The suitability of UV mutagenesis as a tool to generate autolytic derivatives from previously selected second fermentation Saccharomyces cerevisiae strains was investigated. The properties of the mutant strains lead to expect them to be useful to accelerate the autolytic process during industrial sparkling wine production. S. cerevisiae IFI473, a yeast strain previously selected as starter for the second fermentation of sparkling wines was used as the parental strain for UV mutagenesis. After the mutagenesis three strains (IFI473I, IFI473K, and IFI473E), were retained for further characterization. The effect of the mutations on the ability of the strains to ferment the sucrose in industrial conditions and their autolytic ability was evaluated. The parental, IFI473E, IFI473I and IFI473K strains were assayed in a synthetic wine after incubation at 20, 25 and 37°C, evaluating the amount of proteins and amino acid released in the medium after shaking. A small effect of the mutation was evident for IFI473K, showing no increase in amino acids release, and increase in proteins only evident at the highest temperature tested. IFI473E and IFI473I increased the liberation of intracellular compounds as compared to the parental strain. Fermentation took 1.3 times longer by using IFI473I than with the parental strain but Authors expect it to be balanced by the faster autolysis rate of IFI473I. The phenotype of this latter mutant, including liberation of nitrogen compounds, growth kinetics, sporulation and cell morphology, is affected by the temperature, but its use could be compatible with the temperatures traditionally used in sparkling wine production. (We advise you to read the entire article. Original Title: Yeast autolytic mutants potentially useful for sparkling wine production)

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