Table 1. The effect of L-carnosine, D-carnosine, L-histidine and β-alanine on the specific growth rate and viability of yeast cultures grown on fermentable (glucose) and non-fermentable (glycerol) carbon sources.
| μ (h−1) | Viability (%) | |||
| L-Carnosine, D-carnosine, L-histidine or β-alanine concentrationadded to the indicated growth medium | +2% glucose (2×CBS) | +2% glycerol (YP) | +2% glucose (2×CBS) | +2% glycerol (YP) |
| Control (0 mM L-carnosine); n = 3 | 0.41 (0.00) | 0.20 (0.01) | 99.56 (0.12) | 97.60 (1.04) |
| 10 mM L-carnosine; n = 3 | 0.36** (0.01) | 0.22* (0.01) | 90.09* (0.28) | 99.14 (0.63) |
| 20 mM L-carnosine; n = 5 | 0.28** (0.01) | – | 86.31** (0.94) | – |
| 30 mM L-carnosine; n = 5 | 0.27** (0.02) | 0.25** (0.01) | 82.71** (1.67) | 97.52 (1.92) |
| 10 mM D-carnosine; n = 3 | 0.44 (0.00) | 0.30** (0.00) | 99.35 (0.33) | 97.31 (0.34) |
| 10 mM L-histidine; n = 6 | 0.40 (0.02) | – | 99.94 (0.04) | – |
| 10 mM β-alanine; n = 3 | 0.41 (0.00) | – | 99.78 (0.12) | – |
| 10 mM L-histidine, 10 mM β-alanine; n = 2 | 0.42 (0.00) | – | 100 (0.00) | – |
| 30 mM L-histidine, 30 mM β-alanine; n = 3 | 0.37** (0.01) | 0.23* (0.00) | 99.81 (0.24) | 98.45 (1.55) |
Yeast cells were grown in shake-flasks at 30°C in 2×CBS medium supplemented with 2% glucose or in YP supplemented with 2% glycerol as well as L-carnosine, D-carnosine, L-histidine or β-alanine (0–30 mM). Replicate cultures were performed as indicated and specific growth rates (μ; derived from OD600 growth curves) and viability (%; determined by trypan blue dye exclusion) were determined; a dash (–) indicates that the experimental condition indicated was not investigated. Data were analyzed using a one-way ANOVA (P<0.0001). Asterisks show the significance of the specific growth rate data for each culture condition compared to the control, as determined by a Dunnett’s multiple comparison test, where * = P≤0.05 and ** = P≤0.01. The standard error of the mean (SEM) is given in parentheses.