Table 2.
Proline content in the culture supernatants of cells grown either in SMM without additional NaCl or in the presence of 1 M additional NaCla
| Strain | Relevant genotype | Extracellular proline concn (μM) |
|
|---|---|---|---|
| Without NaCl | With 1 M NaCl | ||
| JH642 | Wild type | 6 ± 1 | 7 ± 1 |
| BLOB9 | Δ(opuE::tet)1 | 5 ± 1 | 406 ± 15 |
| BLOB20 | sapB::neo | 6 ± 1 | 13 ± 2 |
| TMB140 | Δ(sapB::spc)2 | 6 ± 1 | 7 ± 1 |
| TMB139 | Δ[(opuE-sapB)::spc]1 | 4 ± 1 | 340 ± 74 |
a
Cultures of the indicated strains were cultivated in SMM in the absence or in the presence of 1 M NaCl. When the cultures reached mid-exponential growth phase (OD578 of 1.5), the cells were removed from the growth medium by centrifugation and the proline contents of the supernatants were measured by a colorimetric assay (2). The proline values given were normalized for each culture corresponding to an OD578 of 1. The given proline concentrations represent measurements from three independently grown cultures and in each case included two technical replicates of the proline assay.