TABLE 2.

Involvement of prophage 1 genes in LipA production by B. subtilis^a

Strain	IPTG	Lipase activity (103)
168 pLip2031	−	6.8 ± 0.8
	+	7.3 ± 0.9
168 ybcM::pMutin2 pLip2031	−	9.1 ± 0.4
	+	5.6 ± 2.7
168 skfA::pMutin1 pLip2031	−	1.3 ± 0.1
	+	1.3 ± 0.1
168 skfB::pMutin2 pLip2031	−	1.4 ± 0.2
	+	1.5 ± 0.3
168 skfC::pMutin2 pLip2031	−	3.2 ± 0.9
	+	2.7 ± 0.5
168 skfD::pMutin1 pLip2031	−	1.8 ± 0.6
	+	1.6 ± 0.8
168 skfE::pMutin2 pLip2031	−	7.3 ± 0.9
	+	8.2 ± 2.4
168 skfF::pMutin2 pLip2031	−	6.5 ± 0.3
	+	6.8 ± 1.4
168 skfG::pMutin2 pLip2031	−	6.0 ± 1.5
	+	5.9 ± 0.6
168 skfH::pMutin2 pLip2031	−	4.1 ± 0.4
	+	2.9 ± 1.6

^aTo determine which prophage 1 genes are involved in LipA production, cells of different B. subtilis mutant strains, transformed with plasmid pLip2031, were grown overnight in the absence (−) or presence (+) of 1 mM IPTG. Cultures were grown in parallel. Cells and growth media were separated by centrifugation, and 10 μl of culture supernatant was used for lipase activity determinations as described in Materials and Methods. LipA activities are indicated as the increase in the absorbance at 405 nm · min⁻¹ per OD unit.