Scientists create plastic-free vegan leather that dyes itself, grown from bacteria

Researchers at Imperial College London have genetically engineered bacteria to grow animal- and plastic-free leather that dyes itself.

Lead author Professor Tom Ellis, from Imperial College London's Department of Bioengineering, said, "Inventing a new, faster way to produce sustainable, self-dyed leather alternatives is a major achievement for synthetic biology and sustainable fashion.

"Bacterial cellulose is inherently vegan, and its growth requires a tiny fraction of the carbon emissions, water, land use and time of farming cows for leather. "Unlike plastic-based leather alternatives, bacterial cellulose can also be made without petrochemicals, and will biodegrade safely and non-toxically in the environment."

The researchers created the self-dyeing leather alternative by modifying the genes of a bacteria species that produces sheets of microbial cellulose – a strong, flexible and malleable material that is already commonly used in food, cosmetics and textiles. The genetic modifications "instructed" the same microbes that were growing the material to also produce the dark black pigment, eumelanin.

They worked with designers to grow the upper part of a shoe (without the sole) by growing a sheet of bacterial cellulose in a bespoke, shoe-shaped vessel. After 14 days of growth wherein the cellulose took on the correct shape, they subjected the shoe to two days of gentle shaking at 30°C to activate the production of black pigment from the bacteria so that it dyed the material from the inside.

Image source: Walker et al. (2024), Nature Biotechnology.