Bacillibactin (Corynebactin) is a cyclic tricatecholate iron carrier. Its primary role is to assist bacteria in acquiring iron by chelating Fe3+ ions from the environment, particularly under iron-limited conditions. Bacillibactin also exhibits direct antimicrobial activity, capable of inhibiting the growth of bacteria such as Pseudomonas aeruginosa, Aeromonas veronii, and plant pathogens like Pseudomonas syringae. It is useful for antibacterial and antifungal research.

Bacillibactin exhibits potent inhibitory activity against Pseudomonas aeruginosa and Aeromonas veronii. Under iron-deficient conditions, Bacillibactin significantly suppresses the growth of Pseudomonas cichorii in tomatoes and also inhibits the growth of fungal pathogens such as Fusarium spp., Rhizoctonia spp., Aspergillus spp., and Verticillium spp.. Bacillibactin, at a concentration of 10 μM, shows an inhibition rate of less than 20% on two human cancer cell lines, HepG2 (liver cancer cells) and MCF7 (breast cancer cells), indicating a lack of significant in vitro antitumor activity.