TABLE 1.
Estimated recoveries of carbon and reducing equivalents (i.e., electrons) in amino acid treatmentsa
| Product | Recovery (%)b
|
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Glutamate |
Aspartate |
Threonine |
Alanine/glycine |
Valine/glycine |
Casamino Acids |
|||||||
| Carbon | REc | Carbon | RE | Carbon | RE | Carbon | RE | Carbon | RE | Carbon | RE | |
| CO2 | 10 | NAd | 13 | NA | 4.6 | NA | 1.0 | NA | 1.3 | NA | 4.0 | NA |
| H2 | NA | 2.8 | NA | —e | NA | 0.6 | NA | — | NA | — | NA | 0.1 |
| Acetate | 69 | 76 | 11 | 14 | 3.8 | 3.8 | 4.1 | 5.5 | 1.7 | 1.5 | 14 | 13 |
| Ethanol | 0.2 | 0.4 | 0.2 | 0.4 | 0.1 | 0.1 | — | — | 0.1 | 0.1 | — | — |
| Lactate | 0.4 | 0.4 | 0.3 | 0.4 | 0.2 | 0.2 | 0.1 | 0.1 | 0.1 | 0.0 | 0.1 | 0.1 |
| Succinate | 1.1 | 1.0 | 35 | 41 | 0.8 | 0.7 | — | — | — | — | — | — |
| Formate | 3.1 | 1.7 | — | — | 0.2 | 0.1 | — | — | — | — | — | — |
| Butyrate | 6.4 | 8.8 | 0.2 | 0.3 | 2.9 | 3.6 | 0.2 | 0.3 | — | — | 2.7 | 3.1 |
| Propionate | — | — | 13 | 21 | 26 | 30 | 0.0 | 0.1 | 0.1 | 0.1 | 4.2 | 4.7 |
| Isobutyrate | — | — | 0.1 | 0.2 | 0.1 | 0.2 | — | — | 2.7 | 3.1 | 0.1 | 0.1 |
| Methylbutyrate | — | — | 0.2 | 0.3 | — | — | — | — | — | — | 2.3 | 2.9 |
| Total | 90 | 92 | 73 | 77 | 39 | 39 | 5.4 | 6.0 | 5.9 | 5.0 | 28 | 25 |
a
See Fig. 1 for product profiles. Net amounts of products formed in the unsupplemented control were subtracted from those of supplemented treatments.
b
Recoveries are based on the amount of substrate provided. Values are based on the arithmetic average from three replicate analyses.
c
RE, reducing equivalents.
d
NA, not applicable.
e
—, no net increase of the product during the incubation in supplemented treatments relative to that in the control treatment.