Table 2.

Alkaline phosphatase activities of the TnphoA mutants of B. avium

StrainFe availability (sp act)aFold inductionb
Fe repleteFe limited
41690.018 ± 0.0010.014 ± 0.0010.8
Pho-60.004 ± 0.0050.129 ± 0.04232.3
Pho-200.033 ± 0.0210.217 ± 0.0456.6
  • a Values are the results from three replicate cultures of each strain. All values are means ± SD. Specific activities (41) are reported as micromoles of NPP hydrolyzed per minute per OD600 unit by the formulaActivity=[Δ(OD420OD550)/0.0162]/OD600ofthestationary­phasecultureFe-replete results are from cells grown in BHI supplemented with 36 μM FeSO4, and Fe-limited results are from cells grown in BHI supplemented with 100 μM EDDA.

  • b Activity during Fe-limited culture/activity during Fe-replete culture.