Table 1.
Intracellular proline and Hyp concentrations in various halotolerant and halophilic bacteria under optimum (Opt) and NaCl stress (Str; corresponding to 1.5–3 times the optimum NaCl concentration) conditions.
| Strain | NaCl (%) in Opt/Str conditions | Proline (μmol/g-dry cell) | Hyp (μmol/g-dry cell) | |||
|---|---|---|---|---|---|---|
| Opt | Str | Opt | Str | |||
| Gram (+) | Halobacillus halophilus | 10/15 | 163.4 ± 12.6 | 248.16 ± 8.8 | 188.7 ± 2.9 | 209.5 ± 4.2 |
| Bacillus subtilis | 3.5/7 | ND | 9.8 ± 5.6 | 0.8 ± 0.2 | 2.9 ± 0.1 | |
| Virgibacillus pantothenticus | 6/10 | 6.5 ± 0.1 | 1.9 ± 0.2 | 12.3 ± 1.4 | 27.2 ± 1.2 | |
| Virgibacillus siamensis | 10/15 | ND | ND | 4.1 ± 0.4 | 2.8 ± 0.6 | |
| Lentibacillus juripiscarius | 10/15 | ND | ND | 0.3 ± 0.1 | 1.1 ± 0.1 | |
| Lentibacillus salicampi | 6/10 | 0.7 ± 0.2 | ND | 1.3 ± 0.70 | ND | |
| Salimicrobium halophilum | 10/15 | ND | ND | ND | ND | |
| Gram (−) | Maribacter stanieri | 2/5 | 5.3 ± 0.8 | 80.0 ± 6.3 | 4.4 ± 0.8 | 17.6 ± 1.7 |
| Bordetella bronchiseptica | 0.5/1.5 | 0.8 ± 0.4 | ND | 0.7 ± 0.2 | 0.5 ± 0.1 | |
| Pseudomonas stutzeri | 2/5 | ND | ND | 0.8 ± 0.1 | 0.8 ± 0.2 | |
| Halomonas elongata | 5/15 | ND | ND | ND | ND | |
ND, not detected.