Vegan leather shoes grown from bacteria
A Faux-leather shoe has been grown from bacteria in a lab in just 14 days and programmed to dye itself black.
The plastic-free vegan creation was cultivated by researchers at Imperial College London (ICL) from genetically engineered microbes.
It is the first time bacteria have been designed to produce a material and its own pigment simultaneously.
Researchers believe the process could be adapted to produce vegan materials with vibrant colours and even patterns, and to offer alternatives to fabrics such as cotton and cashmere.
Prof Tom Ellis, the lead author from ICL’S department of bioengineering, said: “Inventing a new, faster way to prod uce 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.”
Manufacturers are trying to move away from synthetic chemical dyeing because it is environmentally toxic.
The black dyes which are used to colour leather are particularly harmful. The self-dyeing leather alternative was created by modifying the genes of a bac- teria species that produces sheets of microbial cellulose – a strong, flexible material that is already commonly used in food, cosmetics and textiles.
Genetic modifications “instructed” the same microbes that were growing the material to also produce a dark black pigment called eumelanin.
The cellulose was grown around a shoe-shaped mould to give it the shape of a traditional “upper” and after 14 days had taken on the correct shape.
To encourage the shoe to turn black, it was subjected to gentle shaking at 30C (86F) to activate the production of black pigment from the bacteria so that it dyed the material from the inside.
The team, who worked with the London-based biodesign company Modern Synthesis, also made a black wallet by growing two separate cellulose sheets, cutting them to size and sewing them together.
Co-author Dr Kenneth Walker, who conducted the work at ICL, said: “Our technique works at large enough scales to create real-life products, as shown by our prototypes.
“From here we can consider aesthetics as well as alternative shapes, patterns, textiles, and colours,” he added.