Fashion's web: how spiders can help the industry's polluting problem

Man-made silk spirals.

As one of the world’s most polluting industries, fashion needs to clean up its act. Might the answer be in the hands of our eight-legged friends?

By Ryan Thompson   Tuesday 24 March, 2020

When Sir Alexander Fleming went on a two-week holiday without bothering to clear his desk of contaminated culture plates, he gave the world two things. The first was penicillin: one of the greatest medical discoveries of the 20th century. That alone is a worthy contribution. But what this lab technician, with a (apparently deserved) reputation for carelessness, also gave us was the idea that sometimes progress just happens naturally. It’s an organic matter. And it’s an idea that’s making inroads in an industry whose very foundations are, arguably, built on the idea of artifice: fashion. Because for all its efforts, the fashion industry has so far only managed to make a small dent in its devastating environmental impact. For real progress, we have to go back to basics. We need a bioengineer, a biophysicist, a biochemist and some spiders. And while we’re at it, throw in a few mushrooms, too.

Back in 2009, a new player in the fashion industry was born – but this one would not be interested in rivalling the gothic romanticism of Alexander McQueen or Christophe Decarnin’s pagoda silhouettes at Balmain. Rather, this Bay Area-based company was led by our aforementioned bio-protagonists, also known as Dan Widmaier, David Breslauer and Ethan Mirsky, with the shared vision of growing biotechnological fabrics that could look, act and feel like the natural fibres we use today, but with a fraction of the environmental impact. That vision became Bolt Threads, and it might just help push the fashion industry forward.

If you’re wondering where the spiders enter the picture, allow me to explain. While arachnids might not be everyone’s favourite cohabiters, the silk they produce boasts some truly amazing properties. It is a high-performance fibre in every sense of the term – incidentally, something the military have known for some time, since its ability to absorb in excess of 100,000 joules of kinetic energy makes it an ideal material for structural blast protection and bulletproof vests. In 2012, armed with this knowledge, Widmaier, Breslauer and Mirsky began to look into the DNA of spider silk to try to understand how to replicate its key properties – including high-tensile strength, elasticity, durability and softness – in a way that could be sustainable and scalable, as well as biodegradable, unlike other ‘performance fabrics’, which are typically polymer-based.
Man-made silk spirals.
Man-made silk spirals.
Here’s where it gets a bit Marvel Comics: a company called Kraig Biocraft Laboratories has, in fact, managed to genetically engineer traditional silkworms using spider silk gene sequences – but that approach didn’t work for Bolt Threads, since it still requires large-scale farming, which has its own sustainability problems. Another challenge presented itself in the fact that, unlike the silkworm, which can be domesticated and farmed, spiders will eat one another in similar lab
conditions. The breakthrough finally came by incorporating a host that exists all around us: yeast.

Bolt Threads’ synthetic method relies on the planting, harvesting and replanting of sugar-producing plants – in short, it has bioengineered a yeast to produce a silk protein in large quantities. From there, the protein is spun into fibres and then knitted into Microsilk, its signature fabric. Compare this renewable process to polyesters, which are made from petroleum derivatives. Currently, more than 60 per cent of textiles are made that way.

So why isn’t every designer and brand using Microsilk? As anyone who has ever tried to brew their own beer or make their own bread can attest, many things can go wrong in the fermentation process, from subtle temperature changes to fluctuating pH levels. And when you’re talking about scaling up, these variables become even more volatile. So, the next step for Bolt Threads is to translate its process to fermentation vessels large enough to be able to create sufficient volumes of protein fibres. But what they have produced so far has gone down very well indeed. In 2017, the firm partnered with sustainability pioneer Stella McCartney to produce a gold Microsilk shift dress for the Museum of Modern Art’s exhibition, Items: Is Fashion Modern?. Bolt Threads CEO, Widmaier, said at the time, ‘We’re excited to leverage our signature protein-based yarn, inspired by spider silk, within upcoming Stella McCartney collections. As our partnership develops, our teams are eager to collaborate on additional technologies and textiles, and explore the possibilities of innovation by working together.’

And innovate they have, by adding mushrooms into the mix – and more specifically, their subterranean bacterial colony, known as mycelium. In 2017, Bolt Threads partnered with Ecovative Design, a startup that creates a faux leather which it calls Mylo. By developing mycelium cells to assemble into a textile, Mylo can be grown in a matter of days and is ultimately biodegradable. According to McCartney, who is working with the fabric, it looks and feels like handcrafted leather, and every sheet yields unique variations, making each product one of a kind.

What makes these sustainable fabrics so exciting is that they are really just the tip of the biotech iceberg. From squid beaks to dragonfly wings, nature has an abundance of super-materials which can all, in theory, be bioengineered to form materials that could dramatically reduce the environmental impact of the fashion and textile industries. That’s an idea that could literally grow on us.