Table 1.
Metabolite production in all cultures: cumulative gas production and accumulation of metabolites in the test cultures after 49 day of incubation
| Substrate | Inoculum | H2 (ml) | CH4 (ml) | CO2 (ml) | Sum of VFA and alcohols (mM) |
|---|---|---|---|---|---|
| None | U-C | 0.0 ± 0.0 | 0.2 ± 0.3 | 2.3 ± 0.4 | -0.6 ± 0.7 |
| None | B-C | 0.0 ± 0.0 | 0.0 ± 0.0 | 4.7 ± 0.2 | 5.1 ± 0.5 |
| None | U-D | 0.0 ± 0.0 | 0.0 ± 0.0 | 1.8 ± 0.0 | -0.5 ± 0.1 |
| None | B-D | 0.0 ± 0.0 | 0.0 ± 0.0 | 4.5 ± 0.2 | 3.7 ± 0.4 |
| Chlorella vulgaris | None | 2.1 ± 0.7 | 0.0 ± 0.0 | 10.8 ± 0.6 | 22.1 ± 1.8 |
| C. vulgaris and BESA | None | 1.3 ± 0.2 | 0.0 ± 0.0 | 12.0 ± 0.7 | 19.1 ± 5.1 |
| Dunaliella tertiolecta | None | 2.8 ± 0.1 | 0.0 ± 0.0 | 3.0 ± 0.4 | 5.1 ± 0.1 |
| D. tertiolecta and BESA | None | 1.5 ± 0.3 | 0.0 ± 0.0 | 4.2 ± 0.2 | 4.0 ± 0.3 |
| C. vulgaris | U-C | 0.0 ± 0.0 | 74.9 ± 3.6 | 35.2 ± 0.3 | -3.8 ± 1.0 |
| C. vulgaris | B-C | 0.1 ± 0.0 | 0.0 ± 0.0 | 24.8 ± 0.0 | 31.2 ± 0.7 |
| D. tertiolecta | U-D | 0.0 ± 0.0 | 4.7 ± 0.2 | 4.9 ± 0.0 | 0.4 ± 0.1 |
| D. tertiolecta | B-D | 0.0 ± 0.0 | 0.0 ± 0.0 | 7.4 ± 0.8 | 8.9 ± 0.4 |
| Glucose | U-C | 4.9 ± 0.4 | 56.4 ± 0.1 | 62.5 ± 0.4 | 2.9 ± 0.7 |
| Glucose | B-C | 7.1 ± 0.4 | 0.0 ± 0.0 | 57.9 ± 0.9 | 46.1 ± 0.4 |
| Glucose | U-D | 5.2 ± 0.9 | 38.5 ± 14.0 | 56.2 ± 7.0 | 13.3 ± 14.9 |
| Glucose | B-D | 14.6 ± 2.3 | 0.0 ± 0.0 | 60.8 ± 0.5 | 44.4 ± 7.1 |
| Cellulose | U-C | 0.0 ± 0.0 | 0.3 ± 0.4 | 0.9 ± 0.1 | 0.7 ± 1.4 |
| Cellulose | B-C | 0.0 ± 0.0 | 0.0 ± 0.0 | 4.0 ± 0.0 | 7.6 ± 0.4 |
| Cellulose | U-D | 0.0 ± 0.0 | 0.1 ± 0.1 | 1.8 ± 0.1 | 0.0 ± 0.1 |
| Cellulose | B-D | 0.0 ± 0.0 | 0.0 ± 0.0 | 4.6 ± 0.3 | 5.4 ± 1.3 |
| Chitosan | U-C | 0.0 ± 0.0 | 3.6 ± 4.1 | 2.4 ± 2.5 | 0.4 ± 1.5 |
| Chitosan | B-C | 0.0 ± 0.0 | 0.0 ± 0.0 | 3.1 ± 0.3 | 6.9 ± 0.5 |
| Chitosan | U-D | 0.0 ± 0.0 | 0.0 ± 0.0 | 1.0 ± 0.0 | 0.1 ± 0.1 |
| Chitosan | B-D | 0.0 ± 0.0 | 0.0 ± 0.0 | 3.2 ± 0.1 | 5.6 ± 0.8 |
A minus sign in front of sum of VFA and alcohols indicates that the sum of VFA and alcohols was higher on day 0 than on day 49. The values include standard errors.
H2-fermenting cultures: C. vulgaris biomass as substrate = B-C; D. tertiolecta biomass as substrate = B-D; CH4-producing cultures: C. vulgaris biomass as substrate = U-C; D. tertiolecta biomass as substrate = U-D.
BESA = 2-bromoethanesulfonic acid; VFA = volatile fatty acids.