Estrategia de recuperación de un sector de la Cuenca Matanza Riachuelo mediante fitorremediación asistida por microorganismos

Varios grupos de investigación trabajan desde hace tiempo con el fin de diseñar estrategias de saneamiento integral para la cuenca Matanza Riachuelo, que sean de bajo costo y buena aceptabilidad social. La implantación de humedales artificiales basados en especies macrófitas de diferente porte se presenta como una alternativa promisoria. En ese contexto se ha documentado que algunos microorganismos asociativos o endófitos podrían ser especialmente útiles para maximizar el crecimiento de tales especies, así como para optimizar la remoción de tóxicos orgánicos o inorgánicos y la recuperación de los niveles de O 2 disuelto en el agua. Sobre la base de esta idea, investigadores del CONICET, de la UBA y de la Agencia de Protección Ambiental del Gobierno de la Ciudad de Buenos Aires (APRA) han emprendido un trabajo colaborativo que apunta a diseñar una estrategia de fitorremediación asistida por microorganismos tomando como base el caso del arroyo Cildáñez.Fil: Zawoznik, Myriam. Universidad de Buenos AiresFil: Bigi, Roxana. Buenos Aires. Agencia de Protección AmbientalFil: Marconi, Patricia L.. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Groppa, María Daniela. Consejo Nacional de Investigaciones Científicas y Técnica

Optimization of a Bioremediation Strategy for an Urban Stream of Matanza- Riachuelo Basin

In the present work, a remediation bioprocess based on the use of a local isolate of the microalgae Chlorella vulgaris immobilized in alginate beads is proposed. This process was shown to be effective for the reduction of several chemical and microbial contaminants present in Cildáñez stream, a water course that is part of the Matanza-Riachuelo Basin (Buenos Aires, Argentina). The bioprocess, involving the culture of the microalga in autotrophic conditions in a stirred-tank bioreactor supplied with a marine propeller for 6 days, allowed a significant reduction of Escherichia coli and total coliform numbers (over 95%), as well as of ammoniacal nitrogen (96%), nitrates (86%), nitrites (98%), and total phosphorus (53%) contents. Pb content was also significantly diminished after the bioprocess (95%). Standardized cytotoxicity tests using Allium cepa seeds and Cildáñez water pre- and post-remediation were also performed. Germination rate and mitotic index of onion seeds imbibed in Cildáñez water subjected to the bioprocess was similar to that observed in seeds imbibed in distilled water and significantly superior to that registered when untreated Cildáñez water was used for imbibition. Our results demonstrate the potential of this simple and cost-effective technology to remove urban-water contaminants, offering as an additional advantage the possibility of an easy biomass recovery, which may become a source of alternative energy.Fil: Groppa, María Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Trentini, Andrea Giannina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaFil: Zawoznik, Myriam Sara. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Bigi, Roxana Ines. Agencia de Protección Ambiental; Argentina. Centro de Información y Formación Ambiental; ArgentinaFil: Nadra, Carlos. Autoridad de Cuenca Matanza Riachuelo.; ArgentinaFil: Marconi, Patricia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; ArgentinaInternational Conference on Bioremediation and BiodegradationEstambulTurquíaWorld Academy of Science, Engineering and Technolog

Automatic word segmentation for spoken Cantonese

International audienceThough Cantonese is the most influential variety of Chinese other than Mandarin, there are only a limited number of Cantonese corpora available for linguistic studies. Among the essential steps of building a corpus, word segmentation is a necessary but highly challenging task due to the lack of clear word boundary in Cantonese. This paper reports the construction and evaluation of an open-source automatic Cantonese word segmenter developed for Cantonese. The tool is a component of the multilingual SPPAS program designed to be used directly by linguists. It is a free software distributed under a GPL license. The effectiveness of the tool was evaluated by comparing the result of segmenting some samples of a spoken Cantonese corpus manually and automatically using the tool developed. High precision and recall were found in our study. Upon completion, the tool would definitely promote the development of more Cantonese corpora for language related studies

BIORREMEDIAÇÃO DO LAGO DE LUGANO DA CIDADE AUTÓNOMA DE BUENOS AIRES PARA ALGAS DE TÚNEL ÚNICO - ESTUDOS PRELIMINARESBiorremediação do Lago Lugano na Cidade Autônoma de Buenos Aires por algas unicelulares - estudos preliminares

Bioremediation relies on the use of different organisms for environmental sanitation. This work investigates the use of microalgae as a model system for the bioremediation of contaminated water from Lugano Lake, in the City of Buenos Aires.During this first stage of our experimental approach, the growth of Chlorella vulgaris, free or immobilized inside alginate beads, was optimized for the treatment of contaminated water at a laboratory scale. The cocultivation of the microalgae in the inert substrate with the plant growth promoting bacteria Azospirillum brasilense was also studied, as well as the scaling to bioreactors. We found that Chlorella vulgaris cells immobilized in alginate beads allowed a strong decrease in total phosphorus, lead, cadmium, cobalt and chromium concentrations in Lugano lake water, showing the potential of this microalgae to be used in integrated processes intended to remove solutes from contaminated waters. Keywords: bioremediation, Chlorella, Azospirillum, bioreactor, microalgaeLa biorremediación consiste en el uso de diferentes organismos para el saneamiento ambiental. El presente trabajo investiga la utilización de microalgas como sistema modelo de biorremediación del agua contaminada proveniente del lago Lugano en la Ciudad de Buenos Aires.Durante esta primera etapa de desarrollo experimental, se optimizó el crecimiento de cultivos de Chlorella vulgaris, libres o inmovilizadas en sustratos inertes, para el tratamiento del agua contaminada en escala de laboratorio. También se analizó el cocultivo con una bacteria que promueve el crecimiento vegetal (Azospirillum brasilense) en sistemas de inmovilización, y se estudió el escalado a biorreactores. El escalado del cultivo de Chlorella inmovilizada en perlas de alginato a biorreactor utilizando agua del lago Lugano permitió la disminución de la concentración de fósforo total, plomo, cadmio, cobalto y cromo, mostrando su potencial para ser empleada en procesos integrados que busquen la remoción de solutos de estas aguas. Palabras clave: biorremediación, Chlorella, Azospirillum, bioreactor, microalgasA biorremediação consiste no uso de diferentes organismos para o saneamento ambiental. O presente trabalho investiga o uso de microalgas como um sistema modelo de biorremediação de água contaminada do Lago de Lugano, na cidade de Buenos Aires.Durante este primeiro estágio de desenvolvimento experimental, o crescimento de culturas de Chlorella vulgaris, livres ou imobilizadas em substratos inertes, foi otimizado para o tratamento de água contaminada em escala laboratorial. O cocultivo também foi analisado com uma bactéria que promove o crescimento de plantas (Azospirillum brasilense) em sistemas de imobilização, ea escalada para biorreatores foi estudada. Dimensionamento da cultura de Chlorella imobilizada em esferas de alginato de bioreactor utilizando Lugano lago água permitiu diminuição total de fósforo, o chumbo, o cádmio, o cobalto e o crómio, mostrando o seu potencial para ser usado em processos integrados que procuram remoção solutos dessas águas. Palavras-chave: biorremediação, Chlorella, Azospirillum, biorreator, microalga

Biorremediación del lago lugano de la ciudad autónoma de buenos aires por algas unicelulares – estudios preliminares

La biorremediación consiste en el uso de diferentes organismos para el saneamiento ambiental. El presente trabajo investiga la utilización de microalgas como sistema modelo de biorremediación del agua contaminada proveniente del lago Lugano en la Ciudad de Buenos Aires. Durante esta primera etapa de desarrollo experimental, se optimizó el crecimiento de cultivos de Chlorella vulgaris, libres o inmovilizadas en sustratos inertes, para el tratamiento del agua contaminada en escala de laboratorio. También se analizó el cocultivo con una bacteria que promueve el crecimiento vegetal (Azospirillum brasilense) en sistemas de inmovilización, y se estudió el escalado a biorreactores. El escalado del cultivo de Chlorella inmovilizada en perlas de alginato a biorreactor utilizando agua del lago Lugano permitió la disminución de la concentración de fósforo total, plomo, cadmio, cobalto y cromo, mostrando su potencial para ser empleada en procesos integrados que busquen la remoción de solutos de estas aguas.Bioremediation relies on the use of different organisms for environmental sanitation. This work investigates the use of microalgae as a model system for the bioremediation of contaminated water from Lugano Lake, in the City of Buenos Aires. During this first stage of our experimental approach, the growth of Chlorella vulgaris, free or immobilized inside alginate beads, was optimized for the treatment of contaminated water at a laboratory scale. The cocultivation of the microalgae in the inert substrate with the plant growth promoting bacteria Azospirillum brasilense was also studied, as well as the scaling to bioreactors. We found that Chlorella vulgaris cells immobilized in alginate beads allowed a strong decrease in total phosphorus, lead, cadmium, cobalt and chromium concentrations in Lugano lake water, showing the potential of this microalgae to be used in integrated processes intended to remove solutes from contaminated waters.Fil: Trentini, Andrea. Universidad Maimónides; ArgentinaFil: Groppa, Maria Daniela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Zawoznik, Myriam Sara. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Bigi, Roxana Ines. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Perelman, Patricia Eleonora. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Marconi, Patricia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Maimónides; Argentin

Differential Expression of Immunogenic Proteins on Virulent Mycobacterium tuberculosis Clinical Isolates

Molecular epidemiology has revealed that Mycobacterium tuberculosis (Mtb), formerly regarded as highly conserved species, displays a considerable degree of genetic variability that can influence the outcome of the disease as well as the innate and adaptive immune response. Recent studies have demonstrated that Mtb families found worldwide today differ in pathology, transmissibility, virulence, and development of immune response. By proteomic approaches seven proteins that were differentially expressed between a local clinical isolate from Latin-American-Mediterranean (LAM) and from Haarlem (H) lineages were identified. In order to analyze the immunogenic ability, recombinant Rv2241, Rv0009, Rv0407, and Rv2624c proteins were produced for testing specific antibody responses. We found that these proteins induced humoral immune responses in patients with drug-sensitive and drug-resistant tuberculosis with substantial cross-reactivity among the four proteins. Moreover, such reactivity was also correlated with anti-Mtb-cell surface IgM, but not with anti-ManLAM, anti-PPD, or anti-Mtb-surface IgG antibodies. Therefore, the present results describe new Mtb antigens with potential application as biomarkers of TB

Role of <it>P27 </it>-<it>P55 </it>operon from <it>Mycobacterium tuberculosis </it>in the resistance to toxic compounds

<p>Abstract</p> <p>Background</p> <p>The <it>P27-P55 </it>(<it>lprG-Rv1410c</it>) operon is crucial for the survival of <it>Mycobacterium </it><it>tuberculosis</it>, the causative agent of human tuberculosis, during infection in mice. <it>P55 </it>encodes an efflux pump that has been shown to provide <it>Mycobacterium smegmatis </it>and <it>Mycobacterium bovis </it>BCG with resistance to several drugs, while <it>P27 </it>encodes a mannosylated glycoprotein previously described as an antigen that modulates the immune response against mycobacteria. The objective of this study was to determine the individual contribution of the proteins encoded in the <it>P27-P55 </it>operon to the resistance to toxic compounds and to the cell wall integrity of <it>M. tuberculosis</it>.</p> <p>Method</p> <p>In order to test the susceptibility of a mutant of <it>M. tuberculosis </it>H37Rv in the <it>P27-P55 </it>operon to malachite green, sodium dodecyl sulfate, ethidium bromide, and first-line antituberculosis drugs, this strain together with the wild type strain and a set of complemented strains were cultivated in the presence and in the absence of these drugs. In addition, the malachite green decolorization rate of each strain was obtained from decolorization curves of malachite green in PBS containing bacterial suspensions.</p> <p>Results</p> <p>The mutant strain decolorized malachite green faster than the wild type strain and was hypersensitive to both malachite green and ethidium bromide, and more susceptible to the first-line antituberculosis drugs: isoniazid and ethambutol. The pump inhibitor reserpine reversed <it>M. tuberculosis </it>resistance to ethidium bromide. These results suggest that P27-P55 functions through an efflux-pump like mechanism. In addition, deletion of the <it>P27-P55 </it>operon made <it>M. tuberculosis </it>susceptible to sodium dodecyl sulfate, suggesting that the lack of both proteins causes alterations in the cell wall permeability of the bacterium. Importantly, both P27 and P55 are required to restore the wild type phenotypes in the mutant.</p> <p>Conclusions</p> <p>The results clearly indicate that P27 and P55 are functionally connected in processes that involve the preservation of the cell wall and the transport of toxic compounds away from the cells.</p