Purification and partial characterization of a bacteriocin from Serratia marcescens

Bacteriocin JF246 has been purified from mitomycin C-induced Serratia marcescens cells by salt extraction, ammonium sulfate fractionation, and chromatography on QAE-Sephadex and SP-Sephadex. The purified material is homogeneous on polyacrylamide gel electrophoresis in the presence of 2% sodium dodecyl sulfate or 6 m urea. In the absence of these agents, the bacteriocin associates into aggregates which can be dissociated with 0.4 m NaCl. The bacteriocin is probably composed of a single subunit with a molecular weight of 64,000 daltons. Analytical studies show the bacteriocin to be essentially protein in nature containing less than one residue of glucose or phosphorus per 64,000 daltons.