title: Sulfometuron resistance as a genetic marker for yeast populations in wine fermentations.
abstract: Winemaking with selected yeasts requires simple and cheap techniques to monitor the yeast population dynamics. We obtained new sulfometuron (smr) resistant mutants, easy to detect by replica-plate assay, from selected wine yeasts. The mutations were dominant and were located at the ilv2 locus that encodes for acetolactate synthase enzyme. The mutants were genetically stable and maintained the killer phenotype of the parent yeast strain. They were genetically improved by elimination of recessive growth-retarding alleles followed by spore clone selection according to the must fermentation kinetics and the organoleptic quality of the wine. Some mutants were tested in industrial winemaking and were easily monitored during must fermentation using a simple plate assay. They accounted for more than 95% of the total yeasts in the must, and the resulting wine had as good a quality as those made with standard commercial wine yeasts.
authors.affiliation: Departamento de Microbiología, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Ambrona
authors.forename: Matilde
authors.initials: M
authors.lastname: Maqueda
authors.forename: Emiliano
authors.initials: E
authors.lastname: Zamora
authors.forename: Manuel
authors.initials: M
authors.lastname: Ramírez
mesh_terms: D000095:Acetolactate Synthase / Q000235:genetics; D025141:Drug Resistance, Fungal / Q000235:genetics*; D004791:Enzyme Inhibitors; D005285:Fermentation; D005819:Genetic Markers; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D013453:Sulfonylurea Compounds; D014920:Wine
chemical_list: D004791:Enzyme Inhibitors; D005819:Genetic Markers; D013453:Sulfonylurea Compounds; D000095:Acetolactate Synthase; C042031:sulfometuron methyl