Table 6. Changes in the transcript levels of selected denitrification genes determined by RT-qPCR.
| Strain NL23 | Strain JAM1 | |||
|---|---|---|---|---|
| napA | nirK | narG1 | narG2 | |
| Reactor 2 | ||||
| 0.5% | 630 (347)a | 478 (219)a | 151 (18)a | 54 (5)a |
| 2.75% | 56 (18)b | 224 (154)a,b | 185 (33)a | 88 (12)b |
| IO | 37 (6)b | 77 (31)b | 182 (100)a | 140 (42)c |
| Reactor 3 | ||||
| 0.5% | 40 (19)b | 180 (143)a,b | NA | NA |
| 2.0% | 15 (7)b | 286 (155)a,b | NA | NA |
Notes.
Values are expressed as gene copies per 100 copies of rpoB of respective strain. Values between parentheses are standard errors.
Superscript letter: For a specific gene, values with the same superscript letter between the biofilm samples are not significantly different (One-way analysis of variance, P < 0.05, Tukey’s multiple comparison test).
Results are from 4 to 9 RT-qPCR assays. NA: not applicable.