HIGH GLYCEROL PRODUCING AMINO-ACID ANALOG-RESISTANT SACCHAROMYCES-CEREVISIAE MUTANT

The alcohol dehydrogenase (ADH) activity of a yeast was lower while gl ycerol production of the same yeast was higher in media containing ino rganic nitrogen than in media containing amino nitrogen. From this res ult, me developed the working hypothesis that activation of amino acid biosynthesis might enhance glycerol production. We isolated mutants w hich were resistant to 5,5,5-trifluoro-leucine (TFL), p-fluoro-DL-phen ylalanine (FPA), canavanine (CAN), or cerulenin (CER) from shochu yeas t BAW-6 (Saccharomyces cerevisiae). The amount of glycerol produced by 47 out of 50 TFL-mutant strains and 37 out of 50 FPA-mutant strains w ere at least 110% that produced by BAW-6. On the other hand, the amoun ts of glycerol produced by CAN and CER mutants were almost the same as that produced by BAW-6. TFL and FPA mutants produced larger amounts o f glycerol and smaller amounts of ethanol than BAW-6 did. The ADH acti vities in TFL and FPA mutants were lower than that in BAW-6. The amoun ts of isoamyl alcohol produced by TFL-mutants and beta-phenylethyl alc ohol produced by FPA-mutants increased with increasing amount of glyce rol produced by the mutants. We obtained a large number of glycerol-pr oducing strains exhibiting leucine or phenylalanine analogue resistanc e at a high frequency. This is a new method for the isolation of high glycerol producing yeast.