Growing engineered silk fibres in fermentation vats might sound more like science fiction than science fact, but a California-based start-up has secured $40m in funding to bring these "next generation" high performance fibres and fabrics to market.

The Emeryville-based company Bolt Threads last week revealed it has closed on a $32.3m Series B funding round, adding new investors and bringing the total raised so far to $40m.

Its new technology replicates the silk production process of spiders and silkworms on a very large scale, producing a high-performance silk protein that can be spun into fibres with specific attributes, like strength, stretch or softness, can be washed, and do not yellow or tear with age. The silk is produced through fermentation, using yeast, sugar and water - very much like the beer-making process – and has the exact same chemistry as naturally occurring animal silks.

Claiming the programmable fibres "represent the most significant innovation the textile industry has seen for decades," and provide consumers "with material products they’ve never had access to before," Bolt Threads also believes its new textile materials minimise impacts on the environment. The main input in its fibre-making process is sugar from plants that are grown, harvested and replanted, whereas more than 60% of textiles are currently made of polyester and other petroleum-derived fibres.

The company says it now plans to use the funding to fuel research and commercialisation of its Engineered Silk technology, and grow its team of technology and apparel experts.

"While it's one of the oldest industries in existence, I believe textiles is still ripe for innovation," said Steve Vassallo, general partner at Foundation Capital, which led the latest funding round. "Bolt Threads…have developed a way to make Engineered Silk fibres at a commercial scale, at a cost that makes it viable for widespread use in consumer products – something no one else has done."

CEO Dan Widmaier, chief scientific officer David Breslauer and vice president of operations Ethan Mirsky founded the company in 2009 to create materials with exceptional performance properties.

"Our technology combines biology and computational methods to create performance fibres with carefully crafted properties," Widmaier said. "We’re very excited to sustainably develop the next generation of performance fabrics that will transform what we wear and how we live."

The company uses feedstock grown in the Midwest for production, and is also collaborating with textile manufacturers in North Carolina to commercially scale production.