Examinando por Autor "Sierra Zapata, Laura"
Mostrando 1 - 3 de 3
Resultados por página
Opciones de ordenación
Ítem Lipopeptides from Bacillus sp. EA-CB0959: Active metabolites responsible for in vitro and in vivo control of Ralstonia solanacearum(Academic Press Inc., 2018-07-31) Villegas Escobar, Valeska; González-Jaramillo LM; Ramirez, Maria; MONCADA, RUTH NATALIA; Sierra Zapata, Laura; Orduz, Sergio; Romero, Magally; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)Broadening the spectrum of action of microbial bioactive compounds is a priority nowadays. From a collection of 1493 aerobic endospore forming bacteria, 3.1% (47) inhibited Serratia marcescens and were highly active against R. solanacearum. Thirty-six of these strains were identified as part of the ‘Operational Group B. amyloliquefaciens’ denoting the potential of strains from these species to produce antibacterial substances. Specifically, the strain Bacillus sp. EA-CB0959 was selected for further trials. Three families of lipopeptides: surfactins, iturins and fengycins were found as the active compounds produced by this strain. The highest bioactivity, produced by fengycins, had a minimal inhibitory concentration of 32 µg/mL. Treating greenhouse banana plants with a mixed fraction of lipopeptides reduced by 35% the incidence of Moko disease caused by R. solanacearum. Here we provide first time evidence of in vitro antibacterial activity of purified fengycins and in vivo activity of mixed lipopetides against Moko disease in banana plants. © 2018 Elsevier Inc.Ítem Reviewing microbial behaviors in ecosystems leading to a natural quorum quenching occurrence(INST TECNOLOGIA PARANA, 2017-01-01) Sierra Zapata, Laura; Romero Tabarez, Magally; Correa Alvarez, Javier; Villegas Escobar, Valeska; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)Quorum sensing is considered one of the most important discoveries in cell-to-cell communication. Although revealed in Bacteria, it has been identified as well as a mechanism present in the other two domains, Eukaryota and Archaea. This phenomenon consists mainly of an exchange and sensing of "words" produced by each cell: chemical signals known as autoinducers. The process takes places at high cell densities and confined environments, triggering the expression of specific genes that manifest in a determined phenotype. Quorum sensing has a fundamental importance in the organisms' fitness in natural ecosystems since it activates many of the traits needed by cells to survive under specific conditions, and thus a wide variety of chemical signals, which are detailed throughout the review, have evolved in response to the needs of an organism in the ecosystem it inhabits. As a counterpart, derived from the natural occurrence of quorum sensing, comes it's antagonistic process named quorum quenching. Acting in the exact opposite way, quorum quenching interferes or degrades the autoinducers confusing and stopping communication, hence affecting transcriptional regulation and expression of a specific phenotype. The main reasons for stopping this mechanism go from fading their own signals when perceiving scarce nutrients conditions, to degrading competitors' signals to take advantage in the ecosystem. Some of the most studied purposes and means known up to date to be used by cells for making quorum quenching in their ecosystems is what will be discussed along this review, offering information for future works on quorum quencher molecules bioprospection.Publicación Reviewing microbial behaviors in ecosystems leading to a natural quorum quenching occurrence(INST TECNOLOGIA PARANA, 2017-01-01) Sierra Zapata, Laura; Romero Tabarez, Magally; Correa Alvarez, Javier; Villegas Escobar, Valeska; Universidad EAFIT. Departamento de Ciencias; Biodiversidad, Evolución y ConservaciónQuorum sensing is considered one of the most important discoveries in cell-to-cell communication. Although revealed in Bacteria, it has been identified as well as a mechanism present in the other two domains, Eukaryota and Archaea. This phenomenon consists mainly of an exchange and sensing of "words" produced by each cell: chemical signals known as autoinducers. The process takes places at high cell densities and confined environments, triggering the expression of specific genes that manifest in a determined phenotype. Quorum sensing has a fundamental importance in the organisms' fitness in natural ecosystems since it activates many of the traits needed by cells to survive under specific conditions, and thus a wide variety of chemical signals, which are detailed throughout the review, have evolved in response to the needs of an organism in the ecosystem it inhabits. As a counterpart, derived from the natural occurrence of quorum sensing, comes it's antagonistic process named quorum quenching. Acting in the exact opposite way, quorum quenching interferes or degrades the autoinducers confusing and stopping communication, hence affecting transcriptional regulation and expression of a specific phenotype. The main reasons for stopping this mechanism go from fading their own signals when perceiving scarce nutrients conditions, to degrading competitors' signals to take advantage in the ecosystem. Some of the most studied purposes and means known up to date to be used by cells for making quorum quenching in their ecosystems is what will be discussed along this review, offering information for future works on quorum quencher molecules bioprospection.