Applied Microbiology and Biotechnology, Vol.104, No.23, 10119-10132, 2020
Metabolic reconstruction ofPseudomonas chlororaphisATCC 9446 to understand its metabolic potential as a phenazine-1-carboxamide-producing strain
Pseudomonas chlororaphisis a plant-associated bacterium with reported antagonistic activity against different organisms and plant growth-promoting properties.P. chlororaphispossesses exciting biotechnological features shared with anotherPseudomonaswith a nonpathogenic phenotype. Part of the antagonistic role ofP. chlororaphisis 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 ofP. chlororaphisATCC 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 ofP. chlororaphisto 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 H(2)O(2)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 ofP. chlororaphis.
Keywords:Pseudomonas chlororaphis;Metabolic reconstruction;Genome-scale model;Phenazine-1-carboxamide;Metabolic engineering