Metabolome dynamic responses of Saccharomyces cerevisiae to simultaneous rapid perturbations in external electron acceptor and electron donor
Metabolome dynamic responses of Saccharomyces cerevisiae to simultaneous rapid perturbations in external electron acceptor and electron donor
复制标题
DOI：
10.1111/j.1567-1364.2006.00144.x
复制
发表时间：
2007-01-01
影响因子：
3.2
通讯作者：
Heijnen, Joseph J.
中科院分区：
文献类型：
--
作者：
Mashego, Mlawule R.;van Gulik, Walter M.;Heijnen, Joseph J.
快速扰动实验是高度相关的，以阐述在体内代谢的数学模型，这是需要为代谢工程选择基因靶动力学。使用酿酒酵母CEN的BioScope对恒化器培养的生物质施加扰动（D=0.05 h（-1），需氧葡萄糖/乙醇限制）。PK 113- 7 D在90和180秒的时间跨度内。外部电子受体氧的可用性从完全好氧到厌氧条件降低。观察到在这些条件下代谢组响应的变化仅限于丙酮酸节点。乙醛供应被用作一个额外的外部电子受体在葡萄糖扰动在完全有氧条件下。这对代谢组动力学具有强烈影响，并导致显著更高的初始糖酵解通量。腺嘌呤核苷酸的动态响应表明，它们的行为不是由糖酵解通量决定的，而是通过果糖1，6-二磷酸和2/3-磷酸甘油酸的平衡池与细胞溶质的NADH/NAD（+）比率耦合得多。此外，电子供体可用性（葡萄糖）降低。这并没有导致糖酵解和三羧酸循环代谢产物的浓度发生显着变化，而腺嘌呤核苷酸，特别是ADP和AMP，表现出相反的反应，在葡萄糖脉冲实验中观察到的。令人惊讶的是，海藻糖在180秒的时间范围内没有被动员。
Rapid perturbation experiments are highly relevant to elaborate the in vivo kinetics for mathematical models of metabolism, which are needed for selecting gene targets for metabolic engineering. Perturbations were applied to chemostat-cultivated biomass (D=0.05 h(-1), aerobic glucose/ethanol-limited) using the BioScope of Saccharomyces cerevisiae CEN. PK 113-7D over time span of 90 and 180 s. The availability of the external electron acceptor oxygen was decreased from fully aerobic to anaerobic conditions. It was observed that the changes in metabolome response under these conditions were limited to the pyruvate node. Acetaldehyde supply was used as an extra external electron acceptor during glucose perturbation under fully aerobic conditions. This had a strong effect on the metabolome dynamics and resulted in a significantly higher initial glycolytic flux. Dynamic response of the adenine nucleotides indicated that their behavior is not dictated by the glycolytic flux but is much more coupled to the cytosolic NADH/NAD(+) ratio through the equilibrium pool of fructose 1,6-bisphosphate and 2/3-phosphoglycerate. Also, the electron donor availability (glucose) was decreased. This did not result in significant changes in the concentrations of the glycolytic and tricarboxylic acid cycle metabolites, whereas the adenine nucleotides, especially ADP and AMP, showed the opposite response to that observed in a glucose pulse experiment. Surprisingly, trehalose was not mobilized in the time frame of 180 s.