Reatores Aeróbicos para o Biotratamento de Águas Poluídas e Efluentes Sintéticos Contendo Ácido 3-Clorobenzóico

The degradation of 3-chlorobenzoic acid in polluted waters and synthetic effluents by a previously isolated indigenous strain of Pseudomonas putida was studied. Batch biodegradation assays were performed using a 2 L microfermentor at 28 °C with agitation. To simulate polluted water, 100 mg.L–1 of 3-chlorobenzoic acid were added to surface river water. Continuous‑flow assays were performed in an aerobic up-flow fixed-bed reactor constructed from PVC employing hollow PVC cylinders as support material. Synthetic wastewater was prepared by dissolving 3-chlorobenzoic acid in non-sterile groundwater. Biodegradation was evaluated by spectrophotometry, chloride release, gas chromatography and microbial growth. In batch experiments the indigenous strain of Pseudomonas putida degrades 100 mg.L–1 of 3-chlorobenzoic acid in 28 hours with a removal efficiency of 92.2 and 87.2%, expressed as compound and chemical oxygen demand removal, respectively. In the continuous-flow reactor the removal of an average influent concentration of 98.6 mg.L–1 reached 91.7% of compound and 88.9% of COD removal. The process efficiency remained approximately constant despite changes in the influent flow, compound concentration and temperature. The absence of metabolites was determined by gas chromatography performed at the end of the batch process and at the effluent of the continuous reactor. The ability of the isolated indigenous strain to degrade 3-chlorobenzoic acid in both batch and continuous reactors represents a promising feature to improve the treatment of effluents.Foi estudada a degradação do ácido 3-clorobenzóico em águas poluídas e efluentes sintéticos por uma cepa nativa previamente isolada de Pseudomonas putida. Ensaios de biodegradação de lotes foram realizados usando um microfermentador de 2 L a 28 °C sob agitação. Para simular água poluída, 100 mg.L–1 de ácido 3-clorobenzóico foram adicionados a água superficial de rio. Foram realizados ensaios de fluxo contínuo num reator aeróbico de fluxo ascendente de leito fixo construído em PVC, utilizando cilindros de PVC como material de suporte. Água sintética residuária foi preparada dissolvendo ácido 3-clorobenzóico em água subterrânea não estéril. A biodegradação foi avaliada por espectrofotometria, liberação de cloreto, cromatografia gasosa e crescimento microbiano. Nos experimentos em lote, a cepa nativa de Pseudomonas putida degrada 100 mg.L–1 de ácido 3-clorobenzóico em 28 horas com uma eficiência de remoção de 92,2 e 87,2%, expressada como remoção de composto e demanda de oxigênio químico, respectivamente. No reator de fluxo contínuo, a remoção de uma concentração média de afluente de 98,6 mg.L–1 atingiu 91,7% do composto e 88,9% da remoção de COD. A eficiência do processo permaneceu aproximadamente constante apesar das mudanças de fluxo, concentração do composto e temperatura. A ausência de metabólitos foi determinada por cromatografia gasosa realizada no final do processo em lote e no efluente do reator continuo. A capacidade da cepa nativa para degradar o ácido 3-clorobenzóico em ambos os lotes e reatores contínuos representa uma função promissora para melhorar o tratamento de efluentes.Fil: Gallego, A.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; ArgentinaFil: Rossen, Ariana Altair. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; ArgentinaFil: Gemini, V.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; Argentina. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Fortunato, M. S.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; ArgentinaFil: Rossi, S.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; ArgentinaFil: Planes, E.. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Korol, S.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; Argentin

Aerobic degradation of 3-chlorobenzoic acid by an indigenous strain isolated from a polluted river

An indigenous strain of Pseudomonas putida capable of degrading 3-chlorobenzoic acid as the sole carbon source was isolated from the Riachuelo, a polluted river in Buenos Aires. Aerobic biodegradation assays were performed using a 2-l microfermentor. Biodegradation was evaluated by spectrophotometry, chloride release, gas chromatography and microbial growth. Detoxification was evaluated by using Vibrio fischeri, Pseudokirchneriellasubcapitata and Lactuca sativa as test organisms. The indigenous bacterial strain degrades 100 mg l-1 3-chlorobenzoic acid in 14 h with a removal efficiency of 92. 0 and 86. 1% expressed as compound and chemical oxygen demand removal, respectively. The strain was capable of degrading up to 1,000 mg of the compound l-1. Toxicity was not detected at the end of the biodegradation process. Besides initial concentration, the effect of different factors, such as initial pH, initial inoculum, adaptation to the compound and presence of other substrates and toxic related compounds, was studied.Fil: Gallego, Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Gemini, Virginia L.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Rossen, Ariana Altair. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Rossi, Susana L.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Tripodi, Valeria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Servicio de Huellas Digitales Genéticas; ArgentinaFil: Corach, Daniel. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Servicio de Huellas Digitales Genéticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Planes, Estela. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Korol, Sonia Edith. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Aerobic Reactors for Biotreatment of Polluted Waters and Synthetic Effluents Containing 3-Chlorobenzoic Acid

The degradation of 3-chlorobenzoic acid in polluted waters and synthetic effluents by a previously isolated indigenous strain of Pseudomonas putida was studied. Batch biodegradation assays were performed using a 2 L microfermentor at 28 °C with agitation. To simulate polluted water, 100 mg.L–1 of 3-chlorobenzoic acid were added to surface river water. Continuous‑flow assays were performed in an aerobic up-flow fixed-bed reactor constructed from PVC employing hollow PVC cylinders as support material. Synthetic wastewater was prepared by dissolving 3-chlorobenzoic acid in non-sterile groundwater. Biodegradation was evaluated by spectrophotometry, chloride release, gas chromatography and microbial growth. In batch experiments the indigenous strain of Pseudomonas putida degrades 100 mg.L–1 of 3-chlorobenzoic acid in 28 hours with a removal efficiency of 92.2 and 87.2%, expressed as compound and chemical oxygen demand removal, respectively. In the continuous-flow reactor the removal of an average influent concentration of 98.6 mg.L–1 reached 91.7% of compound and 88.9% of COD removal. The process efficiency remained approximately constant despite changes in the influent flow, compound concentration and temperature. The absence of metabolites was determined by gas chromatography performed at the end of the batch process and at the effluent of the continuous reactor. The ability of the isolated indigenous strain to degrade 3-chlorobenzoic acid in both batch and continuous reactors represents a promising feature to improve the treatment of effluents.Foi estudada a degradação do ácido 3-clorobenzóico em águas poluídas e efluentes sintéticos por uma cepa nativa previamente isolada de Pseudomonas putida. Ensaios de biodegradação de lotes foram realizados usando um microfermentador de 2 L a 28 °C sob agitação. Para simular água poluída, 100 mg.L–1 de ácido 3-clorobenzóico foram adicionados a água superficial de rio. Foram realizados ensaios de fluxo contínuo num reator aeróbico de fluxo ascendente de leito fixo construído em PVC, utilizando cilindros de PVC como material de suporte. Água sintética residuária foi preparada dissolvendo ácido 3-clorobenzóico em água subterrânea não estéril. A biodegradação foi avaliada por espectrofotometria, liberação de cloreto, cromatografia gasosa e crescimento microbiano. Nos experimentos em lote, a cepa nativa de Pseudomonas putida degrada 100 mg.L–1 de ácido 3-clorobenzóico em 28 horas com uma eficiência de remoção de 92,2 e 87,2%, expressada como remoção de composto e demanda de oxigênio químico, respectivamente. No reator de fluxo contínuo, a remoção de uma concentração média de afluente de 98,6 mg.L–1 atingiu 91,7% do composto e 88,9% da remoção de COD. A eficiência do processo permaneceu aproximadamente constante apesar das mudanças de fluxo, concentração do composto e temperatura. A ausência de metabólitos foi determinada por cromatografia gasosa realizada no final do processo em lote e no efluente do reator continuo. A capacidade da cepa nativa para degradar o ácido 3-clorobenzóico em ambos os lotes e reatores contínuos representa uma função promissora para melhorar o tratamento de efluentes.Fil: Gallego, A.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; ArgentinaFil: Rossen, Ariana Altair. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; ArgentinaFil: Gemini, V.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; Argentina. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Fortunato, M. S.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; ArgentinaFil: Rossi, S.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; ArgentinaFil: Planes, E.. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Korol, S.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Sanidad Nutrición Bromatología y Toxicología; Argentin

Water Quality and Toxicological Impact Assessment Using the Nematode Caenorhabditis elegans Bioassay in a Long-Term Intensive Agricultural Area

Due to intensive agricultural activities to meet the growing needs for food, large volumes of water are consumed and an increasing amount of agrochemicals are released into the environment threatening the aquatic ecosystem. In order to ensure a sustainable agricultural management, it is crucial to develop an integrated water assessment plan that includes not only water quantity and quality but also toxicological assessments. The Pergamino River basin (province of Buenos Aires, Argentina) was selected as a representative case of study to monitor and assess the impact of both the long-term intensification of soybean production and fast-growing urban development on surface and groundwater sources. Physicochemical analyses and a Water Quality Index were determined and showed that water quality falls into the marginal category, compromising the irrigation purposes and threatening aquatic life. Glyphosate and aminomethylphosphonic acid were detected at least once in all sites. Caenorhabditis elegans toxic bioassays were performed and a toxicological ranking was developed. This analysis proved to be useful to detect toxicity even when water parameters met regulatory requirements and water quality seemed to be satisfactory. This research constitutes a valuable model to be replicated in other river basins that have been impacted by intensive agriculture and growing urban development in order to assess water quality conditions and ensure sound water resources management.Fil: Clavijo Lara, Araceli Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Rossen, Ariana Altair. Ministerio del Interior, Obras Públicas y Vivienda. Secretaría de Obras Públicas. Subsecretaría de Recursos Hídricos. Instituto Nacional del Agua y del Ambiente (Ezeiza); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Calvo, Daniel. Ministerio del Interior, Obras Públicas y Vivienda. Secretaría de Obras Públicas. Subsecretaría de Recursos Hídricos. Instituto Nacional del Agua y del Ambiente (Ezeiza); ArgentinaFil: Kronberg, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Moya, Aldana. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Pagano, Eduardo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Munarriz, Eliana Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentin

Glyphosate-based herbicides modulate oxidative stress response in the nematode Caenorhabditis elegans

Glyphosate-based formulation is used as non-selective and post-emergent herbicides in urban and rural activities. In view of its recurring applications in agricultural producing countries, the increase of glyphosate concentration in the environment stresses the need to test the adverse effects on non-target organisms and assess the risk of its use. This paper analyzes the toxicological and oxidative stress and modulatory effects of a glyphosate commercial formulation (glyphosate F) on the nematode Caenorhabditis elegans. We detected ROS production and enhancement of oxidative stress response in glyphosate F-treated nematodes. Particularly, we found an increased ctl-1 catalase gene expression of a catalase specific activity. In addition, we showed that glyphosate F treatment activated the FOXO transcription factor DAF-16, a critical target of the insulin/IGF-1 signaling pathway, which modulates the transcription of a broad range of genes involved in stress resistance, reproductive development, dauer formation, and longevity. In summary, the exposure of glyphosate F induces an oxidative imbalance in C. elegans that leads to the DAF-16 activation and consequently to the expression of genes that boost the antioxidant defense system. In this regard, clt-1 gene and catalase activity proved to be excellent biomarkers to develop more sensitive protocols to assess the environmental risk of glyphosate use.Fil: Kronberg, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Clavijo Lara, Araceli Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Moya, Aldana. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Rossen, Ariana Altair. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional del Agua; ArgentinaFil: Calvo, Daniel. Instituto Nacional del Agua; ArgentinaFil: Pagano, Eduardo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Munarriz, Eliana Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentin

The nematode Caenorhabditis elegans as an integrated toxicological tool to assess water quality and pollution

Determination of water quality status in rivers is critical to establish a sustainable water management policy. For this reason, over the last decades it has been recommended to perform integrated water assessments that include water quantities and physicochemical, ecological and toxicological tests. However, sometimes resources are limited and it is not possible to perform large-scale chemical determinations of pollutants or conduct numerous ecotoxicological tests. To overcome this problem we use and measure the growth, as a response parameter, of the soil nematode Caenorhabditis elegans to assess water quality in rivers. The C. elegans is a ubiquitous organism that has emerged as an important model organism in aquatic and soil toxicology research. The Tunuyán River Basin (Province of Mendoza, Argentina) has been selected as a representative traditional water monitoring system to test the applicability of the C. elegans toxicological bioassay to generate an integrated water quality evaluation. Jointly with the C. elegans toxic assays, physicochemical and bacteriological parameters were determined for each monitoring site. C. elegans bioassays help to identify different water qualities in the river basin. Multivariate statistical analysis (PCA and linear regression models) has allowed us to confirm that traditional water quality studies do not predict potential toxic effects on living organisms. On the contrary, physicochemical and bacteriological analyzes explain < 62% of the C. elegans growth response variability, showing that ecotoxicological bioassays are important to obtain a realistic scenario of water quality threats. Our results confirm that the C. elegans bioassay is a sensible and suitable tool to assess toxicity and should be implemented in routine water quality monitoring.Fil: Clavijo Lara, Araceli Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Kronberg, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Rossen, Ariana Altair. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio del Interior, Obras Públicas y Vivienda. Secretaría de Obras Públicas. Subsecretaría de Recursos Hídricos. Instituto Nacional del Agua y del Ambiente (Ezeiza); ArgentinaFil: Moya, Aldana. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Protección Vegetal; ArgentinaFil: Calvo, Daniel Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio del Interior, Obras Públicas y Vivienda. Secretaría de Obras Públicas. Subsecretaría de Recursos Hídricos. Instituto Nacional del Agua y del Ambiente (Ezeiza); ArgentinaFil: Salatino, Santa Esmeralda. Provincia de Mendoza. Ministerio de Infraestructura y Vivienda. Secretaria de Obras Publicas. Instituto Nacional del Agua; ArgentinaFil: Pagano, Eduardo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Morabito, Jose Antonio. Provincia de Mendoza. Ministerio de Infraestructura y Vivienda. Secretaria de Obras Publicas. Instituto Nacional del Agua; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Munarriz, Eliana Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentin