Examinando por Materia "Ralstonia solanacearum"
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Ítem Bacillus spp. antibacterial activity induced by triphenyl tetrazolium chloride : metabolome changes and oxidative stress response(Universidad EAFIT, 2023) González Marín, Carolina; Villegas Escobar, ValeskaÍtem Caracterización química y evaluación de la actividad biológica de extractos de Gliricidia sepium con variación latitudinal(2018) Franco Leyva, Ana Maria de los Angeles; Marín Palacio, Luz DeisyRecently, Bioactive compounds of plants have recently been studied because of their multiple benefits. In this sense, the biological activity of Gliricidia sepium taken from of three different altitudes (0, 800 y 1500 m.a.s.l) of Colombian tropic has been tested. In the present study three solvents (Ethanol, Ethanol-Water and Water) were evaluated for the solid-liquid conventional extraction with two solids charges (1:4 and 1:8) and supercritical CO2 extraction. The highest yields of extraction were obtained with the hydroethanolic extraction treatment and 800 m.a.s.l (273.07± 6.52 mg/g on average). Additionally, phenol, flavonoids and terpenoids were quantified in which the Ethanolic extraction with solid charge of 1:8 and 0 m.a.s.l presented the highest concentrations (79.9±2.5 ppm, 112.1±4.8 ppm y 640.9 ±15.9 ppm respectively). Additionally, the treatment with the highest antioxidant activity (ORAC) corresponded to the one performed with a solid charge of 1:8 in ethanol and 800 m.a.s.l (1919.4 µM de TE/g). At the same time the antioxidant activity results of extraction with supercritical CO2 reached concentration of 677.9; 864.9; 939.6 µM de TE/g 0, 800 Y 1500 m.a.s.l respectively. Finally, the antimicrobial activity of extracts was tested in different microorganisms, the highest inhibition was the one presented against Ralstonia solanacearum EAP09 with inhibition percentage of 90.11±11.20% after 48 hours of exposure. This results permit lead us to the conclusion that ethanolic extract with solids charge 1:8 of G. sepium collected to 800 m.a.s.l present the highest biologic activity, proposing the extracts of the plant as possible source of antioxidant and antimicrobial compounds. KeyÍtem Cloning and expression of the predicted α/β hydrolase enzyme from Variovorax sp. EA-ED0101(Universidad EAFIT, 2020) Carmona Berrío, David; Villegas Escobar, Valeska; Correa Álvarez, Javier; Correa Álvarez, Javier; Villegas Escobar, ValeskaÍtem Esta investigación adelanta esfuerzos para crear nuevos antibióticos(2021-04-07) Martinez Guerrero, Christian Alexander; Christian Alexander Martinez-Guerrero; Christian Alexander Martinez-Guerrero; Sierra Zapata, Laura; Alvarez, Javier; Romero Tabarez, Magally; Silby, Mark; Traxler, Matthew; Behie, Scott; Pessotti, Rita de Cassia; Villegas Escobar, Valeska; Vicerrectoría de Descubrimiento y CreaciónÍtem 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 Moko en las plantas de plátano y banano: ¿para combatirlo hay que conocerlo?(Universidad EAFIT, 2020-12-01) Martinez Guerrero, Christian Alexander; Martinez-Guerrero, Christian Alexander; Ramírez, M; Moncada, N; Villegas Escobar, Valeska; Jackson, R.W; Ramírez, C. A.; Ciencias Biológicas y Bioprocesos