Product developers lining up for USU's synthetic spider silk

It’s five times stronger than steel, but extremely flexible. That makes spider silk a hot commodity for the development of everything from tires to tennis rackets.

The difficulties of working with arachnids, though, have long prohibited companies from investing in spider silk farming. But now things are changing, thanks to Utah State University, where biology professor Randy Lewis and his research team are using goats, silkworms, E. coli and alfalfa to make synthetic spider silk.

“We are trying to mimic natural spider silk because spiders can’t be farmed. They will eat each other,” Lewis said. “Since we can’t use the natural material for the kinds of applications we are working with, we are making our own synthetic spider silk material instead.”

Having isolated the silk-producing gene found in spiders, the team transported the gene into different organisms, such as goats. Once the goats are genetically modified, spider silk can be generated from their milk.

“We collect the goats’ milk that carries the spider silk protein,” Lewis said. “Then we spin the protein from the milk into fibers, which will then be used for various types of product development. We replicate the spinning routine for each of the organisms.”
Product developers can’t seem to get enough.

“Goodyear has used the silk for their tires, parachute companies are using it, brands of tennis rackets use the silk in their strings. Companies even braid the silk to make artificial ligaments,” said senior research scientist Michael Hinman, who is in charge of developing the modified E. coli.  

Hinman said the challenge with E. coli is “whether it can be commercially scaled up at a reasonable cost.”

For now, the transgenic goats produce the majority of the synthetic spider silk. But Lewis thinks silkworms hold the key to making spider silk easier to harvest and mass-produce. “At this time, the worms are still producing more silkworm silk than spider silk,” Lewis said. “But the spider silk they are generating has the closest properties to the actual spider silk.”

As they pursue cost-effective spider silk production, Lewis and his team members are enjoying the challenge of transgenic innovation.

“I think for us, it’s exhilarating every time we discover something new or an idea works,” Lewis said. “Doing something that no one has ever done before gives you kind of a rush.”

Mary Taggart, Sam Bennion, Landon Kohler, Hannah Heninger and Amanda Ahlman contributed to this article.