title: Evolution of cross-feeding in microbial populations.
abstract: Although limited by a single resource, microbial populations that grow for long periods in continuous culture (chemostat) frequently evolve stable polymorphisms. These polymorphisms may be maintained by cross-feeding, where one strain partially degrades the primary energy resource and excretes an intermediate that is used as an energy resource by a second strain. It is unclear what selective advantage cross-feeding strains have over a single competitor that completely degrades the primary resource. Here we show that cross-feeding may evolve in microbial populations as a consequence of the following optimization principles: the rate of ATP production is maximized, the concentration of enzymes of the pathway is minimized, and the concentration of intermediates of the pathway is minimized.
authors.affiliation: Ecology and Evolution, Eidgenössische Technische Hochschule Zurich, Switzerland. pfeiffer@eco.umnw.ethz.ch
authors.forename: Thomas
authors.initials: T
authors.lastname: Pfeiffer
authors.forename: Sebastian
authors.initials: S
authors.lastname: Bonhoeffer
mesh_terms: D000222:Adaptation, Physiological; D000255:Adenosine Triphosphate / Q000378:metabolism; D001419:Bacteria / Q000201:enzymology* / Q000254:growth & development*; D018407:Bacterial Physiological Phenomena; D005075:Biological Evolution; D003470:Culture Media; D004734:Energy Metabolism; D004798:Enzymes / Q000378:metabolism; D011157:Population Dynamics
chemical_list: D003470:Culture Media; D004798:Enzymes; D000255:Adenosine Triphosphate