Whole genome sequencing and mass spectrometry of the purified peptide confirmed that <i>S. capitis</i> APC2923 produces a 3458 Da bacteriocin, designated nisin J, which exhibited antimicrobial activity against a range of Gram-positive pathogens including MRSA and <i>Cutibacterium acnes.</i> The gene order in the nisin J gene cluster (<i>nsjFEGBTCJP</i>) differs from those of other nisin variants, in that it is lacking the nisin regulatory genes, <i>nisRK</i>, as well as the nisin immunity gene, <i>nisI</i> Nisin J has 9 amino acid changes when compared to prototypical nisin A; 8 amino acid substitutions, 6 of which are not present in other nisin variants (Ile4Lys, Met17Gln, Gly18Thr, Asn20Phe, Met21Ala, Ile30Gly, Val33His and Lys34Thr) and an extra amino acid close to the C-terminus, rendering nisin J the only nisin variant to contain 35 amino acids.