1997 Volume 92 Issue 2 Pages 143-150
To develop a new type of sake flavor, sake yeasts strains producing altered flavor were isolated and studied.Sake strains, Kyokai 701 and Kyokai 901 of Saccharomyces cerevisiae, were treated with ethylmethane sulfonate and selected on 0.67% yeast nitrogen base without amino acids, 4% glycerol agar medium added with either 0.5mg per l cerulenin or 0.2mg/l cycloheximide.Through the primary and the secondary screenings, 3 mutants were isolated. Sake made with PDR 102 strain, in sake making experiments in a laboratory-scale, contained 1.35 times malic acid of the parental strain Kyokai 901, giving higher ratio of malic acid to succinic acid. Sake made with PDR 104 strain had 53% malic acid, 27% isoamylacetate and 50% ethylcaproate comparing with sake made with strain Kyokai 901.Sake made with PDR 114 strain contained 1.4 times malic acid and 1.9 times glycerol of those in sake made with strain Kyokai 901.Through the minimum inhibitory concentrations test of cerulenin, cycloheximide, oligomycin and clotrimazole to the isolated strains varied, all strains were resisitant to the drugs tested except that PDR 114 strain was sensitive to clotrimazole.The 3 strains were resistant to dimethyl succinate and sensitive to allylalcohol.
