Table 1.
Phenotypic traits distinguishing strain L21-Syr-ABT from type strains of closely related species and Desulfovibrio desulfuricans.
| Characteristica | 1b | 2 | 3 | 4 |
|---|---|---|---|---|
| Isolation source | Hypersaline mat | Biofilm growing in alkaline waters of a district heating system | Well water | Sandy clay soil |
| Morphology | Sigmoid, aggregates | Vibrio | Sigmoid, spherical | Sigmoid |
| Cell size [μm] | 0.7 × 2.5–5 | 0.5–0.8 × 1.4-1.9 | 0.5 × 5–10 | 0.5–0.8 × 1.5–4 |
| Flagellation | Single polar | Single polar | Multiple polar | Single polar |
| Temperatures [°C] | ||||
| Range | 25–42 | 16–47 | 20–40 | ND |
| Optimum | 37 | 43 | 37 | 30–36 |
| NaCl conc. [g/l] | ||||
| Range | 40–180 | 0.9–7 | 0–40 | 0–24 |
| Optimum | 40–60 | 1.3 | 0–1 | 0–1 |
| pH | ||||
| Range | 6.5–8.5 | 6.9–9.9 | 6.6–7.7 | 4.5–8.7 |
| Optimum | 7.5 | 9.0–9.4 | 7.0 | 7.2–7.8 |
| Catalase | + | + c | w c | – c |
| Cytochrome c Oxidase | – | –c | – c | – c |
| Growth factor requirement | – | Yeast extract | – | – |
| Electron donors (with sulfate) | ||||
| Ethanol | + | – | + | + |
| N-propanol | – | – | ND | + |
| Malate | – | – | – | + |
| Fumarate | – | – | ND | + |
| Electron acceptors (with lactate) | ||||
| Nitrate | – | – | – | + |
| Sulfur | – | – | ND | – |
| Respiratory quinones | MK-7 (MK-6) | MK-7 c | MK-7 (MK-6) d | MK-6 (MK-5) |
| Major cellular fatty acids (>15% of total) | ai-C15:0, C16:0 | i-C15:0, ai-C15:0 c | C16:1 c9, C18:1 c11 c | i-C17:1 c7, i-C15:0 |
| Polar lipids | PE, PG, AL, GLN, PN | PE, PG, AL c | PE, PG, DPG, PL, AL c | ND |
| DNA G+C content [mol%] | 65.5 | 64.5 e | 61.1 e | 57.4 e |
aAll strains are Gram-negative; contain desulfoviridin and cytochrome c3; require an organic carbon source for growth; utilize hydrogen, formate, pyruvate and lactate as electron donors and sulfate, sulfite and thiosulfate as electron acceptors; ferment pyruvate; do not utilize acetate, propionate, butyrate and fructose as substrates. ND, not determined; +, positive, -, negative; w, weakly positive; i and ai indicate iso- and anteiso-branched fatty acids, respectively; PE, phosphatidylethanolamine; PG, phosphatidylglycerol; AL, unidentified aminolipids; DPG, diphosphatidylglycerol; GLN, unidentified aminoglycolipids, PN, unidentified aminophospholipid; PL, unidentified phospholipids. bStrains and used references: 1, L21-Syr-ABT (this study); 2, D. alkalitolerans DSM 16529T (this study, Abildgaard et al., 2006); 3, D. africanus subsp. africanus DSM 2603T (this study, Castañeda-Carrión et al., 2010); 4, D. desulfuricans DSM 642T (Vainshtein et al., 1992; Fröhlich et al., 1999; Kuever, 2014). cResults obtained in this study. dThe respiratory quinones MK6(H2) and MK5(H2) were reported previously for strain Desulfovibrio africanus subsp. africanus NCIMB 8401T (Collins and Widdel, 1986), which is in contrast to our results. Therefore, it is unclear if the authentic type strain was analyzed. eDeduced from genome sequence.