Skip to main content

Table 1 Lactic acid, acetic acid, and ethanol concentrations over 72 h from experimentally infected fermentations

From: Saccharomyces cerevisiae expressing bacteriophage endolysins reduce Lactobacillus contamination during fermentation

Treatment and yeast variant1 N Lactic acid2 Acetic acid2 Ethanol2
   (mg/mL ± SEM) (mg/mL ± SEM) (mg/mL ± SEM)
    0 h 24 h 48 h 72 h 0 h 24 h 48 h 72 h 0 h 24 h 48 h 72 h
Induced LysA 4 0.1a ± 0.0 0.4b ± 0.2 1.9b ± 0.7 2.7bc ± 1.0 0.2a ± 0.0 1.0bc ± 0.2 2.1cd ± 0.4 2.8bc ± 0.6 2.8a ± 0.8 22.0a ± 3.5 36.5a ± 2.6 45.4a ± 2.7
LysA2 4 0.1a ± 0.0 0.1b ± 0.0 0.5c ± 0.3 1.7cd ± 0.6 0.1a ± 0.0 0.6c ± 0.1 1.4de ± 0.2 1.9cd ± 0.4 2.6a ± 0.6 18.0a ± 4.4 35.7a ± 6.6 41.2ab ± 7.9
Untransformed 4 0.1a ± 0.0 0.9b ± 0.5 2.7b ± 0.4 3.4b ± 0.5 0.1a ± 0.0 1.3b ± 0.3 2.5bc ±0.3 3.0b ± 0.3 3.0a ± 0.4 23.6a ± 3.3 36.9a ± 5.1 41.5ab ± 6.6
Induced and yeast lysate-treated (BB) LysA 4 0.1a ± 0.0 0.1b ± 0.0 0.1c ± 0.0 0.1d ± 0.0 0.1a ± 0.0 0.8bc ± 0.2 1.1e ± 0.2 1.3de ± 0.3 3.3a ± 0.7 22.3a ± 3.8 36.9a ± 5.2 46.2a ± 7.0
LysA2 4 0.1a ± 0.0 0.1b ± 0.0 0.1c ± 0.0 0.1d ± 0.0 0.1a ± 0.0 0.7bc ± 0.1 0.9e ± 0.2 1.0e ± 0.2 2.9a ± 0.8 20.2a ± 4.6 29.9ab ± 5.2 34.1ab ± 5.3
Untransformed 3 0.1a ± 0.0 0.3b ± 0.2 2.1b ± 0.2 3.7b ± 0.6 0.1a ± 0.0 0.9bc ± 0.1 2.1cd ± 0.2 2.9bc ± 0.1 2.4a ± 0.5 17.1a ± 2.8 29.4ab ± 4.3 37.4ab ± 6.0
Non-induced LysA 3 0.1a ± 0.0 3.3a ± 0.7 4.8a ± 0.8 6.5a ± 0.8 0.1a ± 0.0 2.1a ± 0.4 3.2ab ± 0.4 4.3a ± 0.4 2.5a ± 1.0 15.4a ± 2.4 21.0b ± 2.8 24.5b ± 2.7
LysA2 3 0.1a ± 0.0 3.1a ± 0.5 5.5a ± 0.6 6.4a ± 0.8 0.1a ± 0.0 2.2a ± 0.1 3.7a ± 0.1 4.4a ± 0.2 2.3a ± 0.2 19.3a ± 2.1 30.2ab ± 3.5 33.4ab ± 4.1
Untransformed 4 0.1a ± 0.0 2.9a ± 0.2 4.4a ± 0.6 6.1a ± 0.6 0.2a ± 0.1 2.0a ± 0.1 3.0ab ± 0.2 4.1a ± 0.3 2.8a ± 0.3 24.0a ± 1.2 31.5ab ± 0.7 35.6ab ± 2.7
  1. 1Fermentations were conducted using S. cerevisiae strain BY4727. Induced fermentations contained 10% galactose, while non-induced fermentations were supplemented with deionized water. Experimentally infected fermentations were inoculated at time zero with 5 log10 (CFU/mL) L. fermentum 0605-B44. To prepare a yeast lysate containing LysA or LysA2, 10% of the fermentation volume was removed at 0 h and 0.5 h and was mechanically lysed (bead beating; BB) for five rounds of 30 s followed by 30 s on ice and returned to the fermentation.
  2. 2Concentrations (mg/mL ± SEM) of ethanol, lactic acid, and acetic acid with different superscript letters within a column are significantly different (P < 0.05) from each other using Student’s t-test.