Spider-inspired silken threads

David Breslauer David Breslauer (Photo courtesy Bolt Threads)Where some people see mere cobwebs, David Breslauer (Ph.D.’10 BioE) sees nature’s most robust fiber. Spider silk exhibits a unique combination of strength and elasticity that makes it tougher than steel and Kevlar. For decades, researchers have been trying to come up with an affordable way of mass-producing spider silk on a commercial scale.

Now Breslauer — along with Dan Widmaier and Ethan Mirsky — has found a way to produce spider silk without spiders. Their company, Bolt Threads, has genetically modified a yeast that, when fermented with sugar and water, generates silk proteins similar to those produced by spiders. These protein strings are then spun into fibers for knitting or weaving into fabrics and garments.

Bolt Threads is poised to become the world’s first company to bring the benefits of spider silk to the masses, in the form of high-performance fabrics, an application that the trio decided would have the biggest early impact. Breslauer says the new fabrics are still as soft, warm and breathable as those made by silkworm silk. And by controlling the amino acid sequence of the silk proteins, Bolt can enhance qualities like stretch, strength, weight and water resistance.

The company — which has nearly 50 employees, including Berkeley alums from engineering and chemistry — is already producing test runs from its Emeryville headquarters. And with sufficient funding in hand, the company is ready to break into the apparel industry in a big way. Their first fabrics will reach store shelves sometime next year.

Read more: Improving the work of silkworms and spiders, with yeast

Topics: Bioengineering, Alumni

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