TABLE 2.
Lactose, lactate, and l-methionine consumption and KMTBA and HMTBA production by K. marxianus, D. hansenii, and Y. lipolytica cultivated in pure cultures and in coculturesa
| Yeast | Time (h) | % of consumption (g · liter−1) of:
|
% of production (g · liter−1) of:
|
|||
|---|---|---|---|---|---|---|
| Lactose | Lactate | l-Methionine | KMTBA | HMTBA | ||
| K. marxianus | 0 | 18.4 ± 0.1 | 22.9 ± 0.1 | 5.73 ± 0.05 | ND | ND |
| 30 | 18.3 ± 0.1 | 22.9 ± 0.1 | 5.77 ± 0.19 | ND | ND | |
| 36 | 18.2 ± 0.1 | 22.8 ± 0.2 | 5.82 ± 0.04 | 0.01 ± 0.00 | 0.03 ± 0.00 | |
| 55 | 8.9 ± 0.8 | 22.6 ± 0.7 | 5.39 ± 0.15 | 0.03 ± 0.00 | 0.09 ± 0.00 | |
| 62 | 1.4 ± 0.1 | 22.2 ± 0.3 | 5.05 ± 0.10 | 0.01 ± 0.00 | 0.12 ± 0.01 | |
| 72 | ND | 19.6 ± 0.6 | 4.79 ± 0.11 | 0.02 ± 0.00 | 0.16 ± 0.01 | |
| 84 | ND | 18.6 ± 0.7 | 4.69 ± 0.06 | 0.02 ± 0.00 | 0.22 ± 0.02 | |
| D. hansenii | 0 | 18.3 ± 0.1 | 22.9 ± 0.1 | 5.81 ± 0.02 | ND | ND |
| 30 | 16.5 ± 0.7 | 22.7 ± 0.1 | 5.93 ± 0.38 | ND | ND | |
| 36 | 14.1 ± 0.2 | 22.4 ± 0.2 | 5.95 ± 0.60 | 0.02 ± 0.00 | 0.04 ± 0.01 | |
| 55 | 12.0 ± 0.0 | 20.1 ± 0.7 | 5.86 ± 0.29 | 0.01 ± 0.00 | 0.05 ± 0.01 | |
| 62 | 9.6 ± 0.9 | 19.4 ± 0.4 | 5.75 ± 0.02 | 0.02 ± 0.00 | 0.14 ± 0.06 | |
| 72 | 6.1 ± 0.6 | 19.4 ± 0.9 | 5.59 ± 0.12 | 0.03 ± 0.01 | 0.32 ± 0.06 | |
| 84 | 4.7 ± 0.5 | 19.9 ± 0.4 | 5.26 ± 0.10 | 0.03 ± 0.01 | 0.55 ± 0.10 | |
| Y. lipolytica | 0 | 18.3 ± 0.1 | 22.9 ± 0.1 | 5.87 ± 0.03 | ND | ND |
| 30 | 18.5 ± 0.1 | 23.0 ± 0.1 | 5.75 ± 0.10 | 0.16 ± 0.01 | ND | |
| 36 | 18.6 ± 0.1 | 23.1 ± 0.1 | 5.29 ± 0.07 | 0.32 ± 0.01 | ND | |
| 55 | 18.6 ± 0.0 | 23.0 ± 0.1 | 2.95 ± 0.05 | 0.51 ± 0.02 | ND | |
| 62 | 18.5 ± 0.1 | 22.9 ± 0.1 | 2.10 ± 0.04 | 0.55 ± 0.01 | ND | |
| 72 | 18.7 ± 0.2 | 22.9 ± 0.1 | 1.37 ± 0.07 | 0.52 ± 0.02 | ND | |
| 84 | 18.6 ± 0.0 | 22.8 ± 0.1 | 0.72 ± 0.05 | 0.46 ± 0.02 | ND | |
| K. marxianus, D. hansenii, and Y. lipolytica in coculture | 0 | 18.3 ± 0.1 | 22.9 ± 0.1 | 5.72 ± 0.09 | ND | ND |
| 36 | 13.8 ± 0.3 | 23.0 ± 0.3 | 5.16 ± 0.00 | 0.13 ± 0.00 | ND | |
| 55 | 10.5 ± 0.3 | 23.0 ± 0.3 | 4.86 ± 0.06 | 0.20 ± 0.01 | 0.04 ± 0.01 | |
| 62 | 7.2 ± 0.4 | 22.9 ± 0.2 | 4.58 ± 0.03 | 0.27 ± 0.01 | 0.05 ± 0.01 | |
| 72 | 5.4 ± 0.2 | 22.9 ± 0.2 | 4.44 ± 0.06 | 0.32 ± 0.01 | 0.08 ± 0.01 | |
| 84 | 2.6 ± 0.1 | 23.0 ± 0.1 | 4.34 ± 0.03 | 0.34 ± 0.02 | 0.10 ± 0.02 | |
| 110 | 0.3 ± 0.1 | 22.8 ± 0.2 | 3.98 ± 0.07 | 0.44 ± 0.02 | 0.18 ± 0.03 | |
| 120 | 0.1 ± 0.0 | 21.8 ± 0.6 | 3.88 ± 0.03 | 0.45 ± 0.03 | 0.20 ± 0.02 | |
a
Results are the means ± standard deviations of six different experiments. ND, not detected.