TABLE 2.
Comparison of fermentation parameters of strains T1 and T1-E in lactose, glucose, and galactose cultivations, as well as K. lactis CBS2359 in lactosea
| Sugar | Strain | μ (h−1) | Xfinal (g liter−1) | Emax (g liter−1) | Eyield (%) |
|---|---|---|---|---|---|
| Lactose | T1 | 0.14 ± 0.01 | 3.48 ± 0.09 | 7.08 ± 0.79 | 53 ± 5 |
| T1-E | 0.21 ± 0.01 | 2.81 ± 0.09 | 10.52 ± 0.04 | 69 ± 1 | |
| K. lactis | 0.28 | 2.56 | 8.86 | 65 | |
| Glucose | T1 | 0.32 ± 0.03 | 2.14 ± 0.03 | 8.19 ± 0.19 | 81 ± 2 |
| T1-E | 0.34 ± 0.03 | 2.13 ± 0.03 | 8.05 ± 0.26 | 80 ± 2 | |
| Galactose | T1 | 0.15 ± 0.01 | 2.94 ± 0.13 | 7.10 ± 0.40 | 69 ± 4 |
| T1-E | 0.15 ± 0.01 | 2.94 ± 0.00 | 7.65 ± 0.64 | 76 ± 7 |
Cultivations were done as described in Materials and Methods. The initial lactose concentration was 25 g liter−1; the initial glucose and galactose concentrations were 20 g liter−1. μ, specific growth rate; Xfinal: final biomass concentration (when sugar from the medium was exhausted); Emax, maximum ethanol concentration; Eyield, ethanol conversion yield (percentage of the theoretical value). Data for T1 and T1-E are means ± ranges of results from duplicate independent cultivations, except data for T1-E in lactose, which correspond to the means ± standard deviations of results from triplicate cultivations with single-colony isolates.