Biobeds: a sustainable alternative to reduce point-source pesticides pollution

Pesticides are among the most employed organic compounds worldwide and play an important role in modern agriculture and food production. However, their inadequate management can lead to contamination of soil, surface, and groundwater. In the last decades, point-source pesticides pollution has been rigorously addressed, through the evaluation and implementation of bioprophylaxis strategies, in order to reduce or avoid these environmental impacts. For this purpose, biobeds (BB), initially developed in Sweden, are among the most promising technologies. They consist of a simple, ecological and cost-effective construction designed to retain and degrade pesticides, with three main components: a clay layer, a biomixture and a grass layer that covers the surface. Biomixture (BM) represents the biologically active part of a BB, where the adsorption and degradation of pesticides take place. It is composed of a lignocellulosic substrate, a humic rich component and a soil; each component plays an important role in the pesticides dissipation. However, the design of a BM should be adapted to each region and will depend on the availability of the materials. Also, the adequate efficiency of the BM can be improved by bioaugmentation with microorganisms with specific degrading capacities. Among a wide range of microorganisms, actinobacteria play an important ecological role in the environment due to their ability to remove a large diversity of xenobiotic compounds.Based on the above, this conference will present studies related to the behavior of BM formulated with different kind of soils and locally available by-products derived from the sugarcane industry in Argentina, and the effect of their bioaugmentation with autochthonous actinobacteria, on the pesticides removal ability. In a first stage, the performance of biomixtures formulated with a byproduct derived from a local industry (bagasse) and soils of different textures, and the effect of the bioaugmentation with a consortium of actinobacteria and fungi, on their lindane removal capacity was evaluated. As result of this preliminary work, silty loam soil was selected as the most efficient for formulating a BM.Then, the removal of atrazine (ATZ) was evaluated in BM formulated with three sugarcane by-products as alternative lignocellulosic substrates. Also, the effect of the bioaugmentation with actinobacteria was evaluated as a strategy to enhance the depuration capacity of BM. BM formulated with bagasse, filter cake, or harvest residue, reached ATZ removal of 37–41% at 28 d of incubation, with t1/2 between 37.9 and 52.3 d. The bioaugmentation with Streptomyces sp. M7 accelerated the dissipation of the pesticide in the BM, reducing ATZ t1/2 regarding the controls, and achieved up to 72% of ATZ removal. The bioaugmentation improved the development of the microbiota in BM, specially actinobacteria and fungi and enhanced acid phosphatase activity and/or reversed a possible effect of ATZ over this enzymatic activity.Fil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; ArgentinaXVII Congreso Argentino de Microbiología GeneralLos CocosArgentinaSociedad Argentina de Microbiología Genera

Furfural removal from liquid systems by actinobacteria

Many industries such as petrochemical, pulp and paper, pharmaceutical, and food industries involve processes that use or produce furfural. Furfural is a heterocyclic aldehyde obtained by dehydrating at high temperatures of xylose; therefore, it is a characteristic compound present in acid hydrolyzates in which the furfural concentration can usually reach 2–3 g l−1. In the region Northeast of Argentina (NEA), furfural is produced from detanized quebracho sawdust. In NEA, wastewaters derived from furfural production contain around 800 mg l-1 of this compound, which can cause toxic effects on living systems if they are released into the environment without proper treatment. In the present work, the removal of different concentrations of furfural by actinobacteria from liquid systems was studied. Isolates of actinobacteria called L4, L6, L9 and L13 obtained from sediments of stabilization ponds of a furfural-producing plant in the NEA region, and Streptomyces sp. A5, A6, A12, A14 and M7, obtained from sites contaminated with other xenobiotic compounds, were selected on base of their tolerance to furfural in Starch Casein Agar medium. In order to select the most efficient actinobacteria with respect to their growth and furfural removal ability in liquid medium, Minimal Medium (MM) added with a furfural concentration of 418±1 mg l-1 as the only carbon and energy source was used. This selection was carried out by determining the minimum relationship between the concentration of residual furfural and the microbial growth. Streptomyces sp. A12 and M7 and strain L9 were selected because they showed the minimal relationship. Subsequently, the selected strains, as pure and mixed cultures, were inoculated in MM supplemented with furfural 807±10 mg l-1 as the only carbon and energy source. The results showed that the three pure cultures were able to grow and develop under these conditions; however, the culture for which the relationship mentioned above was minimal, was the consortium formed by the actinobacteria L9, A12 and M7. In order to evaluate the effectiveness of the bioremediation process, ecotoxicity tests were carried out using Raphanus sativus seeds (radish, Punta Blanca variety). The culture supernatants were evaluated before and after its treatment for each condition. In response, inhibition of germination and elongation of the radicle and hypocotyl were determined in the presence of furfural. Significant increases in these bioindicators (p < 0.05) were obtained when the treatment was carried out with the consortium formed by the actinobacteria L9, A12 and M7. The results obtained suggest that the selected actinobacteria consortium represents a promising bioremediation tool for the treatment of effluents containing furfural.Fil: Echeverría, M. C.. Universidad Tecnológica Nacional. Facultad Regional Resistencia; ArgentinaFil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; ArgentinaXVII Congreso Argentino de Microbiología GeneralLos CocosArgentinaSociedad Argentina de Microbiología Genera

Bioremediation of lindane and chrome (vi) co-contaminated soils by bioaugmentation with an indigenous consortium of actinobacteria

The technological advances and the growth of the world population have created severe problems of mixed contamination in soils, by both organic and inorganic compounds. In particular, mixed pollution by chromium VI [Cr(VI)] and lindane (LIN) has been reported in different environments around the world, including the Northwest of Argentina.The treatment of co-contaminated soils is complex and presents numerous challenges. Bioremediation is a promising technology that could successfully remove mixed compounds.Bioaugmentation with actinobacteria represents an efficient biotechnological tool for the mixed polluted soil reclamation.The objective of the present work was to remove simultaneously LIN and Cr(VI) from silty loam soils, by the bioaugmentation with an actinobacteria consortium formed by Streptomyces sp. M7, MC1, A5, and Amycolatopsis tucumanensis AB0. Mesocosmos of 1 Kg of soil were prepared, contaminated with both pollutants and allowed to stabilize for a month at room temperature and 50% of water holding capacity. They were then inoculated at 0 and 30 d with the actinobacteria consortium (2 g Kg-1, each strain in the same proportion). Mesocosms were incubated for 90 d with minimal intervention of environmental parameters. All corresponding controls were carried out.The contaminated system (CS), did not remove LIN until the end of the assay; however, the contaminated and bioaugmented system (CBS) showed 80% removal of the pesticide during 90 d of incubation. Both CS and CBS were able to remove almost all Cr(VI), however, CBS could do it faster and more efficiently.The microbial counts (MC) showed an inhibitory effect of the contaminants on the native flora of the soil, since the lowest MC were observed in CS (8.7 x 10 7 UFC g-1), which were significantly lower at the end of assay respect to 0 d (1.44 x 10 8 CFU g-1). The highest MC were reached in bioaugmented systems (BS) (1.6 x 10 9 CFU g-1), which showed a growing profile up to 40 d of incubation and remained constant until the end of the assay. The natural soil (NS), without any treatment, presented a constant profile in the MC throughout 90 d (1.70-2.71 x 10 8 UFC g-1), while the CBS showed a variable profile up to 40 d of incubation and then increased, reaching similar values to SB (1.2 x 10 9 CFU g-1).The enzymatic soil activities showed a negative effect of the contaminants on them, especially catalase, which was totally inhibited until 50 d of incubation; since then this activity was recovered, in coincidence with the greater removal of the contaminants. The fluorescein diacetate hydrolysis activity (FDA) showed a strong correlation with the MC. FDA ranged between 8.01 and 135.07 g fluorescein g-1 h-1; NS showed the lowest FDA. Acid phosphatase activity exhibited variable profiles, but following a certain correlation with the MC in all systems. The maximum value was 130.03 g p-nitrophenol g-1 h-1 in NS, whereas the lowest was observed in CS (4.29 g p-nitrophenol g-1 h-1).Fil: Bigliardo, Ana Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Polti, Marta Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaXVIII Congreso Argentino de Microbiología GeneralLos CocosArgentinaSociedad Argentina de Microbiología Genera

Conocimiento, actitudes y prácticas relacionadas con la aplicación de plaguicidas en trabajadores agrícolas de las comunidades del oeste de la provincia de Catamarca, Argentina

Introducción: Las prácticas inseguras de manipulación de plaguicidas y su uso excesivo han conducido a la contaminación ambiental y a la intoxicación de los trabajadores agrícolas. Por ello, la problemática de la exposición a plaguicidas debe enmarcarse en un contexto sociocultural y ambiental de las comunidades afectadas, analizando los factores que contribuyen al mayor riesgo de exposición de los trabajadores agrícolas y sus familias, con el fin de proponer estrategias educativas y desarrollar estrategias efectivas de salud pública. Este estudio evaluó los conocimientos, actitudes y prácticas sobre el manejo local de plaguicidas de trabajadores agrícolas de la localidad de Singuil, provincia de Catamarca, noroeste de Argentina, y el posible impacto de estos patrones de comportamiento en el río Singuil. Método: Los trabajadores agrícolas de Singuil participaron a través de una encuesta desarrollada de manera personal. Posteriormente, se tomaron muestras del río Singuil para la determinación de residuos de plaguicidas.Resultados: Todos los entrevistados fueron hombres, con una edad promedio de 44,6 años, y tienen al menos educación de nivel primario. Aproximadamente, el 83% de ellos ha trabajado con plaguicidas durante más de 10 años. Aunque la mayoría de los trabajadores prepara sus formulaciones de plaguicidas, el 25% de ellos no usa ningún equipo de protección personal, mientras que el 75% restante generalmente usa mascarillas y guantes para protegerse. Las prácticas de higiene personal posteriores a la pulverización, como cambiarse de ropa o ducharse, a menudo no se aplican. Para reducir los riesgos que estas prácticas ocasionan a la salud, muchos encuestados aplican los plaguicidas al atardecer (66,7%) o temprano en la mañana (50%), evitando realizarlo durante los días ventosos y soleados. Además, suelen quemar (58,3%) o almacenar (41,7%) los envases vacíos de plaguicidas. En caso de intoxicación, el 91,7% de los trabajadores acudiría al hospital para recibir atención médica. El glifosato, mancozeb y propamocarb son los plaguicidas más utilizados. Finalmente, no se detectaron residuos de plaguicidas en muestras de agua recolectadas del río Singuil. Conclusión: Este estudio destaca la falta de conocimiento sobre el correcto manejo de plaguicidas y sus envases en los trabajadores agrícolas encuestados. Debería desarrollarse una formación eficaz sobre prácticas seguras para concienciar a los trabajadores y reducir sus riesgos de exposición a los plaguicidas.Unsafe management practices and overuse of pesticides have led to environmental contamination and farmworkers poisoning. For this reason, the problem of pesticide exposure must be framed in the socio-cultural and environmental context of the affected communities, analyzing the factors that contribute to the greater risk of exposure of farmworkers and their families, in order to propose educational strategies and develop effective public health strategies. This study evaluated the knowledge, attitudes, and practices regarding local pesticides handling of farmworkers from Singuil town, Catamarca province, northwestern Argentina, and the possible impact of these behavioral patterns on Singuil River. Farmworkers from Singuil town participated through a cross-sectional, face-to-face survey. Subsequently, samples from Singuil River were taken for determination of pesticides residues. Approximately 83 % of those surveyed have worked with pesticides for more than 10 years. Although most workers prepare their pesticide formulations, 25 % of them never use any personal protective equipment, while the remaining 75 % usually use face masks and gloves to protect themselves. Post-spraying personal hygiene practices, such as changing clothes or showering, are often not applied. To reduce health risks, many respondents perform sprinkling at sunset (66.7 %) or early morning (50 %), and avoid it during windy and sunny weather. Besides, they usually burn (58.3 %) or stockpile (41.7 %) empty pesticide containers. In case of poisoning, 91.7 % of workers would go to hospital for medical attention. Glyphosate, mancozeb, and propamocarb are the most commonly used pesticides. Finally, no pesticide residues were detected in the water samples collected from Singuil River.Fil: Raimondo, Enzo Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Costa Gutierrez, Stefanie Bernardette. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Cabrera, Susana Edith. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Benimeli, Claudia Susana. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin

Integral use of sugarcane vinasse for biomass production of actinobacteria: Potential application in soil remediation

The use of living actinobacteria biomass to clean up contaminated soils is an attractive biotechnology approach. However, biomass generation from cheap feedstock is the first step to ensure process sustainability. The present work reports the ability of four actinobacteria, Streptomyces sp. M7, MC1, A5, and Amycolatopsis tucumanensis, to generate biomass from sugarcane vinasse. Optimal vinasse concentration to obtain the required biomass (more than 0.4 g L−1) was 20% for all strains, either grown individually or as mixed cultures. However, the biomass fraction recovered from first vinasse was discarded as it retained trace metals present in the effluent. Fractions recovered from three consecutive cycles of vinasse re-use obtained by mixing equal amounts of biomass from single cultures or produced as a mixed culture were evaluated to clean up contaminated soil with lindane and chromium. In all cases, the decrease in pesticide was about 50% after 14 d of incubation. However, chromium removal was statistically different depending on the preparation methodology of the inoculum. While the combined actinobacteria biomass recovered from their respective single cultures removed about 85% of the chromium, the mixed culture biomass removed more than 95%. At the end of the reused vinasse cycle, the mixed culture removed more than 70% of the biological oxygen demand suggesting a proportional reduction in the effluent toxicity. These results represent the first integral approach to address a problematic of multiple contaminations, concerning pesticides, heavy metals and a regionally important effluent like vinasse.Fil: Aparicio, Juan Daniel. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentina. Universidad Santo Tomás de Aquino; ArgentinaFil: Almeida, César Américo. Universidad Nacional de San Luis; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Polti, Marta Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentin

Applied of actinobacteria consortia-based bioremediation to restore co-contaminated systems

Global industrialization and natural resources extraction have left cocktails of environmental pollutants. Thus, this work focuses on developing a defined actinobacteria consortium able to restore systems co-contaminated with pollutants occurring in Argentinian environments. In this context, five actinobacteria were tested in solid medium to evaluate antagonistic interactions and tolerance against lindane (LIN), Reactive Black B–V (RBV), phenanthrene (Ph) and Cr(VI). The strains showed absence of antagonism, and most of them tolerated the presence of individual pollutants and their mixtures, except Micromonospora sp. A10. Thus, a quadruple consortium constituted by Streptomyces sp. A5, M7, MC1, and Amycolatopsis tucumanensis DSM 45259T, was tested in liquid systems with individual contaminants. The best microbial growth was observed in the presence of RBV and the lowest on Cr(VI). Removals detected were 83.3%, 65.0% and 52.4% for Ph, RBV and LIN, respectively, with absence of Cr(VI) dissipation. Consequently, the consortium performance was tested against the organic mixture, and a microbial growth similar to the biotic control and a LIN removal increase (61.2%) were observed. Moreover, the four actinobacteria of the consortium survived the mixture bioremediation process. These results demonstrate the potential of the defined actinobacteria consortium as a tool to restore environments co-contaminated with organic pollutants.Fil: Antezana, Pablo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Bourguignon, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Fuentes, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin

Chlordane biodegradation under aerobic conditions by indigenous Streptomyces strains

Four actinobacteria strains isolated from pesticide-contaminated soil were able to grow in the presence of 16.6 mg L1 chlordane, an organochlorine pesticide. The strain that showed best growth after 96 h of incubation in synthetic medium with chlordane as the sole carbon source was identified as Streptomyces sp. A5. When Streptomyces sp. A5 was cultured in the presence of chlordane, the pesticide was degraded from the culture medium after 24 h of incubation. In soil assays, a reduction of 56% in g-chlordane was observed after 28 days of incubation. This is the first report about chlordane degradation under aerobic conditions by a Streptomyces strain.Fil: Cuozzo, Sergio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad San Pablo Tucumán; ArgentinaFil: Fuentes, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad San Pablo Tucumán; ArgentinaFil: Bourguignon, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad del Norte Santo Tomás de Aquino; ArgentinaFil: Amoroso, Maria Julia del R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad del Norte Santo Tomás de Aquino; Argentin

Dechlorinase activity and chlordane removal by Streptomyces strains as pure and mixed defined cultures

Chlordane (CLD) is a toxic fumigating agent widely used in the past, which is now found in air, soil and water resources. Technical chlordane consists in 147 components, and it has been included in the list of the 12 persistent organic pollutants of Stockholm Convention (2001) because of its persistence, toxicity and tendency to biomagnification. Bioremediation is an attractive cleaning technique of polluted environments. The use of actinobacteria for this purpose, results an effective biotechnological approach due to their metabolic versatility and furthermore their use in mixed cultures can increase the catabolic pathways available for biodegrading these contaminants. The aim of this work was to evaluate the chlordane removal capacity and dechlorinase activity by pure and mixed actinobacteria cultures, under controlled laboratory conditions, and to select one mixed culture for further morphological studies. Streptomyces spp. M7, A2, A5, A6, A13 previously isolated in the laboratory and Streptomyces coelicolor A3 (2) were cultivated individually in minimal medium (MM) with CLD for acclimation. These strains, as pure cultures and consortia from two to six microorganisms, were cultivated in MM with CLD (1.66 mg L-1). Microbial cells were used to obtain cell-free extracts for dechlorinase activity assays and the supernatants of these cultures were used to determine residual CLD by gas chromatography. The selected mixed culture according to their dechlorinase activity and capacity to remove CLD was grown in MM either with glucose or chlordane as carbon source and analyzed at 72 h in an optical microscope the probability of morphological changes. Dechlorinase activity ranged between 0.00 to 1291.28 mmolCl-/h/mg protein and CLD removal percentages was between 82.6 to 95.5%. The mixed culture consisting of Streptomyces sp. A2-A13-Streptomyces coelicolor A3(2) showed the best enzyme activity but not the minimal residual CLD concentration. Because no linear relationship between residual CLD and enzyme activity was obtained, the ratio between these two parameters was evaluated, and the mixed culture Streptomyces sp. A2-A5-A13 with the minimal obtained relationship was selected. In CLD presence, the microscopic analysis of this culture showed scarce vegetative cells and numerous spores, which results of the hyphal fragmentation. These Streptomyces strains were able to grow as mixed cultures, in CLD presence, and showed ability to dechlorinate and remove this toxic compound from the culture medium. Therefore the mixed culture of Streptomyces sp. A2-A5-A13 could be a promising tool for CLD biodegradation.Fil: Fuentes, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Raimondo, Enzo Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad del Norte Santo Tomás de Aquino; ArgentinaFil: Amoroso, Maria Julia del R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaIX Congreso Argentino de Microbiología GeneralRosarioArgentinaSociedad Argentina de Microbiología Genera

Inmovilización de actinobacterias en soportes naturales: evaluación de su empleo para la remoción de atrazina en biomezclas

La inmovilización microbiana en soportes adecuados es una estrategia que ha demostradomayor eficiencia que las células libres en los procesos de biorremediación de plaguicidas.El objetivo de este trabajo fue evaluar el empleo de actinobacterias inmovilizadas ensoportes naturales para potenciar la remoción de atrazina (ATZ) en biomezclas destinadasa un sistema de biopurificación. Para ello, se inmovilizaron células de Streptomyces sp. M7(M7) en tres soportes orgánicos provenientes de la industria azucarera. Se determinó laeficiencia de inmovilización en tales soportes, la viabilidad y el estado fisiológico de lascélulas inmovilizadas. También se evaluó la remoción de ATZ en biomezclas bioaumentadascon M7 inmovilizada (BBM7); se realizaron estudios enzimáticos y recuentos microbianossemanales durante 28 días. Se seleccionó el bagazo como soporte, ya que demostró mayoreficiencia de inmovilización (81%) y mayor biomasa de células inmovilizadas [(1,6 ± 0,2) x107 UFC g-1]. Las células de M7 inmovilizadas en bagazo y conservadas a 4 °C presentaron72% de viabilidad hasta los 14 días, mientras que las células libres 22% en ese período. Enlas BBM7, los recuentos de heterótrofos totales fueron mayores que en las biomezclas sininocular. En la BBM7 se observó una remoción de ATZ del 69%, y una disminución en el t1/2de ATZ de casi 14 veces (6,4 d) con respecto a la biomezcla sin bioaumentar (88,9 d). No seobservó un efecto claro de ATZ o de la bioaumentación sobre las actividades enzimáticasevaluadas. El empleo de células de M7 inmovilizadas en bagazo constituye una herramientapromisoria para mejorar la disipación de este herbicida ampliamente utilizado en Tucumán,en sistemas de biopurificación y evitar la contaminación ambiental.Fil: González, Samanta Katherina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Maldonado, Lourdes María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Catamarca. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Sáez, Juliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina30° Jornadas Jóvenes Investigadores de la Asociación de Universidades del Grupo MontevideoAsunciónParaguayUnivesidad Nacional de AsunciónAsociación de Universidades del Grupo Montevide

Enhanced removal of a pesticides mixture by single cultures and consortia of free and immobilized Streptomyces strains

Pesticides are normally used to control specific pests and to increase the productivity in crops; as a result, soils are contaminated with mixtures of pesticides. In this work, the ability of Streptomyces strains (either as pure or mixed cultures) to remove pentachlorophenol and chlorpyrifos was studied. The antagonism among the strains and their tolerance to the toxic mixture was evaluated. Results revealed that the strains did not have any antagonistic effects and showed tolerance against the pesticides mixture. In fact, the growth of mixed cultures was significantly higher than in pure cultures. Moreover, a pure culture (Streptomyces sp. A5) and a quadruple culture had the highest pentachlorophenol removal percentages (10.6% and 10.1%, resp.),while Streptomyces sp.M7 presented the best chlorpyrifos removal (99.2%).Mixed culture of all Streptomyces spp. when assayed either as free or immobilized cells showed chlorpyrifos removal percentages of 40.17% and 71.05%, respectively, and for pentachlorophenol 5.24% and 14.72%, respectively, suggesting better removal of both pesticides by using immobilized cells. These results reveal that environments contaminated with mixtures of xenobiotics could be successfully cleaned up by using either free or immobilized cultures of Streptomyces, through in situ or ex situ remediation techniques.Fil: Fuentes, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Briceño, Gabriela E.. Universidad de la Frontera; Chile;Fil: Sáez, Juliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Benimeli, Claudia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Tucumán. Unidad de Administración Territorial; Argentina. Universidad del Norte Santo Tomás de Aquino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Diez, Maria Cecilia. Universidad de la Frontera; Chile;Fil: Amoroso, Maria Julia del R.. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad del Norte Santo Tomás de Aquino; Argentin