Nisin E, a New Nisin Variant Produced by Streptococcus equinus MDC1

Members of the genus Streptococcus inhabit a variety sites in humans and other animals some species are prolific producers proteinaceous antibiotics (bacteriocins). As little is known about (i) streptococci inhabiting domestic pets, (ii) whether novel bacteriocin-producing can be isolated from aim this study to address these gaps research literature. In study, equinus MDC1, healthy dog, was found exhibit potent antibacterial activity against Micrococcus luteus simultaneous antagonism assay, suggesting that strain MDC1 produces lantibiotic bacteriocin. The inhibitory spectrum S. determined using agar-based deferred assays >70 indicator strains, similar nisin U (a produced by uberis). However, spectra two bacteriocins differed 23 mainly with bacteriocin having no towards certain human origin (e.g., gordonii, anginosus, salivarius). genome which sequenced completely single-molecule real-time (SMRT) next-generation DNA sequencing technology, comprises single 1,936,555-basepair chromosome containing seven copies ribosomal RNA operon, 69 tRNA genes nearly 1900 putative coding sequences. Analysis sequence detection algorithms BAGEL4 antiSMASH revealed location 13,164-basepair 11-gene locus, designated nmd, encoded mature E peptide only amino acids (Ile15?Ala Leu21?Ile) an extra C-terminal asparagine residue, proteins required for post-translational modification bacteriocin, processing, export, producer immunity. Despite high homology (90.6% identity, 93.8% similarity) between U, there considerably less (47.4–76.3% 68.4–88.8% their respective biosynthetic loci. This new natural variant nisin, called E, represents first reported equinus; additionally, its differences may provide insight into influence potency killing spectrum.