TABLE 2.
Effect of nppBCD and dppBCDF mutations on the use of peptides as nitrogen sourcesa
| Nitrogen source | Length (aa) | Avg OD600 ± SD |
|||
|---|---|---|---|---|---|
| PA14 | ΔnppBCD | ΔdppBCDF | ΔnppBCD ΔdppBCDF | ||
| Controls | |||||
| None | 0.02 ± 0.00 | 0.01 ± 0.00 | 0.02 ± 0.00 | 0.02 ± 0.00 | |
| 0.2 mM NH4Cl | 0.35 ± 0.01 | 0.38 ± 0.02 | 0.35 ± 0.02 | 0.36 ± 0.03 | |
| Oligopeptidesb | |||||
| Gly-Pro-Ile-Ser | 4 | 0.07 ± 0.01 | 0.09 ± 0.00 | 0.06 ± 0.01 | 0.05 ± 0.00 |
| Gly-Pro-Arg-Pro | 4 | 0.08 ± 0.01 | 0.06 ± 0.00 | 0.07 ± 0.00 | 0.06 ± 0.00 |
| Gly-Arg-Gly-Asp | 4 | 0.14 ± 0.02 | 0.13 ± 0.01 | 0.14 ± 0.01 | 0.13 ± 0.00 |
| Val-Ile-His-Asn | 4 | 0.14 ± 0.01 | 0.13 ± 0.00 | 0.14 ± 0.02 | 0.13 ± 0.01 |
| Lys-Thr-Thr-Lys-Ser | 5 | 0.18 ± 0.03 | 0.19 ± 0.02 | 0.17 ± 0.02 | 0.16 ± 0.02 |
| Phe-Leu-Glu-Glu-Val | 5 | 0.05 ± 0.00 | 0.05 ± 0.00 | 0.05 ± 0.00 | 0.04 ± 0.01 |
| Phe-Tyr-Gly-Pro-Val | 5 | 0.14 ± 0.01 | 0.11 ± 0.03 | 0.14 ± 0.01 | 0.13 ± 0.00 |
| Tyr-Gly-Gly-Phe-Leu | 5 | 0.15 ± 0.00 | 0.16 ± 0.02 | 0.06 ± 0.00 | 0.04 ± 0.01 |
| Tyr-Gly-Gly-Phe-Met | 5 | 0.17 ± 0.02 | 0.15 ± 0.02 | 0.11 ± 0.01 | 0.11 ± 0.02 |
| Gly-Arg-Gly-Asp-Asn-Pro | 6 | 0.07 ± 0.02 | 0.05 ± 0.00 | 0.08 ± 0.02 | 0.05 ± 0.01 |
| Lys-Lys-Thr-Pro-Glu-Glu | 6 | 0.09 ± 0.02 | 0.07 ± 0.01 | 0.09 ± 0.02 | 0.08 ± 0.01 |
| Val-Tyr-Ile-His-Pro-Phe | 6 | 0.16 ± 0.01 | 0.16 ± 0.02 | 0.16 ± 0.02 | 0.13 ± 0.02 |
| Asp-Arg-Val-Tyr-Ile-His-Pro | 7 | 0.10 ± 0.01 | 0.09 ± 0.01 | 0.09 ± 0.01 | 0.10 ± 0.01 |
| Ile-Ile-Asn-Phe-Glu-Lys-Leu | 7 | 0.08 ± 0.03 | 0.08 ± 0.01 | 0.09 ± 0.02 | 0.10 ± 0.03 |
| Ser-Gln-Asn-Tyr-Pro-Ile-Val | 7 | 0.36 ± 0.07 | 0.32 ± 0.05 | 0.30 ± 0.03 | 0.32 ± 0.03 |
| Asp-Arg-Val-Tyr-Ile-His-Pro-Phe | 8 | 0.34 ± 0.04 | 0.34 ± 0.03 | 0.31 ± 0.01 | 0.32 ± 0.02 |
| Asp-Arg-Val-Tyr-Val-His-Pro-Phe | 8 | 0.39 ± 0.06 | 0.38 ± 0.03 | 0.36 ± 0.04 | 0.38 ± 0.01 |
| Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys | 8 | 0.12 ± 0.03 | 0.10 ± 0.02 | 0.13 ± 0.04 | 0.11 ± 0.02 |
| Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly | 10 | 0.39 ± 0.03 | 0.38 ± 0.02 | 0.36 ± 0.03 | 0.35 ± 0.04 |
| Ala-Pro-Gly-Asp-Arg-Ile-Tyr-Val-His-Pro-Phe | 11 | 0.05 ± 0.00 | 0.07 ± 0.01 | 0.07 ± 0.01 | 0.05 ± 0.00 |
| AMPsb | |||||
| HHC36 | 9 | 0.05 ± 0.03 | 0.06 ± 0.02 | 0.07 ± 0.03 | 0.04 ± 0.02 |
| Bac2a | 12 | 0.06 ± 0.01 | 0.06 ± 0.00 | 0.05 ± 0.01 | 0.06 ± 0.00 |
| Indolicidin | 13 | 0.09 ± 0.01 | 0.10 ± 0.01 | 0.14 ± 0.03 | 0.12 ± 0.01 |
| LL37 | 37 | 0.14 ± 0.00 | 0.14 ± 0.00 | 0.13 ± 0.01 | 0.12 ± 0.01 |
| Cell wall peptides (0.1 mg/ml) | |||||
| B. subtilis PGN | 0.18 ± 0.01 | 0.18 ± 0.00 | 0.16 ± 0.02 | 0.15 ± 0.02 | |
| Tri-DAP | 0.08 ± 0.00 | 0.07 ± 0.01 | 0.08 ± 0.01 | 0.06 ± 0.02 | |
| Miscellaneous | |||||
| Phe-Arg-β-naphthylamide (0.2 mM) | 0.24 ± 0.02 | 0.22 ± 0.02 | 0.24 ± 0.01 | 0.21 ± 0.03 | |
| Aminolevulinic acid (0.2 mM) | 0.06 ± 0.01 | 0.06 ± 0.01 | 0.07 ± 0.01 | 0.06 ± 0.00 | |
| Aminopterin (0.2 mM) | 0.08 ± 0.01 | 0.04 ± 0.02 | 0.05 ± 0.02 | 0.04 ± 0.01 | |
| Pacidamycin D (0.1 mg/ml) | 0.05 ± 0.00 | 0.04 ± 0.00 | 0.04 ± 0.01 | 0.04 ± 0.00 | |
| Glutathione (0.2 mM)c | 0.41 ± 0.01 | 0.38 ± 0.04 | 0.42 ± 0.01 | 0.38 ± 0.02 | |
a
Bacterial growth was measured in triplicate by determining the increase in OD600. Boldface values are significantly different as determined by a two-tailed t test (P < 0.05).
b
The concentration of peptides in growth assays was 0.2 mM.
c
Glutathione was tested in growth assays as a nitrogen or sulfur source with similar results.