Activates the seven peptidyl carrier protein (PCP) domains of the first three subunits (SrfAA, SrfAB and SrfAC) of surfactin synthetase by transferring the 4'-phosphopantetheinyl moiety of coenzyme A (CoA) to a serine residue. Required for cells of B.subtilis to become producers of the lipopeptide antibiotics surfactin and plipastatin B1. apo-[ACP] + CoA = adenosine 3',5'-bisphosphate + H(+) + holo-[ACP] kcat is 104 min(-1) with a peptide fragment encompassing residues 960-1084 of surfactin synthetase SrfAB subunit as substrate. kcat is 56 min(-1) with a peptide fragment encompassing residues 2006-2123 of surfactin synthetase SrfAB subunit as substrate (PubMed:9484229). kcat is 7.2 min(-1) with S.mobaraensis apo-PCP BlmI as substrate and 0.89 min(-1) with S.glaucescens apo-ACP TcmM as substrate (PubMed:11451672). Optimum pH is 6.0. Displays less than 20% of Vmax at both pH 5.0 and pH 7.0. Monomer in solution. Belongs to the P-Pant transferase superfamily. Gsp/Sfp/HetI/AcpT family. Strain 168 and its derivatives encode a truncated, inactive version of this protein. The sequence shown here corresponds to that of strain ATCC 21332 which is active.