TABLE 2.
SRR in microbial mat slurries prepared from marine stromatolites (Highborne Cay, Bahamas), a salt pond (Guerrero Negro, Mexico), and a salt marsh (Stonington, Conn.) after electron donors were addeda
| Carbon source | SRR (d[S2−]/dt) (μM · h−1)
|
||
|---|---|---|---|
| Stromatolite mat | Salt pond matb | Salt marsh matc | |
| Acetate | 127 (8)d | 201 (17) | 184 (12) |
| Lactate | 79 (11) | 153 (14) | 177 (15) |
| Ethanol | 64 (8) | NTe | NT |
| Glycolate | 38 (5) | NT | NT |
| EPS | 29 (2) | NT | NT |
| Glutamate | 30 (3) | NT | 33 (6) |
| Taurine | 35 (2) | 38 (6) | 27 (4) |
| Cysteate | 24 (3) | 36 (1) | 18 (2) |
| Isethionate | 10 (2) | NT | NT |
| 2-Sulfobenzoate | 13 (2) | NT | NT |
| Sulfosuccinate | 10 (2) | NT | NT |
| Endogenous rate | 8 (1) | 11 (1) | 13 (1) |
With the stromatolite slurries, experiments were replicated three times for acetate, lactate, taurine, and cysteate and twice for the other substrates. The salt pond and salt marsh experiments were replicated twice. In stromatolite slurries, the presence of MoO42− inhibited HS− production 82, 87, 48, and 21% when acetate, lactate, taurine, and cysteate, respectively, were added.
To account for the reaction of HS− with Fe2+, the rates were determined after preincubation for 10 min.
To account for the reaction of HS− with Fe2+, the rates were determined after preincubation for 60 min.
Average (standard deviation).
NT, not tested.