Comparison of heavy metal accumulation by a bloom-forming cyanobacterium,Microcystis aeruginosa  

作　　者：ZENG Jin ZHAO DaYong JI YongBan WU QingLong 

机构地区：[1]State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China [2]State Key Laboratory of Hydrology-Water Resources and Hydraulie Engineering College of Hydrology and Water Resources,Hohai University,Nanjing 210098,China

出　　处：《Chinese Science Bulletin》2012年第28期3790-3797,共8页

基　　金：supported by the National Basic Research Program of China(2008CB418104,2008CB418102);the National Natural Science Foundation of China(41101052,41001044);the Natural Science Foundation of Jiangsu Province(BK2011876);the Open Foundation from the State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering at Hohai University(2010490311);the Open Foundation from the State Key Laboratory of Pollution Control and Resources Reuse at Nanjing University(PCRRF11022);the Project of Nanjing Institute of Geography & Limnology(NIGLAS2010QD10)

摘　　要：Microcystis aeruginosa is the dominant species during cyanobacterial blooms in freshwater lakes.In the present study,we compared the bioaccumulation characteristics of cadmium(Cd) and zinc(Zn) in Microcystis cells.In short-term uptake tests,a rapid sorption of Cd and Zn occurred in the first few minutes,with a subsequent slower internalization process.No obvious difference was observed between Zn and Cd in terms of their short-term uptake kinetics.In efflux experiments,elimination of Zn from the cells was faster than that of Cd.In the 72-h exposure tests,the intracellular Cd concentrations increased with exposure time whereas the intracellular Zn concentrations always reached a plateau.The cellular Cd showed greater variation than the cellular Zn at various free Cd 2+ or Zn 2+ concentrations.The differences in Cd and Zn accumulation and elimination indicated that Microcystis cells had a higher bioaccumulation capacity for Cd than for Zn.In field studies,the bioconcentration factor(BCF) of Cd in lake-harvested Microcystis was more than 10 times higher than those of other metals.The results of the present study strongly suggested that the bloom-forming Microcystis may affect the Cd transportation and biogeochemical cycling in eutrophic freshwater ecosystems.Microcystis aeruginosa is the dominant species during cyanobacterial blooms in freshwater lakes. In the present study, we com- pared the bioaccumulation characteristics of cadmium （Cd） and zinc （Zn） in Microcystis cells. In short-term uptake tests, a rapid sorption of Cd and Zn occurred in the first few minutes, with a subsequent slower internalization process. No obvious difference was observed between Zn and Cd in terms of their short-term uptake kinetics. In efflux experiments, elimination of Zn from the cells was faster than that of Cd. In the 72-h exposure tests, the intracellular Cd concentrations increased with exposure time whereas the intracellular Zn concentrations always reached a plateau. The cellular Cd showed greater variation than the cellular Zn at various free Cd2＋ or Zn2＋ concentrations. The differences in Cd and Zn accumulation and elimination indicated that Micro- cystis cells had a higher bioaccumulation capacity for Cd than for Zn. In field studies, the bioconcentration factor （BCF） of Cd in lake-harvested Microcystis was more than 10 times higher than those of other metals. The results of the present study strongly suggested that the bloom-forming Microcystis may affect the Cd transportation and biogeochemical cycling in eutrophic freshwa- ter ecosystems.

关 键 词：铜绿微囊藻 重金属积累 蓝藻水华 镉(CD) 生物地球化学循环 吸收动力学 生物富集 淡水生态系统 

分 类 号：X524[环境科学与工程—环境工程] S141.6[农业科学—肥料学]