Novak Maja, Pfeiffer Thomas, Ackermann Martin, Bonhoeffer Sebastian
Institute of Integrative Biology, ETH Zurich, Zurich 8093, Switzerland.
Antonie Van Leeuwenhoek. 2009 Oct;96(3):267-74. doi: 10.1007/s10482-009-9342-7. Epub 2009 Apr 24.
A method for accurate quantification of growth rate and yield of bacterial populations at low densities was developed with a modified version of a stepwise linear model for fitting growth curves based on optical density measurements, and adapted to measurements at low optical densities in 96-well microtiter plates. The method can be used for rapid and precise estimates of growth rate and yield, based on optical density measurements of large numbers of cultures of Escherichia coli. E. coli B lines were serially propagated at low glucose concentration during a long-term evolution experiment. Growth rate and yield of populations sampled from each of 12 lines that evolved for 20,000 generations under these conditions and two ancestral clones was measured. Populations were grown at three different glucose concentrations. Consistent with earlier findings, statistical analysis showed that both exponential growth rate and yield per unit of glucose differed significantly between the three glucose concentrations tested. Significant adaptation of the evolved populations to the nutrient conditions in which they evolved for 20,000 generations was observed.
基于光密度测量，通过改进的逐步线性模型拟合生长曲线，开发了一种用于准确量化低密度细菌群体生长速率和产量的方法，并将其应用于96孔微量滴定板中低光密度的测量。该方法可基于大量大肠杆菌培养物的光密度测量，快速准确地估计生长速率和产量。在长期进化实验中，大肠杆菌B系在低葡萄糖浓度下连续传代。测量了在这些条件下进化20000代的12个品系以及两个祖先克隆中每个品系的群体生长速率和产量。群体在三种不同的葡萄糖浓度下生长。与早期研究结果一致，统计分析表明，在测试的三种葡萄糖浓度下，指数生长速率和每单位葡萄糖的产量均存在显著差异。观察到进化群体对其进化20000代的营养条件有显著适应性。
