(120g) Multidimensional Resource Allocation Predicts Contrarian Reverse Diauxie Phenotype in Pseudomonas Aeruginosa

Pseudomonas aeruginosa is a globally-distributed bacterium with many industrial applications and often found in medical infections. The bacterium does not utilize a classic diauxie phenotype, as defined by model microorganisms, nor does it follow common systems biology assumptions including preferential consumption of glucose with an ‘overflow’ metabolism. Despite these contradictions, P. aeruginosa is competitive in many, disparate environments underscoring knowledge gaps in microbial ecology and systems biology. Physiological, omics, and in silico analyses were used to quantify the P. aeruginosa carbon catabolite repression strategy known as ‘reverse diauxie’. An ecological basis of reverse diauxie was identified using a genome-scale, metabolic model interrogated with in vitro omics data. Reverse diauxie preference for lower energy, nonfermentable carbon sources, such as acetate or succinate over glucose, was predicted using a multidimensional strategy which minimized resource investment into central metabolism while completely oxidizing substrates. Application of a common, in silico optimization criterion, which maximizes growth rate, did not predict the reverse diauxie phenotypes. This study quantifies P. aeruginosametabolic strategies foundational to its wide distribution, usefulness as a biocatalyst, and virulence including its potential for mutualistic interactions with microorganisms found commonly in the environment and in medical infections.