Scientists have developed a method to mass-produce xanthommatin, the pigment responsible for octopus camouflage abilities, opening up possibilities for applications ranging from natural sunscreens to military camouflage technology and colour-changing household paints.
The new technique produces up to 1,000 times more pigment than traditional methods, yielding between one to three grams per litre compared to around five milligrams previously. Researchers at UC San Diego’s Scripps Institution of Oceanography created a growth feedback loop that tricks bacteria into producing large amounts of the colour-shifting material for the first time.
The US Department of Defense and cosmetics companies have expressed active interest in the breakthrough. Military collaborators are exploring the material’s natural camouflage capabilities, whilst skincare companies are interested in using it for natural sunscreens. Other potential applications include photoelectronic devices, thermal coatings, environmental sensors and colour-changing paints.
“We’ve developed a new technique that has sped up our capabilities to make a material, in this case xanthommatin, in a bacterium for the first time,” said Bradley Moore, the study’s senior author and a marine chemist with joint appointments at Scripps Oceanography and UC San Diego Skaggs School of Pharmacy and Pharmaceutical Sciences. “This natural pigment is what gives an octopus or a squid its ability to camouflage — a fantastic superpower — and our achievement to advance production of this material is just the tip of the iceberg.”
Remarkable ability to change
Xanthommatin gives cephalopods their remarkable ability to change skin colour and blend with their surroundings. The pigment also appears in insects, contributing to the orange and yellow hues of monarch butterfly wings and bright reds in dragonfly bodies and fly eyes.
Traditional lab methods for producing xanthommatin are labour-intensive and rely on chemical synthesis with low yields. Harvesting the pigment from animals isn’t scalable or efficient. The breakthrough approach connects pigment production with bacterial survival, creating a self-sustaining loop.
The team began with a genetically engineered cell that could only survive if it produced both the desired pigment and a second chemical, formic acid. For every molecule of pigment generated, the cell also produces one molecule of formic acid, which provides fuel for the cell’s growth. Researchers described the approach as tricking the bacteria into making the material essential for its own survival.
Lead author Leah Bushin, now a faculty member at Stanford University, explained that the pathway for making the compound becomes essential for life. If the organism doesn’t produce xanthommatin, it won’t grow.
The team used robots to evolve and optimise the engineered microbes through two high-throughput adaptive laboratory evolution campaigns. Custom bioinformatics tools identified key genetic mutations that enhanced efficiency, enabling the bacteria to produce the pigment directly from a single nutrient source.
“As we look to the future, humans will want to rethink how we make materials to support our synthetic lifestyle of 8 billion people on Earth,” said Moore. “Thanks to federal funding, we’ve unlocked a promising new pathway for designing nature-inspired materials that are better for people and the planet.”
The study was published in Nature Biotechnology and funded by the National Institutes of Health, the Office of Naval Research, the Swiss National Science Foundation and the Novo Nordisk Foundation.
