TABLE 1.
Proportions of source-derived carbon in metabolite poolsa
| Carbon source | Day | Atom% 13C (mean ± SD) |
|||
|---|---|---|---|---|---|
| Amino acids | Amino acid derivatives | DNA | Organic acids | ||
| No label | 48 | 2.4 ± 0.04 | 1.8 ± 0.5 | 2.2 ± 0.1 | 1.6 ± 0.2 |
| Amino acids | 14 | 14.2 | 8.7 | 4.7 | 5.0 |
| Glucose | 14 | 6.6 | 4.9 | 6.2 | 4.6 |
| Glycerol | 14 | 6.3 | 4.1 | 4.6 | 4.1 |
| Xylose | 14 | 8.6 | 5.9 | 6.0 | 5.2 |
| Oxalate | 14 | 5.5 ± 1.2 | 2.8 ± 0.4 | 3.7 ± 0.3 | 2.0 ± 0.2 |
| Lactate | 6 | 8.5 ± 0.7 | 7.2 ± 0.4 | 5.6 ± 0.1 | 5.4 ± 0.5 |
| Cellulose | 48 | 11.0 ± 2.1 | 8.2 ± 1.6 | 6.8 ± 0.6 | 6.5 ± 0.07 |
| Palmitic acid | 48 | 13.1 ± 3.3 | 7.6 ± 1.8 | 6.9 ± 1.2 | 6.7 ± 2.1 |
| Vanillin | 48 | 6.6 ± 1.5 | 5.6 ± 2.5 | 4.2 ± 0.3 | 3.5 ± 0.2 |
| Avgb | 8.1 | 5.6 | 4.9 | 4.3 | |
a
Higher proportions of source-derived carbon remained in amino acids and their derivatives over time, relative to other compound classes, such as organic acid and nucleic acid metabolite pools, according to the average atom% 13C at the end of each incubation. The specific metabolites grouped into these classes are provided in Table S3. The standard deviation among triplicates is shown, except for amino acids, glucose, glycerol, and xylose, for which only a single sample was available at the final time point.
b
The last row summarizes the unweighted mean 13C enrichment for all carbon sources.