13C-Labeled metabolic flux analysis of a fed-batch culture of elutriated Saccharomyces cerevisiae
13C-Labeled metabolic flux analysis of a fed-batch culture of elutriated Saccharomyces cerevisiae
复制标题
DOI：
10.1111/j.1567-1364.2006.00199.x
复制
发表时间：
2007-06-01
影响因子：
3.2
通讯作者：
Heijnen, Joseph J.
中科院分区：
文献类型：
--
作者：
Costenoble, Roeland;Mueller, Dirk;Heijnen, Joseph J.
本研究探讨了酿酒酵母初级碳代谢通量的可观察变化是否发生在细胞分裂周期的不同阶段之间。为了通过代谢通量分析检测这种变化，我们进行了一项c -13标记实验，用离心洗脱获得的部分同步细胞群接种补料批培养物。随着时间的推移，这种培养在不同细胞周期阶段的细胞组分中表现出动态变化。采用液相色谱-质谱法测定了中心碳代谢过程中游离胞内代谢物的质量同位素分布。在培养过程中的四个时间点，这些分布被用来获得代谢通量的最佳估计。得到的通量拟合表明，在实验过程中，戊糖磷酸途径的最佳拟合分裂比在0.27左右上下变化了近2倍。统计分析表明，不同时间点的一些拟合通量分布存在显著差异，表明确实存在细胞周期依赖性的胞质代谢通量变化。
This study addresses the question of whether observable changes in fluxes in the primary carbon metabolism of Saccharomyces cerevisiae occur between the different phases of the cell division cycle. To detect such changes by metabolic flux analysis, a C-13-labeling experiment was performed with a fed-batch culture inoculated with a partially synchronized cell population obtained through centrifugal elutriation. Such a culture exhibits dynamic changes in the fractions of cells in different cell cycle phases over time. The mass isotopomer distributions of free intracellular metabolites in central carbon metabolism were measured by liquid chromatography-mass spectrometry. For four time points during the culture, these distributions were used to obtain the best estimates for the metabolic fluxes. The obtained flux fits suggested that the optimally fitted split ratio for the pentose phosphate pathway changed by almost a factor of 2 up and down around a value of 0.27 during the experiment. Statistical analysis revealed that some of the fitted flux distributions for different time points were significantly different from each other, indicating that cell cycle-dependent variations in cytosolic metabolic fluxes indeed occurred.