The encyclopedia · Software & IT · Technical decision · 2012–2019
Bolt Threads grew spider-silk fibre in yeast instead of on spiders
It spliced spider-silk genes into yeast, fermented sugar, and spun a strong, biodegradable yarn called Microsilk.
Bolt Threads
the move
Polyester is strong and cheap but lasts for decades in landfill and sheds microplastics, and most biodegradable alternatives do not match its strength.
Bolt Threads reversed the process: instead of farming spiders, it read spider-silk DNA and engineered yeast to produce the same proteins at scale.
Those proteins are fermented, purified and spun into Microsilk, a durable, biodegradable yarn that brands including Stella McCartney and Adidas used in garments, including a concept tennis dress.
why it works
- Fermenting protein in yeast is scalable in a way harvesting from spiders never can be.
- It matches silk's performance independently of petroleum, so durability does not cost the planet.
- The process is a standard fermentation and spinning line, so production can scale with existing equipment.
- It replaces a petrochemical feedstock with a biological one while keeping the fibre's useful properties.
what transfers
If a material is expensive because the source is rare, grow the recipe instead of harvesting the source.
what came after
Bolt Threads made Microsilk products and partnered with Stella McCartney and Adidas on concept garments, and the approach is cited as a leading example of engineered silk; the company later pivoted away from volume textile production as the material stayed in development.
references
- Native-sized recombinant spider silk protein produced in metabolically engineered Escherichia coli results in a strong fiber
- Microsilk by Bolt Threads: A bioengineered fibre inspired by spider silk
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