TABLE 2.
Amounts of total EPS measured in fermented medium of the EPS-producing strain S. thermophilus Sfi20a grown on glucose or on combinations of glucose and fructose, galactose, or lactose on the one hand and on lactose or on combinations of lactose and fructose, galactose, or glucose on the other hand
| Carbohydrate source(s) (concn [M]) | Amt (mg of PDM liter−1) of EPS produced at time point:
|
||
|---|---|---|---|
| 1 | 2 | 3 | |
| Glucose (0.42) | 668 | 1,063 | 912 |
| Glucose (0.28) + fructose (0.14) | 386 | 771 | 482 |
| Glucose (0.28) + galactose (0.14) | 437 | 691 | 552 |
| Glucose (0.28) + lactose (0.07) | 595 | 1,018 | 590 |
| Lactose (0.22) | 644 | 880 | 736 |
| Lactose (0.15) + fructose (0.14) | 549 | 506 | 651 |
| Lactose (0.15) + galactose (0.14) | 390 | 597 | 480 |
| Lactose (0.15) + glucose (0.14) | 961 | 1,283 | 1,057 |
S. thermophilus Sfi20 was grown in batch cultures in MRS broth on glucose or lactose or on combinations of glucose or lactose with other carbohydrates at 42°C and at a constant pH of 6.2. Samples were taken at three time points of the fermentation course, representing the exponential growth phase (point 1), the end of the exponential growth phase (point 2), and the stationary phase (point 3). Each value is always the average of two measurements; the standard deviation is approximately 20%. For the results of S. thermophilus LY03, see reference 6.