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Jones et al. Microbiome Res Rep 2024;3:24 https://dx.doi.org/10.20517/mrr.2023.78 Page 7 of 12

Figure 3. Mechanism of action of the putative bacteriocins identified in Table 1.

[43]
to inhibit enteric bacteria and retain activity in colon conditions in vitro . Production of multiple
bacteriocins by a single strain is a desirable trait and can expand their spectrum of inhibition against
different pathogenic strains. For example, Jiang et al. found synergistic activity, in vitro, of a two-peptide
bacteriocin against a pathogenic Salmonella strain .
[44]
The putative class IIb PBGC shown in Figure 2A contained two core bacteriocin peptides: bacteriocin LS2
chain b and an unidentified bacteriocin. After analysis using BLASTP and EMBI-EBI EMBOSS Needle, the
bacteriocin LS2 chain b showed a 43.8% identity to BIp family class II bacteriocin isolated from
Ligilactobacillus salivarius , demonstrating a potentially novel variant of a class II bacteriocin. Similarly,
[40]
the unidentified bacteriocin exhibited 100% identity to an uncharacterised bacteriocin; however, further
investigation using BLASTP and EBI EMBOSS Needle alignment showed 91.1% identity to a previously
characterised BIp family class II bacteriocin. These two putative BIp peptides were also found in
Lactobacillus gasseri strain UMB0056. Among the Lactobacillus urobiome isolates, numerous strains
encoded putative novel BIp class II bacteriocins with all the necessary accessory genes required for
production present. Strains encoding novel class II two peptide bacteriocins include Lactobacillus crispatus
strains UMB0040, UMB0803, UMB0805, UMB0044, UMB1398 and Lactobacillus rhamnosus UMB0004.
Bacteriocins from LAB are of particular interest, with some already approved by the FDA for their use in
food preservation, including nisin and pediocin . Importantly, LAB bacteriocins have shown promise in
[38]
inhibiting human pathogens in both in vitro studies against Pseudomonas aeruginosa , uropathogenic
[45]
[48]
[47]
[46]
E.coli , and Candida spp. and in in vivo studies against Gardnerella vaginalis , and in trials using
bacteriocin-producing probiotics against bacterial vaginosis and UTIs . Novel variants of these
[49]
bacteriocins can aid in the treatment/prevention of infections, further highlighting the importance of in
silico screening studies.