重金属铜、锌、铅、镉对小形月牙藻生长及亚显微结构的影响

本文研究了重金属铜、锌、铅、镉对小形月牙藻(Selenastrum minutum )生长的影响, 以及小形月牙藻对重金属的吸收富集情况, 并着重研究了四种重金属对小形月牙藻的亚显微结构的影响.从电镜观察可见, 四种重金属对小形月牙藻的毒性症状首先表现在叶绿体, 其呈平行排列的、片状的类囊体受毒害后,变成指纹状排列、条索状排列、甚至不规则的波纹状;四种重金属对液泡的影响也很明显, 随着重金属浓度的增加, 原来的多数小液泡变成一个或几个大液泡;细胞壁变得结构松散, 重金属浓度高时, 外层呈剥落状.根据本实验结果, 四种重金属对小形月牙藻的毒性顺序是:Cd >Cu>Pb>Zn .本实验结果还表明, 小形月牙藻对重金属铜、锌、铅、镉都有一定的吸收富集能力, 尤其对铅和锌有更大的耐受力, 能够大量吸收水体中的铅和锌.

The Effect of Copper, Zinc, Lead , Cadmium on the Growth and the Ultrastructure of Selenastrum Minutum

This paper studies the effects of Copper , Zinc , Lead , Cadmium on the ultrastructure and the grow th of Selenastrumminutum and studies the accumulation of heav y metal o n Selenastrum minutum .The experimental results show that :the inhibitory sequence o n Selenastrum minutum is Cd2 +>Cu2 +>Pb2 +>Zn2 +.Selenastrum minutum exposed to 0.001 mg/ L Cd2 +and0 .05mg/ L Cu2 + shows marked reduction in cells number .And it expo sed to 1.0mg/ L Pb2 + and Zn2 + comes into showingthe same thing s.The effect of Copper , Zinc , Lead , Cadmium on ultrastructure of Selenastrum minutum is conspicuousin the chloroplast :The parallel lay ers of thy lakoids in the chloroplast are o f a fingerprint -like appearance , or of astrip -like and a co rrug atio n-like appearance .The influence of heavy metals o n vacuole is also obvious.The size of vacuole is greatly increased with the increase of the concentration of heavy me tals .As to cell, the high concentra tio n of heavy metal makes it peel off layerly .The experimental results also show that Selenastrum minutum has the ability to accumulate heavy metals , especially Lead and Zinc.So w e can use the algae(Selenastrum minutum )to clean the w ater system