## 4 Discussion  
In the present study, we have identified a strain of _A. aneurinibticus_ (strain NH) that is highly effective in controlling the human foodborne pathogens _C. jejuni_ and _L. monocytogenes_ through the secretion of one of more substances, including a relatively high molecular weight component of 50 kDa (Figures 3 and 4). Bacteriocins (bactericidal peptides and proteins) have been extensively investigated in lactic acid bacteria and _Bacillus_ species. Three classes of bacteriocins have been described [56]. Class I includes peptides thatundergo post-translational modifications. This class includes lanthionine-containing antibiotic peptides (\"lantibiotics\"). Lanthionine is an amino acid that results from post-translational cross-linking of alanine residues via a thioether linkage. Other common post-translational modifications present in Class I bacteriocins are the unsaturated amino acids 2,3-didehydroalanine (Dha) and 2,3-didehydrobutyrate (Dhb), derived from the action of serine/threonine dehydatase and addition of thioether linkages via internal cysteine residues. These modifications introduce internal cyclic thioether structures to the peptide. Class I bacteriocins are <5 kDa in size, and examples include nisin, subtilis, and epidermis, produced by _L. lactis_, _B. subtilis_, and _S. epidermidis_, respectively [57]. Class II bacteriocins (<10 kDa) are non-modified, linear peptides that are heat and pH stable. Three subclasses of class II have been identified based on conserved amino acid motifs near the N-terminus. Subclass II.1 includes pedicoin-like proteins such as coagulin (_B. coagulans_) [58] and the _Paenibacillus polymya_ bacteriocins SRCAM 37 and similar proteins [32] with a conserved YGNGVXC domain. Subclass II.2 includes the thuricin group of _Bacillus thuringiensis_ and _B. cereus_, containing a conserved DWTXWSXL motif. Subclass II.3 includes the lichenicidins (_B. licheniformis_), cereins, ericins, mersacidin, and haloduracins, and lacks conserved domains. Class III bacteriocins (>30 kDa) are large, heat-labile bacteriocins with phospholipase activity, such as the megacins (_B. megaterium_) [59; 60; 61]. The NH strain's 50 kDa active protein (Figure 4) is consistent with a class III bacteriocin, but further purification and analysis are needed to check for phospholipase activity. The mode of action of strain NH appears to be the lysis of the _Listeria_ cells (Figure 2) and is thus bactericidal. _Campylobacter jejuni_ fails to grow back in the presence of the NH CFCSAS precipitate dialysate, even after many days of microaerobic incubation, despite the presence of fresh growth media in these assays. Thus, the mode of action is likely bactericidal against C. _ jejuni_, as well. A previous report estimated that reducing _Campylobacter_ in the poultry cream by as little as 3 log CFU/g could reduce the risk of human disease by as much as 90-100% [62]. Given the very substantial 7 log reductions in C. _ jejuni_ resulting from exposure to strain NH culture filtrate (Figure 1), if the activity against _Campylobacter_ exhibited by strain NH can be harnessed, this could represent an effective control strategy against this pathogen. To the best of our knowledge, this study is the first to demonstrate that _A. anururilivticus_ is bactericidal towards human or foodborne pathogens, specifically C. _jejuni_ and _L. monocytogenes_. However, the role of _Aneurinhacillus_ spp. in the control of plant pathogens has been previously reported. An _A. anurinilivticus_ isolate that was shown to be an endophyte of _Cuminum sanctum_ plants was found to inhibit the mycelia of the fungal pathogens _Rhizoctonia solani_, _Fusarium oxysporum_, and _Phythia aphamiderratum_. The _A. aneurinilyticus_ isolate has also exhibited siderophore production and induction of systemic resistance in pea plants [63], including significant elevation of phenylalanine ammonia lyase (PAL), an enzyme involved in the production of phenolic metabolites such as flavonoids, isoflavoids, and lignins [64].