TABLE 2.
Differential characteristics of the six novel species and closely related Halomonas species.
| Characteristic | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 |
| Cell size (μm) | 0.5–0.7×1.0–3.0 | 0.6–1.1×1.7–2.7 | 0.7–0.8×1.3–2.0 | 0.6–0.8×1.6–2.4 | 0.6–0.7×1.7–2.4 | 0.6–0.7×1.3–2.1 | 0.7–0.8×1.0–1.2 | 0.4–0.6×1.0–2.6 | 0.5–0.7×1.5–2.5 | 0.4–0.5×1.5–2.5 | 0.3–0.5×1.0–1.6 | 0.8–2.0×0.2–0.5 | 0.4–0.7×1.2–1.7 |
| Optimum temperature (°C) | 37–40 | 37 | 37–40 | 37–40 | 37–40 | 37–40 | 30 | 37–42 | 36–40 | 28–37 | 30 | 30 | 30–35 |
| Temperature range (°C) | 4–50 | 4–50 | 4–50 | 4–50 | 4–55 | 4–50 | 10–50 | 10–45 | 10–55 | 10–50 | 10–52 | 10–45 | 5–45 |
| Optimum pH | 7–8 | 7–8 | 7–8 | 7–8 | 7–8 | 7–8 | 9 | 9.7 | 9.5 | 7–8 | 8 | 8 | 8 |
| pH range | 7–10 | 7–10 | 6–10 | 7–10 | 6–10 | 6–10 | 8–10 | 7–11 | 7.5–10.6 | 6–9 | 6–10 | 6–10 | 7–11 |
| Optimum NaCl concentration (%, w/v) | 2–8 | 2–8 | 2–6 | 1–10 | 2–8 | 2–8 | 5–10 | 9 | 3–7 | 4–10 | 10–15 | 10 | 3–8 |
| NaCl concentration range (%, w/v) | 0–18 | 0–18 | 0–18 | 0–18 | 0–20 | 0–18 | 1–15 | 1–18 | 0–13 | 1–12 | 0–17 | 1–17 | 0–20 |
| Hydrolysis of: | |||||||||||||
| Tween-20 | − | + | − | + | − | − | + | + | −# | + | −# | + | − |
| Tween-40 | − | + | − | + | − | − | + | − | − | + | −# | − | − |
| Tween-60 | − | + | − | + | − | − | − | − | − | + | − | − | − |
| Tween-80 | − | + | − | + | − | − | + | − | + | − | − | − | |
| DNA | − | − | − | − | + | + | + | + | − | − | +# | − | + |
| Gelatin | − | − | + | − | − | − | w# | +# | −# | − | + | − | + |
| Starch | − | + | − | − | + | + | − | − | − | − | − | − | − |
| Casein | − | − | − | − | − | − | −# | − | − | + | − | − | − |
| ONPG | − | − | − | − | − | − | − | − | − | + | − | − | −# |
| Voges–Proskauer test | w | w | w | w | + | + | w | w | + | − | −# | + | |
| D-Glucose fermentation | w | w | w | w | w | w | w | w | − | − | w | + | |
| API ZYM | |||||||||||||
| Esterase lipase (C8) | w | w | w | + | w | − | w | + | w | + | w | nd | w |
| Lipase (C14) | w | w | w | − | w | w | − | − | w | + | − | nd | w |
| Leucine aminopeptidase | + | + | + | + | + | + | − | + | + | + | + | nd | + |
| Cystine aminopeptidase | w | w | w | w | w | w | − | w | w | + | + | nd | w |
| Trypsin | − | + | w | − | − | − | w | + | w | + | w | nd | w |
| α-Glucosidase | − | + | + | + | − | + | + | + | w | + | − | nd | + |
| API 20NE | |||||||||||||
| Reduction of nitrate | + | + | + | + | + | + | + | + | + | + | − | + | + |
| Denitrification | + | + | + | + | + | + | + | + | + | − | − | + | − |
| Arginine dihydrolase | − | − | w | − | − | − | −# | − | − | − | − | nd | + |
| β-Glucosidase (aesculin hydrolysis) | − | − | − | − | − | − | − | − | − | − | + | − | + |
| Gelatinase | − | − | + | − | − | − | w# | +# | −# | − | + | − | + |
| Assimilation of (API 20NE): | |||||||||||||
| D-Glucose | w | w | + | w | + | + | + | w | w | + | + | + | + |
| L-Arabinose | w | − | + | − | + | + | + | − | − | + | + | + | + |
| D-Mannose | − | − | − | − | − | − | − | − | − | − | + | − | + |
| D-Mannitol | + | + | + | + | + | + | + | w | − | + | + | − | + |
| N-Acetyl-glucosamine | − | − | − | − | + | − | − | − | − | + | + | nd | + |
| D-Maltose | − | + | + | + | + | + | + | + | − | + | +# | + | + |
| Potassium gluconate | + | + | + | + | + | + | + | w | w | + | + | − | + |
| Capric acid | − | − | − | − | − | − | − | − | − | − | − | nd | w |
| Adipic acid | − | + | + | w | + | + | + | − | − | + | + | nd | − |
| Malic acid | + | + | + | + | + | + | + | + | − | + | + | − | + |
| Trisodium citrate | + | + | + | + | + | + | + | + | − | + | + | + | + |
| Phenylacetic acid | − | − | − | − | − | + | − | − | − | − | + | nd | − |
| Sulfide oxidation | w | w | + | w | + | w | w | w | + | − | − | − | − |
| Thiosulfate oxidation | − | − | + | − | + | − | − | − | − | + | − | − | − |
| DNA G+C content (%) | 63.3 | 64 | 66 | 64.5 | 64.2 | 63.9 | 64.9 | 64.7 | 63.7 | 66.7 | 64.1 | 63.5 | 63.6 |
Strains: 1, MCCC 1A11036T; 2, MCCC 1A11058T; 3, MCCC 1A11059T; 4, MCCC 1A11081T; 5, MCCC 1A13718T; 6, MCCC 1A14433T; 7, Halomonas daqingensis CGMCC 1.6443T (Wu et al., 2008); 8, Halomonas desiderata DSM 9502T (Berendes et al., 1996); 9, Halomonas kenyensis DSM 17331T (Boltianskaia et al., 2007); 10, Halomonas lactosivorans KCTC 52281T (Ming et al., 2020); 11, Halomonas saliphila LCB169T (Gan et al., 2018); 12, Halomonas pellis L5T (Li et al., 2020); 13, Halomonas elongata DSM 2581T. The data for strains 1–6 and the data from API 20E, API 20NE, and API ZYM tests for strains 7–11 and 13 were obtained from this study. The data for strain 12 were from Li et al. (2020). All strains were Gram-stain-negative, catalase- and oxidase-positive, and negative for hydrolysis of cellulose and urea, H2S production, and indole production. For API 20E, all strains were negative for lysine decarboxylase, ornithine decarboxylase, urease, and tryptophan deaminase. For API ZYM, all strains were positive for alkaline phosphatase, esterase, valine aminopeptidase, acid phosphatase, and naphthol-AS-Bl-phosphoamidase and negative for α-chymotrypsin, α-galactosidase, β-galactosidase, β-glucuronidase, β-glucosidase, N-acetyl-β-glucosaminidase, α-mannosidase, and α-fucosidase. +, positive; −, negative; w, weakly positive; nd, not determined; #, the results differed with reference.