Fungal inoculation effect on post-harvest sugarcane residue decomposition under field conditions

Fungal inoculation effect on post-harvest sugarcane residue (SCR) decomposition in field conditions was studied. In vitro interaction between selected fungi was determined by direct confrontation. Mycelial growth response to different concentrations of herbicides and urea was also assessed. Fungal combinations did not show inhibitory effects. Bjerkandera sp. Y-HHM2 and Myrothecium sp. S-3.20 growth decreased in 2.4-D agar plates. However, Pleurotus sp. Y- RN3 showed a stimulation in 10 ppm 2.4-D agar plates. The biggest growth in ametrine supplemented cultures was observed in Pleurotus sp. Y-RN3. Evaluation of increasing urea concentrations on mycelial growth showed that 5,000 ppm significantly inhibits mycelial growth. The field assay under rainfed condition showed that post-harvest SCR decomposition rate significantly increases in Y-HHM2, Y-RN3 and Y-HHM2/Y-RN3/S-3.20 treatments. This is the first report on the capability of Bjerkandera sp. Y-HHM2 and Pleurotus sp. Y-RN3 to accelerate post-harvest SCR decomposition in rainfed conditions at field scale, suggesting that these fungi might be useful tools in the sugarcane crop system.Fil: Maza, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Investigación Animal del Chaco Semiárido; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Sanidad Vegetal. Cátedra Fitopatología; ArgentinaFil: Medina, M.. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Plasencia, Adriana María. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Amoroso, Maria Julia del R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Yasem, Marta Graciela. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Sanidad Vegetal. Cátedra Fitopatología; Argentin

Soil washing contaminated with heavy metals by using bacterial bioemulsifier at laboratory scale

Heavy metal cannot be degradable into innocuous products and they tend to be strongly absorbed on the matrix of soils and sediments. These characteristics limit their solubilization and subsequent removal. An effective method to increase the metal-desorption of soil and sediments involves washing technologies assisted with surface active compounds as such bioemulsifiers. However, there is little information found in the literature regarding bacterial bioemulsfiers used for this purpose. In previous studies, it have being demonstrated the ability to produce bioemulsifier by an actinobacterium, Amycolatopsis tucumanensis DSM 45259, using different carbon and nitrogen sources. Also it was showed that both production and hence functional properties of bioemulsifier is associated mainly to carbon sources used for biosynthesis. Following these studies, the objective of the present work was to study the applicability of bioemulsifiers produced by A. tucumanensis DSM 45259 from different carbon a nitrogen sources, as washing agents in environmental remediation technologies, as well as to determine whether Cu(II) or Cr(VI) presence affecting the bioemuslfier production. To achieve this, soil samples were artificially contaminated with Cu(II) or Cr(VI) added as CuSO 4 .5H 2 O and K 2 Cr 2 O 7 , respectively, at final concentration of 200 mg kg −1 of soil. Washing experiments were performed using 2.0 g of contaminated soil in flasks. Soils were washed with 10 ml of aqueous solutions of the partially purified bioemulsifiers, using deionized water as control. Emulsification index of each bioemulsifier solution was previously adjusted to 60%. The washing procedures were performed by shaking at 30 ºC between 12 to 24 h. Soil samples were centrifuged at 10,000g and the concentration of Cu(II) and Cr(VI) in supernatants were analyzed by atomic absorption spectrometry and Cr(VI) concentration was measured using a colorimetric method. Under these assayed conditions, no significant Cu(II) removal could be detected after 12 h of washed either with H 2 Od or bioemulsifier solutions. However, A. tucumanensis bioemulsifiers seemed to be effective for Cr(VI) recovery, whose removal from soil increased 2 fold while compared to H 2 Od. Cr removed in the washing experiments remains in its hexavalent state. The increase of the in the washing time, did not improve the Cu(II) and Cr(VI) removal. Analysing the different effects of carbon and nitrogen sources and metal type, the last one was the most relevant variable that influence on the washing efficiency. In relation to the production of bioemulsifier by A. tucumanensis DSM 45259 in the presence of metals, the results showed that the assayed concentrations of Cu(II) and Cr(VI) (10, 20 and 30 ppm) in the culture media did not affect the bioemulsifier production. These are the first advances conducted in our research group focused on the direct application of microbial products in heavy metal remediation strategies.Fil: Castro, María Fernanda. Universidad Nacional de Tucumán; ArgentinaFil: Colin, Veronica Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Amoroso, Maria Julia del R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Villegas, Liliana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaIX Congreso de Microbiologia GeneralRosarioArgentinaSociedad Argentina de Microbiología Genera

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

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

Remoción de lindano por un consorcio de Streptomyces sp.: diferentes estrategias de biorremediación

El lindano es un plaguicida organoclorado que fue ampliamente utilizado; es un tóxico persistente que contamina la biósfera. Una técnica para su remoción es la biorremediación, la cual puede realizarse mediante diferentes estrategias, como el empleo de microorganismos libres, inmovilizados y/o combinados con productos vegetales. El objetivo fue evaluar la remoción de lindano por un consorcio definido de Streptomyces cultivado en lodos (libre e inmovilizado) y con exudados radiculares de maíz (ERs). Cuatro cepas (2 g L-1) fueron inoculadas en reactores de lodo; inmovilizadas en bolsas de tela suspendidas en lodo y en medio mínimo con ERs liofilizados (1 g L-1). La concentración de lindano fue 1,66 mg L-1. Se determinó crecimiento, plaguicida residual y liberación de iones cloruro (Cl-). Se encontró 85,7% de lindano removido y 92,0% de Cl- liberados en reactor. El consorcio inmovilizado presentó un crecimiento de 1,3x106 ± 8,2x104 UFC mL-1 y una remoción de lindano de 72,0 ± 5,7%. Con el suplemento de ERs, el crecimiento fue 0,40 ± 0,02 g L-1 y la remoción fue 41,2 ± 1,1%. Estos resultados permiten concluir que el consorcio de Streptomyces puede ser empleado eficientemente para la biorremediación de lindano mediante diferentes estrategias biotecnológicas, debido a su versatilidad para tolerar, remover y degradar dicho tóxico.Fil: Sáez, Juliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Fuentes, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Alvarez, Analia. 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; 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. Facultad de Ciencias de la Salud; 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; Argentina. Universidad del Norte Santo Tomás de Aquino. Facultad de Ciencias de la Salud; ArgentinaVIII Encuentro para Latino América y el Caribe de BiotecnologíaMar del PlataArgentinaREDBIO Argentina Asociación Civi

Effective fisheries management instrumental in improving fish stock status

Marine fish stocks are an important part of the world food system and are particularly important for many of the poorest people of the world. Most existing analyses suggest overfishing is increasing, and there is widespread concern that fish stocks are decreasing throughout most of the world. We assembled trends in abundance and harvest rate of stocks that are scientifically assessed, constituting half of the reported globalmarine fish catch. For these stocks, on average, abundance is increasing and is at proposed target levels. Compared with regions that are intensively managed, regions with less-developed fisheries management have, on average, 3-fold greater harvest rates and half the abundance as assessed stocks. Available evidence suggests that the regions without assessments of abundance have little fisheries management, and stocks are in poor shape. Increased application of area-appropriate fisheries science recommendations and management tools are still needed for sustaining fisheries in places where they are lacking.Fil: Hilborn, Ray. University of Washington; Estados UnidosFil: Amoroso, Ricardo Oscar. University of Washington; Estados UnidosFil: Anderson, Christopher M.. University of Washington; Estados UnidosFil: Baum, Julia K.. University of Victoria; CanadáFil: Branch, Trevor A.. University of Washington; Estados UnidosFil: Costello, Christopher. University of California at Santa Barbara; Estados UnidosFil: de Moor, Carryn L.. University of Cape Town; SudáfricaFil: Faraj, Abdelmalek. Einstitut National de Recherche Halieutique; MarruecosFil: Hively, Daniel. University of Washington; Estados UnidosFil: Jensen, Olaf P.. Rutgers University; Estados UnidosFil: Kurota, Hiroyuki. Japan Fisheries Research and Education Agency; JapónFil: Little, L. Richard. Csiro Oceans and Atmosphere; AustraliaFil: Mace, Pamela. Ministry for Primary Industries; Nueva ZelandaFil: McClanahan, Tim. Wildlife Conservation Society; Estados UnidosFil: Melnychuk, Michael C.. University of Washington; Estados UnidosFil: Minto, Cóilín. Galway-Mayo Institute of Technology; IrlandaFil: Osio, Giacomo Chato. Joint Research Centre (JRC); Italia. DG Maritime Affairs and Fisheries, European Commission; BélgicaFil: Pons, Maite. University of Washington; Estados UnidosFil: Parma, Ana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Segurado, Susana. Sustainable Fisheries Partnership; Estados UnidosFil: Szuwalski, Cody S.. University of California at Santa Barbara; Estados UnidosFil: Wilson, Jono R.. University of California at Santa Barbara; Estados Unidos. The Nature Conservancy; Estados UnidosFil: Ye, Yimin. Food and Agriculture Organization of the United Nations; Itali

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements