A stable dark variant separated from photobacterium phosphoreum (A2) was fixed in agar-gel membrane and immobilized onto an exposed end of a fiber-optic linked with bioluminometer. The variant could emit a luminescent...A stable dark variant separated from photobacterium phosphoreum (A2) was fixed in agar-gel membrane and immobilized onto an exposed end of a fiber-optic linked with bioluminometer. The variant could emit a luminescent signal in the presence of genotoxic agents, such as Mitomycin C (MC). The performance of this whole-cell optical fiber sensor system was examined as a function of several parameters, including gel probe thickness, bacterial cell density, and diameter of the fiber-optic core and working temperature. An optimal response to a model genotoxicant, Mitomycin C, was achieved with agar-bacterial gel membrane: the thickness of gel membrane was about 5 mm; the cell density of bacteria in gel membrane was about 2.0×107 /ml; the diameter of fiber-optic core was 5.0 mm; the working temperature was 25 ℃. Under these optimized conditions, the response time was less than 10 h to Mitomycin C, with a lower detection threshold of 0.1 mg/L.展开更多
The aim of this study was to identify the intermediates in clofibric acid degradation under various advanced oxidation processes, namely ultraviolet （UV）, UV/H2O2, vacuum ultraviolet （VUV）, VUV/H2O2, and solar/TiO...The aim of this study was to identify the intermediates in clofibric acid degradation under various advanced oxidation processes, namely ultraviolet （UV）, UV/H2O2, vacuum ultraviolet （VUV）, VUV/H2O2, and solar/TiO2 processes, as well as to assess the toxicity of these intermediates. Eleven intermediates have been detected by gas chromatography-mass spectrometer, most of which were reported for the first time to our best knowledge. Combining the evolution of the dissolved organic carbon, CF and specific ultraviolet absorption at 254 nm, it could be deduced that cleavage of aromatic ring followed by dechlorination was the mechanism in solar/ TiO2 process, while dechlorination happened first and accumulation of aromatic intermediates occurred in the other processes. Different transformation pathways were proposed for UV-, VUV-assisted and solar/TiO2 processes, respectively. The acute toxicity was evaluated by means of Photobacterium phosphoreurn T3 spp. bioassay. It was believed that aromatic intermediates increased the toxicity and the ring-opening pathway in solar/TiO2 process could relieve the toxicity.展开更多
Quantitative structure activity relationships(QSARs)were developed for 43 aromatic compounds toxicity to Photobacterium phosphoreum and Daphnia magna based on four methods: octanol/water partition coefficient...Quantitative structure activity relationships(QSARs)were developed for 43 aromatic compounds toxicity to Photobacterium phosphoreum and Daphnia magna based on four methods: octanol/water partition coefficient, linear solvation energy relationship, molecular connectivity index and group contribution. Through the evaluation of four QSAR methods, LSER was proved to be the best. And it applied to the widest range of chemicals with the greatest accuracy.展开更多
The single toxicity of aniline and its derivatives and the joint toxicity of the binary mixtures of aniline and each of its derivatives with the toxic unit ratios of 1∶1, 1∶4, 4∶1 to photobacterium phosphoreum were...The single toxicity of aniline and its derivatives and the joint toxicity of the binary mixtures of aniline and each of its derivatives with the toxic unit ratios of 1∶1, 1∶4, 4∶1 to photobacterium phosphoreum were determined, respectively. The toxic unit and the additive index were used to evaluate the joint toxicity. The result shows that the joint toxicity of each of the binary mixtures of aniline and each of its derivatives is mainly simple addition of the toxicities of the two compounds. On this basis, the QSAR equation that was built from the single toxicity of aniline was used to predict the toxicity of the derivatives of aniline in the mixtures. Good agreement between the predicted and experimental values was found with R 2=0.921.展开更多
The single toxicity of cadmium（Cd） or 9 substituted phenols to Phtobacterium phosphoreum was determined, respectively. The results indicate that the single toxicity was related to group variety, group sum and substi...The single toxicity of cadmium（Cd） or 9 substituted phenols to Phtobacterium phosphoreum was determined, respectively. The results indicate that the single toxicity was related to group variety, group sum and substitutive positions. On the basis of single toxicity, the joint toxicity of Cd and 9 substituted phenols was measured. The result indicates that the joint toxicity was basically a simple addition of the single toxicity of them or close to simple addition of the single toxicity of them. QSAR equations were built from the joint toxicity and molecular structural descriptors of substituted phenols under the different Cd concentrations. It was shown that the joint toxicity under different Cd concentrations was related to the identical descriptors, the logarithm of n-octanol/water partition coefficient（lgP） and the heat of formation（△Hf）, with R2=0.855, 0.878 and 0.780, respectively. Good agreement between the predicted and observed values was found with R2=0.837.展开更多
A new,simple,rapid microbial assay was put forward for the detection of chloramphenicol(CAP)residues in Turbot muscles using luminescent bacteria DB(Photobacterium phosphoreum)as test organ-ism.By the luminescence inh...A new,simple,rapid microbial assay was put forward for the detection of chloramphenicol(CAP)residues in Turbot muscles using luminescent bacteria DB(Photobacterium phosphoreum)as test organ-ism.By the luminescence inhibition of DB,the concentrations of CAP were determined.CAP spiked inTurbot muscle tissues ranging from 0.5 to 100μg/kg was extracted using ethyl acetate and hexane.Themethod had a good recovery of 93.69% with a minimum detection limit of 0.65μg/kg.It can be per-formed within 30min following simple extraction.The method therefore proved to be advantageous overchromatographic procedures as it was inexpensive,quite sensitive and can be adopted for rapid screeningof CAP in Turbot tissues.展开更多
Johnson et al. (1993) showed that coexposure to UV-A between 300-400 nm enhanced the toxicity of nitrotoluenes to Phoiobacterium phosphoreum, a marine bioluminescent bacteria used in the Microtox test (Microbics Inc.)...Johnson et al. (1993) showed that coexposure to UV-A between 300-400 nm enhanced the toxicity of nitrotoluenes to Phoiobacterium phosphoreum, a marine bioluminescent bacteria used in the Microtox test (Microbics Inc.). This paper reports that UV-A photoenhanced the toxicity of polynuclear aromatic hydrocarbons, other types of organic compounds, and some transition metals to P. phosphoreum. Coexposure to 400 μw/cm2 for 15 min increased the toxicity of psoralen, α-terthienyl, anthracene, acridine, fluoranthene,TNT, Cu2+, As3+, Ni2, and Cd2+. Phenanthrene was photoenhanced after 30 min coexposure at 400 μw/cm2+, and Mn2+ at 800 μw/cm2 aftef 15 min. Naphthalene was not enhanced at 800 μw/cm2 for 30 min展开更多
文摘A stable dark variant separated from photobacterium phosphoreum (A2) was fixed in agar-gel membrane and immobilized onto an exposed end of a fiber-optic linked with bioluminometer. The variant could emit a luminescent signal in the presence of genotoxic agents, such as Mitomycin C (MC). The performance of this whole-cell optical fiber sensor system was examined as a function of several parameters, including gel probe thickness, bacterial cell density, and diameter of the fiber-optic core and working temperature. An optimal response to a model genotoxicant, Mitomycin C, was achieved with agar-bacterial gel membrane: the thickness of gel membrane was about 5 mm; the cell density of bacteria in gel membrane was about 2.0×107 /ml; the diameter of fiber-optic core was 5.0 mm; the working temperature was 25 ℃. Under these optimized conditions, the response time was less than 10 h to Mitomycin C, with a lower detection threshold of 0.1 mg/L.
基金This study was supported by the National Natural Science Foundation of China （Grant Nos. 20677015 and 40871223）, the National High Technology Research and Development Program of China （No. 2007AA06Z331）, the Chinese Shanghai Leading Academic Discipline Project （B506） and National Post-Doctoral Science Foundation （No. 2011M500071）.
文摘The aim of this study was to identify the intermediates in clofibric acid degradation under various advanced oxidation processes, namely ultraviolet （UV）, UV/H2O2, vacuum ultraviolet （VUV）, VUV/H2O2, and solar/TiO2 processes, as well as to assess the toxicity of these intermediates. Eleven intermediates have been detected by gas chromatography-mass spectrometer, most of which were reported for the first time to our best knowledge. Combining the evolution of the dissolved organic carbon, CF and specific ultraviolet absorption at 254 nm, it could be deduced that cleavage of aromatic ring followed by dechlorination was the mechanism in solar/ TiO2 process, while dechlorination happened first and accumulation of aromatic intermediates occurred in the other processes. Different transformation pathways were proposed for UV-, VUV-assisted and solar/TiO2 processes, respectively. The acute toxicity was evaluated by means of Photobacterium phosphoreurn T3 spp. bioassay. It was believed that aromatic intermediates increased the toxicity and the ring-opening pathway in solar/TiO2 process could relieve the toxicity.
文摘Quantitative structure activity relationships(QSARs)were developed for 43 aromatic compounds toxicity to Photobacterium phosphoreum and Daphnia magna based on four methods: octanol/water partition coefficient, linear solvation energy relationship, molecular connectivity index and group contribution. Through the evaluation of four QSAR methods, LSER was proved to be the best. And it applied to the widest range of chemicals with the greatest accuracy.
文摘The single toxicity of aniline and its derivatives and the joint toxicity of the binary mixtures of aniline and each of its derivatives with the toxic unit ratios of 1∶1, 1∶4, 4∶1 to photobacterium phosphoreum were determined, respectively. The toxic unit and the additive index were used to evaluate the joint toxicity. The result shows that the joint toxicity of each of the binary mixtures of aniline and each of its derivatives is mainly simple addition of the toxicities of the two compounds. On this basis, the QSAR equation that was built from the single toxicity of aniline was used to predict the toxicity of the derivatives of aniline in the mixtures. Good agreement between the predicted and experimental values was found with R 2=0.921.
基金the National Nature Science Foundation of China(No.40673059)Science Foundation for Young Teachers of Northeast Normal University(No.20080501).
文摘The single toxicity of cadmium（Cd） or 9 substituted phenols to Phtobacterium phosphoreum was determined, respectively. The results indicate that the single toxicity was related to group variety, group sum and substitutive positions. On the basis of single toxicity, the joint toxicity of Cd and 9 substituted phenols was measured. The result indicates that the joint toxicity was basically a simple addition of the single toxicity of them or close to simple addition of the single toxicity of them. QSAR equations were built from the joint toxicity and molecular structural descriptors of substituted phenols under the different Cd concentrations. It was shown that the joint toxicity under different Cd concentrations was related to the identical descriptors, the logarithm of n-octanol/water partition coefficient（lgP） and the heat of formation（△Hf）, with R2=0.855, 0.878 and 0.780, respectively. Good agreement between the predicted and observed values was found with R2=0.837.
基金Supported by the National Natural Science Foundation of China ( No. 30500384)the High Technology Research and Development Programme of China (No. 2006AA09Z431)
文摘A new,simple,rapid microbial assay was put forward for the detection of chloramphenicol(CAP)residues in Turbot muscles using luminescent bacteria DB(Photobacterium phosphoreum)as test organ-ism.By the luminescence inhibition of DB,the concentrations of CAP were determined.CAP spiked inTurbot muscle tissues ranging from 0.5 to 100μg/kg was extracted using ethyl acetate and hexane.Themethod had a good recovery of 93.69% with a minimum detection limit of 0.65μg/kg.It can be per-formed within 30min following simple extraction.The method therefore proved to be advantageous overchromatographic procedures as it was inexpensive,quite sensitive and can be adopted for rapid screeningof CAP in Turbot tissues.
文摘Johnson et al. (1993) showed that coexposure to UV-A between 300-400 nm enhanced the toxicity of nitrotoluenes to Phoiobacterium phosphoreum, a marine bioluminescent bacteria used in the Microtox test (Microbics Inc.). This paper reports that UV-A photoenhanced the toxicity of polynuclear aromatic hydrocarbons, other types of organic compounds, and some transition metals to P. phosphoreum. Coexposure to 400 μw/cm2 for 15 min increased the toxicity of psoralen, α-terthienyl, anthracene, acridine, fluoranthene,TNT, Cu2+, As3+, Ni2, and Cd2+. Phenanthrene was photoenhanced after 30 min coexposure at 400 μw/cm2+, and Mn2+ at 800 μw/cm2 aftef 15 min. Naphthalene was not enhanced at 800 μw/cm2 for 30 min
