Antibacterial activity of marine violet-pigmented Alteromonas with special reference to the production of brominated compounds

Abstract

The synthesis of several types of antibiotics was investigated in 4 strains of violet-pigmented bacteria belonging to the species A. luteo-violaceus. Two of the strains simultaneously produce an antibiotic polyanionic polysaccharide, weakly bound to the cells and diffusing throughout the medium, and 2 intracellular brominated bactericidal substances. The 3rd strain only synthesizes the polyanionic antibiotic. The 4th one is totally inactive. The macromolecular antibiotic, probably responsible for the autointoxication of the bacteria in their cultures, acts at the respiratory level; it induces an increase of O2 uptake and the production of peroxides by test bacteria. Its activity is inhibited by catalase and peroxidase.