Graphical Abstract The antimicrobial mode of action brevicidines. Brevicidines are potent cyclic lipopeptides active against Gram-negative pathogens. They have low hemolytic activity and cytotoxicity. BrevicidineB, a single amino acid residue mutant brevicidine, displays an altered spectrum, showing also Gram-positive Due to disruption the proton motive force pathogens, brevicidines act as bact...