TY - JOUR T1 - Cheating on orthogonal social traits prevents the tragedy of the commons in <em>Pseudomonas aeruginosa</em> JF - bioRxiv DO - 10.1101/118240 SP - 118240 AU - Özhan Özkaya AU - Roberto Balbontín AU - Isabel Gordo AU - Karina B. Xavier Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/03/19/118240.abstract N2 - Bacterial cooperation can be disrupted by non-producers, which can access public goods without paying their production cost. These cheaters can increase in frequency, exhausting the public goods and causing a population collapse. We investigated how interactions among cheaters in orthogonal social traits influence such collapse. We characterized the dynamics of Pseudomonas aeruginosa polymorphic populations under conditions where two social traits, production of iron-scavenging pyoverdine and quorum sensing regulated elastase, are necessary. We demonstrate that cheaters for either trait compete with both the wild type and each other and, since production of pyoverdine is costlier than elastase production, pyoverdine cheaters impair invasion by quorum sensing mutants, preventing the collapse caused by the latter. A mathematical model shows that these dynamics are determined by the costs of the social traits involved, while their benefits only influence population mean fitness. Finally, we show how quorum sensing regulation can avoid full loss of cooperation. ER -