Butyricin 7423: a Bacteriocin Produced by Clostridium butyricum NCIB7423

Abstract

SUMMARYButyricin 7423 is a trypsin-sensitive bacteriocin produced by Clostridium butyricum ~~1~7 4 2 3 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 8sRb+ 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, EI, I and K.

On the Mode of Action of the Bacteriocin Butyricin 7423. Effects on Membrane Potential and Potassium-Ion Accumulation in Clostridium pasteurianum

“…Butyricin 7423 also is capable of inhibiting the H+-ATPase of Cl. pasteurianum in its BFo region, both in intact organisms [27] and in reconstituted proteoliposomes [9]. The work described in this paper shows furthermore that butyricin 7423 can mimic the ability exhibited by dicyclohexylcarbodiimide and efrapeptin to dissipate the apparent bulk-phase A $ .…”

“…It had previously been noted that butyricin 7423 provoked even more rapid efflux of preloaded "Rb' ions when the organisms were suspended in an isotonic buffer mixture essentially free of K + ions [27]. Therefore an experiment similar to that described above was performed using 1 5 % (w/v) sucrose-supplemented, 50 mM sodium phosphate buffer pH 7.0 as the incubation medium.…”

“…Samples (1 ml) were removed as quickly as possible and each was vacuum-filtered through a Millipore membrane (0.22-pm pore size) which was then washed with 5 ml of the resuspension mixture. The filter membrane was dried under an infrared lamp and its radioactivity measured as previously described [27]. The " R b + / K + ratio at the addition of the radiochemical was known and thus radioactive tracer flux could be expressed as pmol equivalents of K + ions.…”

The dual role of bacteriocins as anti- and probiotics

“…Nutrient and water enrichment with commercial PB, designated Alchem Poseidon™ (a mixture of Bacillus subtilis, L. acidophilus, Clostridium butyricum , and Saccharomyces cerevisiae) , administered to Japanese flounder significantly enhanced lysozyme activity, lowered levels of mucosal proteins and also improved survival after bacterial immersion challenge with Vibrio anguillarum (Taoka et al 2006). Previously, these bacterial species were shown to produce potent bacteriocins: bacillocin 22 and a BLIS were identified in B. subtilis cultures (Zheng and Slavik 1999), lactacin and acidocin in L. acidophilus (Dobson et al 2007; Han et al 2007), and butyricin 7423 in C. butyricum (Clarke and Morris 1976). It is likely thus that these toxins play a role in controlling opportunistic aquaculture pathogens.…”

Construction ofClostridium butyricum hybrid plasmids and transfer toBacillus subtilis

“…1). Since the NCIB type strain of C. butyricum has been reported to be bacteriocinogenic (Clarke and Morris 1976), the C. butyricum strains were assayed for bacteriocin production using C. pasteurianum and C. acetobutylicum as indicator organisms. Mapping of the HindlII sites of pCBU2 was facilitated by the presence of an EcoRII site located within the HindlIIB fragment at map position 2.65 kb (data not shown).…”