Journal of Fermentation and Bioengineering, Vol.80, No.3, 218-222, 1995
High Glycerol Producing Amino-Acid Analog-Resistant Saccharomyces-Cerevisiae Mutant
The alcohol dehydrogenase (ADH) activity of a yeast was lower while glycerol production of the same yeast was higher in media containing inorganic nitrogen than in media containing amino nitrogen. From this result, me developed the working hypothesis that activation of amino acid biosynthesis might enhance glycerol production. We isolated mutants which were resistant to 5,5,5-trifluoro-leucine (TFL), p-fluoro-DL-phenylalanine (FPA), canavanine (CAN), or cerulenin (CER) from shochu yeast 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 were at least 110% that produced by BAW-6. On the other hand, the amounts 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 of glycerol and smaller amounts of ethanol than BAW-6 did. The ADH activities in TFL and FPA mutants were lower than that in BAW-6. The amounts of isoamyl alcohol produced by TFL-mutants and beta-phenylethyl alcohol produced by FPA-mutants increased with increasing amount of glycerol produced by the mutants. We obtained a large number of glycerol-producing strains exhibiting leucine or phenylalanine analogue resistance at a high frequency. This is a new method for the isolation of high glycerol producing yeast.