Cultivation conditions for pigment production by Chromobacterium violaceum

Chromobacterium violaceum is a beta proteobacterium, gram-negative, facultative anaerobe, found in soil, riverbanks and waters of tropical and subtropical regions all around the world. The species produces, through secondary metabolism, several indole pigments derived from tryptophan. Violacein and desoxyviolacein are the most abundant pigments produced by C. violaceum. Previous studies have reported that culture extracts from C. violaceum, containing the pigments, possess important biological properties, such as antitumoral and antibiotic activities. This accounts for the current interest in defining cultivation conditions for the improvement of violacein and other pigment production. Our results showed that violacein production depends on carbon source. The pigment production is stimulated by glycerol, but its production is reduced in the presence of an easily metabolized carbon source, such as glucose or fructose. In addition, the utilization of a solid medium in the presence of glycerol is a better medium for the production of violacein and related pigments by C. violaceum.