Researchers at Imperial College London have created genetically engineered bacteria to cultivate leather that dyes itself, providing a vegan-friendly alternative to both animal leathers and plastic leathers, and reducing the negative environmental impact of chemical dying. 

The study, titled “Self-pigmenting textiles grown from cellulose-producing bacteria with engineered tyrosinase expression”, was published in the journal Nature Biotechnology on 2nd April 2024. The genetic modifications researchers made to the bacteria made them grow cellulose together with the dark black pigment, eumelanin.

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 fashioned prototypes including shoes and wallets. They worked with material designer Jen Keane to grow the upper part of a shoe by growing a sheet of bacterial cellulose in a shoe-shaped vessel. It took 14 days for the bacteria to grow the cellulose in the correct shape.

The researchers hope to be able to expand this technology to other textiles like cotton. They had received a £2 million grant from the Biotechnology and Biological Sciences Research Council, to tackle different challenges affecting the fashion industry.

Research on vegan leather is quite popular now. Last year, a Turkish company showed how it was upcycling tea waste and turning it into vegan leather and other eco-friendly products. Also, a company in India is producing a vegan eco-friendly alternative to synthetic leather by using mango fruits. Currently, up to 40% of the mangos are abandoned in the fields because they fail regulatory and market standards, so they can be used to produce fake leather.

“Originally from Catalonia, but resident in the UK for several decades, Jordi is a vegan zoologist and author, who has been involved in different aspects of animal protection for many years. In addition to scientific research, he has worked mostly as an undercover investigator, animal welfare consultant, and animal protection campaigner. He has been an ethical vegan since 2002, and in 2020 he secured the legal protection of all ethical vegans in Great Britain from discrimination in a landmark employment tribunal case that was discussed all over the world. He is also the author of the book, ‘Ethical Vegan: a personal and political journey to change the world’.