Abstract

Pseudomonas chlororaphis is a plant-associated bacterium with reported antagonistic activity against different organisms and plant growth–promoting properties. P. chlororaphis possesses exciting biotechnological features shared with another Pseudomonas with a nonpathogenic phenotype. Part of the antagonistic role of P. chlororaphis is due to its production of a wide variety of phenazines. To expand the knowledge of the metabolic traits of this organism, we constructed the first experimentally validated genome-scale model of P. chlororaphis ATCC 9446, containing 1267 genes and 2289 reactions, and analyzed strategies to maximize its potential for the production of phenazine-1-carboxamide (PCN). The resulting model also describes the capability of P. chlororaphis to carry out the denitrification process and its ability to consume sucrose (Scr), trehalose, mannose, and galactose as carbon sources. Additionally, metabolic network analysis suggested fatty acids as the best carbon source for PCN production. Moreover, the optimization of PCN production was performed with glucose and glycerol. The optimal PCN production phenotype requires an increased carbon flux in TCA and glutamine synthesis. Our simulations highlight the intrinsic H₂O₂ flux associated with PCN production, which may generate cellular stress in an overproducing strain. These results suggest that an improved antioxidative strategy could lead to optimal performance of phenazine-producing strains of P. chlororaphis.

Key points

• This is the first publication of a metabolic model for a strain of P. chlororaphis.

• Genome-scale model is worthy tool to increase the knowledge of a non model organism.

• Fluxes simulations indicate a possible effect of H ₂ O ₂ on phenazines production.

• P. chlororaphis can be a suitable model for a wide variety of compounds.

中文翻译：

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绿假单胞菌ATCC 9446的代谢重建，以了解其作为生产吩嗪-1-羧酰胺菌株的代谢潜能。

摘要

绿假单胞菌（Pseudomonas chlororaphis）是一种与植物相关的细菌，据报道对不同生物具有拮抗活性，并具有促进植物生长的特性。绿腐疟原虫具有与另一种非致病性表型的假单胞菌共有的令人兴奋的生物技术特征。绿腐霉菌的部分拮抗作用是由于其产生了多种吩嗪。为了扩展对这种生物的代谢特性的了解，我们构建了第一个经过实验验证的叶绿假单胞菌的基因组规模模型。ATCC 9446包含1267个基因和2289个反应，并分析了最大限度地发挥其生产吩嗪-1-甲酰胺（PCN）潜力的策略。所得模型还描述了叶绿假单胞菌进行反硝化过程的能力及其消耗蔗糖（Scr），海藻糖，甘露糖和半乳糖作为碳源的能力。此外，代谢网络分析表明脂肪酸是PCN生产的最佳碳源。此外，用葡萄糖和甘油进行PCN生产的优化。最佳的PCN生产表型要求在TCA和谷氨酰胺合成中增加碳通量。我们的模拟突出了本征H ₂ O ₂与PCN产生相关的流量，可能会在过度产生的应变中产生细胞应力。这些结果表明，改进的抗氧化策略可以导致生产吩嗪的P. chlororaphis菌株具有最佳性能。

关键点

•这是关于P. chlororaphis菌株的代谢模型的第一个出版物。

•基因组规模的模型是增加非模型生物知识的有价值的工具。

•助焊剂模拟表明H ₂ O _2可能对吩嗪的产生产生影响。

•绿腐霉菌可能是适合多种化合物的模型。