Polypropylene degrading actinobacteria

La acumulación de polímeros sintéticos es un gran problema de contaminación ambiental, ya que no existen métodos eficientes para su eliminación segura; sin embargo, hay evidencias sobre su degradación por actinobacterias. En este trabajo se evaluó la capacidad de degradación de actinobacterias aisladas de suelo del vertedero de Bariloche, sobre tres biopolímeros y un polímero sintético. Por un lado, se estudió la degradación de polímeros naturales (almidón, hemicelulosa, celulosa) en medio sólido, y por otro el otro se evaluó la degradación de láminas de polipropileno inoculadas con los aislamientos y cultivadas en medio líquido durante seis semanas a 37 ºC. Luego se midió la pérdida de peso en las láminas y se estudió la colonización de la superficie del polipropileno mediante microscopia óptica y electrónica. Los datos fueron analizados con un ANOVA de dos vías y la prueba de Tukey. De los 35 aislamientos totales, el 88 % correspondió al género Streptomyces y el 3 % a los demás géneros (Actinomadura, Pseudonocardia, Saccharomonospora y Thermoactinomyces). El 63 % de los aislamientos tuvo la capacidad de degradar almidón, el 86 % hemicelulosa, el 34 % celulosa microcristalina (exoglucanasas) y el 88 % carboximetilcelulosa (endoglucanasas). Se observó colonización de la superficie de polipropileno en todos los tratamientos. Dos de las cepas estudiadas (Streptomyces sp. MP32 y Actinomadura sp. MP5) redujeron el peso de las láminas de polipropileno (p ≤ 0.05). Estos resultados preliminares muestran la capacidad de las actinobacterias para colonizar la superficie del polipropileno, con potencial uso en suelos o ambientes contaminados por plásticos.The accumulation of synthetic polymers is a great environmental contamination issue, since there are no efficient methods to dispose them safely; however, there is evidence about the degradation of plastics by actinobacteria. In this work we tested the degradation capacity of tree biopolymers and a synthetic polymer by actinobacteria isolated from the soil of a landfill in Bariloche. On the one hand, we studied the degradation of natural polymers (starch, hemicellulose, cellulose) in a solid medium, and on the other hand, we studied the degradation of polypropylene sheets inoculated with the isolates and cultured in liquid medium for six weeks at 37 ºC. We then measured weight loss in the sheets and studied colonization of the polypropylene surface using light and electron microscopy. The data were analyzed with a two-way ANOVA and Tukey’s test. Of the 35 total isolates, 88 % corresponded to the Streptomyces genus and 3 % to the rest of genera (Actinomadura, Pseudonocardia, Saccharomonospora and Thermoactinomyces). Of the isolates, 63 % were able to degrade starch, 86 % hemicellulose, 34 % microcrystalline cellulose (exoglucanases), and 88% carboxymethyl cellulose (endoglucanases). Colonization of the polypropylene surface was observed in all treatments. Two of the strains studied, Streptomyces sp. MP32 and Actinomadura sp. MP5 reduced the weight of the polypropylene sheets (p ≤ 0.05). These preliminary results show the ability of actinobacteria to colonize the polypropylene surface, with potential use in soils or environments contaminated by synthetic polymers.Fil: Boenel, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; ArgentinaFil: Vobis, Gernot. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Solans, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin

Effect of yeast and mycorrhizae inoculation on tomato production under normal and water stress conditions

The integration of beneficial microorganisms into agricultural systems can improve crop resistance to stress and increase yields. We studied tomato (Solanum lycopersicum) production in a greenhouse experimental trial over a complete growing season. The experimental design involved three factors: irrigation condition (normal/low), addition of the arbuscular mycorrhizal fungi Funneliformis mosseae (with/without), and inoculation with four native soil yeasts (Candida aff. ralunensis; Candida sake; Lachancea nothofagi and Candida oleophila). Co-inoculation of F. mosseae and yeasts did not affect the tomato plants. Addition of F. mosseae increased mycorrhizal colonization and production variables regardless of irrigation level; however, its effects on growth were variable. None of the inoculated yeasts increased mycorrhizal colonization. C. aff. ralunensis and C. oleophila inoculation increased stem diameter under all conditions studied. C. aff. ralunensis inoculation enhanced fruit set and the fruit/flower ratio under normal irrigation conditions, while C. sake inoculation increased the fruit/flower ratio under low irrigation conditions. Arbuscular mycorrhizae inoculation is presented as a beneficial production strategy to increase plant tolerance and improve water use. We propose that C. aff. ralunensis and C. oleophila inoculation improves plant vigor. Highlights: Tomato production under greenhouse conditions was studied during a complete growing season following a three-factor trial: irrigation condition (normal/low), addition of arbuscular mycorrhizal fungi and inoculation with four native soil yeasts. Addition of arbuscular mycorrhizal increased mycorrhizal colonization and production variables regardless of irrigation level. Inoculation with two of the yeasts studied increased stem diameter under all conditions studied. Utilizing indigenous microorganisms could represent a promising alternative to external inoculants, potentially cutting down production costs and eliminating the necessity of introducing foreign microorganisms into the environment.The integration of beneficial microorganisms into agricultural systems can improve crop resistance to stress and increase yields. We studied tomato (Solanum lycopersicum) production in a greenhouse experimental trial over a complete growing season. The experimental design involved three factors: irrigation condition (normal/low), addition of the arbuscular mycorrhizal fungi Funneliformis mosseae (with/without), and inoculation with four native soil yeasts (Candida aff. ralunensis; Candida sake; Lachancea nothofagi and Candida oleophila). Co-inoculation of F. mosseae and yeasts did not affect the tomato plants. Addition of F. mosseae increased mycorrhizal colonization and production variables regardless of irrigation level; however, its effects on growth were variable. None of the inoculated yeasts increased mycorrhizal colonization. C. aff. ralunensis and C. oleophila inoculation increased stem diameter under all conditions studied. C. aff. ralunensis inoculation enhanced fruit set and the fruit/flower ratio under normal irrigation conditions, while C. sake inoculation increased the fruit/flower ratio under low irrigation conditions. Arbuscular mycorrhizae inoculation is presented as a beneficial production strategy to increase plant tolerance and improve water use. We propose that C. aff. ralunensis and C. oleophila inoculation improves plant vigor. Highlights: Tomato production under greenhouse conditions was studied during a complete growing season following a three-factor trial: irrigation condition (normal/low), addition of arbuscular mycorrhizal fungi and inoculation with four native soil yeasts. Addition of arbuscular mycorrhizal increased mycorrhizal colonization and production variables regardless of irrigation level. Inoculation with two of the yeasts studied increased stem diameter under all conditions studied. Utilizing indigenous microorganisms could represent a promising alternative to external inoculants, potentially cutting down production costs and eliminating the necessity of introducing foreign microorganisms into the environment