Expression of gpd1L164P-CBS4C and GPD1 -ER7A in segregant 26B, ER7A, the diploid 26B/ER7A and BY4742. Glycerol and ethanol yield (on glucose) in the gpd1Δ strains, 26B, ER7A, 26B/ER7A and BY4742, harboring the plasmids YCplac33, YCplac33 GPD1-ER7A, and YCplac33 gpd1L164P-CBS4C. Fermentations were carried out in 100 ml YP 10% glucose. Each strain construct was tested in triplicate. Glycerol and ethanol yield of the strains were related to the yield of 26B, which was set at 100%. In the BY4742 and ER7A backgrounds, which lack the smp1R110Q,P269Q and hot1P107S,H274Y alleles, the gpd1L164P allele clearly reduced glycerol yield and concomitantly increased ethanol yield compared to the wild type GPD1 allele. In the strains 26B and 26B/ER7A, which contain the smp1R110Q,P269Q and hot1P107S,H274Y alleles, the gpd1L164P allele resulted in a similar glycerol yield as the wild type GPD1 allele.