utricles) and from different geographic locations (São Paulo and Mato Grosso). We were able to build the first bacterium collection for U. breviscapa and study the diversity of cultivable bacteria. The results show that U. breviscapa bacterial diversity varied according to the geographic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Utricularia breviscapa; Microbial ecology; Aquatic microbiota; Microbial communities. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822018000400714 |
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Richert, Laurent; Golubic, Stjepko; Le Guedes, Roland; Herve, Annie; Payr, Claude. |
Cyanobacterial populations, the primary producers and builders of 'kopara' microbial mats were studied in four selected ponds along the rim of the Rangiroa Atoll, French Polynesia using a polyphasic approach. Seven isolates were maintained in uni-cyanobacterial cultures, characterized morphotypically and phylogenetically by evaluating sequences of the 16S rRNA gene of about 620 base pairs in length. Cyanobacteria in natural populations were analyzed microscopically, characterized morphotypically, and compared with cultured strains. Three of the isolates were identified in the field samples: Lyngbya aestuarii, Johannesbaptistia pellucida and Chroococcus submarinus were present in the mats only as minor components, whereas the species of Schizothrix that... |
Tipo: Text |
Palavras-chave: 16S rRNA; Polyphasic approach; Phylogeny; Microbial mats; Microbial ecology; Kopara; Diversity; Cyanobacteria; Culture. |
Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2050.PDF |
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Romero Yam, Lourdes Alejandra. |
Se estudió la dinámica microbiana y el contenido de nitrógeno mineral y total durante el proceso de compostaje de cachaza reactivada con gallinaza. Se evaluaron cuatro tratamientos con diferentes proporciones de cachaza y gallinaza (10:0, 9:1, 7:3 y 5:5), en contenedores de 68 L durante 87 días. Las variables evaluadas fueron: temperatura, poblaciones de bacterias, hongos, microorganismos ligninolíticos, evolución de CO2, nitrógeno total, amonio y nitratos. La adición de gallinaza a la cachaza almacenada, incrementó las poblaciones de bacterias, hongos y microorganismos ligninolíticos, estos grupos microbianos mostraron poblaciones de 9.9, 5.5 y 6.4 unidades logarítmicas (ULog), respectivamente. El tratamiento 5:5 presentó una disminución en NH+4 –N (de... |
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Palavras-chave: Ecología microbiana; Lignocelulosa; Biotransformación de cachaza; Compost; Microbial ecology; Lignocellulose; Biotransformation of filter cake; Compost; Maestría; Edafología. |
Ano: 2013 |
URL: http://hdl.handle.net/10521/2093 |
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Kivela, Mikko; Arnaud-haond, Sophie; Saramaki, Jari. |
The recent application of graph-based network theory analysis to biogeography, community ecology and population genetics has created a need for user-friendly software, which would allow a wider accessibility to and adaptation of these methods. EDENetworks aims to fill this void by providing an easy-to-use interface for the whole analysis pipeline of ecological and evolutionary networks starting from matrices of species distributions, genotypes, bacterial OTUs or populations characterized genetically. The user can choose between several different ecological distance metrics, such as Bray-Curtis or Sorensen distance, or population genetic metrics such as FST or Goldstein distances, to turn the raw data into a distance/dissimilarity matrix. This matrix is... |
Tipo: Text |
Palavras-chave: Biogeography; Biological communities; Graph theory; Microbial ecology; Network analysis; Population genetics. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00197/30853/29217.pdf |
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Brandt, Miriam; Pradillon, Florence; Trouche, Blandine; Henry, Nicolas; Liautard-haag, Cathy; Cambon-bonavita, Marie-anne; Cueff-gauchard, Valerie; Wincker, Patrick; Belser, Caroline; Poulain, Julie; Arnaud-haond, Sophie; Zeppilli, Daniela. |
Despite representing one of the largest biomes on earth, biodiversity of the deep seafloor is still poorly known. Environmental DNA metabarcoding offers prospects for fast inventories and surveys, yet requires standardized sampling approaches and careful choice of environmental substrate. Here, we aimed to optimize the genetic assessment of prokaryote (16S), protistan (18S V4), and metazoan (18S V1–V2, COI) communities, by evaluating sampling strategies for sediment and aboveground water, deployed simultaneously at one deep-sea site. For sediment, while size-class sorting through sieving had no significant effect on total detected alpha diversity and resolved similar taxonomic compositions at the phylum level for all markers studied, it effectively... |
Tipo: Text |
Palavras-chave: Biodiversity; Ecological genetics; Microbial ecology; Molecular ecology. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00689/80094/83149.pdf |
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Germano,Mariana Gomes; Cannavan,Fabiana de Souza; Mendes,Lucas William; Lima,Amanda Barbosa; Teixeira,Wenceslau Geraldes; Pellizari,Vivian Helena; Tsai,Siu Mui. |
The objective of this work was to evaluate the catabolic gene diversity for the bacterial degradation of aromatic hydrocarbons in anthropogenic dark earth of Amazonia (ADE) and their biochar (BC). Functional diversity analyses in ADE soils can provide information on how adaptive microorganisms may influence the fertility of soils and what is their involvement in biogeochemical cycles. For this, clone libraries containing the gene encoding for the alpha subunit of aromatic ring-hydroxylating dioxygenases (α-ARHD bacterial gene) were constructed, totaling 800 clones. These libraries were prepared from samples of an ADE soil under two different land uses, located at the Caldeirão Experimental Station - secondary forest (SF) and agriculture (AG) -, and the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Catabolic genes; Genetic diversity; Land use systems; Microbial ecology; Tropical soils. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000500004 |
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Reali,Catiusca; Pilz Júnior,Harry Luiz; Meile,Jean Christophe; Galindo,Sabine Shorr; Fiuza,Lidia Mariana. |
ABSTRACT The microbial composition of different types,in ecosystems (including agro-ecosystems), has been investigated in a rapidly growing number of studies in the past few years. The importance of microorganisms, regarding the maintenance and stability of nutrients in agroecosystems, is a key to maintain the sustainability of a crop. Molecular tools to study microbial communities are possible through many methods such as RISA, DGGE, TGGE, clone libraries, T-RFLP, RAPD, SSCP and more recently NGS (Next-Generation Sequencing). DGGE is widely employed to characterize the diversity and the community dynamics of microorganisms in the environment, making possible to find out specific groups through functional genes, allowing access to data that cannot be... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agroecosystems; Functional genes; Bacteria; DGGE; Metagenomics; Microbial ecology. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132017000100201 |
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Trigodet, Florian; Larché, Nicolas; Morrison, Hilary G.; Maignien, Lois; Thierry, Dominique. |
The ennoblement of stainless steel (e.g., the increase of open circuit potential [OCP]) is associated with bacterial colonization. This increases the risk of localized corrosion as the critical pitting/crevice potential can be overcome, especially for lower grade stainless steel. In this study, we assessed the influence of dissolved oxygen content (DOC) on the crevice corrosion of duplex and super duplex stainless steels. In addition, we used DNA amplicon sequencing to identify the bacteria most likely associated with the ennoblement. Above approximately 100 parts per billion (ppb) of dissolved oxygen, the ennoblement of OCP was observed leading to an increased risk of localized corrosion. Below approximately 100 ppb of dissolved oxygen, no ennoblement... |
Tipo: Text |
Palavras-chave: 16S rRNA gene; Electroactive bacteria; Ennoblement; Microbial ecology; Natural seawater; Stainless steel. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70026/67934.pdf |
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Sun, Ying; Debeljak, Pavla; Obernosterer, Ingrid. |
Marine microbes are major drivers of all elemental cycles. The processing of organic carbon by heterotrophic prokaryotes is tightly coupled to the availability of the trace element iron in large regions of the Southern Ocean. However, the functional diversity in iron and carbon metabolism within diverse communities remains a major unresolved issue. Using novel Southern Ocean meta-omics resources including 133 metagenome-assembled genomes (MAGs), we show a mosaic of taxonomy-specific ecological strategies in naturally iron-fertilized and high nutrient low chlorophyll (HNLC) waters. Taxonomic profiling revealed apparent community shifts across contrasting nutrient regimes. Community-level and genome-resolved metatranscriptomics evidenced a moderate... |
Tipo: Text |
Palavras-chave: Metagenomics; Microbial biooceanography; Microbial ecology. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00693/80483/83626.pdf |
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Vadstein, Olav; Bergh, Oivind; Gatesoupe, Joel; Galindo-villegas, Jorge; Mulero, Victoriano; Picchietti, Simona; Scapigliati, Giuseppe; Makridis, Pavlos; Olsen, Yngvar; Dierckens, Kristof; Defoirdt, Tom; Boon, Nico; De Schryver, Peter; Bossier, Peter. |
For most marine aquaculture species, one of the main bottlenecks is the stable production of high quality juveniles. The high and unpredictable mortality in the first weeks after hatching of marine fish larvae remains a challenging problem that needs to be solved. The severity of the problem differs between species, but cannot be considered adequately solved for any species. Both scientific evidence and experience in hatcheries for a variety of fish, shrimp and shellfish species are accumulating as support for the hypothesis that detrimental fish-microbe interactions are the cause of these problems. Host-microbe interactions in reared fish are still poorly understood, except for a few pathogens, and empirical data of the quality required to test this... |
Tipo: Text |
Palavras-chave: Host-microbe interaction; Mast cell; Microbial ecology; Piscidin; Quorum sensing. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00144/25510/23654.pdf |
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Arcuri,Pedro Braga; Thonney,Michael Larry; Schofield,Peter; Pell,Alice Nelson. |
In order to detect fluctuations in ruminal microbial populations due to forage tannins using 16S ribosomal RNA (rRNA) probes, recovery of intact rRNA is required. The objective of this work was to evaluate the effect of polyethylene glycol (PEG) and polyvinylpirrolidone (PVP) on extraction of bacterial rRNA, in the presence of tannins from tropical legume forages and other sources, that hybridize with oligonucleotide probes. Ruminococcus albus 8 cells were exposed to 8 g/L tannic acid or 1 g/L condensed tannins extracted from Acacia angustissima, banana (Musa sp.) skin, Desmodium ovalifolium, red grape (Vitis vinifera) skin and Inga edulis, or no tannins. Cells were rinsed with Tris buffer pH 7 containing either 8% PEG or 6% PVP prior to cell lysis. Total... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ruminococcus albus; Microbial ecology; Animal nutrition. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2003000900008 |
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Registros recuperados: 24 | |
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