Chang C F, Shuman H, Somlyo A P
J Bacteriol. 1986 Sep;167(3):935-9. doi: 10.1128/jb.167.3.935-939.1986.
The elemental composition of individual cells of rapidly frozen and cryosectioned Escherichia coli B was measured with electron optical microanalytic methods. The Ca content was high (26.2 mmol/kg) in a 10-nm-wide region of the cell envelope. Amounts of cytoplasmic Ca in actively dividing cells were significantly higher (32.6 mmol/kg [dry weight]) than in the log-phase (1.5 mmol/kg) cells. Cellular Mg was 205 mmol/kg (dry weight) and it was uniformly distributed throughout the cell. Cells washed in distilled water before freezing lost monovalent ions (Na, Cl, and K), but the membrane-bound Ca and cellular Mg were not reduced, indicating that cellular Mg and membrane Ca are more tightly bound.
采用电子光学微分析方法测定了快速冷冻和冷冻切片的大肠杆菌B单个细胞的元素组成。在细胞包膜10纳米宽的区域内钙含量很高（26.2毫摩尔/千克）。正在进行分裂的细胞中细胞质钙含量（干重为32.6毫摩尔/千克）显著高于对数期细胞（1.5毫摩尔/千克）。细胞中的镁含量为205毫摩尔/千克（干重），且在整个细胞中均匀分布。冷冻前用蒸馏水洗涤的细胞失去了单价离子（钠、氯和钾），但膜结合钙和细胞内镁没有减少，这表明细胞内镁和膜钙结合得更紧密。
