Tailoring Corynebacterium glutamicum towards increased malonyl-CoA availability for efficient synthesis of the plant pentaketide noreugenin
Tailoring Corynebacterium glutamicum towards increased malonyl-CoA availability for efficient synthesis of the plant pentaketide noreugenin
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DOI：
10.1186/s12934-019-1117-x
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发表时间：
2019-04-11
影响因子：
6.4
通讯作者：
Marienhagen, Jan
中科院分区：
文献类型：
--
作者：
Milke, Lars;Kallscheuerr, Nicolai;Marienhagen, Jan
背景;在过去的几年中，不同的生物技术相关的微生物已经被工程化用于合成植物多酚，如类黄酮和芪。然而，低的细胞内可用性的丙二酰辅酶A作为必要的前体，大多数植物多酚的利益被认为是决定性的瓶颈，防止高产品titers.Results：在这项研究中，谷氨酸棒杆菌，出现了有前途的细胞工厂，植物多酚生产，是量身定制的合理的代谢工程对提供显着更多的丙二酰辅酶A的产品合成。这是通过改善碳源摄取、编码乙酰辅酶A羧化酶（ACC）两个亚基的accBC和accD 1的转录失调、减少进入三羧酸（TCA）循环的通量以及消除丙酮酸的回补羧化来实现的。构建的菌株用于合成感兴趣的植物pentaketide noreugenin，其由植物如木立芦荟从五个分子的丙二酰辅酶A产生。在此背景下，观察到C-1/C-6环化中间体1-（2，4，6-三羟基苯基）丁烷-1，3-二酮（TPBD）的积累，其可通过酸化完全环化为双环产物去甲黄苷元。谷氨酸Nor 2 C5 mufasO（BCD 1）P-O 6-iolT 1 Δ pyc在添加酪蛋白氨基酸的CGXII培养基中24 h内可合成53.32mg/L（0.278 mM）的noreugenin。
Background; In the last years, different biotechnologically relevant microorganisms have been engineered for the synthesis of plant polyphenols such as flavonoids and stilbenes. However, low intracellular availability of malonyl-CoA as essential precursor for most plant polyphenols of interest is regarded as the decisive bottleneck preventing high product titers.Results: In this study, Corynebacterium glutamicum, which emerged as promising cell factory for plant polyphenol production, was tailored by rational metabolic engineering towards providing significantly more malonyl-CoA for product synthesis. This was achieved by improving carbon source uptake, transcriptionalderegulation of accBC and accD1 encoding the two subunits of the acetyl-CoA carboxylase (ACC), reduced flux into the tricarboxylic acid (TCA) cycle, and elimination of anaplerotic carboxylation of pyruvate. The constructed strains were used for the synthesis of the pharmacologically interesting plant pentaketide noreugenin, which is produced by plants such as Aloe arborescens from five molecules of malonyl-CoA. In this context, accumulation of the C-1/C-6 cyclized intermediate 1-(2,4,6-trihydroxyphenyl)butane-1,3-dione (TPBD) was observed, which could be fully cyclized to the bicyclic product noreugenin by acidification.Conclusion: The best strain C. glutamicum Nor2 C5 mufasO(BCD1) P-O6-iolT1 Delta pyc allowed for synthesis of 53.32mg/L (0.278 mM) noreugenin in CGXII mediumsupplemented with casamino acids within 24 h.