The Experts below are selected from a list of 1881 Experts worldwide ranked by ideXlab platform
Myrna J Simpson - One of the best experts on this subject based on the ideXlab platform.
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evaluation of daphnia magna metabolic responses to organic Contaminant exposure with and without dissolved organic matter using 1h nuclear magnetic resonance nmr based metabolomics
Ecotoxicology and Environmental Safety, 2018Co-Authors: Vera Kovacevic, Andre J Simpson, Myrna J SimpsonAbstract:Abstract Previous studies have shown that Contaminant toxicity to target organisms is altered by the presence of dissolved organic matter (DOM). Contaminants can bind to DOM and this may alter the bioavailability and subsequent toxicity of the Contaminants. However, molecular-level techniques are needed to more closely evaluate the impact of DOM on the sub-lethal biochemical responses to emerging Contaminants. To investigate how DOM may alter the metabolic response to organic Contaminant exposure, 1H nuclear magnetic resonance (NMR)-based metabolomics was used to investigate how the metabolome of Daphnia magna changes when Suwannee River DOM (5 mg organic carbon/L) is included in the acute exposure of four Contaminants with varying Hydrophobicity. Sub-lethal concentrations of the Hydrophobic Contaminant 17α-ethynylestradiol (EE2), the relatively more polar compounds carbamazepine and imidacloprid, or the anionic Contaminant perfluorooctane sulfonate (PFOS) were used. A 48-h exposure to DOM alone had a minor impact on the metabolome of D. magna. There were significant increases in amino acids from EE2 exposure which were reduced in the presence of DOM, suggesting that DOM may alleviate the sub-lethal metabolic response from EE2 exposure through sorption and a reduction in freely dissolved EE2. The metabolome was relatively unaltered with exposure to carbamazepine and imidacloprid in the presence of DOM which is likely because these Contaminants are water soluble and did not strongly interact with DOM. PFOS exposure resulted in a more significant metabolic response with DOM suggesting that DOM enhanced the uptake and bioavailability of PFOS in D. magna. As such, the presence of DOM should be considered when determining sensitive molecular-level changes in organisms to sub-lethal organic Contaminant exposure.
Vera Kovacevic - One of the best experts on this subject based on the ideXlab platform.
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evaluation of daphnia magna metabolic responses to organic Contaminant exposure with and without dissolved organic matter using 1h nuclear magnetic resonance nmr based metabolomics
Ecotoxicology and Environmental Safety, 2018Co-Authors: Vera Kovacevic, Andre J Simpson, Myrna J SimpsonAbstract:Abstract Previous studies have shown that Contaminant toxicity to target organisms is altered by the presence of dissolved organic matter (DOM). Contaminants can bind to DOM and this may alter the bioavailability and subsequent toxicity of the Contaminants. However, molecular-level techniques are needed to more closely evaluate the impact of DOM on the sub-lethal biochemical responses to emerging Contaminants. To investigate how DOM may alter the metabolic response to organic Contaminant exposure, 1H nuclear magnetic resonance (NMR)-based metabolomics was used to investigate how the metabolome of Daphnia magna changes when Suwannee River DOM (5 mg organic carbon/L) is included in the acute exposure of four Contaminants with varying Hydrophobicity. Sub-lethal concentrations of the Hydrophobic Contaminant 17α-ethynylestradiol (EE2), the relatively more polar compounds carbamazepine and imidacloprid, or the anionic Contaminant perfluorooctane sulfonate (PFOS) were used. A 48-h exposure to DOM alone had a minor impact on the metabolome of D. magna. There were significant increases in amino acids from EE2 exposure which were reduced in the presence of DOM, suggesting that DOM may alleviate the sub-lethal metabolic response from EE2 exposure through sorption and a reduction in freely dissolved EE2. The metabolome was relatively unaltered with exposure to carbamazepine and imidacloprid in the presence of DOM which is likely because these Contaminants are water soluble and did not strongly interact with DOM. PFOS exposure resulted in a more significant metabolic response with DOM suggesting that DOM enhanced the uptake and bioavailability of PFOS in D. magna. As such, the presence of DOM should be considered when determining sensitive molecular-level changes in organisms to sub-lethal organic Contaminant exposure.
Andre J Simpson - One of the best experts on this subject based on the ideXlab platform.
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evaluation of daphnia magna metabolic responses to organic Contaminant exposure with and without dissolved organic matter using 1h nuclear magnetic resonance nmr based metabolomics
Ecotoxicology and Environmental Safety, 2018Co-Authors: Vera Kovacevic, Andre J Simpson, Myrna J SimpsonAbstract:Abstract Previous studies have shown that Contaminant toxicity to target organisms is altered by the presence of dissolved organic matter (DOM). Contaminants can bind to DOM and this may alter the bioavailability and subsequent toxicity of the Contaminants. However, molecular-level techniques are needed to more closely evaluate the impact of DOM on the sub-lethal biochemical responses to emerging Contaminants. To investigate how DOM may alter the metabolic response to organic Contaminant exposure, 1H nuclear magnetic resonance (NMR)-based metabolomics was used to investigate how the metabolome of Daphnia magna changes when Suwannee River DOM (5 mg organic carbon/L) is included in the acute exposure of four Contaminants with varying Hydrophobicity. Sub-lethal concentrations of the Hydrophobic Contaminant 17α-ethynylestradiol (EE2), the relatively more polar compounds carbamazepine and imidacloprid, or the anionic Contaminant perfluorooctane sulfonate (PFOS) were used. A 48-h exposure to DOM alone had a minor impact on the metabolome of D. magna. There were significant increases in amino acids from EE2 exposure which were reduced in the presence of DOM, suggesting that DOM may alleviate the sub-lethal metabolic response from EE2 exposure through sorption and a reduction in freely dissolved EE2. The metabolome was relatively unaltered with exposure to carbamazepine and imidacloprid in the presence of DOM which is likely because these Contaminants are water soluble and did not strongly interact with DOM. PFOS exposure resulted in a more significant metabolic response with DOM suggesting that DOM enhanced the uptake and bioavailability of PFOS in D. magna. As such, the presence of DOM should be considered when determining sensitive molecular-level changes in organisms to sub-lethal organic Contaminant exposure.
Leonie Asfora Sarubbo - One of the best experts on this subject based on the ideXlab platform.
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application of a yeast biosurfactant in the removal of heavy metals and Hydrophobic Contaminant in a soil used as slurry barrier
Applied and Environmental Soil Science, 2011Co-Authors: Raquel Diniz Rufino, Leonie Asfora Sarubbo, G I B Rodrigues, Galba Maria De Campostakaki, Silvio Romero De Melo FerreiraAbstract:This work describes the application of a yeast biosurfactant in the removal of heavy metals and petroleum derivate in a soil used as slurry barrier using a triaxial permeability apparatus. Test specimens were prepared with soil and Contaminants for percolation of the biosurfactant. The hydraulic conductivity measured along percolation of the fluids showed that the biosurfactant reduced significantly the soil permeability, demonstrating its applicability as an additive in reactive barriers. The crude biosurfactant removed around 96% Zn and Cu and reduced the concentrations of Pb, Cd, and Fe from the test specimen. The biosurfactant removed 20% of the waste oil using the permeability apparatus. The results show that the biosurfactant can be applied in new technologies where the removal of heavy metals and petroleum derivates is desirable. These results demonstrate the versatility of biomolecules with amphipathic nature, a property that makes them increasingly competitive with real possibilities for use in industries.
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economic optimized medium for tensio active agent production by candida sphaerica ucp0995 and application in the removal of Hydrophobic Contaminant from sand
International Journal of Molecular Sciences, 2011Co-Authors: Juliana M Luna, Raquel D Rufino, Leonie Asfora Sarubbo, Clarissa Daisy Da Costa Albuquerque, Galba Maria De CampostakakiAbstract:Statistical experimental designs and response surface methodology were employed to optimize the concentrations of agroindustrial residues as soybean oil (SORR) from refinery, and corn steep liquor (CSL) from corn industry, for tensio-active agent produced by Candida sphaerica UCP 0995. Three 22 full factorial design were applied sequentially to investigate the effects of the concentrations and interactions of soybean oil refinery residue and corn steep liquor on the surface tension of free-cell culture broth for 144 h. Two 22 central composite designs and response surface methodology were adopted to derive a statistical model to measure the effect of SORR and CSL on the surface tension of the free-cell culture broth for 144 h. The regression equation obtained from the experimental data using a central composite design was solved, and by analyzing the response surface contour plots, the optimal concentrations of the constituents of the medium were determined: 8.63% v/v (≈9% v/v) of SORR and 8.80% v/v (≈9% v/v) CSL. The minimum surface tension predicted and experimentally confirmed was 25.25 mN/m. The new biosurfactant, denominated Lunasan, recovered 95% of motor oil adsorbed in a sand sample, thus showing great potential for use in bioremediation processes, especially in the petroleum industry.
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laboratory production and characterization of a new biosurfactant from candida glabrata ucp1002 cultivated in vegetable fat waste applied to the removal of Hydrophobic Contaminant
World Journal of Microbiology & Biotechnology, 2010Co-Authors: Carolina A B De Gusmao, Raquel D Rufino, Leonie Asfora SarubboAbstract:Biosurfactant production by Candida glabrata was studied using vegetable fat waste as substrate. A factorial design was initially carried out to investigate the effects and interactions of waste, yeast extract and glucose on the surface tension after 144 h cultivation. Maximum surface tension reduction was achieved with vegetable fat waste at 5% and yeast extract at 0.2%. The biosurfactant containing cell-free broth retained its surface-active properties after incubation at high temperatures, at a wide range of pH values and salt concentrations. Comparison between three solvent systems for surfactant recovery showed that ethyl acetate extracted both crude extracellular and intracellular biosurfactant with high product recovery. The isolated extracellular biosurfactant showed a CMC of 1% and the surface tension at that point was 24 mN m−1. Preliminary chemical composition revealed the presence of carbohydrates, proteins and lipids. The application of the crude biosurfactant to a soil–water-Hydrophobic Contaminant system was investigated and the apparent critical micelle concentration was determined at 7% of the broth, although the best oil removal (92.6%) had been obtained with 10% of the cell-free broth. The cost of application of the biosurfactant in soils was estimated based on the cost of a commercial biosurfactant.
Galba Maria De Campostakaki - One of the best experts on this subject based on the ideXlab platform.
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application of a yeast biosurfactant in the removal of heavy metals and Hydrophobic Contaminant in a soil used as slurry barrier
Applied and Environmental Soil Science, 2011Co-Authors: Raquel Diniz Rufino, Leonie Asfora Sarubbo, G I B Rodrigues, Galba Maria De Campostakaki, Silvio Romero De Melo FerreiraAbstract:This work describes the application of a yeast biosurfactant in the removal of heavy metals and petroleum derivate in a soil used as slurry barrier using a triaxial permeability apparatus. Test specimens were prepared with soil and Contaminants for percolation of the biosurfactant. The hydraulic conductivity measured along percolation of the fluids showed that the biosurfactant reduced significantly the soil permeability, demonstrating its applicability as an additive in reactive barriers. The crude biosurfactant removed around 96% Zn and Cu and reduced the concentrations of Pb, Cd, and Fe from the test specimen. The biosurfactant removed 20% of the waste oil using the permeability apparatus. The results show that the biosurfactant can be applied in new technologies where the removal of heavy metals and petroleum derivates is desirable. These results demonstrate the versatility of biomolecules with amphipathic nature, a property that makes them increasingly competitive with real possibilities for use in industries.
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economic optimized medium for tensio active agent production by candida sphaerica ucp0995 and application in the removal of Hydrophobic Contaminant from sand
International Journal of Molecular Sciences, 2011Co-Authors: Juliana M Luna, Raquel D Rufino, Leonie Asfora Sarubbo, Clarissa Daisy Da Costa Albuquerque, Galba Maria De CampostakakiAbstract:Statistical experimental designs and response surface methodology were employed to optimize the concentrations of agroindustrial residues as soybean oil (SORR) from refinery, and corn steep liquor (CSL) from corn industry, for tensio-active agent produced by Candida sphaerica UCP 0995. Three 22 full factorial design were applied sequentially to investigate the effects of the concentrations and interactions of soybean oil refinery residue and corn steep liquor on the surface tension of free-cell culture broth for 144 h. Two 22 central composite designs and response surface methodology were adopted to derive a statistical model to measure the effect of SORR and CSL on the surface tension of the free-cell culture broth for 144 h. The regression equation obtained from the experimental data using a central composite design was solved, and by analyzing the response surface contour plots, the optimal concentrations of the constituents of the medium were determined: 8.63% v/v (≈9% v/v) of SORR and 8.80% v/v (≈9% v/v) CSL. The minimum surface tension predicted and experimentally confirmed was 25.25 mN/m. The new biosurfactant, denominated Lunasan, recovered 95% of motor oil adsorbed in a sand sample, thus showing great potential for use in bioremediation processes, especially in the petroleum industry.
