Butyricin 7423: a bacteriocin produced by Clostridium butyricum NCIB7423.

Butyricin 7423 is a trypsin-sensitive bacteriocin produced by Clostridium butyricum NCIB7423 and active against some other species of Clostridium. It has a bactericidal but non-lytic action on growing cultures of Clostridium pasteurianum. The primary action of butyricin 7423 appears to be at the cell membrane. Thus treatment of C. pasteurianum with an excess of butyricin altered the permeability of its cell membrane, allowing the release of several metabolites and ions. Efflux of rubidium ions from organisms preloaded with 86Rb+ was particularly rapid and extensive. The action of butyricin 7423 on Clostridium species seems to differ from that of other clostridocins, such as the boticins and perfringocin 28, and more closely resembles the mode of action on susceptible (aerobic) organisms of bacteriocins such as staphylococcin 1580 or colicins A, E1, I and K.