Researchers derive naturally occurring melanin at a massive scale from mushrooms

The pigment melanin protects human skin from harmful UV light (and gives us a summer tan), and is a veritable treasure trove for new materials and technologies. Although melanin occurs naturally, the complex biopolymer can only be produced artificially at an industrial scale through expensive and complex processes, during which some of the compound's properties are lost.

To date, processes for extracting natural melanin from microorganisms have low yields. It is therefore not surprising that melanin is many times more expensive than gold.

Empa researchers have now developed a method to produce melanin in a simple and highly scalable process. "Melanin is extremely stable when exposed to environmental influences and is interesting not only as a pigment, but also far beyond for the development of innovative composite materials," says Empa researcher Francis Schwarze from Empa's Cellulose & Wood Materials lab.

In their quest for simpler, cheaper processes for the production of natural melanin in large quantities, Schwarze and his team came across a common saprophytic fungus that grows in the forest: Armillaria cepistipes.

Its amazing metabolism enables the fungus to bind heavy metals, make wood glow in the dark, and produce melanin on a massive scale. "We have selected a promising strain of A. cepistipes that allows us to produce around 1,000 times more melanin than with other fungi," says Schwarze.