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1.
Enzymatic synthesis of bromo- and chlorocarbazoles and elucidation of their structures by molecular modeling 总被引:1,自引:0,他引:1
John Mumbo Dieter Lenoir Bernhard Henkelmann Karl-Werner Schramm 《Environmental science and pollution research international》2013,20(12):8996-9005
3-Chlorocarbazole, 3,6-dichlorocarbazole, dibromocarbazole, and 1,3,6,8-tetrabromocarbazole are emerging environmental contaminants which have been detected recently in water, sediment, and soil samples. However, their sources and occurrence have not been explained. Here, we report an enzymatic synthesis of bromo- and chlorocarbazoles by chloroperoxidase from Caldariomyces fumago in water. Density functional theory (DFT) method was used to predict the most stable products. Carbazole and chloroperoxidase were assayed in vitro in the presence of hydrogen peroxide, bromide, and chloride ions in different substrate ratio treatments against constant and varying enzyme concentrations. Halogenated carbazoles formed were identified by high-resolution gas chromatography coupled to mass spectrometry. In all treatments, bromination and chlorination took place, but the composition and concentration of compounds formed varied from one treatment to another. Mono-, di-, tri-, and tetra-substituted bromo- and chlorocarbazoles which include the reported environmental contaminants were synthesized. 3-Substituted and 3,6-substituted congeners were relatively higher in concentration. Enzyme concentration did not favor preferential formation of any of the compounds synthesized. However, their synthesis was influenced by halide concentration. Congeners with bromine and chlorine at position of C-3, C-3,6, C-1,3,6, and C-1,3,6,8 were calculated as the stable intermediate sigma complexes by DFT method. Regioselectivity in halogenation is discussed and hypothesis of the likely stable products in the environment explained. This study provides evidence that bromo- and chlorocarbazoles reported previously can be formed enzymatically in the environment, demonstrating the need to consider aromatic pollutants transformation and their potential toxicity enhancements in the management of water pollution and contaminated sites. 相似文献
2.
Strok M Smodiš B Eler K 《Environmental science and pollution research international》2011,18(5):819-826
Objective
The purpose of the study was to investigate natural radionuclide uptake and allocation by trees. 相似文献3.
Hédi Ben Mansour Yosra Ayed-Ajmi Ridha Mosrati David Corroler Kamel Ghedira Daniel Barillier Leila Chekir-Ghedira 《Environmental science and pollution research international》2010,17(7):1371-1378
Introduction
Acid violet 7 (AV7), mostly used in food, paper, cosmetic, and especially in textile industries, was degraded by Pseudomonas putida mt-2 at concentrations up to 200 mg/l. 相似文献4.
Background, aim, and scope
Ferro-cyanide is one of the commonly found species at cyanide-contaminated soils and groundwater. Unlike botanical metabolism of KCN via the β-cyanoalanine pathway, processes involved in the plant-mediated assimilation of ferro-cyanide are still unclear. The objective of this study was to investigate a possible mechanism involved in uptake and assimilation of ferro-cyanide by plants. 相似文献5.
6.
Ashis K. Mukherjee Naba K. Bordoloi 《Environmental science and pollution research international》2011,18(3):471-478
Purpose
Spillage of petroleum hydrocarbons causes significant environmental pollution. Bioremediation is an effective process to remediate petroleum oil contaminant from the ecosystem. The aim of the present study was to reclaim a petroleum oil-contaminated soil which was unsuitable for the cultivation of crop plants by using petroleum oil hydrocarbon-degrading microbial consortium. 相似文献7.
Noorizadeh H Farmany A 《Environmental science and pollution research international》2012,19(4):1252-1259
Introduction
A quantitative structure-retention relation (QSRR) study was conducted on the retention times of organic pollutants in textile wastewaters and landfill leachate which was obtained by liquid chromatography-reversed phase-atmospheric pressure chemical ionization-mass spectrometry. 相似文献8.
Wang Y Zhou D Wang Y Wang L Cang L 《Environmental science and pollution research international》2012,19(2):448-457
Purpose
Dechlorination of polychlorinated biphenyls (PCBs) by nanoscale zerovalent iron (NZVI) is often strongly hindered by increased pH because large amounts of H+ ions were consumed during the surface reaction. The main objective of this work was to evaluate the effect of pH control in acid on the dechlorination processes of PCBs and to compare the dechlorination efficiency between 2,4,4′-trichlorobiphenyl (2,4,4′-CB) and the extracted PCBs from the field PCBs-contaminated soil in this system. 相似文献9.
Chlorpyrifos degradation by the cyanobacterium <Emphasis Type="Italic">Synechocystis</Emphasis> sp. strain PUPCCC 64 总被引:1,自引:0,他引:1
Singh DP Khattar JI Nadda J Singh Y Garg A Kaur N Gulati A 《Environmental science and pollution research international》2011,18(8):1351-1359
Background, aim, and scope
Indiscriminate use of insecticides leads to environmental problems and poses a great threat to beneficial microorganisms. The aim of the present work was to study chlorpyrifos degradation by a rice field cyanobacterium Synechocystis sp. strain PUPCCC 64 so that the organism is able to reduce insecticide pollution in situ. 相似文献10.
Linlin Cong Yingyu Fang Miao He Xinshun Wang Narayanan Kannan Donghao Li 《Environmental science and pollution research international》2010,17(7):1379-1387
Background, aim and scope
The climatic characteristic is a major parameter affecting on the distribution variation of organic pollutants such as polycyclic aromatic hydrocarbons (PAHs). The Tumen River is located in Northeastern of China. The winter era lasts for more than 5 months in a year, and the river water was frozen and covered by ice phase. Coal combustion is an essential heating source in the Tumen River Basin. The objective of this research is to study ice phase effect on the seasonal variation of PAHs in the Tumen River environment. 相似文献11.
Spasić-Jokić V Zupunski L Janković L Gordanić V 《Environmental science and pollution research international》2011,18(5):708-715
Purpose
The purpose of this paper is to determine the activity concentrations of radionuclide 137Cs in soil samples on the territory of Belgrade and the province of Vojvodina. Also, the lifetime cancer mortality risk from external exposure during 1 year is assessed, and the effective dose is estimated. 相似文献12.
Varun M D'Souza R Pratas J Paul MS 《Environmental science and pollution research international》2012,19(1):269-281
Introduction
The effect of the glass industry on urban soil metal characterization was assessed in the area of Firozabad, India. A comprehensive profile of metal contamination was obtained in five zones each containing five specific sites. 相似文献13.
Hairong Cheng Hai Guo Xinming Wang Sam M. Saunders S. H. M. Lam Fei Jiang Tijian Wang Aijun Ding Shuncheng Lee K. F. Ho 《Environmental science and pollution research international》2010,17(3):547-560
Background, aim, and scope
Photochemical smog, characterized by high concentrations of O3 and fine particles, is of great concern in the urban areas, in particular megacities and city clusters like the Pearl River Delta. 相似文献14.
Yusuf M Fariduddin Q Varshney P Ahmad A 《Environmental science and pollution research international》2012,19(1):8-18
Introduction
This study was hypothesized that salicylic acid elevates the level of antioxidant system that will protect plants from the stress generated by nickel and/or salinity. 相似文献15.
Lu Q He ZL Graetz DA Stoffella PJ Yang X 《Environmental science and pollution research international》2011,18(6):978-986
Background, aim and scope
Water quality impairment by heavy metal contamination is on the rise worldwide. Phytoremediation technology has been increasingly applied to remediate wastewater and stormwater polluted by heavy metals. 相似文献16.
Hung-Lung Chiang Cho-Ching Lo Sen-Yi Ma 《Environmental science and pollution research international》2010,17(3):624-633
Introduction
The pyrolytic method was employed to recycle metals and brominated compounds blended into printed circuit boards (PCBs). 相似文献17.
Chen L Shen C Tang X Chen C Chen Y 《Environmental science and pollution research international》2012,19(2):522-528
Background and purpose
The ubiquitous dissolved organic matter (DOM) is actually not inert as we always think, and the hormone-like effects of DOM have been reported. The objective of this study was to investigate the estrogenic effects of DOM and its impact on the activity of the natural estrogen 17β-estradiol (E2). 相似文献18.
García-Rosales G Olguin MT Colín-Cruz A Romero-Guzmán ET 《Environmental science and pollution research international》2012,19(1):177-185
Objective
The present work was carried out to investigate the effects of temperature, initial pH, initial concentration, and contact time on the biosorption of lead (Pb) and cadmium (Cd) by modified stalk sponge of Zea mays using a batch technique. 相似文献19.
Characterization of tannery sludge activated carbon and its utilization in the removal of azo reactive dye 总被引:1,自引:1,他引:0
Geethakarthi A Phanikumar BR 《Environmental science and pollution research international》2012,19(3):656-665
Introduction
The removal of azo Reactive Red 31(RR31) from synthetic dye solution using tannery sludge-developed activated carbon (TSC) was investigated. 相似文献20.
Stefanie Grund Eric Higley René Schönenberger Marc J-F. Suter John P. Giesy Markus Hecker Henner Hollert 《Environmental science and pollution research international》2011,18(3):446-460