Micobiota parásita de ambientes acuáticos de la provincia de Buenos Aires

Fil: Steciow, Mónica Mirta. Instituto de Botánica Spegazzini, 53 nro. 477, 1900 La Plata, Buenos Aires, ArgentinaFil: Marano, Agostina Virginia. Instituto de Botánica Spegazzini, 53 nro. 477, 1900 La Plata, Buenos Aires, Argentin

Colonización de sustratos artificiales y naturales por hongos acuáticos zoospóricos

We study the «in situ» colonization of different kinds of substrata by zoosporic fungi (S.D Mastigomycotina), making weekly samplings during a month in the streams «El Zanjón» and «Las Cañas» (Ensenada, Bs. As., Argentina). In those sites we put twelve different substrata, both naturals (monocotyledon leaves, crustacean shells, Rosa sp. fruits, snake sheds and little fishes) and artificial ones (cellophane fragments, polypropylene bags, slides, and two kinds of different plastic materials). The substrata were put separately in drilled plastic bags, and left for a week to allow colonization. In both sites, we observed that Saprolegnia colonized every kind of substratum (both natural and artificial ones), while Achlya was encountered in the majority of them (little fishes, slides, cellophane fragments, pieces of X-rays, Rosa sp. fruits, and monocotyledon leaves), Dichtyuchus was observed in fishes and Rosa sp. fruits, Brevilegnia and Pythium in pieces of X-rays plate and Aphanomyces only in plastic materials. Based on these preliminary results, we can infer that there is an apparent selection of some genera for particular substrata. It’s interesting to emphasize that colonization of artificial substrata by Saprolegnia, Achlya, Brevilegnia, Pythium and Aphanomyces, might suggest the possibility of using these genera in superficial biodegradation of plastic materials.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

Colonización de sustratos artificiales y naturales por hongos acuáticos zoospóricos

We study the «in situ» colonization of different kinds of substrata by zoosporic fungi (S.D Mastigomycotina), making weekly samplings during a month in the streams «El Zanjón» and «Las Cañas» (Ensenada, Bs. As., Argentina). In those sites we put twelve different substrata, both naturals (monocotyledon leaves, crustacean shells, Rosa sp. fruits, snake sheds and little fishes) and artificial ones (cellophane fragments, polypropylene bags, slides, and two kinds of different plastic materials). The substrata were put separately in drilled plastic bags, and left for a week to allow colonization. In both sites, we observed that Saprolegnia colonized every kind of substratum (both natural and artificial ones), while Achlya was encountered in the majority of them (little fishes, slides, cellophane fragments, pieces of X-rays, Rosa sp. fruits, and monocotyledon leaves), Dichtyuchus was observed in fishes and Rosa sp. fruits, Brevilegnia and Pythium in pieces of X-rays plate and Aphanomyces only in plastic materials. Based on these preliminary results, we can infer that there is an apparent selection of some genera for particular substrata. It’s interesting to emphasize that colonization of artificial substrata by Saprolegnia, Achlya, Brevilegnia, Pythium and Aphanomyces, might suggest the possibility of using these genera in superficial biodegradation of plastic materials.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

Micobiota parásita de ambientes acuáticos de la provincia de Buenos Aires

Zoosporic fungi (Chytridiomycota, Hyphochytridiomycota and Peronosporomycota) include organisms that occur as saprotrophs on vegetable debris or as parasites of invertebrates, plants, algae and of other zoosporic fungi. Water samples and floating organic matter were collected during a 2005-2006 survey at Las Cañas stream and Villa Elisa channel (Reserva Natural Selva Marginal Punta Lara, Pdo. de Ensenada, Bs. As.), and samples were processed with the baiting technique. Six taxa of parasitic zoosporic fungi were recovered: Olpidium sp. (Braun) Rabenhorst, Chytridium sp. Braun and Rhizophydium carpophyllum (Chytridiomycota), Rhizidiomyces apophysatus and R. hirsutus (Hyphochytridiomycota), Olpidiopsis pythii (Butler) Karling and Dictyuchus sp. Leitgeb, (Peronosporomycota). Olpidiopsis pythii is the first record for Argentina and South America.Facultad de Ciencias Naturales y Muse

Colonización de sustratos artificiales y naturales por hongos acuáticos zoospóricos

We study the in situ colonization of different kinds of substrata by zoosporic fungi (S.D Mastigomycotina), making weekly samplings during a month in the streams «El Zanjón» and «Las Cañas» (Ensenada, Bs. As., Argentina). In those sites we put twelve different substrata, both naturals (monocotyledon leaves, crustacean shells, Rosa sp. fruits, snake sheds and little fishes) and artificial ones (cellophane fragments, polypropylene bags, slides, and two kinds of different plastic materials). The substrata were put separately in drilled plastic bags, and left for a week to allow colonization. In both sites, we observed that Saprolegnia colonized every kind of substratum (both natural and artificial ones), while Achlya was encountered in the majority of them (little fishes, slides, cellophane fragments, pieces of X-rays, Rosa sp. fruits, and monocotyledon leaves), Dichtyuchus was observed in fishes and Rosa sp. fruits, Brevilegnia and Pythium in pieces of X-rays plate and Aphanomyces only in plastic materials. Based on these preliminary results, we can infer that there is an apparent selection of some genera for particular substrata. It’s interesting to emphasize that colonization of artificial substrata by Saprolegnia, Achlya, Brevilegnia, Pythium and Aphanomyces, might suggest the possibility of using these genera in superficial biodegradation of plastic materials.We study the in situ colonization of different kinds of substrata by zoosporic fungi (S.D Mastigomycotina), making weekly samplings during a month in the streams «El Zanjón» and «Las Cañas» (Ensenada, Bs. As., Argentina). In those sites we put twelve different substrata, both naturals (monocotyledon leaves, crustacean shells, Rosa sp. fruits, snake sheds and little fishes) and artificial ones (cellophane fragments, polypropylene bags, slides, and two kinds of different plastic materials). The substrata were put separately in drilled plastic bags, and left for a week to allow colonization. In both sites, we observed that Saprolegnia colonized every kind of substratum (both natural and artificial ones), while Achlya was encountered in the majority of them (little fishes, slides, cellophane fragments, pieces of X-rays, Rosa sp. fruits, and monocotyledon leaves), Dichtyuchus was observed in fishes and Rosa sp. fruits, Brevilegnia and Pythium in pieces of X-rays plate and Aphanomyces only in plastic materials. Based on these preliminary results, we can infer that there is an apparent selection of some genera for particular substrata. It’s interesting to emphasize that colonization of artificial substrata by Saprolegnia, Achlya, Brevilegnia, Pythium and Aphanomyces, might suggest the possibility of using these genera in superficial biodegradation of plastic materials

Colonización de sustratos artificiales y naturales por hongos acuáticos zoospóricos

We study the «in situ» colonization of different kinds of substrata by zoosporic fungi (S.D Mastigomycotina), making weekly samplings during a month in the streams «El Zanjón» and «Las Cañas» (Ensenada, Bs. As., Argentina). In those sites we put twelve different substrata, both naturals (monocotyledon leaves, crustacean shells, Rosa sp. fruits, snake sheds and little fishes) and artificial ones (cellophane fragments, polypropylene bags, slides, and two kinds of different plastic materials). The substrata were put separately in drilled plastic bags, and left for a week to allow colonization. In both sites, we observed that Saprolegnia colonized every kind of substratum (both natural and artificial ones), while Achlya was encountered in the majority of them (little fishes, slides, cellophane fragments, pieces of X-rays, Rosa sp. fruits, and monocotyledon leaves), Dichtyuchus was observed in fishes and Rosa sp. fruits, Brevilegnia and Pythium in pieces of X-rays plate and Aphanomyces only in plastic materials. Based on these preliminary results, we can infer that there is an apparent selection of some genera for particular substrata. It’s interesting to emphasize that colonization of artificial substrata by Saprolegnia, Achlya, Brevilegnia, Pythium and Aphanomyces, might suggest the possibility of using these genera in superficial biodegradation of plastic materials.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

Functional and structural characteristics of the epipelic biofilms in a lowland Pampean stream (Argentina) exposed to the increase of the urbanization

El objetivo del presente estudio fue analizar las respuestas estructurales (densidad de organismos, biomasa total, biomasa autotrófica e índice autotrófico) y funcionales (producción primaria neta, respiración, producción primaria bruta y tasa de asimilación) del biofilm epipélico en tres sitios de un arroyo pampeano que presentan diferentes proporciones del uso del suelo expuesto a la urbanización. Los resultados mostraron que el aumento en el porcentaje del uso del suelo destinado a la urbanización fue evidenciado por los cambios en la calidad del agua y por los descriptores funcionales y estructurales del biofilm epipélico. En tal sentido, la calidad del agua disminuyó en los sitios más urbanizados como consecuencia principalmente del incremento de nutrientes. Esto repercutió en la producción primaria neta, la tasa de asimilación y el cociente producción primaria bruta/respiración, reflejando que el biofilm fue marcadamente autotrófico y más eficiente en términos fotosintéticos. Estos cambios en los descriptores metabólicos se condicen con el patrón seguido por la clorofila, que reflejó un cambio en el estado trófico de mesotrófico a eutrófico. Asimismo, la composición específica en aquellos sitios mostró cambios a favor del incremento de organismos tolerantes a la polución.The purpose of the present study was to analyze the structural (organisms density, total biomass, autotrophic biomass and autotrophic index) and functional (net primary production, respiration, gross primary production and assimilation rate) responses of the epipelic biofilm at three sites of a Pampean stream presenting different proportions of land use exposed to urbanization. The results showed that the increase in the percentage of land use destined to urbanization was evidenced by the changes in the water quality and by the functional and structural descriptors of the epipelic biofilm. In this regard, the quality of water diminished at the most urbanized sites mainly as a consequence of the nutrient increase. This affected the net primary production, the assimilation rate and the gross primary production/ respiration ratio, reflecting that the biofilm was markedly autotrophic and more efficient photosynthetically. These changes in the metabolic descriptors are coincident with the pattern followed by the chlorophyll which reflected a change in the trophic state from mesotrophic to eutrophic. Likewise, the specific composition in those sites showed changes favoring the increase of organisms tolerant to pollution.Fil: Sierra, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Gomez, Nora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Marano, Agostina Virginia. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Instituto de Botánica Spegazzini; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Siervi, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentin

Caracterización funcional y estructural del biofilm epipélico en relación al aumento de la urbanización en un arroyo de la Llanura Pampeana (Argentina)

Fil: Sierra, María Victoria. Instituto de Limnología Dr. Raúl A. Ringuelet (ILPLA). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Gómez, Nora. Instituto de Limnología Dr. Raúl A. Ringuelet (ILPLA). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Marano, Agostina Virginia. División Instituto Spegazzini. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Di Siervi, Miguel A.. Instituto de Limnología Dr. Raúl A. Ringuelet (ILPLA). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Functional and structural characteristics of the epipelic biofilms in a lowland Pampean stream (Argentina) exposed to the increase of the urbanization

El objetivo del presente estudio fue analizar las respuestas estructurales (densidad de organismos, biomasa total, biomasa autotrófica e índice autotrófico) y funcionales (producción primaria neta, respiración, producción primaria bruta y tasa de asimilación) del biofilm epipélico en tres sitios de un arroyo pampeano que presentan diferentes proporciones del uso del suelo expuesto a la urbanización. Los resultados mostraron que el aumento en el porcentaje del uso del suelo destinado a la urbanización fue evidenciado por los cambios en la calidad del agua y por los descriptores funcionales y estructurales del biofilm epipélico. En tal sentido, la calidad del agua disminuyó en los sitios más urbanizados como consecuencia principalmente del incremento de nutrientes. Esto repercutió en la producción primaria neta, la tasa de asimilación y el cociente producción primaria bruta/respiración, reflejando que el biofilm fue marcadamente autotrófico y más eficiente en términos fotosintéticos. Estos cambios en los descriptores metabólicos se condicen con el patrón seguido por la clorofila, que reflejó un cambio en el estado trófico de mesotrófico a eutrófico. Asimismo, la composición específica en aquellos sitios mostró cambios a favor del incremento de organismos tolerantes a la polución.The purpose of the present study was to analyze the structural (organisms density, total biomass, autotrophic biomass and autotrophic index) and functional (net primary production, respiration, gross primary production and assimilation rate) responses of the epipelic biofilm at three sites of a Pampean stream presenting different proportions of land use exposed to urbanization. The results showed that the increase in the percentage of land use destined to urbanization was evidenced by the changes in the water quality and by the functional and structural descriptors of the epipelic biofilm. In this regard, the quality of water diminished at the most urbanized sites mainly as a consequence of the nutrient increase. This affected the net primary production, the assimilation rate and the gross primary production/ respiration ratio, reflecting that the biofilm was markedly autotrophic and more efficient photosynthetically. These changes in the metabolic descriptors are coincident with the pattern followed by the chlorophyll which reflected a change in the trophic state from mesotrophic to eutrophic. Likewise, the specific composition in those sites showed changes favoring the increase of organisms tolerant to pollution.Instituto de Limnología "Dr. Raúl A. Ringuelet"Instituto de Botánica "Dr. Carlos Spegazzini

El género Nowakowskiella (Cladochytriaceae, Chytridiomycota) en ambientes de la Pcia. de Buenos Aires (Argentina): taxonomía, frecuencia y abundancia de las especies encontradas

El género Nowakowskiella comprende organismos acuáticos y terrestres, que se encuentran como saprótrofos principalmente sobre restos vegetales en descomposición. El género es citado por primera vez para Argentina y en esta contribución, se describen cuatro especies, analizándose su frecuencia y abundancia en los ambientes estudiados, brindándose una clave basada en caracteres morfológicos para diferenciarlas.The genus Nowakowskiella (Cladochytriaceae, Chytridiomycota) in environments of Buenos Aires Province (Argentina): Taxonomy, frequency and abundance of the found species.The genus Nowakowskiella comprises aquatic and terrestrial organisms, which occur as saprotrophs on decomposed vegetable debris mainly. This genus is recorded for the first time in Argentina and in this contribution four species are described, analyzing their frequency and abundance in the studied environments and providing an identification key based on morphological characters to differentiate them.Instituto de Botánica "Dr. Carlos Spegazzini"Instituto de Limnología "Dr. Raúl A. Ringuelet