Novel expression system for large-scale production and purification of recombinant class IIa bacteriocins and its application to piscicolin 126

Piscicolin 126 is a class IIa bacteriocin isolated from Camobacterium piscicola JG126 that exhibits strong activity against Listeria monocytogenes. The gene encoding mature piscicolin 126 (m-pisA) was cloned into an Escherichia coli expression system and expressed as a thioredoxin-piscicolin 126 fusion protein that was purified by affinity chromatography. Purified recombinant piscicolin 126 was obtained after CNBr cleavage of the fusion protein followed by reversed-phase chromatography. Recombinant piscicolin 126 contained a single disulfide bond and had a mass identical to that of native piscicolin 126. This novel bacteriocin expression system generated approximately 26 mg of purified bacteriocin from 1 liter of E. coli culture. The purified recombinant piscicolin 126 acted by disruption of the bacterial cell membrane.