三种典型淡水藻EOM组成特征及胞外氨基酸释放规律

中国环境科学2017,37(5)：1879~1888ChinaEnvironmentalScience三种典型淡水藻EOM组成特征及胞外氨基酸释放规律杨敬亭1,2,3,杨苏文2,3*,金位栋2,3,刘雷1,闫玉红2,3,毛启迪1,2,3(1.南昌大学资源环境与化工学院,江西南昌330031；2.环境基准与风险评估国家重点实验室,北京100012；3.湖泊水污染治理与生态修复技术国家工程实验室,北京100012)摘要：通过对比分析了藻类EOM的类型和组成,探讨了藻类胞外氨基酸的释放规律.选取典型淡水藻铜绿微囊藻(Microcystisaeruginosa)、四尾栅藻(Scenedesmusquadricauda)、喙头舟形藻(Navicularhynchocephala)为研究对象,采用三维荧光光谱-平行因子分析法(EEMs-PARAFAC)、柱前衍生高效液相色谱(HPLC)分析3种藻在生长稳定期EOM特征与胞外游离氨基酸、结合氨基酸的含量组成等差异.结果表明,藻类均可将无机氮转化为有机氮释放到水体中;3种藻EOM中总色氨酸与总酪氨酸荧光强度关系分别为铜绿微囊藻>四尾栅藻>喙头舟形藻、喙头舟形藻>四尾栅藻>铜绿微囊藻;藻胞外氨基酸中组氨酸、丙氨酸、甘氨酸及丝氨酸含量均较高,苏氨酸、精氨酸、酪氨酸含量均较低;3种藻c(DFAAs)/c(DCAAs)的比值均较低,释放的氨基酸多数以蛋白质和多肽的形式存在;铜绿微囊藻胞外有机物(EOM)中ρ(DON)、ρ(TDAAs)及氨基酸对水体中DON贡献量均为最高,分别为1.31mg/L、5.35mg/L、69.08%,因此蓝藻水华暴发可能会增加水体的氨基酸浓度,加重水体有机氮负荷.关键词：有机氮；胞外有机物；氨基酸；贡献中图分类号：X52文献标识码：A文章编号：1000-6923(2017)05-1879-10EOMcharacteristicsandreleaseofextracellularaminoacidsinthreetypicalfreshwateralgaes.YANGJing-ting1,2,3,YANGSu-wen2,3*,JINWei-dong2,3,LIULei1,YANYu-hong2,3,MAOQi-di1,2,3(1.SchoolofResourcesEnvironmentandChemicalEngineering,NanchangUniversity,Nanchang330031,China；2.StateKeyLaboratoryofEnvironmentalCriteriaandRiskAssessment,Beijing100012,China；3.StateEngineeringLaboratoryforLakePollutionControlandEcologicalRehabilitatingTechnique,Beijing100012,China).ChinaEnvironmentalScience,2017,37(5)：1879~1888Abstract：ThereleaseofextracellularaminoacidsfromalgaewasstudiedthroughcomparativeanalysisofthetypeandcompositionofEOMinalgae.Typicalfreshwateralgaespecies,includingMicrocystisaeruginosa,ScenedesmusquadricaudaandNavicularhynchocephalawereselectedtoexplorethedifferenceofthecharacteristicofEOM,andthequantityandcompositionofextracellularfreeaminoacidandboundaminoacidsinalgaesofstablephase,byexcitation-emissionmatrixspectroscopycombinedwithparallelfactoranalysis(EEMs-PARAFAC)andpre-columnhighperformanceliquidchromatography(HPLC).Resultsshowedthatinorganicnitrogencanbetransformedtoorganicnitrogeninalgaesandsequentiallytobereleasedintowater.ThefluorescenceintensityoftotaltryptophanandoftotaltyrosineinEOMwasMicrocys