Project description:Adaptive laboratory evolution is highly effective for improving desired traits through natural selection. However, its applicability is inherently constrained to growth-correlated traits precluding traits of interest that incur a fitness cost, such as metabolite secretion. Here, we introduce the concept of tacking trait enabling natural selection of fitness-costly metabolic traits. The concept is inspired from the tacking maneuver used in sailing for traversing upwind. We use first-principle metabolic models to design an evolution niche wherein the tacking trait and fitness become correlated. Adaptive evolution in this niche, when followed by the reversal to the original niche, manifests in the improvement of the desired trait due to biochemical coupling between the tacking and the desired trait. We experimentally demonstrated this strategy, termed EvolveX, by evolving wine yeasts for increased aroma production. RNA-sequencing was performed for parental and evolved strains in the respective evolution niche and in natural grape must.
Project description:Adaptive laboratory evolution is highly effective for improving desired traits through natural selection. However, its applicability is inherently constrained to growth-correlated traits precluding traits of interest that incur a fitness cost, such as metabolite secretion. Here, we introduce the concept of tacking trait enabling natural selection of fitness-costly metabolic traits. The concept is inspired from the tacking maneuver used in sailing for traversing upwind. We use first-principle metabolic models to design an evolution niche wherein the tacking trait and fitness become correlated. Adaptive evolution in this niche, when followed by the reversal to the original niche, manifests in the improvement of the desired trait due to biochemical coupling between the tacking and the desired trait. We experimentally demonstrate this strategy, termed EvolveX, by evolving wine yeasts for increased aroma production. Our results pave the way for precision laboratory evolution for biotechnological and ecological applications.
Project description:Fuel ethanol is now considered a global energy commodity that is fully competitive with gasoline. We have determined genome copy number differences that are common to five industrially important fuel ethanol yeast strains responsible for the production of billions of gallons of fuel ethanol per year from sugarcane. The fuel strains used were CAT1, BG1, PE2, SA1, and VR1 (note that two independent isolates were analyzed, denoted by "-1" and "-2"). These array-CGH data were compared with array-CGH data from nine other non-fuel industrial yeasts: An ale brewing strain ("Sc-ale"), four wine strains (GSY2A, GSY3A, GSY10A, GSY11B), and 4 bakers' yeast strains (GSY149, GSY150, GSY154, GSY155). Our results reveal significant amplifications of the telomeric SNO and SNZ genes only in the fuel strains, whose protein products are involved in the biosynthesis of vitamins B6 (pyridoxine) and B1 (thiamin). We show that these amplifications allow these yeasts to grow efficiently, especially at high sugar concentrations, regardless of the presence or absence of either of the two vitamins. Our results reveal important genetic adaptations that have been selected for in the industrial environment, which may be required for the efficient fermentation of biomass-derived sugars from other renewable feedstocks. A strain or line experiment design type assays differences between multiple strains, cultivars, serovars, isolates, lines from organisms of a single species. Strain Name: fuel strains used for aCGH Strain_or_line_design
Project description:The goal of this study was to compare the expression level of the whole genome of two wine yeast strains highly differing in their sulfite production (High producer strain: 10281A; Low producer strain: 1764A). Conditions maximizing SO2 production were selected: nitrogen rich media (425 mg/l assimilable nitrogen) and low temperature (16°C). This transcriptomic analysis was performed during the sulfite production phase, just after the entry in stationary phase. This analysis is part of a global work, aiming at the identification of the molecular basis of sulfite production by wine yeasts through physiologic, transcriptomic and genetic studies.
Project description:Fuel ethanol is now considered a global energy commodity that is fully competitive with gasoline. We have determined genome copy number differences that are common to five industrially important fuel ethanol yeast strains responsible for the production of billions of gallons of fuel ethanol per year from sugarcane. The fuel strains used were CAT1, BG1, PE2, SA1, and VR1 (note that two independent isolates were analyzed, denoted by "-1" and "-2"). These array-CGH data were compared with array-CGH data from nine other non-fuel industrial yeasts: An ale brewing strain ("Sc-ale"), four wine strains (GSY2A, GSY3A, GSY10A, GSY11B), and 4 bakers' yeast strains (GSY149, GSY150, GSY154, GSY155). Our results reveal significant amplifications of the telomeric SNO and SNZ genes only in the fuel strains, whose protein products are involved in the biosynthesis of vitamins B6 (pyridoxine) and B1 (thiamin). We show that these amplifications allow these yeasts to grow efficiently, especially at high sugar concentrations, regardless of the presence or absence of either of the two vitamins. Our results reveal important genetic adaptations that have been selected for in the industrial environment, which may be required for the efficient fermentation of biomass-derived sugars from other renewable feedstocks. A strain or line experiment design type assays differences between multiple strains, cultivars, serovars, isolates, lines from organisms of a single species. Strain Name: fuel strains used for aCGH
2009-09-24 | GSE13875 | GEO
Project description:Wine yeasts of different samples
Project description:The goal of this study was to compare the expression level of the whole genome of two wine yeast strains highly differing in their sulfite production (High producer strain: 10281A; Low producer strain: 1764A). Conditions maximizing SO2 production were selected: nitrogen rich media (425 mg/l assimilable nitrogen) and low temperature (16°C). This transcriptomic analysis was performed during the sulfite production phase, just after the entry in stationary phase. This analysis is part of a global work, aiming at the identification of the molecular basis of sulfite production by wine yeasts through physiologic, transcriptomic and genetic studies. Two strains compared in the same conditions with biological replicates following a dye-swap design.