Abstract The yerba-mate industry is one of the most important economic activities in Misiones, a province in the northeast of Argentina that is the world’s leading producer and exporter of this crop. White thread blight disease caused by Ceratobasidium niltonzousanum affects the cultivation reducing its quality and productivity. Due to the lack of a standardized visual method to quantify the severity of this disease in yerba mate, a diagrammatic scale was developed and validated. Yerba-mate branches were collected in a field in the north of Misiones province, and the actual severity was determined digitally. A six-level scale was developed using the DOSLOG software, based on the Weber-Fechner law. The validation was carried out by twenty raters. One evaluation without the diagrammatic scale and two evaluations with the scale were carried out in 14-day intervals. Accuracy, precision, and reproducibility of the scale were evaluated through linear regressions and correlation analysis, obtaining R2 values ranged between 0.70 and 0.94. Using the diagrammatic scale developed in this work, raters enhanced the accuracy and precision of the estimates, and the repeatability of the scale improved by 94.74%. The scale was appropriate to assess the damage of white thread blight in yerba mate.

Abstract Cassava cultivation in the Misiones province largely contributes to the national production. Part of it is used to obtain starch, which generates industrial effluents with a high load of organic matter and cyanogenic compounds. This constitutes a problem at the environmental level and bioremediation is presented as an alternative to reduce this waste, since it is based on the degradation of the pollutant using microorganisms present in the contaminated matrix. The objective of this work was to isolate microorganisms with starch degradation capacity and tolerance to cyanide from effluents of the starch industry. We isolated 93 bacterial strains and 15 were preselected by qualitative determination of amylolytic activity. Using the 16S rDNA gene for molecular identification, it was determined that some of these isolates belong to the genera Pseudomonas, Acinetobacter and Proteus. These strains were cultivated in minimal medium with different cyanide concentrations and it was possible to determine that one of them has amylolytic activity and tolerance to cyanide, both desirable characteristics for bioremediation of effluents from the cassava starch industry.

Resumen El cultivo de mandioca en la Provincia de Misiones aporta la mayor parte de la producción a nivel nacional. Parte de la misma es destinada a la obtención de fécula, actividad que genera efluentes industriales con una elevada carga de materia orgánica y compuestos cianogénicos. Esto constituye una problemática a nivel ambiental y la biorremediación se presenta como una alternativa para la reducción de estos residuos, ya que se basa en la degradación del contaminante utilizando los microorganismos presentes en la matriz contaminada. El objetivo de este trabajo fue aislar microorganismos con capacidad para degradar almidón y tolerantes a cianuro a partir de efluentes de una industria almidonera. Fueron aisladas93 cepas bacterianas y 15 de ellas fueron preseleccionadas mediante determinación cualitativa de actividad amilolítica. Utilizando el gen 16S rDNA para la identificación molecular, se determinó que algunos de estos aislamientos pertenecen a los géneros Pseudomonas, Acinetobactery Proteus. Esas cepas se cultivaron en medio mínimo con distintas concentraciones cianuro y se logró determinar que una de ellasposee tanto la actividad amilolítica como la tolerancia a cianuro, ambas características deseables para biorremediación de efluentes de la industria almidonera.

The cultivation of Ilex paraguariensis is important in northern Argentina, mainly in Misiones province. The presence of different symptoms of diseases caused by fungi has recently been observed. Neither the causative agents nor the epidemiological or economic damages have been identified yet. In this study, fungi were isolated from yerba mate leaves that showed visible symptoms of foliar lesions. Five isolated samples: Alternaría, Colletotrichum, Phoma and Pilidium; which were selected because of both, their micro and macro morphological characteristics. These fungi were identified by using an optical microscope together with morphological keys. Pathogenicity tests were carried out on yerba mate leaves and on one-year-old plants. The results showed that Colletotrichum sp. LBM 183 and Phoma sp. LBM 207 are pathogens typical of the yerba mate leaves capable of developing within the plant tissue, while Alternaría sp. LBM 186 and Pilidium sp. LBM 208 were able to sicken the plant by entering into the yerba mate root.

El cultivo de Ilexparaguariensis es importante en el norte de Argentina, principalmente en la provincia de Misiones. En los últimos años se ha observado la presencia de diferentes síntomas de enfermedades causadas por hongos de los cuales no se conoce agente causal, epidemiología y daño económico. En este estudio, se aislaron hongos de hojas de yerba mate que presentaban síntomas visibles de lesiones foliares. Cinco aislados (Alternaría, Colletotrichum, Phoma y Pilidium) fueron seleccionados por sus características micro y macromorfológicas. Estos hongos fueron identificados utilizando un microscopio óptico y claves morfológicas. Se realizaron ensayos de patogenicidad en hojas y en plantas de un año de yerba mate. Los resultados mostraron que Colletotrichum sp. LBM 183 y Phoma sp. LBM 207 son patógenos de hoja de yerba mate capaces de desarrollarse en el tejido. Mientras que Alternaría sp. LBM 186 y Pilidium sp. LBM 208 fueron capaces de enfermar la planta ingresando por la raíz de yerba mate.

α-L-rhamnosidase plays a key role in grape juice and derived beverages processing by enhancing the aroma and in citric juices by removing bitterness. The aim of this work was to study and partially characterize marine microorganisms from different coastal areas of the Beagle Channel and intestinal contents of benthic organisms with α-L-rhamnosidase activity. A total of 10 microorganisms were selected because of their proper growth in MMB supplemented with rhamnose as the sole carbon source, at 8 and 20 °C. According to the quantitative determination of the α-L-rhamnosidase activity, G33 isolate showed the highest activity values at 37 °C (411.7 U.L-1), followed by F6 isolate at 30 °C (250.2 U.L-1). Molecular identification methods classified the isolates F6 and G33 as Serratia and Pseudomonas genera respectively. The results showed that α-L-rhamnosidase enzymes from Serratia sp. F6 and Pseudomonas sp. G33 strains are promising to be used in biotechnological strategies.

Las α-L-ramnosidasas desempeñan un rol clave en jugos de uvas y bebidas derivadas aumentando su aroma; y en jugos cítricos eliminando su amargor. El objetivo del trabajo fue el estudio y caracterización parcial de microorganismos marinos procedentes de diferentes zonas costeras del Canal de Beagle y de contenidos intestinales de organismos bentónicos con actividad α-L-ramnosidasa. A partir de 58 aislamientos cultivados en medio mineral de Brunner (MMB) con ramnosa, fueron seleccionados 10 microorganismos por presentar buen crecimiento a 8 y 20 ºC. A través de la determinación cuantitativa de la actividad α-L-ramnosidasa, se demostró que los aislamientos F6 y G33 presentaron los mayores valores de actividad a 30 °C (250,2 U.L-1) y a 37 °C (411,7 U.L-1). Los aislamientos seleccionados fueron identificados molecularmente como pertenecientes a los géneros Serratia y Pseudomonas. Los resultados de este trabajo indican que las enzimas α-L-ramnosidasas presentes en las cepas Serratia sp. F6 y Pseudomonas sp. G33 tienen un uso potencial en procesos biotecnológicos.