Abstract: Pseudomonas species possess diverse metabolic capabilities, which allowed them to thrive in different nutritional environments, produce metal-scavenging molecules, synthesize phytohormones as well as antibiotic compounds against plant pathogens. It is well documented that Pseudomonas species secrete iron-scavenging compounds, or siderophores, as specialized cyclic peptides in response to iron deficiency. Of particular interest is the understanding of the paradox regarding the relationship between a compromised iron-deficient metabolism and the biosynthesis of carbon-expensive siderophores. In this talk, I will present our combined application of stable isotope-assisted metabolomics and flux modeling of iron-dependent carbon metabolism in Pseudomonas putida. We unravel how hierarchy in metabolic fluxes overcomes compromised metabolism to facilitate carbon investment towards siderophore biosynthesis in Pseudomonas species.