利用稳定同位素示踪技术研究大型溞（Daphnia magna）对水环境中溶解性铜的吸收

由于缺乏合适的放射性同位素,生物对Cu的吸收以及Cu在生物体内的迁移转化等动力学研究一直较为匮乏.论文以大型溞(Daphniamagna)为受试生物,以稳定同位素65Cu作为示踪剂,研究了不同Cu浓度下,大型溞对水相中Cu的吸收.结果表明,在低浓度下,大型溞的吸收随着水相中Cu浓度的增加而增加.随着水相中Cu浓度的升高,大型溞的吸收逐渐趋于饱和.水相吸收速率和Cu的暴露浓度符合米氏方程(Michaelis-Menten Function),最大吸收速率Imax为14.6μg·g-1·h-1,米氏常数Km为3.2μg·L-1,平均水相吸收速率常数ku为1.23L·g-1·h-1.

Study of the Uptake of Dissolved Copper in Daphnia magna by Use of Stable Copper Isotope Tracer Technique

Many researches were focused on the heavy metal pollution in aquatic environment.However,few were concerned about copper kinetic uptake due to no appropriate radioisotope available.In present study,stable isotope 65Cu was used to trace the uptake of dissolved copper in Daphnia magna under different concentrations.Results showed that with the increasing of Cu spiked concentration in water,the influx rate increased in initial stage,and then reached saturation,which followed Michaelis-Menten kinetics model.The maximum influx rate(Imax)and the Michaelis constant(Km) were 14.6μg·g-1·h-1 and 3.2μg·L-1,respectively,and the average value of influx rate constant(ku)of Cu was 1.23L·g-1·h-1.