TABLE 5.
13C enrichments of metabolites in the supernatanta
| Metabolite |
13C enrichment
|
Enrichment percentage
|
|||
|---|---|---|---|---|---|
| Type | Locationb | Measured
|
Fitted | ||
| Expt I | Expt II | ||||
| Pyruvate | Positional | C-2 | 1 | 1 | 1 |
| C-3 (δ 1.43) | 46 | 46 | 45 | ||
| C-3 (δ 1.34) | 46 | 45 | 45 | ||
| Malate | Positional | C-1 | 5 | ND | 5 |
| C-2 | 15 | 15 | 17 | ||
| C-3 | 33 | 32 | 32 | ||
| C-4 | 6 | ND | 5 | ||
| Relative | C-1 given that C-2 | 5 | 4.5 | 6 | |
| C-2 given that C-1 | 21 | 20 | 19 | ||
| C-2 given that C-3 | 4 | 4 | 5 | ||
| C-3 given that C-2 | 10 | 10 | 10 | ||
| C-3 given that C-4 | 28 | 30 | 31 | ||
| C-4 given that C-3 | 5 | 4.5 | 4 | ||
| Glycerol | Positional | C-1/C-3 (δ 3.48) | 26 | 25 | 25 |
| C-1/C-3 (δ 3.57) | 25 | 23 | 25 | ||
| C-2 | 1 | 1 | 1 | ||
| Fumarate | Positional | C-2/C-3 | 25 | 25 | 25 |
a
The supernatant was sampled after 72 h of cultivation in shake flasks containing pure [1-13C]glucose. The estimated error for the determination of the 13C enrichments is 1% (absolute to the measurement). Positional 13C enrichments indicate the enrichment at specific carbon positions. Relative enrichments indicate the fraction of molecules, 13C labeled at carbon position A, that are also 13C labeled at neighboring position B. This is presented as “B given that A.” ND, not determined.
b
Chemical shifts (δ, in ppm) are given in parentheses.