Characterization and partial purification of a bacteriocin produced by Leuconostoc carnosum LA44A

摘要: Abstract Twenty Leuconostoc strains isolated from vacuum packaged Vienna-type sausages were screened for antagonistic activity against various Gram-positive organisms (including Listeria spp.). One of the three exhibiting inhibitory was chosen further investigation. This strain identified as Leuc. carnosum and substance produced named carnosin. Carnosin inactivated by trypsin but not catalase or other non-proteolytic enzymes tested. retained after heating at 100°C 20 min, whereas 121°C 15 min resulted in complete loss activity. active pH values ranging 2 to 9. detectable until cells late log-phase growth. At low temperatures (4°C), higher cell densities required before carnosin could be detected. lactic acid bacteria, Enterococcus faecalis faecium spp. Difficulties purification reduced growing a modified MRS medium, having 50% normal peptone concentration no Tween meat extract. Sodium dodecyl sulphate polyacrylamide gel electrophoresis partially purified indicated that it has molecular mass between 2510 6000 Da. Yet, retention exhaustive dialysis suggested > 14kDa. It is hypothesized forms large complexes which can dissociated small (active) components.