CHARACTERIZATION AND BIOLOGICAL-ACTIVITY AGAINST NAEGLERIA-FOWLERI OF AMOEBICINS PRODUCED BY BACILLUS-LICHENIFORMIS D-13

The strain Bacillus licheniformis D-13 produces three hydrophobic peptides (amoebicins d13-A, d13-B, and d13-C) that elicit antiamoebic activity against human-pathogenic and nonpathogenic species of Naegleria and have a broad spectrum of antibacterial activity. The three amoebicins have the same amino acid composition (three Asp, two Glu, two Vat, and nine Leu residues) and molecular weight (1,870). Amoebicin d13-B causes lysis of amoebae through disorganization of the cell membrane. It also induces permeability to Rb-86 and membrane disruption in asolectin vesicles.