市政水体及实际水环境中各类复杂混合污染物的暴露已成为普遍现象,且对人体健康的危害不断在加剧.随着混合物联合毒性的研究越来越多,使得混合物联合毒性作用的研究成为了一个重要领域.为探索重金属混合毒性作用特点,选取水环境中较敏...市政水体及实际水环境中各类复杂混合污染物的暴露已成为普遍现象,且对人体健康的危害不断在加剧.随着混合物联合毒性的研究越来越多,使得混合物联合毒性作用的研究成为了一个重要领域.为探索重金属混合毒性作用特点,选取水环境中较敏感的斜生栅藻为指示生物,实际环境中常见的六种重金属(锌Zn、镍Ni、铬Cr、铜Cu、砷As和铅Pb)为目标污染物,通过等效应浓度比法(equal-effect concentration ratio method,ECRR)设计一系列二元混合物联合毒性试验,研究二元重金属混合物联合胁迫下的斜生栅藻96 h毒性及其相互作用.结果表明:以EquRay设计的45条二元重金属混合物射线,测试混合物对斜生栅藻的毒性效应.分析45条混合物射线相互作用,重金属二元混合物中7条为加和作用,37条为协同作用,1条为拮抗作用.重金属混合预测决定系数大于0.95,均方根误差小于0.08,具有较好的拟合显著性和统计性.展开更多
The wide use of quaternary ammonium cationic surfactants(QACs)results in their release into the environment.Most surfactants have significant biotoxicity.However,existing toxicity data on QACs are still lacking,especi...The wide use of quaternary ammonium cationic surfactants(QACs)results in their release into the environment.Most surfactants have significant biotoxicity.However,existing toxicity data on QACs are still lacking,especially regarding the joint toxic effects of their mixtures.In computer simulation technology,molecular docking technology is commonly used for studying the mode of action of receptors docking with ligands.The research of QACs mixture interaction is relatively rare,and the binding mode of QACs is unknown.In this study,molecular docking technology was applied to explore the QAC binding mode,and the concentration addition(CA)and independent action(IA)models were applied for predicting the mixture toxicity.Firefly luciferase(FLuc)was used as a macromolecular receptor,and five typical QACs:benzalkonium bromide(BLB),tetraethylammonium bromide(TLB),N,N,N-trimethyl-1-tetradecyl ammonium bromide(CTE),tetrabutylammonium chloride(TAC),and dodecyltrimethylammonium chloride(DTC)were used as small molecule ligands.Molecular docking technology was used to investigate the binding mode of macromolecules and small molecules.The luminescence inhibitory effects of individual compounds and binary mixture on FLuc were determined by microplate toxicity assay of luciferase.The prediction of mixture toxicity was performed by CA and IA.The results showed that the relative toxicity follows:TLB<TAC<DTC<BLB<CTE.TLB and TAC showed the BS-Ⅱbinding mode,and BLB,CTE and DTC showed the BS-Ⅲbinding mode.The toxicity of compounds with binding mode BS-Ⅱwas less than that of those with BS-Ⅲbinding mode.Not all mixtures with the same binding mode could be predicted by CA model,and the IA model did not effectively predict the toxicity of mixtures with compound with different binding modes.The mixture toxicities of QACs with the same binding mode mostly presented additive and synergistic effects,while the mixture toxic effects of QACs with different binding modes presented additive or antagonistic effects.展开更多
A facile and effective method for immobilized lipase was presented.The titania submicrospheres were synthesized via a modified sol-gel method followed by amino functionalization through the chelation between dopamine ...A facile and effective method for immobilized lipase was presented.The titania submicrospheres were synthesized via a modified sol-gel method followed by amino functionalization through the chelation between dopamine and titania.Lipase was covalently attached on the functionalized titania surface using glutaraldehyde as the cross linking agent.The loading ratio and relative activity of the immobilized lipase were 230 mg/g titania submicrospheres and 65%,respectively.The kinetic parameters including the Michaelis constant(Km) and the maximum reaction rate(Vmax) changed slightly after immobilization.Compared to free lipase,the immobilized lipase showed favorable pH stability,thermostability,recycling stability and storage stability.The immobilized lipase retained 90% activity after incubation at 50 ℃ for 2 h,while the free lipase retained only 60% activity.The immobilized lipase retained more than 80% activity after 8 batches.展开更多
文摘市政水体及实际水环境中各类复杂混合污染物的暴露已成为普遍现象,且对人体健康的危害不断在加剧.随着混合物联合毒性的研究越来越多,使得混合物联合毒性作用的研究成为了一个重要领域.为探索重金属混合毒性作用特点,选取水环境中较敏感的斜生栅藻为指示生物,实际环境中常见的六种重金属(锌Zn、镍Ni、铬Cr、铜Cu、砷As和铅Pb)为目标污染物,通过等效应浓度比法(equal-effect concentration ratio method,ECRR)设计一系列二元混合物联合毒性试验,研究二元重金属混合物联合胁迫下的斜生栅藻96 h毒性及其相互作用.结果表明:以EquRay设计的45条二元重金属混合物射线,测试混合物对斜生栅藻的毒性效应.分析45条混合物射线相互作用,重金属二元混合物中7条为加和作用,37条为协同作用,1条为拮抗作用.重金属混合预测决定系数大于0.95,均方根误差小于0.08,具有较好的拟合显著性和统计性.
基金Financially supported from the National Natural Science Foundation of China (21667013 and 21866010)Natural Science Foundation of Guangxi Province (2018GXNSFAA281156)+2 种基金Guilin Scientific Research and Technology Development Program (20180107-5)Special Funding for Guangxi’BaGui Scholar’Construction ProjectsGuangxi Key Laboratory of Environmental Pollution Control Theory and Technology for Science and Education Combined with Science and Technology Innovation Base。
文摘The wide use of quaternary ammonium cationic surfactants(QACs)results in their release into the environment.Most surfactants have significant biotoxicity.However,existing toxicity data on QACs are still lacking,especially regarding the joint toxic effects of their mixtures.In computer simulation technology,molecular docking technology is commonly used for studying the mode of action of receptors docking with ligands.The research of QACs mixture interaction is relatively rare,and the binding mode of QACs is unknown.In this study,molecular docking technology was applied to explore the QAC binding mode,and the concentration addition(CA)and independent action(IA)models were applied for predicting the mixture toxicity.Firefly luciferase(FLuc)was used as a macromolecular receptor,and five typical QACs:benzalkonium bromide(BLB),tetraethylammonium bromide(TLB),N,N,N-trimethyl-1-tetradecyl ammonium bromide(CTE),tetrabutylammonium chloride(TAC),and dodecyltrimethylammonium chloride(DTC)were used as small molecule ligands.Molecular docking technology was used to investigate the binding mode of macromolecules and small molecules.The luminescence inhibitory effects of individual compounds and binary mixture on FLuc were determined by microplate toxicity assay of luciferase.The prediction of mixture toxicity was performed by CA and IA.The results showed that the relative toxicity follows:TLB<TAC<DTC<BLB<CTE.TLB and TAC showed the BS-Ⅱbinding mode,and BLB,CTE and DTC showed the BS-Ⅲbinding mode.The toxicity of compounds with binding mode BS-Ⅱwas less than that of those with BS-Ⅲbinding mode.Not all mixtures with the same binding mode could be predicted by CA model,and the IA model did not effectively predict the toxicity of mixtures with compound with different binding modes.The mixture toxicities of QACs with the same binding mode mostly presented additive and synergistic effects,while the mixture toxic effects of QACs with different binding modes presented additive or antagonistic effects.
基金National Science Foundation of China(21076145)the Natural Science Foundation of Tianjin(09JCYBJC06700)the Program for New Century Excellent Talents in University(NCET-10-0623)
文摘A facile and effective method for immobilized lipase was presented.The titania submicrospheres were synthesized via a modified sol-gel method followed by amino functionalization through the chelation between dopamine and titania.Lipase was covalently attached on the functionalized titania surface using glutaraldehyde as the cross linking agent.The loading ratio and relative activity of the immobilized lipase were 230 mg/g titania submicrospheres and 65%,respectively.The kinetic parameters including the Michaelis constant(Km) and the maximum reaction rate(Vmax) changed slightly after immobilization.Compared to free lipase,the immobilized lipase showed favorable pH stability,thermostability,recycling stability and storage stability.The immobilized lipase retained 90% activity after incubation at 50 ℃ for 2 h,while the free lipase retained only 60% activity.The immobilized lipase retained more than 80% activity after 8 batches.
