TABLE 2.
NADH-dependent nitrite reductase activities of various B. subtilis strains grown under aerobic and anaerobic conditions
| Strain | Nitrite reductase activity ± SD (10−4 U/mg of protein)a
|
||
|---|---|---|---|
| Anaerobic growth | Aerobic growth
|
||
| Nitrite | Ammonium | ||
| JH642 (wild type) | 334 ± 12b | 146 ± 14b | ND |
| THB1 (ΔnarGH) | 351 ± 21 | 164 ± 18 | ND |
| LAB1943 (ΔnasE Pspac-nasF)c | ND | ND | ND |
| LAB1972 (ΔnasD) | ND | ND | ND |
| LAB1982 (ΔnasD Pspac-nasEF)c | ND | ND | ND |
| MH5081 (ΔresDE) | ND | ND | ND |
| THB2 (fnr) | 527 ± 21 | 348 ± 24 | ND |
a
NADH-dependent nitrite reductase activities were measured with cell extracts prepared from B. subtilis strains grown aerobically in minimal medium with nitrite and anaerobically in supplemented Luria-Bertani medium with nitrate and nitrite as described in Materials and Methods. Values reported are the averages of at least three experiments performed in triplicate. ND, not detectable (less than 40 × 10−4 U/mg of protein).
b
Activity with NADPH was less than 10% of that with NADH.
c
Cells were grown in the presence of 1 mM IPTG.