Lanthionine-containing peptide antibiotic (lantibiotic) active on Gram-positive bacteria. The bactericidal activity of lantibiotics is based on depolarization of energized bacterial cytoplasmic membranes, initiated by the formation of aqueous transmembrane pores. When present individually, LchA2 exhibits activity towards B.subtilis L1 (IC(50)=30 uM), Rhodococcus sp. SS2 (IC(50)=16.6 uM), M.luteus B1314 (IC(50)=2.6 uM), B.megaterium VKM41 (IC(50)=2 uM), S.aureus 209p (IC(50)=20 uM), B.pumilus 2001, B.globigii I, B.amyloliquefaciens I, M.smegmatis 1171 and M.phlei 1291. However, when combined with LchA1, it displays much stronger activity against B.subtilis L1 (IC(50)=0.64 uM), Rhodococcus sp. SS2 (IC(50)=0.64 uM), M.luteus B1314 (IC(50)=0.09 uM), B.megaterium VKM41 (IC(50)=0.12 uM) and S.aureus 209p (IC(50)=0.64 uM). The activity of the combined LchA1 and LchA2 peptides is strongest at a molar ratio of 1. Even when applied at 17-fold concentration of the highest IC(50) values for Gram-positive bacteria, neither the individual nor the combined peptides display activity against Gram-negative bacteria P.aeruginosa PAO1, P.putida I-97 or E.coli C600.