Kubitschek H E, Freedman M L
J Bacteriol. 1971 Jul;107(1):95-9. doi: 10.1128/jb.107.1.95-99.1971.
The average amount of deoxyribonucleic acid (DNA) per cell was measured in steady-state cultures of Escherichia coli B/r grown at 37 C in glucose-limited chemostats or in batch cultures in the exponential growth phase as maintained with one of several carbon sources. Within experimental errors, DNA content was dependent only on growth rate and independent of the type of culture, the carbon source, or the addition of growth factors. The amount of DNA per cell increased continuously with growth rate over the range of 0.02 to 3 divisions per hour. The data over the entire range of growth rates are in agreement with a constant time for a single replication point to traverse the entire genome, 47 min, and with cell division following 25 min after termination of replication. The measured amount of DNA per genome was 4.2 x 10(-15) g (or 2.5 x 10(9) daltons).
在37℃下，于葡萄糖受限的恒化器中培养的大肠杆菌B/r稳态培养物，或在以几种碳源之一维持的指数生长期分批培养物中，测量了每个细胞的脱氧核糖核酸（DNA）平均含量。在实验误差范围内，DNA含量仅取决于生长速率，而与培养类型、碳源或生长因子的添加无关。在每小时0.02至3次分裂的范围内，每个细胞的DNA量随生长速率持续增加。在整个生长速率范围内的数据与单个复制点遍历整个基因组所需的恒定时间（47分钟）一致，并且细胞分裂在复制终止后25分钟进行。每个基因组测得的DNA量为4.2×10⁻¹⁵克（或2.5×10⁹道尔顿）。
