Catalyzes the conversion of deacetylcephalosporin C to cephalosporin C. acetyl-CoA + deacetylcephalosporin C = cephalosporin C + CoA Antibiotic biosynthesis; cephalosporin C biosynthesis. Heterodimer of chain I and chain II. Belongs to the AB hydrolase superfamily. MetX family. It is uncertain whether Met-1, Met-46 or Met-60 is the initiator.