TABLE 2.
NMR data for compounds detected in cultures of Syntrophus aciditrophicus grown in pure culture with [U-13C]crotonate or with crotonate with [13C]sodium bicarbonate
| Growth condition and sampling time point | Compound detected | Position | δ 13C (ppm)
|
Jcc (Hz)c | |
|---|---|---|---|---|---|
| Expecteda | Observed | ||||
| [U-13C]crotonate at initial time point | Crotonate | C-1 | 172.4 | 171.4 | 77.7 (1-2) |
| C-2 | 122.4 | 122.1 | 77.7 (2-1) | ||
| 69.9 (2-3) | |||||
| 7.0 (2-4) | |||||
| C-3 | 147.6 | 147.7 | 69.9 (3-2) | ||
| 42.0 (3-4) | |||||
| C-4 | 18.1 | 18.0 | |||
| [U-13C]crotonate at final time pointb | Cyclohexane carboxylate | C-7 | 181.0 | 182.4 | 55.2 (7-1) |
| Ring C-1 | 41.5 | 43.0 | 33.2 (1-2) | ||
| 55.2 (1-7) | |||||
| Ring C-2 | 26.6 | 29.0 | 33.2 (2-1, 2-3) | ||
| Ring C-6 | 26.6 | Not observed | |||
| Ring C-4 | 27.1 | 25.0 | Unresolved peaks | ||
| Rings C-3 and C-5 | 24.3 | 25.0 | Unresolved peaks | ||
| Acetate | Carboxyl | 177.0 | 177.4 | 56.7 (1-2) | |
| Methyl | 20.7 | 21.0 | 56.7 (2-1) | ||
| [13C]sodium bicarbonate at final time point | Cyclohexane carboxylate | C-6 | 29.0 | 28.9 | |
a
Predicted chemical shifts (δ 13C) were obtained from ChemNMR (Upstream Solutions).
b
The culture was analyzed when 94% of the crotonate was degraded.
c
Jcc, coupling constants.