Rai L C, Jensen T E, Rachlin J W
Department of Biological Sciences, Lehman College, Bronx, New York 10468.
Arch Environ Contam Toxicol. 1990 Jul-Aug;19(4):479-87. doi: 10.1007/BF01059065.
Cadmium toxicity and uptake as influenced by different pH values have been studied in the freshwater cyanobacterium Anabaena flos-aquae, using the techniques of morphometric analysis, x-ray energy dispersive analysis and atomic absorption spectrophotometry. A general reduction in cell dimension, thylakoid surface area, number and volume of polyhedral bodies, polyphosphate bodies, cyanophycin granules, lipid bodies, membrane limited crystalline inclusions, volume and number of wall layers and mesosomes was observed. These reductions were more pronounced in both acidic and alkaline medium than at pH 7.2. At 0.12 microM Cd, the uptake increased with alkaline pH values, and uptake was greater at pH 7.2 than at either acid or alkaline pHs. Lysis of cell wall at 1.18 microM Cd showed the following decreasing trend: pH 4.0 greater than pH 5.5 greater than pH 10.0 greater than pH 9.0 greater than pH 7.2. There was a total loss of lipid bodies at 1.18 microM Cd at all pH values listed. It is suggested that these techniques can be successfully employed for bioassay studies of metal toxicity to algae. In particular, cell wall lysis and loss of lipids by algae are good indicators of pH effects and metal toxicity in the aquatic ecosystem.
利用形态计量分析、X射线能量色散分析和原子吸收分光光度法等技术，研究了不同pH值对淡水蓝藻水华鱼腥藻中镉毒性和吸收的影响。观察到细胞尺寸、类囊体表面积、多面体、多聚磷酸盐体、蓝藻素颗粒、脂质体、膜限制晶体包涵体、壁层和间体的体积和数量普遍减少。在酸性和碱性介质中，这些减少比在pH 7.2时更明显。在0.12微摩尔镉浓度下，吸收量随碱性pH值增加，且在pH 7.2时的吸收量大于酸性或碱性pH值时的吸收量。在1.18微摩尔镉浓度下，细胞壁裂解呈现以下递减趋势：pH 4.0＞pH 5.5＞pH 10.0＞pH 9.0＞pH 7.2。在列出的所有pH值下，当镉浓度为1.18微摩尔时，脂质体完全消失。建议这些技术可成功用于藻类金属毒性的生物测定研究。特别是，藻类的细胞壁裂解和脂质损失是水生生态系统中pH效应和金属毒性的良好指标。
