The first antibiotic to be manufactured commercially.
Gramicidin is a peptide antibiotic produced by certain strains of soil bacteria (Brevibacillus brevis). It works by forming a cation-selective channel in the cytoplasmic membrane of target bacteria, leading to cell death. Gramicidin is effective against a wide range of Gram-positive bacteria but not against Gram-negative due to the presence of an outer membrane. The discovery of gramicidin was made in 1939 by René Dubos while working at the Rockefeller Institute for Medical Research in New York.
| gramicidin | 1939 |
| René Dubos | New York |