Yun H S, Hong J, Lim H C
Department of Chemical and Biochemical Engineering, University of California, Irvine, California 92717, USA.
Biotechnol Bioeng. 1996 Dec 5;52(5):615-24. doi: 10.1002/(SICI)1097-0290(19961205)52:5<615::AID-BIT9>3.0.CO;2-M.
The effect of temperature on the synthesis of ribosome in Escherichia coli K-12 was investigated. In continuous fermentation, the total and functioning ribosome contents decreased with increasing temperature, while the non-functioning ribosome content remained unchanged. Cells contained higher amounts of functioning ribosome at lower temperatures to compensate for the decrease in translational activity. A transient study was performed to investigate the dynamic response of the cell to changes in the dilution rate. In response to the dilution rate shift-up, the cell mass decreased until the cells produced a sufficient amount of ribosomes to support the new higher growth rate. However, the response to the dilution rate shift-down resulted in an immediate increase in cell mass. This may be due to the fact that the cell already contains enough ribosomes to support a lower growth rate corresponding to the new low dilution rate. Based on the experimental results, a mathematical model was developed to describe the cell growth at transient as well as steady states. The total ribosome content was included as a variable because it affects the growth rate of the cell.
研究了温度对大肠杆菌K-12核糖体合成的影响。在连续发酵中，核糖体的总量和功能含量随温度升高而降低，而非功能核糖体含量保持不变。在较低温度下，细胞含有较多的功能核糖体，以补偿翻译活性的降低。进行了一项瞬态研究，以研究细胞对稀释率变化的动态响应。响应稀释率上调，细胞质量下降，直到细胞产生足够数量的核糖体以支持新的更高生长速率。然而，对稀释率下调的响应导致细胞质量立即增加。这可能是因为细胞已经含有足够的核糖体来支持与新的低稀释率相对应的较低生长速率。基于实验结果，建立了一个数学模型来描述瞬态和稳态下的细胞生长。总核糖体含量作为一个变量包含在内，因为它会影响细胞的生长速率。
