MUTANTS PRODUCING HIGH-CONCENTRATIONS OF THE FLAVOR COMPONENTS ACTIVEAMYLALCOHOL AND NORMAL PROPANOL IN SACCHAROMYCES-CEREVISIAE

Mutants resistant to the isoleucine analogue DL-thiaisoleucine (TIL) w hich produced large amounts of the flavor components active amylalcoho l and normal propanol were isolated from sake, and baker's and laborat ory yeasts Saccharomyces cerevisiae. These mutants had threonine deami nase (EC 4.2.1.16) with decreased feedback sensitivity to L-isoleucine and accumulated a high concentration of isoleucine as well as these h igher alcohols. Genetic analysis using a laboratory strain revealed th at the mutation for increased production of active amylalcohol and nor mal propanol was controlled by a single dominant gene, and evidence wa s found for linkage between TIL-resistance and the increased productio n ability of these higher alcohols. Sake and bread made with the mutan ts contained more of these components and had enhanced flavor.