TABLE 1.
Soil chemical properties and numbers of bacterial 16S rRNA gene copies in five samples
| Samplea | Concn ofb: |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Succinate (mg C kg−1 soil) | CO2 (mg C kg−1 soil) | NO3− (mg N kg−1 soil) | N2O (mg N kg−1 soil) | NH4+ (mg N kg−1 soil) | Fe2+ (g kg−1 soil) | Mn2+ (mg kg−1 soil) | SO42− (mg kg−1 soil) | Bacterial 16S rRNA genes (1011 copies g−1 soil) | |
| TSBA | <10c | NDd | <5c | ND | 33.1 ± 6.7 | 2.22 ± 0.28 A | 9.51 ± 0.04 A | 87 ± 5 | 6.63 ± 0.31 A |
| TSCO | <10c | 165 ± 21 A | <5c | <0.01c | 27.1 ± 12.4 | 2.95 ± 0.14 B | 9.33 ± 0.31 A | 84 ± 11 | 5.28 ± 0.41 A |
| TSNI | <10c | 151 ± 9 A | 79.1 ± 3.6 | 24.4 ± 1.2 A | 33.4 ± 11.8 | 2.65 ± 0.13 B | 8.77 ± 0.12 B | 99 ± 11 | 7.46 ± 0.58 A |
| TSNS | 150.4 ± 7.0 Ae | 394 ± 40 B | <5c | 115.4 ± 3.9 B | 33.1 ± 5.7 | 2.90 ± 0.35 B | 8.49 ± 0.03 B | ND | 10.9 ± 0.99 B |
| TSSU | 291.3 ± 2.5 B | 253 ± 27 C | <5c | <0.01c | 29.5 ± 1.1 | 3.29 ± 0.22 B | 9.07 ± 0.04 A | ND | 5.33 ± 0.46 A |
a
TSBA, unincubated control; TSCO, soil sample incubated without substrate; TSNI, soil sample incubated with 100 mg NO3− N kg−1; TSNS, soil sample incubated with 100 mg NO3− N kg−1 and 500 mg succinate C kg−1; TSSU, soil sample incubated with 500 mg succinate C kg−1.
b
The P values for concentrations of succinate, CO2, N2O, NH4+, Fe2+, Mn2+, SO42−, and bacterial 16S rRNA genes are <0.001, <0.001, <0.001, 0.891, <0.01, <0.001, 0.1867, and <0.05, respectively.
c
Below the detection limit.
d
ND, not determined.
e
Means in the same column followed by the same letter are not significantly different (P > 0.01, n = 3).