PT  - JOURNAL ARTICLE
AU  - Özhan Özkaya
AU  - Roberto Balbontín
AU  - Isabel Gordo
AU  - Karina B. Xavier
TI  - Cheating on orthogonal social traits prevents the tragedy of the commons in <em>Pseudomonas aeruginosa</em>
AID  - 10.1101/118240
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 118240
4099  - http://biorxiv.org/content/early/2017/03/19/118240.short
4100  - http://biorxiv.org/content/early/2017/03/19/118240.full
AB  - 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.