Abstract
Syntheses of carotovoricin Er, a bacteriocin from Erwinia carotovora strain Er, induced by mitomycin-C, was accompanied with cell lysis. Carotovoricin Er is a thermolabile particulate, sedimentable by centrifugation at 100, 000×g for 60min, sensitive to sodium dodecyl sulfate, and unstable at acidic and basic pH, indicating protein in nature. Carotovoricin Er, however, is resistant to hydrolytic digestion by various proteolytic enzymes. Carotovoricin Er was purified approximately 70 fold by ammonium sulfate fractionation, DEAE-Sephadex A-50 column chromatography, Sepharose 2B gel filtration, and sucrose density gradient centrifugation. Single peak of carotovoricin activity coincided with a protein peak in the sucrose density gradient. Negatively stained specimens of purified carotovoricin Er revealed that its structure consists of a contractible sheath, a core, and fibers, and resembled that of the tail part of bacteriophages.
