Table 3.
Relative proportions (%) of selected ecologically relevant prokaryotic functional guilds in different U. vulgaris trap ages (young, mature, and old)
| Functional guild | Young | Mature | Old | All |
|---|---|---|---|---|
| % | ||||
| Cellulolytic bacteria* | 11 | 10 | 9 | 10 |
| Methanotrophs‡ | 15 | 15 | 14 | 15 |
| Polyphenol degraders‡ | 25 | 28 | 29 | 27 |
| Nitrate reducers‡ | 27 | 30 | 28 | 28 |
| Denitrifiers‡ | 16 | 17 | 17 | 16 |
| N2 fixators‡ | 14 | 17 | 18 | 16 |
| DNRA (nrfA gene) | 7 | 8 | 6 | 7 |
| Urea decomposers (ureA gene) | 29 | 34 | 35 | 33 |
| Sulfate reducers‡ | 2 | 2 | 2 | 2 |
Differences between trap ages were not statistically significant for all functional guilds (ANOVA, Tukey’s post hoc test, alpha 0.05, n = 3)
*Cellulolytic bacteria were determined based on known cellulolytic families [50]. Functional genes were annotated based on RDP Fungene database ver. 8.3; DNRA—dissimilatory nitrate reduction to ammonium. For the functional annotation of all OTUs, please refer to Additional file 5: Table S8
‡Averages of relative gene abundance were calculated for those functional groups where more than one gene was responsible for the metabolic pathway; methanotrophs (pmoA and mmoX), polyphenol degraders (laccase_Asco, laccase_Basidio, lip, ppo), nitrate reducers (narG, napA), denitrifiers (nirS, nirK, norB, nosZ), N2 fixators (nifH, nifD), and sulfate reducers (dsrA, dsrB)