Study on roles of anaplerotic pathways in glutamate overproduction of Corynebacterium glutamicum by metabolic flux analysis.
Study on roles of anaplerotic pathways in glutamate overproduction of Corynebacterium glutamicum by metabolic flux analysis.
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DOI：
10.1186/1475-2859-6-19
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发表时间：
2007-06-23
影响因子：
6.4
通讯作者：
Shimizu H
中科院分区：
文献类型：
--
作者：
Shirai T;Fujimura K;Furusawa C;Nagahisa K;Shioya S;Shimizu H
谷氨酸棒杆菌具有几种回补途径（回补作用），其对于产生氨基酸（例如赖氨酸和谷氨酸）是必需的。目前尚不清楚当谷氨酸产生被触发物诱导时，如生物素耗尽和添加去污剂材料吐温40时，回补途径中的通量变化是如何发生的。在这项研究中，我们定量分析了回补途径流量最显着地改变了吐温40诱导的谷氨酸过量生产。我们用[1- 13 C]-和[U-13 C]-标记的葡萄糖在C.通过气相色谱-质谱（GC-MS）分析13 C掺入蛋白质氨基酸的时间过程，磷酸烯醇式丙酮酸羧化酶（PEPc）催化的磷酸烯醇式丙酮酸（PEP）向草酰乙酸（Oxa）的转化在不产生谷氨酸的生长期是活跃的，而丙酮酸羧化酶（Pc）催化的丙酮酸向Oxa的转化是不活跃的。在添加洗涤剂材料Tween 40诱导的谷氨酸过量生产阶段，除了由PEPc催化的反应之外，由Pc催化的反应也变得活跃。通过定量13 C MFA澄清，在吐温40诱导的谷氨酸过量生产中，Pc催化的反应最显著增加，而PEPc和PEPck的其他通量保持恒定。这一结果是一致的遗传重组Pc和PEPc过表达菌株的谷氨酸生产的比较研究中获得的先前的结果。MFA在代谢水平上阐明了回补途径中特定反应的重要性。
Corynebacterium glutamicum has several anaplerotic pathways (anaplerosis), which are essential for the productions of amino acids, such as lysine and glutamate. It is still not clear how flux changes in anaplerotic pathways happen when glutamate production is induced by triggers, such as biotin depletion and the addition of the detergent material, Tween 40. In this study, we quantitatively analyzed which anaplerotic pathway flux most markedly changes the glutamate overproduction induced by Tween 40 addition. We performed a metabolic flux analysis (MFA) with [1-13C]- and [U-13C]-labeled glucose in the glutamate production phase of C. glutamicum, based on the analysis of the time courses of 13C incorporation into proteinogenic amino acids by gas chromatography-mass spectrometry (GC-MS). The flux from phosphoenolpyruvate (PEP) to oxaloacetate (Oxa) catalyzed by phosphoenolpyruvate carboxylase (PEPc) was active in the growth phase not producing glutamate, whereas that from pyruvate to Oxa catalyzed by pyruvate carboxylase (Pc) was inactive. In the glutamate overproduction phase induced by the addition of the detergent material Tween 40, the reaction catalyzed by Pc also became active in addition to the reaction catalyzed by PEPc. It was clarified by a quantitative 13C MFA that the reaction catalyzed by Pc is most markedly increased, whereas other fluxes of PEPc and PEPck remain constant in the glutamate overproduction induced by Tween 40. This result is consistent with the previous results obtained in a comparative study on the glutamate productions of genetically recombinant Pc- and PEPc-overexpressing strains. The importance of a specific reaction in an anaplerotic pathway was elucidated at a metabolic level by MFA.
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影响因子：
4.4
作者：
CocaignBousquet, M;Guyonvarch, A;Lindley, ND
通讯作者：
Lindley, ND
影响因子：
4.4
作者：
Gourdon, P;Baucher, MF;Guyonvarch, A
通讯作者：
Guyonvarch, A
影响因子：
8.4
作者：
Petersen, S;Mack, C;Sahm, H
通讯作者：
Sahm, H
影响因子：
2.8
作者：
PetersWendisch, PG;Wendisch, VF;Sahm, H
通讯作者：
Sahm, H
影响因子：
4.8
作者：
Petersen, S;de Graaf, AA;Sahm, H
通讯作者：
Sahm, H