摘要
通过利用激发-发射矩阵(EEM)荧光光谱,研究蓝藻集胞藻EPS(胞外聚合物)与CAP(氯霉素)的相互作用.结果表明:EPS含有6个峰,其中峰A(ExEm=205304)、峰B(ExEm=230302)、峰C(ExEm=235354)和峰D(ExEm=260372)为类蛋白峰,峰E(ExEm=275446)和峰F(ExEm=350452)为类腐殖质峰.除峰F外,其他各峰都能被CAP猝灭,说明它们所代表的物质能够与CAP发生作用;而峰F则几乎不被CAP猝灭,即荧光峰F不与CAP发生作用.CAP与EPS中荧光基团的反应属于静态猝灭,生成稳定的不发荧光的EPS-CAP络合物,其有效猝灭常数为3.28～4.49,结合常数为4.54～8.13.EPS与CAP强的络合作用意味着环境中普遍存在的EPS可能深刻地影响CAP在水环境中的迁移与转化.
Three-dimensional excitation emission matrix（EEM） fluorescence spectroscopy was used to examine the interaction between chloramphenicol（CAP） and the extracellular polymeric substances（EPS） from Synechocystis sp.The results showed that there were six particular fluorescence peaks in the spectra of EPS.Peak A（ExEm=205304）,peak B（ExEm=230302）,peak C（ExEm=235354） and peak D（ExEm=260372） represented the protein-like fluorescence substances,and the other two peaks at ExEm=275446（peak E） and ExEm=350452（peak F） reflected the humic-like fluorophores.With the exception of peak F,all the fluorescence peaks could be significantly quenched by CAP.This indicated that the fluorophores material can play a role with CAP,but not between CAP and those reflected by peak F.The reaction between CAP and the fluorophores in EPS was a static process,and formed stable EPS-CAP complexes.The effective quenching and binding constants for fluorophores of EPS were 3.28-4.49 and 4.54-8.13,respectively.The strong combination of EPS to CAP implied that EPS may play an important role in the transfer and transformation of CAP in aquatic environments.
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2012年第1期58-62,共5页
Research of Environmental Sciences
基金
中国科学院重要方向性项目(KZCX2-YW-335)
中国科学院“百人计划”项目
关键词
胞外聚合物
氯霉素
荧光猝灭
结合
EPS
chloramphenicol
fluorescence quenching
binding
