Ramon Ahumada-Rudolph | Universidad del Bio-bio (original) (raw)

Papers by Ramon Ahumada-Rudolph

Food and Chemical Toxicology, Jun 1, 2021

Antibiotics are extensively used for growth promotion purposes in intensive aquaculture. In Chile... more Antibiotics are extensively used for growth promotion purposes in intensive aquaculture. In Chile, the use of antibiotics in salmon farming is excessive, approximately 62 times more than is used in Norway. In the salmon industry, antibiotics such as oxytetracycline (OTC) are administered in the diet, both in the juvenile stage in freshwater and in the fattening process of salmon in marine sectors. We have investigated the fjords of Chile, where many salmon farms are located, searching for fungi able to degrade this tetracycline antibiotic. We have evaluated the OTC degradation ability of the following; Penicillium commune, Epicoccum nigrum, Trichoderma harzianum, Aspergillus terreus and Beauveria bassiana, isolated from sediments in salmon farms from southern Chile. In all these fungal strains, the amount of OTC decreased in the culture medium, as adsorbed in the mycelia, after the third day of exposure. These strains were capable of degrading OTC at remarkable rates up to 78%, by the 15th day. This is the first study showing that the mycelium of these fungal strains has the ability to degrade OTC. We believe the knowledge produced by these results has the potential to serve as a basis for implementing a bioremediation process in the near future.

Ecological Indicators, Mar 1, 2019

Journal of Alzheimer's Disease

Background: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive... more Background: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive cognitive impairment and memory loss. One of the hallmarks in AD is amyloid-β peptide (Aβ) accumulation, where the soluble oligomers of Aβ (AβOs) are the most toxic species, deteriorating the synaptic function, membrane integrity, and neuronal structures, which ultimately lead to apoptosis. Currently, there are no drugs to arrest AD progression, and current scientific efforts are focused on searching for novel leads to control this disease. Lignans are compounds extracted from conifers and have several medicinal properties. Eudesmin (Eu) is an extractable lignan from the wood of Araucaria araucana, a native tree from Chile. This metabolite has shown a range of biological properties, including the ability to control inflammation and antibacterial effects. Objective: In this study, the neuroprotective abilities of Eu on synaptic failure induced by AβOs were analyzed. Methods: Using neuron...

Gayana (Concepción), 2015

Se analizó el contenido de metales totales en organismos bentónicos recolectados en Campos de Hie... more Se analizó el contenido de metales totales en organismos bentónicos recolectados en Campos de Hielo Sur, con el objeto de establecer patrones de abundancia de metales en los organismos y concentración de referencia de metales (línea base) en una zona de aguas prístinas. Se estudiaron seis especies 5 moluscos bivalvos y un erizo. Los análisis se realizaron utilizando un espectrómetro de emisión atómica acoplado a plasma (ICP-AES). Se estableció un ranking de abundancia de metales para los analitos y fue similar para las diferentes especies: Zn > Ba > Cu > Co > Cd > Cr > Ni > Pb e independiente de los valores de concentración de cada metal en particular. Se estableció por comparación que la concentración de metales informada fue semejante a otros sistemas no alterados antrópicamente.

Science of The Total Environment

Water, 2020

Coastal wetlands are ecosystems that provide multiple benefits to human settlements; nonetheless,... more Coastal wetlands are ecosystems that provide multiple benefits to human settlements; nonetheless, they are seriously threatened due to both a lack of planning instruments and human activities associated mainly with urban growth. An understanding of their functioning and status is crucial for their protection and conservation. Two wetlands with different degrees of urbanization, Rocuant-Andalién (highly urbanized) and Tubul-Raqui (with little urbanization), were analyzed using temperature, salinity, dissolved oxygen, pH, turbidity, granulometry, fecal coliform, and macroinvertebrate assemblage variables in summer and winter. In both wetlands marked seasonality in salinity, temperature and sediment texture classification, regulated by oceanic influence and changes in the freshwater budget, was observed. In the Rocuant-Andalién wetland, the increases in pH, dissolved oxygen, gravel percentage, and coliform concentration were statistically significant. Urbanization generated negative im...

Science of The Total Environment, 2019

Basin-scale agricultural water consumption was assessed considering climate variability. • A geog... more Basin-scale agricultural water consumption was assessed considering climate variability. • A geographic variable (upper, middle, lower basin) was added to identify local changes. • The WF agricultural WF blue and WF gray were greatest in the dry year and WF green in a normal year. • Avocados, olives and corn had the greatest WF agricultural , in contrast to onions. • The integration of these results would allow rational water allocation.

Environmental Monitoring and Assessment, 2018

Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fj... more Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fjords using microscopy and molecular techniques. We analyzed adaptive responses of cell wall morphology to salinity, temperature, and pH in order to explain the ability of E. nigrum to co-inhabit both marine and freshwater environments. For this purpose, E. nigrum was cultured in a series of media with variations in salinity (freshwater and seawater), pH (acidic, neutral, and basic), and temperature (5 to 25°C). Changes were observed through transmission electron microscopy. A direct correlation between increased salinity and cell wall thickening (> 0.2 μm) was observed, along with a significant relationship between pH and the presence of extracellular polymeric substances (EPS) on the outside of the cell wall. The observed morphological changes could confirm that an ubiquitous fungus such as E. nigrum requires adaptive responses to co-inhabit freshwater, marine, and terrestrial substrates.

Environmental Monitoring and Assessment, 2018

Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fj... more Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fjords using microscopy and molecular techniques. We analyzed adaptive responses of cell wall morphology to salinity, temperature, and pH in order to explain the ability of E. nigrum to co-inhabit both marine and freshwater environments. For this purpose, E. nigrum was cultured in a series of media with variations in salinity (freshwater and seawater), pH (acidic, neutral, and basic), and temperature (5 to 25°C). Changes were observed through transmission electron microscopy. A direct correlation between increased salinity and cell wall thickening (> 0.2 μm) was observed, along with a significant relationship between pH and the presence of extracellular polymeric substances (EPS) on the outside of the cell wall. The observed morphological changes could confirm that an ubiquitous fungus such as E. nigrum requires adaptive responses to co-inhabit freshwater, marine, and terrestrial substrates.

Ecological Indicators, 2019

Amid the growing population, climate change and decreasing water availability, water resources pl... more Amid the growing population, climate change and decreasing water availability, water resources planning faces the challenge of achieving efficient and equitable water use, mainly in food production, its greatest consumer. The sustainability of agricultural water consumption in the Cachapoal River basin (34°S 71°O) is assessed using the blue (WFS blue) and gray water footprint sustainability (WFS gray) indicators under conditions of climate variability. The WFS blue indicator of agricultural water consumption showed unsustainability in the upper basin in the dry year (2007), indicating severe water scarcity in autumn and low scarcity in spring, and in the wet year (2005), in which moderate water scarcity was observed only in spring, as a result of the decrease in blue water availability (WA blue) and the increase in the blue water footprint (WF blue), exceeding environmental flow requirements and the environmental carrying capacity. An opposite situation was found in the lower basin, where no water scarcity was observed in the analyzed years. Surface water quality, based on the concentration of fertilizers applied to crops, was observed to be more affected and unsustainable (WFS gray) in the upper basin in the autumn and winter period of the dry year (2007). Currently, the indicators can be applied to provide useful information on the sustainability of water use in basins in order to establish and meet water resources protection objectives.

Revista de biología marina y oceanografía, 2016

It is proposed that marine fungi are a good alternative for remediation of areas contaminated wit... more It is proposed that marine fungi are a good alternative for remediation of areas contaminated with antibiotics due to their heterotrophic condition, adaptability to environmental changes, and specific resistance to stressors. With this assumption we investigated the fjords of Southern Chile, which are characterized by salmon farming. We evaluated the concentration of oxytetracycline (OTC) in sediments from different areas surrounding salmon cages. In addition, we isolated fungi species to assess their ability to degrade OTC. Measurable amounts of OTC were detected in deeper sediments located at the eastern sector of cages and rafts (Z= 100 m; 4.62 ± 0.12 to 24.1 ± 1.03 µg g-1). Thirty-eight strains of endemic fungi were isolated and identified in the sediments near the farming center. Among these strains we detected species from the Phylum Ascomycetes, including Penicillium commune, Aspergillus terreus, Beauveria bassiana, Trichoderma harzianum, Epicoccum nigrum and Emericellopsis alkaline. These strains fungi were capable of degrading about 76 to 92% of the OTC present in the culture media. The results of this study constitute a first step into implementing processes that could favor waste bioremediation from marine sediments.

Environmental Monitoring and Assessment, 2016

Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity ... more Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity requires the use of antibiotics, such as oxytetracycline, for the control and prevention of diseases, which have a negative impact on the environment. We analyzed the abilities of endemic marine fungi to biodegrade oxytetracycline, an antibiotic used extensively in fish farming. We isolated marine fungi strains from sediment samples obtained from an area of fish farming activity. The five isolated strains showed an activity on oxytetracycline and were identified as Trichoderma harzianum, Trichoderma deliquescens, Penicillium crustosum, Rhodotorula mucilaginosa, and Talaromyces atroroseus by a scanning electron microscopy and characterized by molecular techniques. Results showed significant degradation in the concentration of oxytetracycline at the first 2 days of treatment for all strains analyzed. At 21 days of treatment, the concentration of oxytetracycline was decreased 92 % by T. harzianum, 85 % by T. deliquescens, 83 % by P. crustosum, 73 % by R. mucilaginosa, and 72 % by T. atroroseus, all of which were significantly higher than the controls. Given these results, we propose that fungal strains isolated from marine sediments may be useful tools for biodegradation of antibiotics, such as oxytetracycline, in the salmon industry.

Environmental Monitoring and Assessment, 2016

Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity ... more Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity requires the use of antibiotics, such as oxytetracycline, for the control and prevention of diseases, which have a negative impact on the environment. We analyzed the abilities of endemic marine fungi to biodegrade oxytetracycline, an antibiotic used extensively in fish farming. We isolated marine fungi strains from sediment samples obtained from an area of fish farming activity. The five isolated strains showed an activity on oxytetracycline and were identified as Trichoderma harzianum, Trichoderma deliquescens, Penicillium crustosum, Rhodotorula mucilaginosa, and Talaromyces atroroseus by a scanning electron microscopy and characterized by molecular techniques. Results showed significant degradation in the concentration of oxytetracycline at the first 2 days of treatment for all strains analyzed. At 21 days of treatment, the concentration of oxytetracycline was decreased 92 % by T. harzianum, 85 % by T. deliquescens, 83 % by P. crustosum, 73 % by R. mucilaginosa, and 72 % by T. atroroseus, all of which were significantly higher than the controls. Given these results, we propose that fungal strains isolated from marine sediments may be useful tools for biodegradation of antibiotics, such as oxytetracycline, in the salmon industry.

Revista de biología marina y oceanografía, 2014

Variación de esteroles y ácidos grasos como respuesta adaptativa a cambios de temperatura, salini... more Variación de esteroles y ácidos grasos como respuesta adaptativa a cambios de temperatura, salinidad y pH de un hongo marino Epicoccum nigrum aislado desde los fiordos patagónicos

Coastal wetlands are ecosystems that provide multiple benefits to human settlements; nonetheless,... more Coastal wetlands are ecosystems that provide multiple benefits to human settlements; nonetheless, they are seriously threatened due to both a lack of planning instruments and human activities associated mainly with urban growth. An understanding of their functioning and status is crucial for their protection and conservation. Two wetlands with different degrees of urbanization, Rocuant-Andalién (highly urbanized) and Tubul-Raqui (with little urbanization), were analyzed using temperature, salinity, dissolved oxygen, pH, turbidity, granulometry, fecal coliform, and macroinvertebrate assemblage variables in summer and winter. In both wetlands marked seasonality in salinity, temperature and sediment texture classification, regulated by oceanic influence and changes in the freshwater budget, was observed. In the Rocuant-Andalién wetland, the increases in pH, dissolved oxygen, gravel percentage, and coliform concentration were statistically significant. Urbanization generated negative impacts on macroinvertebrate assemblage structure that inhabit the wetlands; greater richness and abundance (8.5 times greater) were recorded in the Tubul-Raqui wetland than in the more urbanized wetland. The multivariate statistical analysis reflects the alteration of these complex systems.

Science of the Total Environment, 2019

Comprender el consumo de agua es crucial para la gestión sostenible de los recursos hídricos. Baj... more Comprender el consumo de agua es crucial para la gestión sostenible de los recursos hídricos. Bajo los escenarios de cambio climático que proyectan una disponibilidad de agua altamente variable , la necesidad de políticas públicas que aseguren la eficiencia y la equidad en los recursos hídricos está aumentando. Este trabajo analiza el caso de la cuenca agrícola del río Cachapoal (34 ° S 71 ° W), que presenta aumentos de temperatura y un déficit de precipitaciones, con un período de sequía que comenzó hace más de once años y que ha reducido significativamente la disponibilidad de agua. El consumo de agua en la cuenca para la producción de alimentos se determinó a partir de la huella hídrica agrícola (WF agrícola ), utilizando la verde ( verde WF ), azul ( azul WF ) y gris ( gris WF).) indicadores, que se midieron en las cuencas superior, media e inferior en condiciones de variabilidad climática (años secos, húmedos y normales). El mayor WF agrícola se estableció en el año seco, con un total de 18,221 m 3 t −1 , seguido de 15,902 m 3 t −1 en el año húmedo y 14,091 m 3 t −1 en el año normal. Asimismo, en el año seco también se observaron el mayor azul de WF y el gris de WF , de 12,000 m 3 t- 1 y 4934 m 3 t- 1 , respectivamente. El mayor verde de WF , 2000 m 3. t −1 , se calculó para un año normal. El 63% de la superficie agrícola de la cuenca estaba cubierta por los cultivos de aguacate ( Persea americana ), olivo ( Olea europaea ), maíz ( Zea mays ) y uva ( Vitis sp ), que presentó la mayor WF agrícola. Estos datos de la huella hídrica proporcionan una base cuantitativa para la evaluación del consumo y la degradación del agua, considerando la producción agrícola y sus múltiples variables. El éxito de la aplicación de estos resultados radica en el uso de indicadores para comprender los procesos de cambio y complementar los futuros planes de asignación de agua con modelos de gestión de agua más racionales.

Environmental, monitoring and assessment, 2019

Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fj... more Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fjords using microscopy and molecular techniques. We analyzed adaptive responses of cell wall morphology to salinity, temperature, and pH in order to explain the ability of E. nigrum to co-inhabit both marine and freshwater environments. For this purpose, E. nigrum was cultured in a series of media with variations in salinity (freshwater and seawater), pH (acidic, neutral, and basic), and temperature (5 to 25 °C). Changes were observed through transmission electron microscopy. A direct correlation between increased salinity and cell wall thickening (> 0.2 μm) was observed, along with a significant relationship between pH and the presence of extracellular polymeric substances (EPS) on the outside of the cell wall. The observed morphological changes could confirm that an ubiquitous fungus such as E. nigrum requires adaptive responses to co-inhabit freshwater, marine, and terrestrial substrates.

Revista de biología Marina y Oceanografía, 2016

It is proposed that marine fungi are a good alternative for remediation of areas contaminated wit... more It is proposed that marine fungi are a good alternative for remediation of areas contaminated with antibiotics due to their heterotrophic condition, adaptability to environmental changes, and specific resistance to stressors. With this assumption we investigated the fjords of Southern Chile, which are characterized by salmon farming. We evaluated the concentration of oxytetracycline (OTC) in sediments from different areas surrounding salmon cages. In addition, we isolated fungi species to assess their ability to degrade OTC. Measurable amounts of OTC were detected in deeper sediments located at the eastern sector of cages and rafts (Z= 100 m; 4.62 ± 0.12 to 24.1 ± 1.03 μg g-1). Thirty-eight strains of endemic fungi were isolated and identified in the sediments near the farming center. Among these strains we detected species from the Phylum Ascomycetes, including Penicillium commune, Aspergillus terreus, Beauveria bassiana, Trichoderma harzianum, Epicoccum nigrum and Emericellopsis alkaline. These strains fungi were capable of degrading about 76 to 92% of the OTC present in the culture media. The results of this study constitute a first step into implementing processes that could favor waste bioremediation from marine sediments.

Environmental, Monitoring and Assessment, 2016

Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity ... more Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity requires the use of antibiotics, such as oxytetracycline, for the control and prevention of diseases, which have a negative impact on the environment. We analyzed the abilities of endemic marine fungi to biodegrade oxytetracycline, an antibiotic used extensively in fish farming. We isolated marine fungi strains from sediment samples obtained from an area of fish farming activity. The five isolated strains showed an activity on oxytetracycline and were identified as Trichoderma harzianum, Trichoderma deliquescens, Penicillium crustosum, Rhodotorula mucilaginosa, and Talaromyces atroroseus by a scanning electron microsco-py and characterized by molecular techniques. Results showed significant degradation in the concentration of oxytetracycline at the first 2 days of treatment for all strains analyzed. At 21 days of treatment, the concentration of oxytetracycline was decreased 92 % by T. harzianum, 85 % by T. deliquescens, 83 % by P. crustosum, 73 % by R. mucilaginosa, and 72 % by T. atroroseus, all of which were significantly higher than the controls. Given these results, we propose that fungal strains isolated from marine sediments may be useful tools for biodegradation of antibiotics, such as oxytetracycline, in the salmon industry.

Ecological Indicators, 2019

Amid the growing population, climate change and decreasing water availability, water resources pl... more Amid the growing population, climate change and decreasing water availability, water resources planning faces the challenge of achieving efficient and equitable water use, mainly in food production, its greatest consumer. The sustainability of agricultural water consumption in the Cachapoal River basin (34°S 71°O) is assessed using the blue (WFS) and gray water footprint sustainability (WFS indicator of agricultural water consumption showed unsustainability in the upper basin in the dry year (2007), indicating severe water scarcity in autumn and low scarcity in spring, and in the wet year (2005), in which moderate water scarcity was observed only in spring, as a result of the decrease in blue water availability (WA), exceeding environmental flow requirements and the environmental carrying capacity. An opposite situation was found in the lower basin, where no water scarcity was observed in the analyzed years. Surface water quality, based on the concentration of fertilizers applied to crops, was observed to be more affected and unsustainable (WFS) in the upper basin in the autumn and winter period of the dry year (2007). Currently, the indicators can be applied to provide useful information on the sustainability of water use in basins in order to establish and meet water resources protection objectives.

Food and Chemical Toxicology, Jun 1, 2021

Antibiotics are extensively used for growth promotion purposes in intensive aquaculture. In Chile... more Antibiotics are extensively used for growth promotion purposes in intensive aquaculture. In Chile, the use of antibiotics in salmon farming is excessive, approximately 62 times more than is used in Norway. In the salmon industry, antibiotics such as oxytetracycline (OTC) are administered in the diet, both in the juvenile stage in freshwater and in the fattening process of salmon in marine sectors. We have investigated the fjords of Chile, where many salmon farms are located, searching for fungi able to degrade this tetracycline antibiotic. We have evaluated the OTC degradation ability of the following; Penicillium commune, Epicoccum nigrum, Trichoderma harzianum, Aspergillus terreus and Beauveria bassiana, isolated from sediments in salmon farms from southern Chile. In all these fungal strains, the amount of OTC decreased in the culture medium, as adsorbed in the mycelia, after the third day of exposure. These strains were capable of degrading OTC at remarkable rates up to 78%, by the 15th day. This is the first study showing that the mycelium of these fungal strains has the ability to degrade OTC. We believe the knowledge produced by these results has the potential to serve as a basis for implementing a bioremediation process in the near future.

Ecological Indicators, Mar 1, 2019

Journal of Alzheimer's Disease

Background: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive... more Background: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive cognitive impairment and memory loss. One of the hallmarks in AD is amyloid-β peptide (Aβ) accumulation, where the soluble oligomers of Aβ (AβOs) are the most toxic species, deteriorating the synaptic function, membrane integrity, and neuronal structures, which ultimately lead to apoptosis. Currently, there are no drugs to arrest AD progression, and current scientific efforts are focused on searching for novel leads to control this disease. Lignans are compounds extracted from conifers and have several medicinal properties. Eudesmin (Eu) is an extractable lignan from the wood of Araucaria araucana, a native tree from Chile. This metabolite has shown a range of biological properties, including the ability to control inflammation and antibacterial effects. Objective: In this study, the neuroprotective abilities of Eu on synaptic failure induced by AβOs were analyzed. Methods: Using neuron...

Gayana (Concepción), 2015

Se analizó el contenido de metales totales en organismos bentónicos recolectados en Campos de Hie... more Se analizó el contenido de metales totales en organismos bentónicos recolectados en Campos de Hielo Sur, con el objeto de establecer patrones de abundancia de metales en los organismos y concentración de referencia de metales (línea base) en una zona de aguas prístinas. Se estudiaron seis especies 5 moluscos bivalvos y un erizo. Los análisis se realizaron utilizando un espectrómetro de emisión atómica acoplado a plasma (ICP-AES). Se estableció un ranking de abundancia de metales para los analitos y fue similar para las diferentes especies: Zn > Ba > Cu > Co > Cd > Cr > Ni > Pb e independiente de los valores de concentración de cada metal en particular. Se estableció por comparación que la concentración de metales informada fue semejante a otros sistemas no alterados antrópicamente.

Science of The Total Environment

Water, 2020

Coastal wetlands are ecosystems that provide multiple benefits to human settlements; nonetheless,... more Coastal wetlands are ecosystems that provide multiple benefits to human settlements; nonetheless, they are seriously threatened due to both a lack of planning instruments and human activities associated mainly with urban growth. An understanding of their functioning and status is crucial for their protection and conservation. Two wetlands with different degrees of urbanization, Rocuant-Andalién (highly urbanized) and Tubul-Raqui (with little urbanization), were analyzed using temperature, salinity, dissolved oxygen, pH, turbidity, granulometry, fecal coliform, and macroinvertebrate assemblage variables in summer and winter. In both wetlands marked seasonality in salinity, temperature and sediment texture classification, regulated by oceanic influence and changes in the freshwater budget, was observed. In the Rocuant-Andalién wetland, the increases in pH, dissolved oxygen, gravel percentage, and coliform concentration were statistically significant. Urbanization generated negative im...

Science of The Total Environment, 2019

Basin-scale agricultural water consumption was assessed considering climate variability. • A geog... more Basin-scale agricultural water consumption was assessed considering climate variability. • A geographic variable (upper, middle, lower basin) was added to identify local changes. • The WF agricultural WF blue and WF gray were greatest in the dry year and WF green in a normal year. • Avocados, olives and corn had the greatest WF agricultural , in contrast to onions. • The integration of these results would allow rational water allocation.

Environmental Monitoring and Assessment, 2018

Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fj... more Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fjords using microscopy and molecular techniques. We analyzed adaptive responses of cell wall morphology to salinity, temperature, and pH in order to explain the ability of E. nigrum to co-inhabit both marine and freshwater environments. For this purpose, E. nigrum was cultured in a series of media with variations in salinity (freshwater and seawater), pH (acidic, neutral, and basic), and temperature (5 to 25°C). Changes were observed through transmission electron microscopy. A direct correlation between increased salinity and cell wall thickening (> 0.2 μm) was observed, along with a significant relationship between pH and the presence of extracellular polymeric substances (EPS) on the outside of the cell wall. The observed morphological changes could confirm that an ubiquitous fungus such as E. nigrum requires adaptive responses to co-inhabit freshwater, marine, and terrestrial substrates.

Environmental Monitoring and Assessment, 2018

Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fj... more Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fjords using microscopy and molecular techniques. We analyzed adaptive responses of cell wall morphology to salinity, temperature, and pH in order to explain the ability of E. nigrum to co-inhabit both marine and freshwater environments. For this purpose, E. nigrum was cultured in a series of media with variations in salinity (freshwater and seawater), pH (acidic, neutral, and basic), and temperature (5 to 25°C). Changes were observed through transmission electron microscopy. A direct correlation between increased salinity and cell wall thickening (> 0.2 μm) was observed, along with a significant relationship between pH and the presence of extracellular polymeric substances (EPS) on the outside of the cell wall. The observed morphological changes could confirm that an ubiquitous fungus such as E. nigrum requires adaptive responses to co-inhabit freshwater, marine, and terrestrial substrates.

Ecological Indicators, 2019

Amid the growing population, climate change and decreasing water availability, water resources pl... more Amid the growing population, climate change and decreasing water availability, water resources planning faces the challenge of achieving efficient and equitable water use, mainly in food production, its greatest consumer. The sustainability of agricultural water consumption in the Cachapoal River basin (34°S 71°O) is assessed using the blue (WFS blue) and gray water footprint sustainability (WFS gray) indicators under conditions of climate variability. The WFS blue indicator of agricultural water consumption showed unsustainability in the upper basin in the dry year (2007), indicating severe water scarcity in autumn and low scarcity in spring, and in the wet year (2005), in which moderate water scarcity was observed only in spring, as a result of the decrease in blue water availability (WA blue) and the increase in the blue water footprint (WF blue), exceeding environmental flow requirements and the environmental carrying capacity. An opposite situation was found in the lower basin, where no water scarcity was observed in the analyzed years. Surface water quality, based on the concentration of fertilizers applied to crops, was observed to be more affected and unsustainable (WFS gray) in the upper basin in the autumn and winter period of the dry year (2007). Currently, the indicators can be applied to provide useful information on the sustainability of water use in basins in order to establish and meet water resources protection objectives.

Revista de biología marina y oceanografía, 2016

It is proposed that marine fungi are a good alternative for remediation of areas contaminated wit... more It is proposed that marine fungi are a good alternative for remediation of areas contaminated with antibiotics due to their heterotrophic condition, adaptability to environmental changes, and specific resistance to stressors. With this assumption we investigated the fjords of Southern Chile, which are characterized by salmon farming. We evaluated the concentration of oxytetracycline (OTC) in sediments from different areas surrounding salmon cages. In addition, we isolated fungi species to assess their ability to degrade OTC. Measurable amounts of OTC were detected in deeper sediments located at the eastern sector of cages and rafts (Z= 100 m; 4.62 ± 0.12 to 24.1 ± 1.03 µg g-1). Thirty-eight strains of endemic fungi were isolated and identified in the sediments near the farming center. Among these strains we detected species from the Phylum Ascomycetes, including Penicillium commune, Aspergillus terreus, Beauveria bassiana, Trichoderma harzianum, Epicoccum nigrum and Emericellopsis alkaline. These strains fungi were capable of degrading about 76 to 92% of the OTC present in the culture media. The results of this study constitute a first step into implementing processes that could favor waste bioremediation from marine sediments.

Environmental Monitoring and Assessment, 2016

Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity ... more Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity requires the use of antibiotics, such as oxytetracycline, for the control and prevention of diseases, which have a negative impact on the environment. We analyzed the abilities of endemic marine fungi to biodegrade oxytetracycline, an antibiotic used extensively in fish farming. We isolated marine fungi strains from sediment samples obtained from an area of fish farming activity. The five isolated strains showed an activity on oxytetracycline and were identified as Trichoderma harzianum, Trichoderma deliquescens, Penicillium crustosum, Rhodotorula mucilaginosa, and Talaromyces atroroseus by a scanning electron microscopy and characterized by molecular techniques. Results showed significant degradation in the concentration of oxytetracycline at the first 2 days of treatment for all strains analyzed. At 21 days of treatment, the concentration of oxytetracycline was decreased 92 % by T. harzianum, 85 % by T. deliquescens, 83 % by P. crustosum, 73 % by R. mucilaginosa, and 72 % by T. atroroseus, all of which were significantly higher than the controls. Given these results, we propose that fungal strains isolated from marine sediments may be useful tools for biodegradation of antibiotics, such as oxytetracycline, in the salmon industry.

Environmental Monitoring and Assessment, 2016

Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity ... more Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity requires the use of antibiotics, such as oxytetracycline, for the control and prevention of diseases, which have a negative impact on the environment. We analyzed the abilities of endemic marine fungi to biodegrade oxytetracycline, an antibiotic used extensively in fish farming. We isolated marine fungi strains from sediment samples obtained from an area of fish farming activity. The five isolated strains showed an activity on oxytetracycline and were identified as Trichoderma harzianum, Trichoderma deliquescens, Penicillium crustosum, Rhodotorula mucilaginosa, and Talaromyces atroroseus by a scanning electron microscopy and characterized by molecular techniques. Results showed significant degradation in the concentration of oxytetracycline at the first 2 days of treatment for all strains analyzed. At 21 days of treatment, the concentration of oxytetracycline was decreased 92 % by T. harzianum, 85 % by T. deliquescens, 83 % by P. crustosum, 73 % by R. mucilaginosa, and 72 % by T. atroroseus, all of which were significantly higher than the controls. Given these results, we propose that fungal strains isolated from marine sediments may be useful tools for biodegradation of antibiotics, such as oxytetracycline, in the salmon industry.

Revista de biología marina y oceanografía, 2014

Variación de esteroles y ácidos grasos como respuesta adaptativa a cambios de temperatura, salini... more Variación de esteroles y ácidos grasos como respuesta adaptativa a cambios de temperatura, salinidad y pH de un hongo marino Epicoccum nigrum aislado desde los fiordos patagónicos

Coastal wetlands are ecosystems that provide multiple benefits to human settlements; nonetheless,... more Coastal wetlands are ecosystems that provide multiple benefits to human settlements; nonetheless, they are seriously threatened due to both a lack of planning instruments and human activities associated mainly with urban growth. An understanding of their functioning and status is crucial for their protection and conservation. Two wetlands with different degrees of urbanization, Rocuant-Andalién (highly urbanized) and Tubul-Raqui (with little urbanization), were analyzed using temperature, salinity, dissolved oxygen, pH, turbidity, granulometry, fecal coliform, and macroinvertebrate assemblage variables in summer and winter. In both wetlands marked seasonality in salinity, temperature and sediment texture classification, regulated by oceanic influence and changes in the freshwater budget, was observed. In the Rocuant-Andalién wetland, the increases in pH, dissolved oxygen, gravel percentage, and coliform concentration were statistically significant. Urbanization generated negative impacts on macroinvertebrate assemblage structure that inhabit the wetlands; greater richness and abundance (8.5 times greater) were recorded in the Tubul-Raqui wetland than in the more urbanized wetland. The multivariate statistical analysis reflects the alteration of these complex systems.

Science of the Total Environment, 2019

Comprender el consumo de agua es crucial para la gestión sostenible de los recursos hídricos. Baj... more Comprender el consumo de agua es crucial para la gestión sostenible de los recursos hídricos. Bajo los escenarios de cambio climático que proyectan una disponibilidad de agua altamente variable , la necesidad de políticas públicas que aseguren la eficiencia y la equidad en los recursos hídricos está aumentando. Este trabajo analiza el caso de la cuenca agrícola del río Cachapoal (34 ° S 71 ° W), que presenta aumentos de temperatura y un déficit de precipitaciones, con un período de sequía que comenzó hace más de once años y que ha reducido significativamente la disponibilidad de agua. El consumo de agua en la cuenca para la producción de alimentos se determinó a partir de la huella hídrica agrícola (WF agrícola ), utilizando la verde ( verde WF ), azul ( azul WF ) y gris ( gris WF).) indicadores, que se midieron en las cuencas superior, media e inferior en condiciones de variabilidad climática (años secos, húmedos y normales). El mayor WF agrícola se estableció en el año seco, con un total de 18,221 m 3 t −1 , seguido de 15,902 m 3 t −1 en el año húmedo y 14,091 m 3 t −1 en el año normal. Asimismo, en el año seco también se observaron el mayor azul de WF y el gris de WF , de 12,000 m 3 t- 1 y 4934 m 3 t- 1 , respectivamente. El mayor verde de WF , 2000 m 3. t −1 , se calculó para un año normal. El 63% de la superficie agrícola de la cuenca estaba cubierta por los cultivos de aguacate ( Persea americana ), olivo ( Olea europaea ), maíz ( Zea mays ) y uva ( Vitis sp ), que presentó la mayor WF agrícola. Estos datos de la huella hídrica proporcionan una base cuantitativa para la evaluación del consumo y la degradación del agua, considerando la producción agrícola y sus múltiples variables. El éxito de la aplicación de estos resultados radica en el uso de indicadores para comprender los procesos de cambio y complementar los futuros planes de asignación de agua con modelos de gestión de agua más racionales.

Environmental, monitoring and assessment, 2019

Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fj... more Epicoccum nigrum (strain LQRA39-P) was isolated from sediments collected in Chilean Patagonian fjords using microscopy and molecular techniques. We analyzed adaptive responses of cell wall morphology to salinity, temperature, and pH in order to explain the ability of E. nigrum to co-inhabit both marine and freshwater environments. For this purpose, E. nigrum was cultured in a series of media with variations in salinity (freshwater and seawater), pH (acidic, neutral, and basic), and temperature (5 to 25 °C). Changes were observed through transmission electron microscopy. A direct correlation between increased salinity and cell wall thickening (> 0.2 μm) was observed, along with a significant relationship between pH and the presence of extracellular polymeric substances (EPS) on the outside of the cell wall. The observed morphological changes could confirm that an ubiquitous fungus such as E. nigrum requires adaptive responses to co-inhabit freshwater, marine, and terrestrial substrates.

Revista de biología Marina y Oceanografía, 2016

It is proposed that marine fungi are a good alternative for remediation of areas contaminated wit... more It is proposed that marine fungi are a good alternative for remediation of areas contaminated with antibiotics due to their heterotrophic condition, adaptability to environmental changes, and specific resistance to stressors. With this assumption we investigated the fjords of Southern Chile, which are characterized by salmon farming. We evaluated the concentration of oxytetracycline (OTC) in sediments from different areas surrounding salmon cages. In addition, we isolated fungi species to assess their ability to degrade OTC. Measurable amounts of OTC were detected in deeper sediments located at the eastern sector of cages and rafts (Z= 100 m; 4.62 ± 0.12 to 24.1 ± 1.03 μg g-1). Thirty-eight strains of endemic fungi were isolated and identified in the sediments near the farming center. Among these strains we detected species from the Phylum Ascomycetes, including Penicillium commune, Aspergillus terreus, Beauveria bassiana, Trichoderma harzianum, Epicoccum nigrum and Emericellopsis alkaline. These strains fungi were capable of degrading about 76 to 92% of the OTC present in the culture media. The results of this study constitute a first step into implementing processes that could favor waste bioremediation from marine sediments.

Environmental, Monitoring and Assessment, 2016

Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity ... more Salmon farming is the main economic activity in the fjords area of Southern Chile. This activity requires the use of antibiotics, such as oxytetracycline, for the control and prevention of diseases, which have a negative impact on the environment. We analyzed the abilities of endemic marine fungi to biodegrade oxytetracycline, an antibiotic used extensively in fish farming. We isolated marine fungi strains from sediment samples obtained from an area of fish farming activity. The five isolated strains showed an activity on oxytetracycline and were identified as Trichoderma harzianum, Trichoderma deliquescens, Penicillium crustosum, Rhodotorula mucilaginosa, and Talaromyces atroroseus by a scanning electron microsco-py and characterized by molecular techniques. Results showed significant degradation in the concentration of oxytetracycline at the first 2 days of treatment for all strains analyzed. At 21 days of treatment, the concentration of oxytetracycline was decreased 92 % by T. harzianum, 85 % by T. deliquescens, 83 % by P. crustosum, 73 % by R. mucilaginosa, and 72 % by T. atroroseus, all of which were significantly higher than the controls. Given these results, we propose that fungal strains isolated from marine sediments may be useful tools for biodegradation of antibiotics, such as oxytetracycline, in the salmon industry.

Ecological Indicators, 2019

Amid the growing population, climate change and decreasing water availability, water resources pl... more Amid the growing population, climate change and decreasing water availability, water resources planning faces the challenge of achieving efficient and equitable water use, mainly in food production, its greatest consumer. The sustainability of agricultural water consumption in the Cachapoal River basin (34°S 71°O) is assessed using the blue (WFS) and gray water footprint sustainability (WFS indicator of agricultural water consumption showed unsustainability in the upper basin in the dry year (2007), indicating severe water scarcity in autumn and low scarcity in spring, and in the wet year (2005), in which moderate water scarcity was observed only in spring, as a result of the decrease in blue water availability (WA), exceeding environmental flow requirements and the environmental carrying capacity. An opposite situation was found in the lower basin, where no water scarcity was observed in the analyzed years. Surface water quality, based on the concentration of fertilizers applied to crops, was observed to be more affected and unsustainable (WFS) in the upper basin in the autumn and winter period of the dry year (2007). Currently, the indicators can be applied to provide useful information on the sustainability of water use in basins in order to establish and meet water resources protection objectives.