The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform
Oa Ojo - One of the best experts on this subject based on the ideXlab platform.
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Microbial Utilization Of The Hydrocarbon Components Of Atrazine In A Tropical Soil Environment Southwest, Nigeria
'African Journals Online (AJOL)', 2008Co-Authors: Oa OjoAbstract:Biodegradation of atrazine, a Xenobiotic-Substance recently introduced into agricultural practice in Nigeria was assessed using native soil microorganisms. Field experiment and laboratory studies confirmed that microbial consortium utilize the hydrocarbon component of atrazine and thereby mineralize the somewhat recalcitrant organic chemical. The atrazine-degraders were isolated on Minimal salt medium and Sabouraud dextrose agar supplemented with atrazine at 0.05g/L and incubated at 28 ±2oC for 72 hrs and 5 days respectively. The sampled agricultural soil was of alkaline pH while the optimum pH at which the microbial consortium metabolizes atrazine was acidic (mean pH 5.63). Total viable count of bacterial atrazine-degraders was 602.5 x 105cfu/ml. Bacterial atrazine-degraders were: Micrococcus sp., Bacillus sp. Enterobacter Sp and Pseudomonas sp. while fungal atrazine-degraders were: Aspergillus fumigatus, A. niger, Penincillium sp and Fusarium sp. Keywords: Agriculture, Atrazine, Biodegradation, Herbicides, Sustainable development, Xenobiotic African Journal of Infectious Diseases Vol. 1 (1) 2007: pp. 25-2
Ojo O. A. - One of the best experts on this subject based on the ideXlab platform.
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MICROBIAL UTILIZATION OF THE HYDROCARBON COMPONENTS OF ATRAZINE IN A TROPICAL SOIL ENVIRONMENT SOUTHWEST, NIGERIA.
African Traditional Medicine Supporters Initiative (ATHMSI) 7 Road 1 Otunmaiye Square, 2007Co-Authors: Ojo O. A.Abstract:Biodegradation of atrazine, a Xenobiotic-Substance recently introduced into agricultural practice in Nigeria was assessed using native soil microorganisms. Field experiment and laboratory studies confirmed that bacterial and fungal consortium utilize the hydrocarbon component of atrazine and thereby mineralize the somewhat recalcitrant organic chemical. The atrazine-degraders were isolated on Minimal salt medium and sabouraud dextrose agar supplemented with atrazine at 0.05g/L and incubated at 28 ±2oC for 72 hrs and 5 days respectively. The sampled agricultural soil was of alkaline pH while the optimum pH at which the microbial consortium metabolize atrazine was acidic (mean pH 5.63). Total viable count of bacterial atrazine-degraders were 602.5 x 105cfu/ml. Bacterial atrazine-degraders were: Micrococcus sp., Bacillus sp. Enterobacter Sp and Pseudomonas sp. While fungal atrazine-degraders were: Aspergillus fumigatus, A. niger, Penincillium sp and Fusarium sp
Van Den Berg R - One of the best experts on this subject based on the ideXlab platform.
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[Beoordelingssysteem Nieuwe Stoffen: Bodem-Grondwater Module.]
Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2012Co-Authors: Van Der Linden Ama, Van Den Berg RAbstract:A new Soil-Groundwater Module has been developed for incorporation in the Dutch Risk Assessment System for New Chemicals. In this module, the exposure of humans and the environment to Xenobiotic Substances due to sewage sludge application have been determined. Exposure criteria were: 1. accumulation in the uppermost soil layer one year after sewage sludge application, and 2. the maximal Substance-concentration of the deeper groundwater. The calculation procedure is incorporated in the menu driven computer program of the Risk Assessment System. For the quantification of the exposure to each new Xenobiotic Substance the following inputs are needed: - Substance characteristics: the sorption coefficient based on organic matter, Kom, and the half-life, DT50-soil, which represent sorption and transformation of the Substance, respectively. - the actual Substance dose rate on the soil, expressed in kg/ha, which is calculated in the Sewage Sludge Module of the Risk Assessment System. The Kom and DT50-soil should be determined from the n-octanol/water distribution coefficient, Kow, and the Readily Biodegradability test result, respectively.DGM/SV
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Dutch Risk Assessment System for New Chemicals: Soil Groundwater Module
Rijksinstituut voor Volksgezondheid en Milieu RIVM, 1993Co-Authors: Van Der Linden Ama, Van Den Berg RAbstract:A new Soil-Groundwater Module has been developed for incorporation in the Dutch Risk Assessment System for New Chemicals. In this module, the exposure of humans and the environment to Xenobiotic Substances due to sewage sludge application have been determined. Exposure criteria were: 1. accumulation in the uppermost soil layer one year after sewage sludge application, and 2. the maximal Substance-concentration of the deeper groundwater. The calculation procedure is incorporated in the menu driven computer program of the Risk Assessment System. For the quantification of the exposure to each new Xenobiotic Substance the following inputs are needed: - Substance characteristics: the sorption coefficient based on organic matter, Kom, and the half-life, DT50-soil, which represent sorption and transformation of the Substance, respectively. - the actual Substance dose rate on the soil, expressed in kg/ha, which is calculated in the Sewage Sludge Module of the Risk Assessment System. The Kom and DT50-soil should be determined from the n-octanol/water distribution coefficient, Kow, and the Readily Biodegradability test result, respectively.<br>
Padberg Florian - One of the best experts on this subject based on the ideXlab platform.
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Influence of Xenobiotic Substance on hepatic co-cultures
2021Co-Authors: Padberg FlorianAbstract:In the liver, as an important metabolic organ, a large number of complex signaling pathways occur, often simultaneously. Not only hepatocytes are involved in these signaling pathways, also Kupffer cells, the largest population of liver macrophages, are part of these pathways. In this work, structure-dependent molecular cell responses were established based on the adverse effects of bisphenol A and its derivatives in the hepatocyte-like cell line HepG2 indirectly co-cultured with the differentiated macrophage-like cell line THP-1 cells. The causal relationship between the effects of two additional methyl groups in bisphenol A and the depolarisation of the mitochondrial membrane, along with subsequently induced intrinsic apoptosis, has been shown. This adverse effect of the additional methyl groups could be detected through the increased secretion of the prognostic factor TNF α in the cell culture system. So, there is evidence that increases in TNF-α secretion mirrors a potentially increased chemical sensitivity in the indirect co-culture of the cells investigated. Based on the data of this work, this increased sensitivity is correlated with the increased expression and activity of metabolizing enzymes (e.g., cytochrome P450-dependent monooxygenase 1A1) and the accelerated β-oxidation of intracellular fatty acids, which results in the reduction of intracellular lipid droplets. All of these changes are due to the pro-inflammatory influence of the differentiated THP-1 cell line. Its secretion of soluble factors (e.g., cytokines) initiates certain signaling pathways. By looking into the correlation networks of these cytokines, an additive effect of the two cell lines used in this co-culture becomes obvious. However, when this indirect co-culture is replaced by using more primary cells, such as primary human immortalized hepatocytes (Fa2N-4) and primary human monocyte derived macrophages (MDM), cytokine-dependent cell-cell communication can be observed in the correlation network as well. The “inflammatory status” of the system can be influenced by the ratio of MDM to Fa2N-4 cells. For instance, an increase in the MDM cell number is associated with altered gene expression (based on transcriptome data of Fa2N-4 cells) related to an acute phase reaction. The cell system established in this work responds to the treatment with pharmaceuticals such as diclofenac and adalimumab, and to lipopolysaccharides, in terms of altered cytokine secretion. Parallels to the in vivo situation can be seen here. In conclusion, the present work provides evidence for an increased chemical sensitivity of HepG2 cells when growing in an indirect co-culture system along with THP-1 cells. Furthermore, it could be shown that indirect co-cultivation of Fa2N-4 cells and MDM would be advantageous in the detection of chemical-induced adversity in liver cells
Van Der Linden Ama - One of the best experts on this subject based on the ideXlab platform.
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[Beoordelingssysteem Nieuwe Stoffen: Bodem-Grondwater Module.]
Rijksinstituut voor Volksgezondheid en Milieu RIVM, 2012Co-Authors: Van Der Linden Ama, Van Den Berg RAbstract:A new Soil-Groundwater Module has been developed for incorporation in the Dutch Risk Assessment System for New Chemicals. In this module, the exposure of humans and the environment to Xenobiotic Substances due to sewage sludge application have been determined. Exposure criteria were: 1. accumulation in the uppermost soil layer one year after sewage sludge application, and 2. the maximal Substance-concentration of the deeper groundwater. The calculation procedure is incorporated in the menu driven computer program of the Risk Assessment System. For the quantification of the exposure to each new Xenobiotic Substance the following inputs are needed: - Substance characteristics: the sorption coefficient based on organic matter, Kom, and the half-life, DT50-soil, which represent sorption and transformation of the Substance, respectively. - the actual Substance dose rate on the soil, expressed in kg/ha, which is calculated in the Sewage Sludge Module of the Risk Assessment System. The Kom and DT50-soil should be determined from the n-octanol/water distribution coefficient, Kow, and the Readily Biodegradability test result, respectively.DGM/SV
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Dutch Risk Assessment System for New Chemicals: Soil Groundwater Module
Rijksinstituut voor Volksgezondheid en Milieu RIVM, 1993Co-Authors: Van Der Linden Ama, Van Den Berg RAbstract:A new Soil-Groundwater Module has been developed for incorporation in the Dutch Risk Assessment System for New Chemicals. In this module, the exposure of humans and the environment to Xenobiotic Substances due to sewage sludge application have been determined. Exposure criteria were: 1. accumulation in the uppermost soil layer one year after sewage sludge application, and 2. the maximal Substance-concentration of the deeper groundwater. The calculation procedure is incorporated in the menu driven computer program of the Risk Assessment System. For the quantification of the exposure to each new Xenobiotic Substance the following inputs are needed: - Substance characteristics: the sorption coefficient based on organic matter, Kom, and the half-life, DT50-soil, which represent sorption and transformation of the Substance, respectively. - the actual Substance dose rate on the soil, expressed in kg/ha, which is calculated in the Sewage Sludge Module of the Risk Assessment System. The Kom and DT50-soil should be determined from the n-octanol/water distribution coefficient, Kow, and the Readily Biodegradability test result, respectively.<br>
