ESTABLISHMENT OF EXPONENTIAL-GROWTH AFTER A NUTRITIONAL SHIFT-UP IN ESCHERICHIA-COLI B-R - ACCUMULATION OF DEOXYRIBONUCLEIC-ACID, RIBONUCLEIC-ACID, AND PROTEIN
ESTABLISHMENT OF EXPONENTIAL-GROWTH AFTER A NUTRITIONAL SHIFT-UP IN ESCHERICHIA-COLI B-R - ACCUMULATION OF DEOXYRIBONUCLEIC-ACID, RIBONUCLEIC-ACID, AND PROTEIN
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DOI：
10.1128/jb.129.2.1020-1033.1977
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发表时间：
1977-01-01
影响因子：
3.2
通讯作者：
BREMER, H
中科院分区：
文献类型：
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作者：
BRUNSCHEDE, H;DOVE, TL;BREMER, H
在E.大肠杆菌B/r在不同培养基中指数生长期间以及在从琥珀酸盐基本培养基（生长速率[μ 1] = 0.67 double/h）到葡萄糖加氨基酸培养基（μ 2 = 3.14 double/h）的营养转换后2小时。在培养物的转移后生长期间，RNA（R）、DNA（D）和蛋白质（P）的量增加，使得增量的比率（Δ R/Δ P; Δ D/Δ P）为常数（k1，k2）。这意味着核酸和蛋白质的积累速率形成时不变的比率;即，(dR/dt）：（dD/dt）：（dP/dt）= k1：k2：1。这些常数从它们的预移位值改变到它们的最终后移位值（即，k1和k2）在移位后的几分钟内。k1是核糖体活性的函数，但k2与DNA复制轮次的起始有关。使用这些参数和观察到的RNA倍增时间的变化（= μ 2/μ 1）来推导动力学方程，该方程描述了在上移后的2-3小时过渡期期间DNA、RNA、蛋白质和细胞质量的积累。计算的动力学与观察到的动力学密切一致。
The accumulation of DNA, RNA and protein was followed in cultures of E. coli B/r during exponential growth in different media and for 2 h after a nutritional shift-up from succinate minimal medium (growth rate [.mu.1] = 0.67 doublings/h) to glucose plus amino acids medium (.mu.2 = 3.14 doublings/h). During postshift growth of the culture, the amounts of RNA (R), DNA (D) and protein (P) increased such that the ratios of the increments (.DELTA.R/.DELTA.P; .DELTA.D/.DELTA.P) were constants (k1, k2). This implies that the rates of accumulation of nucleic acids and protein form time-invariant ratios; i.e., (dR/dt):(dD/dt):(dP/dt) = k1:k2:1. These constants change from their preshift value to their final postshift value (i.e., k1 and k2) within a few minutes after the shift. k1 is a function of the activity of ribosomes, but k2 is related to the initiation of rounds of DNA replication. These parameters and the observed change in the doubling time of RNA (= .mu.2/.mu.1) were used to derive kinetic equations that describe the accumulation of DNA, RNA, protein and cell mass during the 2-3 h transition period after a shift-up. The calculated kinetics agree closely with the observed kinetics.