Move over silk worms: Australian researchers have for the first time created artificially produced honey bee silk using genetically modified bacteria.
CSIRO entomologist Dr Tara Sutherland, who led the team of research researchers, says "the silks would be good for tough, lightweight textiles, and high-strength applications like advanced aviation and marine composites."
"It would also be useful in medical applications including sutures, artificial tendons and ligaments."
To produce their insect silk from E. coli, Sutherland and colleagues firstly had to genetically modify the bacteria.
"Honey bee silk was chosen because E. coli can't make long stranded silks like spiders or silk worms make, but can produce the shorter protein strands, made by honey bees," says Sutherland.
"Numerous efforts have been made to express other invertebrate silks in transgenic systems but the complicated structure of the silk genes in other organisms means that producing silk outside silk glands is very difficult."
"We had previously identified the honeybee silk genes and knew the silk was encoded by four small non-repetitive genes - a much simpler arrangement which made them excellent candidates for transgenic silk production."
The right diet
Sutherland says the transgenic E. coli are fed a special nutrient mix to make them grow and multiply.
"And when you are ready, you change the nutrients, making the bacteria produce silk proteins."
The next step involved treating the protein solution to concentrate it to form the right kind of structures.
"You can use modern molecular biology to alter the length of the protein," she says. "And you can produce the product in normal ambient environments, without the need for special systems, manufacturing conditions or harsh solvents."
"It's then as simple as dipping your tweezers into the solution and pulling out a thread, just like hot toffy."
Sutherland says the threads were as strong as threads drawn from the honeybee silk gland.
Future production could see sheets of silk or very fine structured material produced ly by drawing them twice to produce a translucent yet stable fibre.
"The next step will be to turn the whole process into a large scale commercial application."