Identification of the Lantibiotic Nisin Q, a New Natural Nisin Variant Produced by<i>Lactococcus lactis</i>61-14 Isolated from a River in Japan

Lactococcus lactis 61-14 isolated from river water produced a bacteriocin active against a wide range of Gram-positive bacteria. N-terminal amino acid sequencing, mass spectral analysis of the purified bacteriocin, and genetic analysis using nisin-specific primers showed that the bacteriocin was a new natural nisin variant, termed nisin Q. Nisin Q and nisin A differ in four amino acids in the mature peptide and two in the leader sequence.