title: Phenotypic evaluation of natural and industrial Saccharomyces yeasts for different traits desirable in industrial bioethanol production.
abstract: Saccharomyces cerevisiae is the organism of choice for many food and beverage fermentations because it thrives in high-sugar and high-ethanol conditions. However, the conditions encountered in bioethanol fermentation pose specific challenges, including extremely high sugar and ethanol concentrations, high temperature, and the presence of specific toxic compounds. It is generally considered that exploring the natural biodiversity of Saccharomyces strains may be an interesting route to find superior bioethanol strains and may also improve our understanding of the challenges faced by yeast cells during bioethanol fermentation. In this study, we phenotypically evaluated a large collection of diverse Saccharomyces strains on six selective traits relevant for bioethanol production with increasing stress intensity. Our results demonstrate a remarkably large phenotypic diversity among different Saccharomyces species and among S. cerevisiae strains from different origins. Currently applied bioethanol strains showed a high tolerance to many of these relevant traits, but several other natural and industrial S. cerevisiae strains outcompeted the bioethanol strains for specific traits. These multitolerant strains performed well in fermentation experiments mimicking industrial bioethanol production. Together, our results illustrate the potential of phenotyping the natural biodiversity of yeasts to find superior industrial strains that may be used in bioethanol production or can be used as a basis for further strain improvement through genetic engineering, experimental evolution, or breeding. Additionally, our study provides a basis for new insights into the relationships between tolerance to different stressors.
authors.affiliation: Laboratory for Process Microbial Ecology and Bioinspirational Management, Cluster for Bioengineering Technology (CBeT), Department of Microbial and Molecular Systems (M2S), Campus De Nayer, KU Leuven, Fortsesteenweg 30A, B-2860, Sint-Katelijne-Waver, Belgium.
authors.forename: Vaskar
authors.initials: V
authors.lastname: Mukherjee
authors.forename: Jan
authors.initials: J
authors.lastname: Steensels
authors.forename: Bart
authors.initials: B
authors.lastname: Lievens
authors.forename: Ilse
authors.initials: I
authors.lastname: Van de Voorde
authors.forename: Alex
authors.initials: A
authors.lastname: Verplaetse
authors.forename: Guido
authors.initials: G
authors.lastname: Aerts
authors.forename: Kris A
authors.initials: KA
authors.lastname: Willems
authors.forename: Johan M
authors.initials: JM
authors.lastname: Thevelein
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Verstrepen
authors.forename: Stefan
authors.initials: S
authors.lastname: Ruyters
mesh_terms: D044822:Biodiversity; D004361:Drug Tolerance; D000431:Ethanol / Q000378:metabolism* / Q000633:toxicity*; D007218:Industrial Microbiology / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism
chemical_list: D000431:Ethanol