The Future of Paint? Shimmering Bacteria in Vibrant Hues
Flavobacteria in a petri dish. Courtesy of the University of Cambridge and Hoekmine BV.
What if you could paint with the vivid, iridescent hues of a peacock’s feather or a butterfly’s wing? New research, conducted by chemists at the University of Cambridge and biotechnology company Hoekmine BV, suggests that could soon be a reality.
In nature, color occurs in two ways: either through pigmentation, where color appears the same from every angle, or structural color, where color changes according to interactions with light. A wide range of living organisms—including plants, insects, and birds—possesses structural color, an evolutionary development that facilitates survival skills such as camouflage, photosynthesis, and mating.
British scientists Robert Hooke and Isaac Newton were the first to identify structural coloration in the 17th and early-18th centuries. But humans have been interested in the subject since the time of ancient Rome—in his 1st-century-B.C. poem De Rerum Natura, Lucretius observes how the color of a peacock’s tail changes depending on the light.
Courtesy of the University of Cambridge and Hoekmine BV.
Courtesy of the University of Cambridge and Hoekmine BV.
This newly published study is the first to investigate the genetics of structural color. Although researchers already knew that the structural color of a given organism is rooted in its DNA, the study sought to identify which exact genes are responsible for coloration.
The model organisms used for the study were colonies of flavobacterium, a rod-shaped bacteria found in soil and freshwater; the colonies were naturally a rich, metallic green hue. By altering the genetic makeup of the flavobacterium, the scientists found they could also change the color of the bacteria. Not only could they produce any color of the rainbow, they could control the intensity of each shade—or even eliminate color altogether.
These lab-produced colors “are really metallic, similar to the color you see in peacock feathers,” said chemist Silvia Vignolini, who worked on the study with Villads Egede Johansen at the University of Cambridge. “They change slightly when you look at different angles.”
Given more funding, the scientists will continue to explore the genetics of structural color, as well as the potential to harvest flavobacterium, which can be grown in only 24 hours.
Courtesy of the University of Cambridge and Hoekmine BV.
Vignolini said that, in principle, it’s possible to add a fixative to the bacteria to create paint. (Without a fixative, the bacteria would only last a few days or weeks, depending on the storage method.) “We’re working to find a way where we can really use them as a sort of pigmentation and color,” she explained. They hope to produce a fixative from all-natural elements, in order to develop a biodegradable paint.
Beyond the potential for an eco-friendly, mass-produced paint used in homes or on automobiles, Vignolini said the researchers are also keen to collaborate with artists. But the cutting-edge medium has already made it onto the palettes of artists in residence at Hoekmine BV, who are currently experimenting with their own bacteria-fueled paintings.
