TABLE 2.

Phenotypes

Strain/plasmidHemolysis (α-hemolytic titer)aProtease activity (%)bCarotenoid production (A450)c
SH1000/pALC20731101000.60
AH1012/pALC20734771,3600.07
AH1012/pALC2109d311240.44
LAC/pALC20732571000.30
AH1096/pALC20731,9901,0500.08
AH1096/pALC2109d57670.36
  • a Hemolytic titers were calculated from rabbit blood cell lysis as described in Materials and Methods.

  • b Protease activity in cell-free supernatants was measured with Azocoll reagent as described in Materials and Methods. Supernatants of wild-type strains with control vector pALC2073 were set to 100%.

  • c Carotenoid production was monitored in methanol extractions of S. aureus samples at wavelengths of 450 and 470 nm although only one value is reported.

  • d Complementation with pALC2109 was performed with 50 ng/μl anhydrotetracycline to induce sigB gene expression.