Growth of Chromobacterium violaceum on R2A and Tryptic Soy Agar

Chromobacterium violaceum (ATCC 12472), a Gram-negative, rod-shaped bacterium capable of synthesizing hydrogen cyanide, was cultivated on R2A and Tryptic Soy Agar (TSA) at 30 ^oC for understanding the relative growth performance of the bacterium on different agars. Experiment results revealed that C. violaceum could grow well on both agars with the generation of small, round, purple colonies. Such morphology was similar to those obtained during growth of C. violaceum on LB Lennox agar. However, amount of purple violacein pigment secreted was significantly higher during growth on TSA agar compared to R2A agar. Swarming motility was not observed on both agars during growth of C. violaceum. Overall, relatively high cell density of C. violaceum could be supported by R2A and TSA agar, but TSA would be a more preferable growth medium for the bacterium if violacein production is a subject of study.