Table 1. The concentrations of S. aureus cytoplasmic amino acids following growth under differing experimental regimes.
| Treatments | (A) Control pH7; 37°C; 0% NaCl nmoles mg-1 dry cell mass; mean ± SD, n = 12 | (B) Centroid pH7; 37°C; 2.5% NaCl nmoles mg-1 dry cell mass; mean ± SD, n = 12 | (C) pH6; 35°C; 0% NaCl nmoles mg-1 dry cell mass mean ± SD, n = 4 | (D) pH8; 35°C; 0% NaCl nmoles mg-1 dry cell mass mean ± SD, n = 4 | (E) pH6; 35°C; 5% NaCl nmoles mg-1 dry cell mass mean ± SD, n = 4 | (F) pH8; 35°C; 5% NaCl nmoles mg-1 dry cell mass mean ± SD, n = 4 |
|---|---|---|---|---|---|---|
| Amino acids | ||||||
| ALA | 13.8 ± 2.77 | 10.7 ± 3.52 | 12.4 ± 0.14 | 15.4 ± 1.98 | 29.5 ± 2.49a | 17.1 ± 2.00 a |
| GLY | 1.14± 0.29 | 1.21± 0.51 | 0.76± 0.01 | 1.35± 0.17 | 2.48± 0.74 a | 4.89± 0.56 a |
| ABA | 1.95 ±0.50 | 1.75 ±0.14 | 0.78 ±0.02 a | 3.72 ±0.48 a | 1.93 ±0.11 | 4.37 ±0.55 a |
| VAL | 1.66 ± 0.82 | 0.64 ± 0.31 a | 1.36 ± 0.79 a | 3.26 ± 0.40 | 1.52 ± 0.16 | 1.59 ± 0.14 |
| BAIB | 7.47 ± 1.10 | 4.24 ± 1.11 a | 4.66 ± 0.31 a | 7.06 ± 1.01 | 0.71 ± 0.05 a | 2.86 ± 0.07 a |
| LEU | 0.81 ± 0.62 | 0.42 ± 0.07 | 0.42 ± 0.03 | 4.76 ± 0.62 a | 0.08 ± 0.10 a | 0.40 ± 0.14 |
| ILE | 0.16 ± 0.14 | 0.07 ± 0.10 | 0.23 ± 0.16 | 0.46 ± 0.06 a | 0.44 ± 0.05 a | 0.28 ± 0.03 |
| SER | 0.14 ± 0.33 | 0.24 ± 0.44 | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.29 ± 0.34 | 0.00 ± 0.00 |
| PRO | 15.5 ± 3.71 | 37.6 ± 2.43 a | 7.39 ± 0.82 a | 28.4 ± 3.51 a | 26.9 ± 1.66 a | 7.13 ± 1.04 a |
| ASN | 0.74 ± 0.17 | 0.72 ± 0.40 | 0.09 ± 0.17 a | 2.56 ± 0.41 a | 2.63 ± 0.12 a | 3.93 ± 0.54 a |
| ASP | 62.9 ± 8.14 | 38.3 ± 4.11 a | 45.7 ± 6.41 a | 91.6 ± 15.91 a | 41.1 ± 3.99 a | 45.3 ± 2.19 a |
| MET | 2.64 ± 0.57 | 1.99 ± 0.60 | 2.57 ± 0.34 | 3.28 ± 0.40 a | 1.70 ± 0.14 a | 2.54 ± 0.19 |
| HYP | 0.25 ± 0.19 | 0.34 ± 0.17 | 0.63 ± 0.08 a | 1.02 ± 0.16 a | 0.96 ± 0.15 a | 0.69 ± 0.10 a |
| GLU | 91.3 ± 11.65 | 66.5 ± 10.56 a | 80.4 ± 10.40 | 130.2 ± 20.55 a | 122.8 ± 13.09 a | 95.7 ± 11.09 |
| PHE | 0.88 ± 0.23 | 0.50 ± 0.06 | 0.94 ± 0.11 a | 1.73 ± 0.20 a | 0.45 ± 0.08 a | 0.55 ± 0.13 a |
| AAA | 0.32 ± 0.29 | 0.22 ± 0.31 | 0.80 ± 0.73 a | 0.97 ± 0.12 a | 0.00 ± 0.00 | 0.00 ± 0.00 |
| GLN | 0.71 ± 0.35 | 0.52 ± 0.47 | 1.98 ± 2.56 a | 1.37 ± 0.91 | 5.17 ± 0.50 a | 0.67 ± 0.22 |
| ORN | 0.60 ± 0.10 | 0.49 ± 0.10 | 0.90 ± 0.11 a | 0.66 ± 0.10 | 0.86 ± 0.04 a | 0.70 ± 0.13 |
| GPR | 0.77 ± 0.17 | 0.88 ± 0.17 | 0.55 ± 0.37 | 0.79 ± 0.10 | 0.00 ± 0.00 a | 0.20 ± 0.13 a |
| LYS | 3.26 ± 1.13 | 2.29 ± 0.45 a | 5.29 ± 0.71 a | 4.07 ± 0.53 | 3.57 ± 0.45 | 2.41 ± 0.21 |
| HIS | 7.54 ± 2.65 | 2.92 ± 1.55 a | 5.21 ± 2.59 | 5.11 ± 3.52 | 4.28 ± 0.38 a | 2.26 ± 0.39 a |
| TYR | 0.40 ± 0.08 | 0.35 ± 0.04 | 0.47 ± 0.06 | 0.60 ± 0.05 a | 0.33 ± 0.04 | 0.35 ± 0.07 |
| Totals | 215±25.2 | 173±19.3 a | 174±19.2 a | 308±48.1 a | 248±19.2 | 194±15.7 |
Cells were harvested and extracted at the mid-exponential phase of growth: (A) control cultures grown under ideal conditions at pH7 and 37°C with no added NaCl; (B) centroid cultures grown at pH 7 and 37°C with 2.5% NaCl, and the four experimental groups: (C) 35°C and pH6 with no added NaCl; (D) 35°C and pH8 with no added NaCl; (E) 35°C and pH6 with 5% NaCl added; (F) 35°C and pH8 with 5% NaCl.
a Significantly different at P<0.05.