Researchers have genetically engineered bacteria to grow animal- and plastic-free “leather” that dyes itself. This is the first time that bacteria have been engineered to produce a material and its own pigment simultaneously.
- The researchers say their self-dyeing plastic-free leather, which has been fashioned into shoe and wallet prototypes, represents a step forward in the quest for more sustainable fashion.
THE RESEARCH: The new process engineered at Imperial College London, which has been published in the journal Nature Biotechnology, could also theoretically be adapted to have bacteria grow materials with various vibrant colours and patterns, and to make more sustainable alternatives to other textiles such as cotton and cashmere.
COLLABORATING WITH DESIGNERS: 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.
- They also made a black wallet by growing two separate cellulose sheets, cutting them to size, and sewing them together.
- The researchers also demonstrated that the bacteria can be engineered using genes from other microbes to produce colours in response to blue light. By projecting a pattern, or logo, onto the sheets using blue light, the bacteria respond by producing coloured proteins which then glow.
- This allows them to project patterns and logos on to the bacterial cultures as the material grows, resulting in patterns and logos forming from within the material.
THE FUNDING: The researchers and collaborators have also just won £2 million in funding from the Biotechnology and Biological Sciences Research Council (BBSRC), part of UK Research and Innovation (UKRI), to use engineering biology and bacterial cellulose to solve more of fashion’s problems, such as the use of toxic chromium in leather’s production lines.
- The project was funded by Engineering and Physical Sciences Research Council and BBSRC, both part of UKRI.
- The authors worked closely with Modern Synthesis, a London-based biodesign and materials company, which specialises in innovative microbial cellulose products.
WHAT THEY 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.”
— Professor Tom Ellis (Lead Author)
Department of Bioengineering
Imperial College London
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. The work also shows the impact that can happen when scientists and designers work together. As current and future users of new bacteria-grown textiles, designers have a key role in championing exciting new materials and giving expert feedback to improve form, function, and the switch to sustainable fashion.
— Dr Kenneth Walker (Co-Author)
Department of Bioengineering
Imperial College London
