Identification and characterization of a circular bacteriocin, garvicin SC, a novel garvicin ML variant, produced by Lactococcus garvieae ABG0038

We have identified and characterized a circular bacteriocin, termed garvicin SC (GarSC), produced by Lactococcus garvieae ABG0038 isolated from pine cones. Genome analysis of L. garvieae ABG0038 revealed that GarSC was a variant of the circular bacteriocin, garvicin ML (GarML), caused by an amino acid substitution, and predicted that GarSC was produced through a biosynthetic mechanism very similar to that of GarML. The two circular bacteriocins were purified and characterized for activity, and several differences were observed in pH stability, enzyme sensitivity, and antimicrobial activity. In particular, GarSC showed excellent stability in the basic pH range, which might extend the range of garvicin's application to one broader than that of GarML.