title: Coevolution with bacteria drives the evolution of aerobic fermentation in Lachancea kluyveri.
abstract: The Crabtree positive yeasts, such as Saccharomyces cerevisiae, prefer fermentation to respiration, even under fully aerobic conditions. The selective pressures that drove the evolution of this trait remain controversial because of the low ATP yield of fermentation compared to respiration. Here we propagate experimental populations of the weak-Crabtree yeast Lachancea kluyveri, in competitive co-culture with bacteria. We find that L. kluyveri adapts by producing quantities of ethanol lethal to bacteria and evolves several of the defining characteristics of Crabtree positive yeasts. We use precise quantitative analysis to show that the rate advantage of fermentation over aerobic respiration is insufficient to provide an overall growth advantage. Thus, the rapid consumption of glucose and the utilization of ethanol are essential for the success of the aerobic fermentation strategy. These results corroborate that selection derived from competition with bacteria could have provided the impetus for the evolution of the Crabtree positive trait.
authors.affiliation: Department of Biology, Lund University, Lund, Sweden.
authors.forename: Nerve
authors.initials: N
authors.lastname: Zhou
authors.affiliation: Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Krishna B S
authors.identifier: http://orcid.org/0000-0002-3868-6699
authors.initials: KB
authors.lastname: Swamy
authors.affiliation: Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Jun-Yi
authors.identifier: http://orcid.org/0000-0001-5445-2799
authors.initials: JY
authors.lastname: Leu
authors.affiliation: School of Biological Sciences, Monash University, Melbourne, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: McDonald
authors.affiliation: Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Galafassi
authors.affiliation: Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan, Italy.
authors.forename: Concetta
authors.initials: C
authors.lastname: Compagno
authors.affiliation: Department of Biology, Lund University, Lund, Sweden.
authors.forename: Jure
authors.initials: J
authors.lastname: Piškur
mesh_terms: D000332:Aerobiosis; D001419:Bacteria / Q000254:growth & development*; D061249:Batch Cell Culture Techniques; D018920:Coculture Techniques; D000431:Ethanol / Q000378:metabolism; D019143:Evolution, Molecular; D006019:Glycolysis; D054643:INDEL Mutation; D020641:Polymorphism, Single Nucleotide; D012331:RNA, Fungal / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D004718:Saccharomycetales / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D017423:Sequence Analysis, RNA; D059467:Transcriptome
chemical_list: D012331:RNA, Fungal; D000431:Ethanol