Pyrrolnitrin, an antibiotic derived from Pseudomonas pyrrocinia, exhibits a broad spectrum of antibiotic activity, effectively targeting fungi, yeast, and gram-positive bacteria.

Pyrrolnitrin, at concentrations ranging from 0 to 100 μg/ml, demonstrates potent antibiotic properties against a diverse array of bacteria and fungi, exhibiting varying Minimum Inhibitory Concentration (MIC) values. Specifically, it is effective against Staphylococcus aureus, Mycobacterium, Bacillus subtillis, Candida albicans, Aspergillus niger, and Trichophyton rubrum, with respective MIC values of 50 μg/ml, 100 μg/ml, 0.78 μg/ml, 10 μg/ml, 12.5 μg/ml, and 1 μg/ml[1]. Additionally, when assessed in a microtitre plate assay, Pyrrolnitrin shows an antimicrobial effect against Arthrobacter oxydans ATCC 14358, Bacillus coagulans ATCC 7050, Bacillus licheniformis ATCC 14580, Bacillus subtilis ATCC 6051, and Bacillus thuringiensis ATCC 10792, all with an MIC of 6.25 μg/ml[2].