Centro de Genómica, Ecología y Medio Ambiente (GEMA)
https://repositorio.umayor.cl/xmlui/handle/sibum/7995
Contiene la producción documental (impresa y audiovisual) del GEMA2024-03-29T00:54:46ZEnvironmental signature and health risk assessment of polybrominated diphenyl ethers (PBDEs) emitted from a landfill fire in Santiago de Chile
https://repositorio.umayor.cl/xmlui/handle/sibum/9521
Environmental signature and health risk assessment of polybrominated diphenyl ethers (PBDEs) emitted from a landfill fire in Santiago de Chile
Pozo, Karla; Oyola, Germán; Jorquera, Héctor; Gómez, Victoria [Univ Mayor, GEMA Ctr Genom Ecol & Environm, Chile]; Galbán-Malagón, Cristóbal [Univ Mayor, GEMA Ctr Genom Ecol & Environm, Chile]; Mena-Carrasco, Marcelo; Audy, Ondrej; Pribylova, Petra; Guida, Yago; Estellano, Victor Hugo; Lammel, Gerhard; Klánová, Jana
Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants in building materials, electronics, furnishings, vehicles, airplanes, plastics, polyurethane foams, and textiles for many years. Currently, the primary commercial mixtures, penta-, octa-, and deca-BDE, are globally restricted. Still, products containing PBDEs are expected to impact waste management and the environment for many years. In January 2016, an open fire in the Santa Marta landfill close to Santiago de Chile affected the city and surroundings. The fire caused several acute health effects and an increase in emergency hospitalizations. We measured PBDE levels in the areas affected by the fire in the air (gaseous and particulate) and soil, and PBDE emissions were estimated using a dispersion model. The results showed an increase in PBDE concentrations by a factor of 2-4 one day after the start of the fire. However, PBDE concentrations measured after the fire in PM10 and the gas phase were considered low compared to other regions. Interestingly, PBDEs' patterns differed across the sites; however, BDE209 was the dominant congener for all environmental matrices. A preliminary risk assessment was conducted using the daily exposure dose (DED) by air inhalation estimation. The results showed low DED values for adults and children and suggested no direct health risk due to PBDE exposure. This study brings new data useful for future solid waste management initiatives in the country.
2023-08-01T00:00:00ZContinuous bioreactors enable high-level bioremediation of diesel-contaminated seawater at low and mesophilic temperatures using Antarctic bacterial consortia: Pollutant analysis and microbial community composition
https://repositorio.umayor.cl/xmlui/handle/sibum/9520
Continuous bioreactors enable high-level bioremediation of diesel-contaminated seawater at low and mesophilic temperatures using Antarctic bacterial consortia: Pollutant analysis and microbial community composition
Sulbaran-Bracho, Yoelvis; Orellana-Sáez, Matías; Castro-Severyn, Juan; Galbán-Malagón, Cristóbal [Univ Mayor, GEMA, Ctr Genom Ecol & Environm, Chile]; Castro-Nallar, Eduardo; Poblete-Castro, Ignacio
In 2020, more than 21,000 tons of diesel oil were released accidently into the environment with most of it contaminating water bodies. There is an urgent need for sustainable technologies to clean up rivers and oceans to protect wildlife and human health. One solution is harnessing the power of bacterial consortia; however isolated microbes from different environments have shown low diesel bioremediation rates in seawater thus far. An outstanding question is whether Antarctic microorganisms that thrive in environments polluted with hydro-carbons exhibit better diesel degrading activities when propagated at higher temperatures than those encoun-tered in their natural ecosystems.Here, we isolated bacterial consortia, LR-30 (30 degrees C) and LR-10 (10 degrees C), from the Antarctic rhizosphere soil of Deschampsia antarctica (Livingston Island), that used diesel oil as the only carbon substrate. We found that LR-30 and LR-10 batch bioreactors metabolized nearly the entire diesel content when the initial concentration was 10 (g/L) in seawater. Increasing the initial diesel concentration to 50 gDiesel/L, LR-30 and LR-10 bioconverted 33.4 and 31.2 gDiesel/L in 7 days, respectively. The 16S rRNA gene sequencing profiles revealed that the dominant bacterial genera of the inoculated LR-30 community were Achromobacter (50.6%), Pseudomonas (25%) and Rhodanobacter (14.9%), whereas for LR-10 were Pseudomonas (58%), Candidimonas (10.3%) and Renibacterium (7.8%). We also established continuous bioreactors for diesel biodegradation where LR-30 bioremediated diesel at an unprecedent rate of (34.4 g/L per day), while LR-10 achieved (24.5 g/L per day) at 10 degrees C for one month. The abundance of each bacterial genera present significantly fluctuated at some point during the diesel biore-mediation process, yet Achromobacter and Pseudomonas were the most abundant member at the end of the batch and continuous bioreactors for LR-30 and LR-10, respectively.
2023-03-15T00:00:00ZWild Floral Visitors Are More Important Than Honeybees as Pollinators of Avocado Crops
https://repositorio.umayor.cl/xmlui/handle/sibum/9517
Wild Floral Visitors Are More Important Than Honeybees as Pollinators of Avocado Crops
Celis-Diez, Juan L. L.; García, Camila B. B.; Armesto, Juan J. J.; Abades, Sebastian [Univ Mayor, GEMA Ctr Genom Ecol & Environm, Chile]; Garratt, Michael P. D.; Fontúrbel, Francisco E. E.
Wild insects provide pollination services in agroecosystems. Avocado is an economically important crop grown in the Chilean Mediterranean climate region and exported worldwide. Avocado pollination is managed using honeybee hives, while the role of wild insects as pollinators remains poorly known. We quantified the relative contributions of wild floral visitors and honeybees to the fruit set of avocados in two contrasting seasons (2015 and 2016) in Central Chile. Observations were made in 60 trees grown nearby (similar to 300 m) to remnant patches of native sclerophyll vegetation. We found that honeybees and wild insects accounted for 48.6% and 51.4% of total floral visitation, respectively, with a 68% taxonomic similarity of floral visitors between seasons. The presence of honeybees significantly modulated the floral visitor composition and modified plant-pollination network parameters, which resulted in the biotic homogenization of the interaction network, through the increase of shared tree-floral visitor interactions, to the detriment of exclusive interactions. Finally, wild insects were more effective than honeybees in pollinating avocado trees and their contribution was greatest during the dry year. Thus, honeybees alone cannot be relied upon to deliver maximum pollination. We highlight ecological intensification practices to encourage wild insect visits and avoid native vegetation replacement with orchards. Therefore, we emphasize that future ecological intensification research should address agricultural practices to promote wild insects and evaluate the role of native vegetation as wild pollinator habitat in agricultural landscapes.
2023-08-12T00:00:00ZCrop-Specific Effects on Pan-Trap Sampling of Potential Pollinators as Influenced by Trap Color and Location
https://repositorio.umayor.cl/xmlui/handle/sibum/9516
Crop-Specific Effects on Pan-Trap Sampling of Potential Pollinators as Influenced by Trap Color and Location
Jaques, Solange A.; Jofré-Pérez, Christian; Murúa, Maureen M. [Univ Mayor, Ctr GEMA Genom Ecol & Medio Ambiente, Chile]; Vieli, Lorena; Fontúrbel, Francisco E.
Characterizing insect communities in pollinator-dependent crops helps determine the potential pollinator effectiveness and their effects on crop yield. Few studies have examined pollinator communities and their services to crops in South America. Furthermore, optimal sampling methods for these communities in the crop habitat have received little attention. Pan traps are one of the simplest and most widely used sampling methods to assess insect diversity. We compared different pan trap arrangements to describe potential pollinator communities in two commercial crops (blueberry and canola) in Southern Chile. We compared communities in the crops and assessed how sampling position (border or center) and pan trap color (blue, white, or yellow) affected sample composition. Species composition was significantly different between crops. Furthermore, trap color affected sample composition in blueberry, but trap position did not, whereas color had no significant effect on canola, but trap position did. In all cases, yellow pans captured the largest number of species. Hymenoptera explained most of the differences in sampling efficiency because of the differential responses across species. We suggest that pan trap assessments of the diversity in potential pollinator insects depend on crop characteristics, including planting configuration and floral morphology. Therefore, comparative studies should include pans of different colors positioned at various locations within the crop.
2023-03-20T00:00:00Z