Saccharomyces cerevisiae 7928 (Korean Collection for Type Cultures) was grown at 30 C in yeast peptone dextrose medium (YPD ; yeast extract 10 g/L, peptone 20 g/L and glucose 20 g/L) and was uesd as a host strian for respiration-deficient mutants induction. The host strain and mutants were incubated on glycerol-based agar (GBA ; glyerol 20 g/L, yeast extract 20 g/L and 15 g/L) at 30 C to verify the respiration deficiency [31].