Bioactividad de extracto de Annona muricata y aceites esenciales de Citrus aurantium contra Phytophthora cinnamomi

The aim of this research was determining raised antifungal activity in vitro against P. cinnamomi essential oils of fresh sour orange leaves collected in the municipalities of Sincelejo, Sampués and La Union and dichloromethane extracts of dried leaves collected soursop in the municipalities of La Union and Sincelejo, Sucre department. Direct seeding method was used to determine the bioactivity of oils and extracts. Essential oil concentrations of 15 uL/mL, 17,5 uL/mL and 20 uL/mL were prepared and plant extracts concentrations of 0,05 g/mL, 0,07 g/mL, 0,1 g/mL and 0,5 g/mL were prepared. Finding that for all essential oils and extracts the concentration that showed similar results with the positive control (Agrifos) was 20 uL/mL and 0,5 g/mL respectively. With regard to the chromatographic profiles Sampués essential oils and La Unión as major metabolite they showed the Linalool, while the collected Sincelejo Linalyl anthranilate showed. Plant extracts for soursop was the major metabolite Phytol. It is demonstrated that essential oils of bitter orange leaves and extracts of soursop leaves can be constituted as an agroecological alternative for the biocontrol of P. cinnamomi.El objetivo de esta investigación fue determinar la actividad antifúngica in vitro contra P. cinnamomi de aceites esenciales de hojas frescas de naranja agria recolectada en los municipios de Sincelejo, Sampués y La Unión, y de extractos en diclorometano de hojas secas de guanábana recolectadas en los municipios de Sincelejo y La Unión, departamento de Sucre. Se utilizó el método de siembra directa para determinar la bioactividad de los aceites y extractos. Para los aceites esenciales se prepararon concentraciones de 15 µL/mL, 17,5 µL/mL y 20 µL/mL y para los extractos vegetales se prepararon concentraciones de 0,05 g/mL, 0,07 g/mL, 0,1 g/mL y 0,5 g/mL. Encontrándose que para todos los aceites esenciales y extractos la concentración que mostró resultados similares al control positivo (Agrifos) fue de 20 µL/mL y 0,5 g/mL respectivamente. Con respecto a los perfiles cromatográfico los aceites esenciales de Sampués y La Unión mostraron como metabolito mayoritario al Linalool, mientras que el recolectado en Sincelejo mostró al Antranilato de linalilo. Para los extractos vegetales de guanábana el metabolito mayoritario fue el Fitol. Queda demostrado que los aceites esenciales de hojas naranja agria y extractos de hojas de guanábana se pueden constituir como una alternativa agroecológica para el biocontrol de P. cinnamomi

Presencia de bacterias rizosféricas resistentes a mercurio en suelos del sur de Bolívar, Colombia

The objective of the present study was to isolate rhizospheric bacteria from samples from the Santa Cruz Mine, department of Bolívar, in order to evaluate in vitro resistance activity at different concentrations of mercury. The samples were collected randomly from different sites near the Santa Cruz gold mine, from which they isolated rhizospheric bacteria. The resistance capacity of bacteria at different concentrations of mercury in the form of mercury chloride (HgCl2) at concentrations of 50 ppm, 100 ppm, 150 ppm, 200 ppm and 250 ppm was evaluated in vitro; also the bacteria resistant to this metal were used to evaluate the ability to promote growth in plants. The results showed that the bacterium identified as Pseudomonas luteola, resisted in vitro at 200 ppm of mercury chloride (HgCl2), and qualitatively had the ability to produce siderophores and biologically fix nitrogen. P luteola was isolated from the rhizosphere near the Santa Cruz mine in the department of Bolívar, Colombia, with soils with high concentrations of mercury and extremely acidic soil reaction.El objetivo del presente estudio fue aislar bacterias rizosféricas de muestras provenientes de la Mina de Santa Cruz, departamento de Bolívar, con el propósito de evaluar in vitro la actividad de resistencia a diferentes concentraciones de mercurio. Las muestras fueron recolectadas aleatoriamente de diferentes sitios de cerca de la mina de oro Santa Cruz, a partir de la cuales de aislaron bacterias rizosférico. Se evaluó in vitro la capacidad de resistencias de las bacterias a diferentes concentraciones de mercurio en forma de cloruro de mercurio (HgCl2) a concentraciones de 50 ppm, 100 ppm, 150 ppm, 200 ppm y 250 ppm; así mismo las bacterias resistentes a este metal se utilizaron para evaluar la capacidad de promoción de crecimiento en las plantas. Los resultados mostraron que la bacteria identificada como Pseudomonas luteola, resistió in vitro a 200 ppm de cloruro de mercurio (HgCl2), y cualitativamente tuvo la capacidad de producir sideróforos y fijar biológicamente nitrógeno. P luteola fue aislada de la rizósfera cerca de la mina de Santa Cruz en el departamento de Bolívar, Colombia, con suelos con altas concentraciones de mercurio y con reacción del suelo extremadamente acida

Presence of mercury-resistant rhizosphere bacteria in soils in the Southern Bolívar, Colombia

The objective of the present study was to isolate rhizospheric bacteria from samples from the Santa Cruz Mine, department of Bolívar, in order to evaluate in vitro resistance activity at different concentrations of mercury. The samples were collected randomly from different sites near the Santa Cruz gold mine, from which they isolated rhizospheric bacteria. The resistance capacity of bacteria at different concentrations of mercury in the form of mercury chloride (HgCl2) at concentrations of 50 ppm, 100 ppm, 150 ppm, 200 ppm and 250 ppm was evaluated in vitro; also the bacteria resistant to this metal were used to evaluate the ability to promote growth in plants. The results showed that the bacterium identified as Pseudomonas luteola, resisted in vitro at 200 ppm of mercury chloride (HgCl2), and qualitatively had the ability to produce siderophores and biologically fix nitrogen. P luteola was isolated from the rhizosphere near the Santa Cruz mine in the department of Bolívar, Colombia, with soils with high concentrations of mercury and extremely acidic soil reaction