Unique genetic basis of the distinct antibiotic potency of high acetic acid production in the probiotic yeast Saccharomyces cerevisiae var. boulardii

Confirmation of the functional relevance of WHI2 for the level of acetic acid production in other S. boulardii strains. (A) Acetic acid production in strain 259 with a single deletion of the full-length WHI2 allele (whi2-FLΔ/whi2-T) or the mutant whi2^S287* allele (WHI2-FL/whi2-TΔ). Strains: wild-type 259 WHI2-FL/whi2-T (♦), 259 whi2-FLΔ/whi2-T (▵), and 259 WHI2-FL/whi2-TΔ (▿). (B) Acetic acid production in strain 7103 with a single deletion of the full-length WHI2 allele (whi2-FLΔ/whi2-T) or the mutant whi2^S287* allele (WHI2-FL/whi2-TΔ). Strains: wild-type 7103 WHI2-FL/whi2-T (○), 7103 whi2-FLΔ/whi2-T (▴), and 7103 WHI2-FL/whi2-TΔ (♦). (C) Acetic acid production in strain 7103 with two full-length WHI2 alleles (WHI2-FL), two mutant whi2^S287* alleles (whi2-T), or a double deletion of both alleles. Strains: 7103 WHI2-FL/WHI2-FL (•), 7103 whi2-T/whi2-T (▪), and 7103 whi2-FLΔ/whi2-TΔ (▴). (D) Acetic acid production in S. cerevisiae S288c containing the causative alleles sdh1^H202Y,F317Y (sdh1^SBERH6) and/or whi2^S287* (whi2^SBERH6) from S. boulardii. Strains: SBERH6 (▴), S288c (▾), S288c sdh1^SBERH6 (□), S288c whi2^SBERH6 (▪), and S288c sdh1^SBERH6 whi2^SBERH6 (•). Results are the means of three biological replicates for each time-point. Error bars show standard deviation at each time-point.