The present invention provides isolated lantibiotics that inhibit. Gram negative and Gram positive microbes. The antibiotic includes an amino acid sequence, wherein the amino acid sequence of the compound and the amino acid sequence of SEQ ID NO:21 or SEQ ID NO:22 have at least 80% identity. The lantibiotics have the characteristic of inhibiting growth of a Gram negative microbe in conditions that do not damage the outer membrane of the Gram negative microbe. The present invention also provides methods for making and using the lantibiotics.
 The present invention was made with government support under Grant No. DE-FG02-98ER82577 and DE-FG02-00ER83009, awarded by the Department of Energy. The Government has certain rights in this invention.