Table 2.
Biological properties measured in un-amended controls and gum-xanthan (GX) enriched microcosms incubated 2 days (T2d) under dark + DCMU conditions.
| Parameter | Units | Control | GX enriched | ||
|---|---|---|---|---|---|
| T0 | T2d | T0 | T2d | ||
| Chl. a | μg L−1 | 2.1±0.6 | 0.3±0.2 | 2.1±0.6 | 0.3±0.3 |
| HBBa | μg C L−1 | 47±22 | 60±29 | 47±22 | 86±44 |
| HNA | x108 Cell L−1 | 15±7.1 | 20±10 | 15±7.1 | 31±14 |
| LNA | x108 Cell L−1 | 8.3±4.6 | 10±4.2 | 8.3±4.6 | 11±6.3 |
| HNA/LNA | Cell/Cell | 2±0.7 | 1.9±0.6 | 2±0.7 | 3.3±1.3 |
| TEPb | μg C L−1 | 160±48 | 384±206 | 1312±52 | 849±351 |
| β-gluc | μg C L−1 d−1 | 34±7.5 | 32±9 | 34±7.5 | 46±9 |
| BPd | μg C L−1 d−1 | 109±21 | 165±34 | 109±21 | 121±24 |
| BCD | μg C L−1 d−1 | NA | 359±167 | NA | 557±276 |
| BGE | % | NA | 42±22 | NA | 37±20 |
| Growth ratee | d−1 | NA | 0.15±0.1 | NA | 0.28±0.09 |
All values are the averages and their standard deviation of nine bottle incubations.
Bacterial abundance was converted into biomass (HBB) by a factor of 20 fg C per cell (Lee and Fuhrman, 1987).
TEP was converted from GX into carbon biomass using a 0.74 factor (Engel and Passow, 2001).
β-glucosidase activity (β-glu) was converted from MUF to carbon biomass using 72 μg C to 1 μM MUF factor (Hoppe, 1993).
Bacterial production was converted into carbon biomass using a conversion factor of 3.1 kg C mol−1 with an isotope dilution factor of 2.0 to calculate BP (Simon and Azam, 1989).
Growth rates calculated according to Equation (1).