Table 1.
Differentially expressed genes in L. paracasei after acid, salt or oxidative stress among the 18 genes for which a corresponding mutant has been identified as sensitive for at least one of these stress conditions.
| Gene | Predicted function | Acid stress | Salt stress | Oxidative stress |
|---|---|---|---|---|
| pH 3.0 15 min | 1 M NaCl 15 min | 1 mM H2O2 15 min | ||
| LSEI_0794 | D-alanine-activating enzyme | 1.51 ± 0.28 | 3.43 ± 0.93* | −1.21 ± 0.35 |
| LSEI_0806 | HP | 1.81 ± 0.40 | 2.60 ± 0.50* | 1.58 ± 0.44 |
| LSEI_0938 | Phosphate ABC transporter | 3.35 ± 0.69* | 1.01 ± 0.25 | 1.34 ± 0.39 |
| LSEI_0990 | Sugar ABC transporter | 1.05 ± 0.25 | −2.64 ± 0.63* | 1.44 ± 0.48 |
| LSEI_1007 | Spermidine/putrescine ABC transporter | −2.33 ± 0.54* | −4.05 ± 1.13* | 1.35 ± 0.52 |
| LSEI_1041 | DNA binding response regulator | 1.35 ± 0.29 | 1.41 ± 0.31 | 1.22 ± 0.38 |
| LSEI_1289 | Cysteine desulfurase | −1.18 ± 0.25 | −1.23 ± 0.27 | −1.10 ± 0.34 |
| LSEI_1293 | Phosphoglycerate mutase | −1.17 ± 0.25 | −1.34 ± 0.33 | 1.22 ± 0.36 |
| LSEI_1360 | 5'-nucleotidase | 1.96 ±, 0.50* | −1.01 ± 0.30 | 1.57 ± 0.51 |
| LSEI_1468 | Ribonucleotide reductase | 1.37 ± 0.33 | 2.45 ± 0.56* | 2.08 ± 0.57* |
| LSEI_1565 | DnaK | −1.29 ± 0.18 | 2.04 ± 0.77* | 3.21 ± 1.01* |
| LSEI_1738 | Peptide ABC transporter | −1.70 ± 0.37* | −1.62 ± 0.52 | 1.88 ± 0.62 |
| LSEI_1931 | HP | 1.26 ± 0.42 | 1.18 ± 0.52 | 1.11 ± 0.36 |
| LSEI_2262 | HP | 1.51 ± 0.41 | 3.99 ± 1.12* | 1.99 ± 0.68* |
| LSEI_2537 | Cell surface protein | −1.13 ± 0.18 | 2.78 ± 0.72* | 2.03 ± 0.51 |
| LSEI_2540 | ATP-dependent Zn protease | 1.00 ± 0.25 | 1.51 ± 0.45 | 1.96 ± 0.64* |
| LSEI_2562 | DNA/RNA helicase | −2.86 ± 0.82* | −1.41 ± 0.34 | −2.23 ± 0.74 |
| LSEI_2806 | HP | 1.47 ± 0.29 | 2.69 ± 0.88 | 1.07 ± 0.39 |
All stresses were performed at 37°C during 15 min. Relative gene expressions were calculated using 2−ΔΔCt method. For MRS control condition, a gene expression value of 1.0 was attributed and genes expressions in stress condition were calculated in function of this value. Positive values (>1.0) represent upregulation and negative values (<1.0) represent downregulation.
*
Significant changes in gene expression (p < 0.05) (in bold) compared to the not stressed culture (4 biological replicates). HP, Hypothetical protein.