The colonies in this image display some of the diversity of pigment production in Pseudomonas aeruginosa. The blue-green colonies contain a pigment called pyocyanin, which is known to be toxic to human cells and helps the bacteria establish a niche during infections. The colonies containing a brown halo produce the brown pigment pyomelanin, which is thought to help the bacteria scavenge for iron, an essential nutrient. The star shaped colonies are exhibiting a version of surface motility, while the colonies at center of each outside edge are wild-type P. aeruginosa.
Contributed by Ian Hill, a fifth year graduate student in the Biological and Biomedical Sciences program at Harvard University, and our Featured Artist for January and February, 2018. To meet Ian and see more of his art, click here.