La demanda mundial de aguacate Hass supera la oferta en más de un 50%. A pesar de los altos rendimientos de este cultivo en Colombia, la productividad se ve seriamente afectada por enfermedades como la pudrición de la raíz, causada por Phytophthora cinnamomi, y las pudriciones poscosecha causadas por Colletotrichum sp. y Phomopsis sp. En este trabajo se evaluó el potencial de 76 aislamientos bacterianos obtenidos de la rizósfera de plantas de aguacate, para la producción de metabolitos con actividad inhibitoria frente a patógenos del cultivo. El efecto antagonista de las rizobacterias frente a P. cinnamomi, Colletotrichum sp. y Phomopsis sp. fue probado a través de cultivos duales. El 36% de los aislamientos evaluados mostraron halos de inhibición frente a P. cinnamomi, 36% frente a Colletotrichum sp. y 67% frente a Phomopsis sp. Tres de los aislamientos más promisorios se fermentaron en diferentes medios de cultivo líquidos. Los extractos de los aislamientos ARP5.1 y AED06 a partir de medio mínimo mostraron actividad inhibitoria frente a los patógenos. Los medios suplementados con cloruro de cobre no incrementaron la actividad de los extractos. Estos resultados demostraron la viabilidad de utilizar extractos metabólicos microbianos como una alternativa para controlar in vitro los patógenos de aguacate.

The demand for Hass avocado in the global market exceeds the supply by over 50%. Colombia has a remarkable advantage as a producer in the region due to its high yields. However, the productivity of this crop can be seriously affected by diseases such as root rot, caused by Phytophthora cinnamomi, postharvest body rot and stem end rot, caused by Colletotrichum sp. and Phomopsis sp., respectively. The potential of 76 bacterial isolates obtained from avocado rhizosphere to produce inhibitory metabolites against avocado's pathogens was evaluated. The antagonistic effect of the rhizobacteria against P. cinnamomi, Colletotrichum sp. and Phomopsis sp. was tested through dual cultures. Thirty-six percent of the tested isolates presented inhibition halos against P. cinnamomi, 36% against Colletotrichum sp. and 67% against Phomopsis sp. Additionally, three isolates were selected for fermentation tests using different broth cultures. The extracts obtained from fermentations in the minimal medium of isolates ARP5.1 and AED06 showed inhibitory activity against the evaluated pathogens, but this effect was not observed with the AED26 extract. The media supplemented with copper chloride did not enhance activity of the extracts. These results suggest that using microbial metabolic extracts is a viable alternative for controlling avocado pathogens in vitro.

En este estudio se cuantificó la limonina presente en extractos etanólicos de residuos cítricos (cáscaras y semillas) de dos especies (Citrus sinensis y C. limonia) y sus respectivas fracciones en n-hexano, diclorometano, acetato de etilo y agua por medio de HPLC. Se realizaron ensayos de actividad antialimentaria, medida a través de los índices antialimentarios (disuasorio y antiapetitivo) e índice antinutricional (tasa de incremento de peso), con los respectivos extractos, fracciones diclorometánicas, sobre Spodoptera frugiperda. También se relacionaron con el contenido de limonina pura en los tratamientos. Las fracciones diclorometánicas de las semillas de C. sinensis y C. limonia presentaron un mayor rendimiento de limonina (1,86 ppm y 1,35 ppm, respectivamente) y una mayor actividad antialimentaria. El análisis de regresión lineal mostró que la bioactividad, medida a través de los índices, tiene relación directa con el contenido de limonina de cada tratamiento. Los resultados permitieron establecer que los residuos de cítricos presentan metabolitos de interés que tienen un potencial uso para el control de S. frugiperda.

In this study was quantified limonin in ethanol extracts of citrus waste (peels and seeds) of two species (C. limonia and Citrus sinensis) and their fractions in n- hexane, dichloromethane, ethyl acetate and water by HPLC. Antifeedant activity assays measured through several antifeedant indices to the respective extracts (dicloromethane fractions) were carried on Spodoptera frugiperda. In addition, a relationship between the content of limonin and the treatments was established. The dicloromethane fractions from seeds of C. sinensis and C. limonia had a higher yield of limonin (1.86 ppm and 1.35 ppm, respectively) and greater antifeedant activity. The linear regression analysis showed that the bioactivity, as measured by the indices, is directly related to the content of limonin on each treatment. The results are promising in terms of the use of citrus waste metabolites as potential control agents of S. frugiperda.

Os microorganismos biocontroladores têm capacidade de produzir compostos ativos que inibem o desenvolvimento de fitopatógenos, constituindo-se em uma ferramenta promissora para a obtenção de princípios ativos que substituem os pesticidas de sínteses. No presente trabalho, avaliou-se a capacidade de um conjunto de gentes com potencial biocontrolador, para produzir metabólitos extracelulares ativos. Avaliou-se a atividade antagônica in vitro de 50 isolamentos bacterianos provenientes de solos rizosféricos de batata (Solanum phureja) através de confrontamentos duplos com diferentes fungos e bactérias fitopatógenicas desta planta. Os isolamentos que mostraram atividade antagônica significativamente superior foram submetidos a fermentações líquidas e a partir dos sobrenadantes se obtiveram extratos brutos, cujas atividades biológicas foram determinadas empregando-se técnicas de densidade óptica. Evidenciou-se inibição sob os fitopatógenos avaliados para concentrações entre 0,5% para 1% dos extratos brutos. Observou-se uma correlação da atividade antimicrobiana dos extratos com o emprego de meios de cultivo ricos em nutrientes nas fermentações bacterianas. De forma biodirigida, isolou-se um composto de natureza peptídica com atividade contra Fusarium oxyporum a partir da cepa 7ANT04 (Pyrobaculum sp.). Com base nas análises por ressonância magnética nuclear e cromatografia líquida acoplada a detector de massas evidenciou-se um composto constituído por onze aminoácidos. O processamento dos dados de massas, mediante softwares de bioinformática, confirmou que o composto isolado é um peptídeo cíclico constituído por onze aminoácidos, em sua maioria, não comuns.

Microorganisms for biological control are capable of producing active compounds that inhibit the development of phytopathogens, constituting a promising tool toob tain active principles that could replace synthetic pesticides. This study evaluatedtheability of severalpotentialbiocontrol microorganismsto produce active extracellular metabolites. In vitro antagonistic capability of 50 bacterial isolates from rhizospheric soils of "criolla" potato (Solanum phureja) was tested through dual culture in this plant with different plant pathogenic fungi and bacteria. Isolates that showed significantly higher antagonistic activity were fermented in liquid media and crude extracts from the supernatants had their biological activities assessed by optical density techniques. Inhibitory effecton tested pathogens was observed for concentrations between 0.5% and 1% of crude extracts. There was a correlation between the antimicrobial activity of extracts and the use of nutrient-rich media in bacteria fermentation. Using a bioguided method, a peptidic compound, active against Fusarium oxysporum, was obtained from the 7ANT04 strain (Pyrobaculum sp.). Analysis by nuclear magnetic resonance and liquid chromatography coupled to mass detector evidenced an 11-amino acid compound. Bioinformatic software using raw mass data confirmed the presence of a cyclic peptide conformed by 11 mostly non-standard amino acids.

Se evaluó la actividad anti-alimentaria de extractos etanólicos y fracciones purificadas de residuos cítricos (Citrus sinensis y Citrus limonia) sobre una colonia establecida in vitro de Spodoptera frugiperda, especie considerada plaga en maíz y otros cultivos en Colombia. Se realizó una extracción etanólica de los residuos (cáscaras y semillas obtenidos a partir de desechos de la producción de jugos) y un posterior fraccionamiento líquido/líquido con n-hexano, diclorometano, acetato de etilo y agua. Los extractos y fracciones se caracterizaron por cromatografía de capa delgada y tamizaje fitoquímico con pruebas en base húmeda para identificar los principales núcleos bioactivos presentes. La actividad antialimentaria se evaluó mediante pruebas de preferencia con discos de Ricinus communis impregnados con una solución a diferentes concentraciones (0,25, 0,5, 0,75, 1% m/v) de los extractos y sus fracciones. Se determinaron los índices disuasivo, anti-apetitivo y la tasa de incremento de peso de las larvas. Los ensayos indicaron que la actividad anti-alimentaria fue dosis-dependiente, siendo los extractos y las fracciones en diclorometano de semillas las que mostraron mayor efecto antialimentario. Las fracciones de cáscara no mostraron actividad significativa a las concentraciones evaluadas. Los resultados sugieren que compuestos recuperados de residuos de cítricos, presentan potencial anti-alimentario y se podrían usar en el control de S. frugiperda.

This study evaluated the antifeedant activity of ethanol extracts and purified fractions of citrus waste (Citrus sinensis and Citrus limonia) on an in vitro colony of Spodoptera frugiperda, a species considered a pest on corn and other crops in Colombia. The citrus residues (peels and seeds obtained from waste from the production of juices), were extracted with ethanol by liquid/liquid fractionation using n-hexane, dichloromethane, ethyl acetate and water. The extracts and fractions were characterized by thin layer chromatography and phytochemical screening tests on wet basis to identify key bioactive cores. The antifeedant activity was evaluated by preference test with discs of Ricinus communis impregnated with solution at different concentrations (0.25, 0.5, 0.75, 1% m/v) of the extracts and their fractions. The deterrent, anti-appetitive index and the rate of increase in weight of larvae were determined. The tests indicated that antifeedant activity was dose-dependent, under treatment of dichloromethane extracts and fractions of seeds, which showed greater antifeedant effect. The peels did not show significant activity at the concentrations tested. The results suggest that kind of compounds found in citrus waste, have an antifeedant activity and could be potentially used in the control of S. frugiperda.

Introduction: the antioxidant capacity in plants has aroused great interest due to their potential use in food for the prevention of oxidative stress-associated diseases. Objectives: to evaluate the effect of CuCl2 and Paraquat® induction on protoplasts and tomato seedlings belonging to Lycopersicon hirsutum Dunal and Lycopersicon esculentum Mill. species. Methods: the production of reactive oxygen species in protoplasts of tomato both species after exposure to CuCl2 and Paraquat® (1.1'-dimethyl-4.4'-bipiridyl dichloride) was evaluated by flow cytometry. Tomato seedlings were evaluated for total polyphenol content and free radical scavenging. Results: Paraquat® induction showed a 17.4 fold increase in reactive oxygen species production for L. hirsutum protoplasts and a 12.4 fold for L. esculentum during early events with respect to their respective untreated controls. L. esculentum showed significant slopes for free radical scavenging and total polyphenol content: 1.81 galic acid eq per hour and 5.3 % DPPH discoloration per hour, respectively. In addition, in response to the two kinds of induction, positive slopes and a correlation between total polyphenol content and free radical scavenging were observed with copper induction (correlation close to 1 and highly significant), but not significant models during Paraquat® induction. Conclusions: these results suggest that the biosynthesis of phenolic compounds and the correlation with the free radical scavenging are not necessarily related to antioxidant activity as a cellular defense mechanism.

Introducción: la capacidad antioxidante presente en las plantas ha despertado gran interés debido al potencial aprovechamiento en la alimentación para la prevención de enfermedades asociadas a estrés oxidativo. Objetivo: evaluar el efecto de la inducción con CuCl2 y Paraquat® (dicloruro de 1,1'-dimetil-4,4'-bipiridilo) sobre protoplastos y plántulas de las especies relacionadas de tomate, Lycopersicon hirsutum Dunal y Lycopersicon esculentum Mill. Métodos: la producción de especies reactivas de oxígeno se evaluó mediante citometría de flujo en protoplastos de las 2 especies de tomate, inducidos con CuCl2 y Paraquat® (dicloruro de 1,1'-dimetil-4,4'-bipiridilo). Adicionalmente, sobre las plántulas se evaluó el contenido de polifenoles totales y la capacidad atrapadora de radicales libres. Resultados: la inducción con Paraquat® durante eventos tempranos mostró un aumento en la producción de especies reactivas de oxígeno en 17,4 veces en protoplastos de Lycopersicon hirsutum y de 12,4 veces en Lycopersicon esculentum con respecto a sus respectivos controles no tratados. La especie Lycopersicon esculentum presentó velocidades de producción significativas de contenido de polifenoles totales y capacidad atrapadora de radicales libres con valores de 1,81 Eq ácido gálico hora-1 y 5,3 % de decoloración del DPPH hora-1, respectivamente. Durante la inducción con Paraquat® se observó una correlación entre contenido de polifenoles totales y capacidad atrapadora de radicales libres cercana a 1 y altamente significativa, en respuesta a los 2 tipos de inducción durante los eventos tempranos. Conclusiones: los resultados sugieren que la biosíntesis de compuestos fenólicos y la correlación con la capacidad atrapadora de radicales libres, no necesariamente se encuentra relacionada con una actividad antioxidante como un mecanismo de defensa a nivel celular.

A pesquisa relacionada com a resposta inata das plantas á estresses tem atraído muito interesse por a similitude com as respostas reportadas nos mamíferos. Assim, foi proposta uma aproximação ás respostas de defesa aos estresses abióticos através da avaliação no modelo biológico Lycopersicon spp. da atividade enzimática caspase 10 em resposta da indução com CuCl2 y paraquat. Os ensaios da atividade caspase 10 mostraram um máximo de atividade na concentração 40 mM, 9 horas depois da elicitação, com uma pendente de 0,0054 e 0,0022 para L. hirsutum y L. esculentum respectivamente. A atividade comparativa dos genótipos sugere que, embora os dois genótipos presenteassem atividade, a resposta é menos variável de maior magnitude para L. hirsutum. A elicitação com paraquat presenteou a maior atividade caspase 10 em torno das 2 horas depois do estímulo, com uma pendente de 0,013 e 0,0012 para L. hirsutum y L. esculentum respectivamente. A determinação direita da atividade caspase 10 nas plântulas de tomate tratadas com cobre e paraquat, usando um substrato específico para mamíferos, mostrou que estes mecanismos estão relacionados provavelmente com processos de apoptose depois da indução abiótica.

Plant defense responses to stress have attracted interest because of their similarity to reported mammalian stress responses. To investigate plant responses to abiotic stress, caspase 10-like enzymatic activities of Lycopersicon hirsutum and Lycopersicon esculentum were assayed in response to copper chloride and paraquat induction. Caspase 10-like activity was greatest at 40 mM CuCl2 at 9 h after elicitation in both L. hirsutum and L. esculentum, for which respective response slopes (Δ absorbance per Δ minute) were 0.0054 and 0.0022 . The response for L. hirsutum was less variable and significantly greater than for L. esculentum. Elicitation of caspase 10-like activity by paraquat was greatest at around 2 h after treatment in both species with slopes of 0.013 and 0.0012, respectively for L. hirsutum and L. esculentum. The direct determination of caspase 10-like activity in tomato seedlings treated with copper and paraquat, using a specific substrate for mammals, suggested that the observed responses were related to apoptosis processes under abiotic induction.

As plantas estão expostas a agentes externos bióticos e abióticos que podem produzir dano nas celulas. Os agentes bióticos incluem moléculas produzidas por patógenos e os agentes abióticos incluem radiação ultravioleta, metais pesados e os agentes xenobióticos como os herbicidas. Devido à importancia do estresse abiotico e o limitado conhecimiento sob as respostas de defensa das plantas ao estresse, este estudo foi feito usando a citometría de fluxo para avaliar os eventos endocelulares de duas espécies de tomate: Lycopersicon hirsutum e Lycopersicon esculentum depois da exposição a 10 mM CuCl2 e 1% do paraquat. Durante os primeiros 30 min da exposição ao CuCl2 os valores da intensidade média da fluorescência em ambas as espécies diminuiu mais do 50% quando comparado com os controles não tratados. No caso do tratamento com o paraquat, depois dos primeiros 30 minutos a produção das espécies reativas do oxigênio, (avaliada pela presença do ânion superóxido) na espécie L. hirsutum e L. esculentum foi de 32,9% e 25,4%, respectivamente. A hiperpolarização das mitocôndrias das duas espécies do tomate foi observada durante as 2 primeiras horas. A ausência de dano no início ao nível da membrana e os efeitos adversos na mitocôndria causados pelos tratamentos sugerem que poda haver mecanismos adicionais que levam à morte celular, e que estes mecanismos podem estar associados à apoptose.

Plants are often exposed to external biotic or abiotic agents that can damage cells. Biotic agents include molecules produced by pathogens, and abiotic agents include ultraviolet radiation, heavy metals and xenobiotic agents such as herbicides. Because of the importance of abiotic stresses and the limited knowledge of the defense responses of plants to stresses, a study was conducted using flow cytometry to evaluate endocellular events in protoplasts of two tomato species, Lycopersicon hirsutum and Lycopersicon esculentum, following exposure to 10 mM CuCl2 and 1% paraquat. During the first 30 min of exposure to 10 mM CuCl2, mean fluorescence intensity values in both species decreased by more than 50% compared to the untreated control. During the first 30 min of paraquat treatment, the production of reactive oxygen species, evaluated as the incidence of protoplasts in which the superoxide anion was present, was 32.9 % and 25.4%, respectively, for L. hirsutum and L. esculentum. Hyperpolarization of the mitochondria for both tomatoes species was observed during the first 2 h. The absence of early membrane damage and the markedly detrimental effects of the treatments on the mitochondria suggest that additional mechanisms which lead to cell death may be involved in these processes, and that these mechanisms may be associated with apoptosis.

Background: The health effects of air pollution have been analyzed in numerous studies over recent years, thus having made it possible to quantify the relationship between the two. This study is aimed at analyzing the theoretical benefits which would be achieved by meeting the air quality objectives set forth under EC Directive 1999/30/EC with regard to suspended particles. Methods: The exposure measurement was taken for Black Smoke (Barcelona, Bilbao, Valencia) and suspended particles under 10 µm (PM10) (Bilbao, Madrid y Sevilla). The health indicators calculated were the mortality due to all causes and respiratory and cardiovascular causes, and emergency hospital admissions and mortality due to respiratory and cardiovascular causes. In the case of PM10 the impact has been calculated because its effects to short-term, within a period of up to 40 days following exposure, and to long-term. For Black Smoke the effects only has been calculated to short-term. Results: The daily levels of PM10 from exceeding 50 µg/m³ in Bilbao, Madrid and Sevilla cause the earlier death of 1.4/100,000 individuals per year because its effects. The effect within a period of up to 40 days following exposure is of 2.8 deaths/100,000. The total number of deaths per year which may be later due to long-term exposure if the yearly average is lowered to 20 µg/m³ is 68/100,000. Conclusions: The health impact of the current air pollution levels is quantifiable and is not insignificant. APHEIS and the impact evaluations may be of aid in healthcare planning and environmental policies.

Fundamento: Los efectos de la contaminación atmosférica sobre la salud han sido objeto en los últimos años de numerosos estudios que han permitido cuantificar la asociación entre ambas El objetivo de este trabajo es llevar a cabo la Evaluación del Impacto en Salud (EIS) calculando los beneficios que se obtendrían al cumplir los objetivos establecidos por la Directiva 1999/30/CE en relación con las partículas en suspensión. Métodos: Se ha valorado el impacto en salud de la contaminación atmosférica por partículas en suspensión, para lo que se han utilizado dos indicadores distintos: Humos Negros (HN) (Barcelona, Bilbao, Valencia) y partículas en suspensión menores de 10 µm (PM10) (Bilbao, Madrid y Sevilla). Los indicadores de salud fueron la mortalidad por todas las causas, por causa respiratoria y por causa cardiovascular, e ingresos hospitalarios urgentes por causa respiratoria y cardiovascular. El EIS se ha realizado mediante el cálculo de la fracción atribuible a la contaminación por partículas. En el caso de PM10 se ha calculado el impacto debido a efectos de la contaminación a corto plazo, los acumulados hasta 40 días después, y a largo plazo. Para HN únicamente se han calculado efectos a corto plazo. Resultados: Los niveles diarios de PM10 por encima de 50 µg/m³ en Bilbao, Madrid y Sevilla son responsables de 1,4 muertes prematuras por 100.000 habitantes y año debido a sus efectos a corto plazo y de 2,8 muertes/100.000 en un periodo de hasta 40 días tras la exposición. A largo plazo, el número de muertes prematuras atribuibles a la contaminación media anual de PM10 por encima de 20 µg/m³ es 68/100.000. Conclusiones: El impacto en salud de los niveles actuales de contaminación atmosférica es cuantificable y no despreciable. APHEIS y las evaluaciones de impacto pueden ayudar a la planificación sanitaria y a las políticas medioambientales.

Background: The health effects of air pollution have been analyzed in numerous studies over recent years, thus having made it possible to quantify the relationship between the two. This study is aimed at analyzing the theoretical benefits which would be achieved by meeting the air quality objectives set forth under EC Directive 1999/30/EC with regard to suspended particles. Methods: The exposure measurement was taken for Black Smoke (Barcelona, Bilbao, Valencia) and suspended particles under 10 µm (PM10) (Bilbao, Madrid y Sevilla). The health indicators calculated were the mortality due to all causes and respiratory and cardiovascular causes, and emergency hospital admissions and mortality due to respiratory and cardiovascular causes. In the case of PM10 the impact has been calculated because its effects to short-term, within a period of up to 40 days following exposure, and to long-term. For Black Smoke the effects only has been calculated to short-term. Results: The daily levels of PM10 from exceeding 50 µg/m³ in Bilbao, Madrid and Sevilla cause the earlier death of 1.4/100,000 individuals per year because its effects. The effect within a period of up to 40 days following exposure is of 2.8 deaths/100,000. The total number of deaths per year which may be later due to long-term exposure if the yearly average is lowered to 20 µg/m³ is 68/100,000. Conclusions: The health impact of the current air pollution levels is quantifiable and is not insignificant. APHEIS and the impact evaluations may be of aid in healthcare planning and environmental policies.

Fundamento: Los efectos de la contaminación atmosférica sobre la salud han sido objeto en los últimos años de numerosos estudios que han permitido cuantificar la asociación entre ambas El objetivo de este trabajo es llevar a cabo la Evaluación del Impacto en Salud (EIS) calculando los beneficios que se obtendrían al cumplir los objetivos establecidos por la Directiva 1999/30/CE en relación con las partículas en suspensión. Métodos: Se ha valorado el impacto en salud de la contaminación atmosférica por partículas en suspensión, para lo que se han utilizado dos indicadores distintos: Humos Negros (HN) (Barcelona, Bilbao, Valencia) y partículas en suspensión menores de 10 µm (PM10) (Bilbao, Madrid y Sevilla). Los indicadores de salud fueron la mortalidad por todas las causas, por causa respiratoria y por causa cardiovascular, e ingresos hospitalarios urgentes por causa respiratoria y cardiovascular. El EIS se ha realizado mediante el cálculo de la fracción atribuible a la contaminación por partículas. En el caso de PM10 se ha calculado el impacto debido a efectos de la contaminación a corto plazo, los acumulados hasta 40 días después, y a largo plazo. Para HN únicamente se han calculado efectos a corto plazo. Resultados: Los niveles diarios de PM10 por encima de 50 µg/m³ en Bilbao, Madrid y Sevilla son responsables de 1,4 muertes prematuras por 100.000 habitantes y año debido a sus efectos a corto plazo y de 2,8 muertes/100.000 en un periodo de hasta 40 días tras la exposición. A largo plazo, el número de muertes prematuras atribuibles a la contaminación media anual de PM10 por encima de 20 µg/m³ es 68/100.000. Conclusiones: El impacto en salud de los niveles actuales de contaminación atmosférica es cuantificable y no despreciable. APHEIS y las evaluaciones de impacto pueden ayudar a la planificación sanitaria y a las políticas medioambientales.