Identification of informative metabolic responses using a minibioreactor: a small step change in the glucose supply rate creates a large metabolic response in Saccharomyces cerevisiae
Identification of informative metabolic responses using a minibioreactor: a small step change in the glucose supply rate creates a large metabolic response in Saccharomyces cerevisiae
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DOI：
10.1002/yea.2892
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发表时间：
2012-03-01
期刊：
影响因子：
2.6
通讯作者：
Heijnen, Joseph J.
中科院分区：
文献类型：
--
作者：
Aboka, Fredrick O.;van Winden, Wouter A.;Heijnen, Joseph J.
在这项研究中，以前开发的微型生物反应器，生物曲线，被用来确定一个翔实的stimulusresponse实验。确定的刺激反应实验是葡萄糖摄取率（qGLC）适度升高50%，意外导致不成比例的瞬时代谢反应。Biocurve中qGLC上移50%导致在线测量的氧摄取（qO2）和二氧化碳产生（qCO2）速率增加近两倍，表明糖原和海藻糖的大量动员。随后在常规生物反应器（4？1工作体积），这证实了用Biocurve获得的结果。特别相关的是观察到葡萄糖摄取速率增加50%导致糖酵解通量增加三倍，这是由于储存材料的动员。这解释了升档后的非预期乙醇和乙酸盐分泌，尽管事实上升档后qGLC远低于临界值。此外，这些结果表明，在葡萄糖脉冲实验中的正确的体内流量不能仅从摄取和分泌速率获得。相反，存储通量也必须准确量化。最后，我们推测qGLC中50%向上移位后溶解CO2的瞬时增加可能在触发糖原和海藻糖动员中发挥了作用。版权所有（c）2012约翰威利父子有限公司
In this study, a previously developed mini-bioreactor, the Biocurve, was used to identify an informative stimulusresponse experiment. The identified stimulusresponse experiment was a modest 50% shift-up in glucose uptake rate (qGLC) that unexpectedly resulted in a disproportionate transient metabolic response. The 50% shift-up in qGLC in the Biocurve resulted in a near tripling of the online measured oxygen uptake (qO2) and carbon dioxide production (qCO2) rates, suggesting a considerable mobilization of glycogen and trehalose. The 50% shift-up in qGLC was subsequently studied in detail in a conventional bioreactor (4?l working volume), which confirmed the results obtained with the Biocurve. Especially relevant is the observation that the 50% increase in glucose uptake rate led to a three-fold increase in glycolytic flux, due to mobilization of storage materials. This explains the unexpected ethanol and acetate secretion after the shift-up, in spite of the fact that after the shift-up the qGLC was far less than the critical value. Moreover, these results show that the correct in vivo fluxes in glucose pulse experiments cannot be obtained from the uptake and secretion rates only. Instead, the storage fluxes must also be accurately quantified. Finally, we speculate on the possible role that the transient increase in dissolved CO2 immediately after the 50% shift-up in qGLC could have played a part in triggering glycogen and trehalose mobilization. Copyright (c) 2012 John Wiley & Sons, Ltd.