Table 5.
Relative abundance of major bacterial groups in field samples combined from Taif and South Platte River riverbeds and two laboratory column systemsa
| Bacterial group | Relative abundance (%) |
||||||
|---|---|---|---|---|---|---|---|
| Infiltration zone |
Unsaturated | Low-DOC column | Moderate-DOC column |
||||
| 1–2 cm | 10–50 cm | 1 cm | 15 cm | 30–60 cm | |||
| Proteobacteria | 50.9 | 40.8 | 22.0 | 36.5 | 75.7 | 33.7 | 33.9 |
| Alphaproteobacteria | 12.1 | 11.2 | 9.7 | 7.9 | 7.8 | 7.5 | 10.2 |
| Betaproteobacteria | 18.5 | 14.5 | 3.9 | 8.5 | 59.6 | 15.7 | 13.8 |
| Gammaproteobacteria | 7.8 | 8.3 | 5.1 | 7.5 | 6.6 | 3.7 | 2.8 |
| Deltaproteobacteria | 7.8 | 3.5 | 2.1 | 4.0 | 0.2 | 6.3 | 6.1 |
| Other | 3.8 | 3.3 | 1.1 | 8.5 | 1.6 | 0.5 | 1.0 |
| Acidobacteria | 3.2 | 6.9 | 3.6 | 9.2 | 0.1 | 3.2 | 4.2 |
| Actinobacteria | 2.5 | 6.3 | 17.4 | 1.5 | 5.7 | 4.1 | 5.3 |
| Bacteroidetes | 18.8 | 10.8 | 9.6 | 5.2 | 12.4 | 12.6 | 11.5 |
| Chloroflexi | 4.1 | 1.4 | 0.7 | 0.2 | 0 | 0.3 | 0.4 |
| Cyanobacteria | 1.5 | 0.4 | 0.2 | 1.5 | 0 | 0 | 0 |
| Firmicutes | 2.2 | 4.6 | 27.4 | 2.9 | 2.8 | 26.8 | 20.1 |
| Gemmatimonadetes | 0.3 | 0.7 | 0.8 | 0.5 | 0.2 | 1.1 | 2.3 |
| Nitrospira | 0.7 | 2.9 | 0.6 | 6.5 | 0 | 0.5 | 1.0 |
| Planctomycetes | 2.7 | 4.1 | 1.4 | 3.5 | 0.1 | 0.6 | 2.1 |
| Verrucomicrobia | 1.2 | 2.1 | 1.4 | 1.3 | 0.2 | 5.5 | 4.1 |
| Other | 11.0 | 16.7 | 10.1 | 26.1 | 2.7 | 11.3 | 14.6 |
a
The two laboratory column systems included low-DOC-sediment columns regardless of depth and moderate-DOC-sediment columns at a 1-cm depth, a 15-cm depth, and collectively binned for 30- to 60-cm depths.