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Sandra M F O Azevedo - One of the best experts on this subject based on the ideXlab platform.
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Effects of toxic and non-toxic cyanobacteria on the life history of tropical and temperate cladocerans
2016Co-Authors: Aloysio Ferra S. O-filho, Sandra M F O Azevedo, William R. DemottAbstract:1. This study compares the effects of four toxic strains of Microcystis aeruginosa on tropical and temperate Cladocera. Survival was tested in acute toxicity experiments using Microcystis alone or in mixtures with the edible green algae Ankistrodesmus falcatus. The effect of chronic exposure on population growth was estimated in life-table experiments by varying the proportion of Microcystis and the green alga. Nutri-tional deficiency was assessed using a non-toxic cyanobacterium in a zooplankton growth experiment. Feeding inhibition was tested using a 14C-labelled green alga as a tracer in mixtures with toxic Microcystis. 2. Toxicity varied consistently between Microcystis strains, while sensitivity varied con-sistently between cladoceran species. However, no relationship was found between sensitivity and geographical origin or cladoceran body size. Two small-bodied clado-cerans from the same tropical lake, Ceriodaphnia cornuta and Moinodaphnia macleayi, were the least sensitive and most sensitive species, respectively. 3. Surprisingly, two small tropical cladocerans survived longer without food than did three large Daphnia species and a third small tropical species
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Accumulation of microcystins by a tropical zooplankton community.
Aquatic toxicology (Amsterdam Netherlands), 2002Co-Authors: Aloysio Da S Ferrão-filho, Betina Kozlowsky-suzuki, Sandra M F O AzevedoAbstract:In the current study, the hepatotoxic peptide microcystins, were measured in the zooplankton community of Jacarepaguá Lagoon during a 6-month period. Concurrent phytoplankton and seston samples were obtained. Microcystins were measured in seston and phytoplankton by High Performance Liquid Chromatography (HPLC), and in zooplankton by an Enzyme-Linked Immunosorbant Assay (ELISA). Zooplankton community was comprised mainly by the rotifers Brachionus angularis and B. plicatilis, the cladocerans Moina micrura and Ceriodaphnia cornuta and the copepod Metacyclops mendocinus. Phytoplankton was dominated by Microcystis aeruginosa during all the studied period. Microcystins in zooplankton ranged from 0.3 to 16.4 microg g(-1) DW, while in the sestonic samples they ranged from undetectable values to 5.8 ng g(-1) DW. Microcystins in net phytoplankton ranged from 0.3 to 3.9 mg g(-1) DW. We conclude that zooplankton from Jacarepaguá Lagoon were efficient accumulators of microcystins from seston and that these animals can be potential vectors in the transferring of such toxins to higher trophic levels in the aquatic food chain.
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Accumulation of microcystins by a tropical zooplankton community.
Aquatic Toxicology, 2001Co-Authors: Aloysio Da S Ferrão-filho, Betina Kozlowsky-suzuki, Sandra M F O AzevedoAbstract:In the current study, the hepatotoxic peptide microcystins, were measured in the zooplankton community of JacarepaguaLagoon during a 6-month period. Concurrent phytoplankton and seston samples were obtained. Microcystins were measured in seston and phytoplankton by High Performance Liquid Chromatography (HPLC), and in zooplankton by an Enzyme-Linked Immunosorbant Assay (ELISA). Zooplankton community was comprised mainly by the rotifers Brachionus angularis and B. plicatilis, the cladocerans Moina micrura and Ceriodaphnia cornuta and the copepod Metacyclops mendocinus. Phytoplankton was dominated by Microcystis aeruginosa during all the studied period. Microcystins in zooplankton ranged from 0.3 to 16.4 gg − 1 DW, while in the sestonic samples they ranged from undetectable values to 5.8 ng g − 1 DW. Microcystins in net phytoplankton ranged from 0.3 to 3.9 mg g −1 DW. We conclude that zooplankton from JacarepaguaLagoon were efficient accumulators of microcystins from seston and that these animals can be potential vectors in the transferring of such toxins to higher trophic levels in the aquatic food chain. © 2002 Elsevier Science B.V. All rights reserved.
Baskaralingam Vaseeharan - One of the best experts on this subject based on the ideXlab platform.
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ecotoxicity of musa paradisiaca leaf extract coated zno nanoparticles to the freshwater microcrustacean Ceriodaphnia cornuta
Limnologica, 2017Co-Authors: Sekar Vijayakumar, Balasubramanian Malaikozhundan, Narayanan Gobi, Baskaralingam Vaseeharan, Mani Divya, Muthukumar Abhinaya, Atanu Bhattacharyya, Nachimuthu Balashanmugam, Dhan Surmistha, Kadarkarai MuruganAbstract:Abstract Currently, nanotechnology has gained much interest due to the unique properties of nanomaterials in science and technology. Different types of metallic nanoparticles are routinely synthesized. However, their release into the aquatic environments is a major ecotoxicological concern. In this scenario, it is important to study the potential impact of engineered nanoparticle in aquatic organisms especially freshwater microcrustaceans, such as Ceriodaphnia cornuta. In this study, ZnO NPs were synthesized using the aqueous leaf extracts of Musa paradisiaca and physico-chemically characterized by UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infra red (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). UV–Vis spectroscopy recorded the absorbance peak of ZnO NPs at 338 nm. XRD analysis showed the various Bragg’s reflection peaks at 100, 002, 101, 102, 110, 103, 200, 112, 201, 004 and 202 lattice planes. FTIR spectroscopy outlined sharp intense peaks at 3416 cm−1, 1388 and 1416 cm−1. SEM showed the spherical shape of ZnO NPs with mean particle size of 23.3 nm. AFM confirmed the spherical shape, nanosize and 3D topography of NPs. The ecotoxicity of ZnO NPs was tested on the freshwater crustacean C. cornuta. ZnO NPs were comparatively less toxic than zinc acetate. ZnO NPs caused 42% mortality of C. cornuta at 50 μg mL−1. However, 80% mortality was observed at 50 μg mL−1 of zinc acetate after 24 h. Light and confocal laser scanning microscopic images evidenced the uptake and accumulation of ZnO NPs in the gut of C. cornuta at 50 μg mL−1 after 24 h. Structural deformities were observed on C. cornuta after treatment with 50 μg mL−1 of ZnO NPs. Overall, this study describes the potential impact of the biologically synthesized ZnO NPs in comparison with zinc acetate in the freshwater crustacean C. cornuta.
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control of biofilm forming clinically important bacteria by green synthesized zno nanoparticles and its ecotoxicity on Ceriodaphnia cornuta
Microbial Pathogenesis, 2017Co-Authors: Sekar Vijayakumar, Balasubramanian Malaikozhundan, Baskaralingam Vaseeharan, Sathappan Shanthi, Nooruddin ThajuddinAbstract:Abstract Zinc oxide nanoparticles were synthesized using the aqueous leaf extracts of Plectranthus barbatus (Plb-ZnO NPs) and characterized by UV–visible spectroscopy, XRD, FTIR, SEM and EDS. UV–Visible spectra recorded the absorbance peak of Plb-ZnO NPs at 343 nm. SEM analyses showed the spherical shape of Plb-ZnO NPs with the particle size between 30 and 60 nm. Plb-ZnO NPs exhibited antibacterial and antibiofilm activity against Gram positive Bacillus subtilis at all tested concentrations. In contrast, Plb-ZnO NPs showed antibacterial and antibiofilm activity against Gram negative Vibrio parahaemolyticus and Proteus vulgaris only at 100 μg/ml. The Atomic absorption spectrometry (AAS) revealed that Zn2+ dissolution was 1.87 and 8.8 μg/L at 10 and 160 μg/L of Plb-ZnO NPs respectively. The body accumulation of Zn2+ was increased from 0.8 μg/g body weight to 3.5 μg/g body weight when C. cornuta exposed to 10 μg/L and 160 μg/L respectively. Plb-ZnO NPs were toxic to Ceriodaphnia cornuta neonates (LC50: 28 μg/L). Plb-ZnO NPs caused 100% mortality of C. cornuta at 160 μg/L after 24 h. However, zinc acetate does not cause any mortality of C. cornuta upto 350 μg/L. The light and confocal laser scanning microscopic images evidenced the uptake and accumulation of Plb-ZnO NPs on the internal gut regions of C. cornuta at 160 μg/L after 5, 10, 15, 20 and 24 h. Abnormalities in the swimming behaviour such as erratic swimming (ERR), migration to bottom (BOT) and migration to water surface (SUR) of C. cornuta were noticed after treatment with different concentrations of Plb-ZnO NPs.
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green synthesized silver nanoparticles toxicity against poecilia reticulata fishes and Ceriodaphnia cornuta crustaceans
Journal of Cluster Science, 2017Co-Authors: Ramachandran Ishwarya, Baskaralingam Vaseeharan, Sekar Vijayakumar, Sathappan Shanthi, Subramani Ramesh, Pitchaimani Manogari, Kannan Dhanalakshmi, Giovanni BenelliAbstract:Recently, the green synthesis of silver nanoparticles gained increasing attention due to interesting properties for optical, antimicrobial and pest control applications. However, their toxicity against micro-crustaceans and fishes has been scarcely explored, while most of the research efforts focused on mosquito control with the green-synthesized nanocomposites. In this study, we investigated the toxic effects of AgNO3, Cissus quadrangularis (Cq)-synthesized AgNPs and Cq extract in two different study models, the larvae of Poecilia reticulata fishes and adults of the micro-crustacean Ceriodaphnia cornuta. In both species, AgNO3 and Cq-AgNPs showed high mortality rates even if tested at very low doses. Molecular analysis revealed high DNA damages induced by Cq-AgNPs on both aquatic organisms. Furthermore, light microscopy studies evidenced lesions in the gills and vacuolization in the gills and in the abdomen of P. reticulata larvae. Overall, our research pointed out that the exposure of aquatic organisms to AgNO3 or green-fabricated AgNPs can damage fishes and crustaceans, posing noteworthy risks to the aquatic ecosystems.
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protective effects of chitosan against the hazardous effects of zinc oxide nanoparticle in freshwater crustaceans Ceriodaphnia cornuta and moina micrura
Limnologica, 2016Co-Authors: Sekar Vijayakumar, Balasubramanian Malaikozhundan, Narayanan Gobi, Baskaralingam Vaseeharan, Chavali MurthyAbstract:Abstract Nanoparticle contamination in freshwater habitat leads to the drastic reduction in the population of freshwater micro crustaceans. Both Ceriodaphnia cornuta and Moina micrura were considered as the potential biological bio-tracers of freshwater ecosystem. This study describes the chemical synthesis of zinc oxide nanoparticles (ZnO NPs) using zinc nitrate as the starting material. The physico-chemical characterization of ZnO NPs was made by UV–Vis spectroscopy, X-Ray Diffraction (XRD), Fourier Transform Infra Red (FTIR) and Transmission Electron Microscopy (TEM). ZnO NPs elicited 100% and 76% mortality of freshwater crustaceans, Ceriodaphnia cornuta and Moina micrura at 160 μg L −1 respectively. The accumulation of ZnO NPs in the intestine and loss of antennae and carapace were clearly visualized through light microscopy. The exposure of C. cornuta and M. micrura neonates at 160 μg L −1 of ZnO NPs showed abnormal swimming behaviour after 12 h. However, chitosan significantly reduced the mortality and enhanced the survival of C. cornuta and M. micrura at 100 μg ml −1 . This study concludes the protective effect of chitosan against the hazardous effect of ZnO NPs in C. cornuta and M. micrura .
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assessment of biopolymer stabilized silver nanoparticle for their ecotoxicity on Ceriodaphnia cornuta and antibiofilm activity
Journal of environmental chemical engineering, 2016Co-Authors: Sekar Vijayakumar, Balasubramanian Malaikozhundan, P Ramasamy, Baskaralingam VaseeharanAbstract:Abstract Sodium alginate (biopolymer) stabilized silver nanoparticles (SA-AgNPs) were synthesized and characterized by UV–vis spectroscopy, XRD, FTIR, SEM, EDAX and TEM. UV–vis spectra recorded the absorbance peak at 407 nm due to its surface plasmon resonance. XRD measurements indicated the crystalline nature of particle with various Bragg’s reflection peaks at (111), (200) (220), (311) and (222) planes. FTIR spectra showed the possible functional groups at 3443, 1616, 1384, 1092, 1209, 835 and 774 cm −1 . SEM and TEM showed that the particles were spherical in shape and the size was in the range of 23 ± 2 nm. EDAX analysis showed that the weight percentage and elemental silver in the composition was 57.80. The ecotoxicity of SA-AgNPs was assessed on the freshwater crustacean, Ceriodaphnia cornuta . SA-AgNPs caused 100% mortality of C. cornuta at 40 μg L −1 , whereas AgNO 3 caused100% mortality of C. cornuta at 10 μg L −1 . The accumulation of Ag + by C. cornuta was increased at increasing concentration and reached 3.4 μg/g dry weight at 50 μg L −1 . C. cornuta exposed to AgNO 3 showed blackening of intestine at 5 and 10 μg L −1 . On the otherhand, the visible uptake, ingestion and accumulation of SA-AgNPs in the intestine of C. cornuta were clearly visualized under CLSM after treated with 10, 20 40 and 50 μg L −1 . The abnormal swimming, reduced heart rate and thoracic limb movement of C. cornuta were also observed after exposure to 50 μg L −1 of SA-AgNPS. The synthesized SA-AgNPs were tested for its antibiofilm activity against Gram positive ( Listeria monocytogenes ) and Gram negative ( Vibrio parahaemolyticus ) bacteria. SA-AgNPs effectively inhibited the biofilm growth of L. monocytogenes and V. parahaemolyticus at 75 μg mL −1 .
Joseph Tarradellas - One of the best experts on this subject based on the ideXlab platform.
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tropical ecotoxicity testing with Ceriodaphnia cornuta
Environmental Toxicology, 2004Co-Authors: Lan Chi Do Hong, Kristin Becker-van Slooten, Joseph TarradellasAbstract:Reference CECOTOX-ARTICLE-2004-006doi:10.1002/tox.20055View record in Web of Science Record created on 2005-07-15, modified on 2016-08-08
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Tropical ecotoxicity testing with Ceriodaphnia cornuta
Environmental toxicology, 2004Co-Authors: Lan Chi Do Hong, Kristin Becker-van Slooten, Joseph TarradellasAbstract:The Sai Gon-Dong Nai river system in southern Vietnam is of great social and economic importance yet receives a large amount of industrial, domestic, and agricultural discharges. Toxicity assessment has started to become an issue in Vietnam, and it is important to employ a test system that is appropriate for typical Vietnamese conditions with a species that is representative of the invertebrates living in its aquatic ecosystems. The aim of this study was to develop and to validate an ecotoxicity test with an autochthonous organism. The microcrustacean Ceriodaphnia cornuta (Cladocera) was isolated from the Sai Gon River. A protocol was developed for the culturing of the organisms, and satisfactory results were obtained for long-term reproduction of C. cornuta. Quality control criteria were established. The toxicity of two relevant pesticides (diazinon and methyl parathion) and two metals (chromium and mercury) to C. cornuta was evaluated and compared to the standard organisms for ecotoxicological testing: Daphnia magna and Vibrio fischeri. Nonlinear regression models were applied to estimate such parameters as EC(50). The results of acute toxicity tests showed that C. cornuta was less tolerant than D. magna and V. fischeri to salinity and that C. cornuta was more sensitive than D. magna and V. fischeri to potassium dichromate, diazinon, methyl parathion, and mercury.
Sekar Vijayakumar - One of the best experts on this subject based on the ideXlab platform.
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ecotoxicity of musa paradisiaca leaf extract coated zno nanoparticles to the freshwater microcrustacean Ceriodaphnia cornuta
Limnologica, 2017Co-Authors: Sekar Vijayakumar, Balasubramanian Malaikozhundan, Narayanan Gobi, Baskaralingam Vaseeharan, Mani Divya, Muthukumar Abhinaya, Atanu Bhattacharyya, Nachimuthu Balashanmugam, Dhan Surmistha, Kadarkarai MuruganAbstract:Abstract Currently, nanotechnology has gained much interest due to the unique properties of nanomaterials in science and technology. Different types of metallic nanoparticles are routinely synthesized. However, their release into the aquatic environments is a major ecotoxicological concern. In this scenario, it is important to study the potential impact of engineered nanoparticle in aquatic organisms especially freshwater microcrustaceans, such as Ceriodaphnia cornuta. In this study, ZnO NPs were synthesized using the aqueous leaf extracts of Musa paradisiaca and physico-chemically characterized by UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier transform infra red (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). UV–Vis spectroscopy recorded the absorbance peak of ZnO NPs at 338 nm. XRD analysis showed the various Bragg’s reflection peaks at 100, 002, 101, 102, 110, 103, 200, 112, 201, 004 and 202 lattice planes. FTIR spectroscopy outlined sharp intense peaks at 3416 cm−1, 1388 and 1416 cm−1. SEM showed the spherical shape of ZnO NPs with mean particle size of 23.3 nm. AFM confirmed the spherical shape, nanosize and 3D topography of NPs. The ecotoxicity of ZnO NPs was tested on the freshwater crustacean C. cornuta. ZnO NPs were comparatively less toxic than zinc acetate. ZnO NPs caused 42% mortality of C. cornuta at 50 μg mL−1. However, 80% mortality was observed at 50 μg mL−1 of zinc acetate after 24 h. Light and confocal laser scanning microscopic images evidenced the uptake and accumulation of ZnO NPs in the gut of C. cornuta at 50 μg mL−1 after 24 h. Structural deformities were observed on C. cornuta after treatment with 50 μg mL−1 of ZnO NPs. Overall, this study describes the potential impact of the biologically synthesized ZnO NPs in comparison with zinc acetate in the freshwater crustacean C. cornuta.
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control of biofilm forming clinically important bacteria by green synthesized zno nanoparticles and its ecotoxicity on Ceriodaphnia cornuta
Microbial Pathogenesis, 2017Co-Authors: Sekar Vijayakumar, Balasubramanian Malaikozhundan, Baskaralingam Vaseeharan, Sathappan Shanthi, Nooruddin ThajuddinAbstract:Abstract Zinc oxide nanoparticles were synthesized using the aqueous leaf extracts of Plectranthus barbatus (Plb-ZnO NPs) and characterized by UV–visible spectroscopy, XRD, FTIR, SEM and EDS. UV–Visible spectra recorded the absorbance peak of Plb-ZnO NPs at 343 nm. SEM analyses showed the spherical shape of Plb-ZnO NPs with the particle size between 30 and 60 nm. Plb-ZnO NPs exhibited antibacterial and antibiofilm activity against Gram positive Bacillus subtilis at all tested concentrations. In contrast, Plb-ZnO NPs showed antibacterial and antibiofilm activity against Gram negative Vibrio parahaemolyticus and Proteus vulgaris only at 100 μg/ml. The Atomic absorption spectrometry (AAS) revealed that Zn2+ dissolution was 1.87 and 8.8 μg/L at 10 and 160 μg/L of Plb-ZnO NPs respectively. The body accumulation of Zn2+ was increased from 0.8 μg/g body weight to 3.5 μg/g body weight when C. cornuta exposed to 10 μg/L and 160 μg/L respectively. Plb-ZnO NPs were toxic to Ceriodaphnia cornuta neonates (LC50: 28 μg/L). Plb-ZnO NPs caused 100% mortality of C. cornuta at 160 μg/L after 24 h. However, zinc acetate does not cause any mortality of C. cornuta upto 350 μg/L. The light and confocal laser scanning microscopic images evidenced the uptake and accumulation of Plb-ZnO NPs on the internal gut regions of C. cornuta at 160 μg/L after 5, 10, 15, 20 and 24 h. Abnormalities in the swimming behaviour such as erratic swimming (ERR), migration to bottom (BOT) and migration to water surface (SUR) of C. cornuta were noticed after treatment with different concentrations of Plb-ZnO NPs.
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green synthesized silver nanoparticles toxicity against poecilia reticulata fishes and Ceriodaphnia cornuta crustaceans
Journal of Cluster Science, 2017Co-Authors: Ramachandran Ishwarya, Baskaralingam Vaseeharan, Sekar Vijayakumar, Sathappan Shanthi, Subramani Ramesh, Pitchaimani Manogari, Kannan Dhanalakshmi, Giovanni BenelliAbstract:Recently, the green synthesis of silver nanoparticles gained increasing attention due to interesting properties for optical, antimicrobial and pest control applications. However, their toxicity against micro-crustaceans and fishes has been scarcely explored, while most of the research efforts focused on mosquito control with the green-synthesized nanocomposites. In this study, we investigated the toxic effects of AgNO3, Cissus quadrangularis (Cq)-synthesized AgNPs and Cq extract in two different study models, the larvae of Poecilia reticulata fishes and adults of the micro-crustacean Ceriodaphnia cornuta. In both species, AgNO3 and Cq-AgNPs showed high mortality rates even if tested at very low doses. Molecular analysis revealed high DNA damages induced by Cq-AgNPs on both aquatic organisms. Furthermore, light microscopy studies evidenced lesions in the gills and vacuolization in the gills and in the abdomen of P. reticulata larvae. Overall, our research pointed out that the exposure of aquatic organisms to AgNO3 or green-fabricated AgNPs can damage fishes and crustaceans, posing noteworthy risks to the aquatic ecosystems.
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protective effects of chitosan against the hazardous effects of zinc oxide nanoparticle in freshwater crustaceans Ceriodaphnia cornuta and moina micrura
Limnologica, 2016Co-Authors: Sekar Vijayakumar, Balasubramanian Malaikozhundan, Narayanan Gobi, Baskaralingam Vaseeharan, Chavali MurthyAbstract:Abstract Nanoparticle contamination in freshwater habitat leads to the drastic reduction in the population of freshwater micro crustaceans. Both Ceriodaphnia cornuta and Moina micrura were considered as the potential biological bio-tracers of freshwater ecosystem. This study describes the chemical synthesis of zinc oxide nanoparticles (ZnO NPs) using zinc nitrate as the starting material. The physico-chemical characterization of ZnO NPs was made by UV–Vis spectroscopy, X-Ray Diffraction (XRD), Fourier Transform Infra Red (FTIR) and Transmission Electron Microscopy (TEM). ZnO NPs elicited 100% and 76% mortality of freshwater crustaceans, Ceriodaphnia cornuta and Moina micrura at 160 μg L −1 respectively. The accumulation of ZnO NPs in the intestine and loss of antennae and carapace were clearly visualized through light microscopy. The exposure of C. cornuta and M. micrura neonates at 160 μg L −1 of ZnO NPs showed abnormal swimming behaviour after 12 h. However, chitosan significantly reduced the mortality and enhanced the survival of C. cornuta and M. micrura at 100 μg ml −1 . This study concludes the protective effect of chitosan against the hazardous effect of ZnO NPs in C. cornuta and M. micrura .
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assessment of biopolymer stabilized silver nanoparticle for their ecotoxicity on Ceriodaphnia cornuta and antibiofilm activity
Journal of environmental chemical engineering, 2016Co-Authors: Sekar Vijayakumar, Balasubramanian Malaikozhundan, P Ramasamy, Baskaralingam VaseeharanAbstract:Abstract Sodium alginate (biopolymer) stabilized silver nanoparticles (SA-AgNPs) were synthesized and characterized by UV–vis spectroscopy, XRD, FTIR, SEM, EDAX and TEM. UV–vis spectra recorded the absorbance peak at 407 nm due to its surface plasmon resonance. XRD measurements indicated the crystalline nature of particle with various Bragg’s reflection peaks at (111), (200) (220), (311) and (222) planes. FTIR spectra showed the possible functional groups at 3443, 1616, 1384, 1092, 1209, 835 and 774 cm −1 . SEM and TEM showed that the particles were spherical in shape and the size was in the range of 23 ± 2 nm. EDAX analysis showed that the weight percentage and elemental silver in the composition was 57.80. The ecotoxicity of SA-AgNPs was assessed on the freshwater crustacean, Ceriodaphnia cornuta . SA-AgNPs caused 100% mortality of C. cornuta at 40 μg L −1 , whereas AgNO 3 caused100% mortality of C. cornuta at 10 μg L −1 . The accumulation of Ag + by C. cornuta was increased at increasing concentration and reached 3.4 μg/g dry weight at 50 μg L −1 . C. cornuta exposed to AgNO 3 showed blackening of intestine at 5 and 10 μg L −1 . On the otherhand, the visible uptake, ingestion and accumulation of SA-AgNPs in the intestine of C. cornuta were clearly visualized under CLSM after treated with 10, 20 40 and 50 μg L −1 . The abnormal swimming, reduced heart rate and thoracic limb movement of C. cornuta were also observed after exposure to 50 μg L −1 of SA-AgNPS. The synthesized SA-AgNPs were tested for its antibiofilm activity against Gram positive ( Listeria monocytogenes ) and Gram negative ( Vibrio parahaemolyticus ) bacteria. SA-AgNPs effectively inhibited the biofilm growth of L. monocytogenes and V. parahaemolyticus at 75 μg mL −1 .
Aloysio Da S Ferrão-filho - One of the best experts on this subject based on the ideXlab platform.
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Accumulation of microcystins by a tropical zooplankton community.
Aquatic toxicology (Amsterdam Netherlands), 2002Co-Authors: Aloysio Da S Ferrão-filho, Betina Kozlowsky-suzuki, Sandra M F O AzevedoAbstract:In the current study, the hepatotoxic peptide microcystins, were measured in the zooplankton community of Jacarepaguá Lagoon during a 6-month period. Concurrent phytoplankton and seston samples were obtained. Microcystins were measured in seston and phytoplankton by High Performance Liquid Chromatography (HPLC), and in zooplankton by an Enzyme-Linked Immunosorbant Assay (ELISA). Zooplankton community was comprised mainly by the rotifers Brachionus angularis and B. plicatilis, the cladocerans Moina micrura and Ceriodaphnia cornuta and the copepod Metacyclops mendocinus. Phytoplankton was dominated by Microcystis aeruginosa during all the studied period. Microcystins in zooplankton ranged from 0.3 to 16.4 microg g(-1) DW, while in the sestonic samples they ranged from undetectable values to 5.8 ng g(-1) DW. Microcystins in net phytoplankton ranged from 0.3 to 3.9 mg g(-1) DW. We conclude that zooplankton from Jacarepaguá Lagoon were efficient accumulators of microcystins from seston and that these animals can be potential vectors in the transferring of such toxins to higher trophic levels in the aquatic food chain.
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Accumulation of microcystins by a tropical zooplankton community.
Aquatic Toxicology, 2001Co-Authors: Aloysio Da S Ferrão-filho, Betina Kozlowsky-suzuki, Sandra M F O AzevedoAbstract:In the current study, the hepatotoxic peptide microcystins, were measured in the zooplankton community of JacarepaguaLagoon during a 6-month period. Concurrent phytoplankton and seston samples were obtained. Microcystins were measured in seston and phytoplankton by High Performance Liquid Chromatography (HPLC), and in zooplankton by an Enzyme-Linked Immunosorbant Assay (ELISA). Zooplankton community was comprised mainly by the rotifers Brachionus angularis and B. plicatilis, the cladocerans Moina micrura and Ceriodaphnia cornuta and the copepod Metacyclops mendocinus. Phytoplankton was dominated by Microcystis aeruginosa during all the studied period. Microcystins in zooplankton ranged from 0.3 to 16.4 gg − 1 DW, while in the sestonic samples they ranged from undetectable values to 5.8 ng g − 1 DW. Microcystins in net phytoplankton ranged from 0.3 to 3.9 mg g −1 DW. We conclude that zooplankton from JacarepaguaLagoon were efficient accumulators of microcystins from seston and that these animals can be potential vectors in the transferring of such toxins to higher trophic levels in the aquatic food chain. © 2002 Elsevier Science B.V. All rights reserved.