细菌工厂如何编织比钢还坚韧的医用线
For decades, the gossamer thread of a spider’s web has haunted materials scientists with an impossible recipe: a protein filament that surpasses Kevlar in toughness, yet remains biodegradable and biocompatible. Harvesting it directly from arachnids has proven impractical—spiders are territorial cannibals that produce silk in vanishingly small amounts. The solution, pursued in laboratories from Utah to Tsukuba, involves coaxing genetically modified microbes—E. coli or yeast—to spin the same proteins in fermentation tanks, a process that marries synthetic biology with molecular-spinning technology.
The core challenge lies in translating spider genes into industrial yields. Researchers have inserted the DNA encoding major ampullate silk proteins into bacterial plasmids, then engineered the microbes to secrete these long, repetitive chains into a liquid broth. Yet raw protein is not thread; it must be extruded through microscale nozzles, stretched, and dried to align the molecular chains into a crystalline structure that gives silk its legendary strength. Even small deviations in pH or temperature can yield a brittle fibre, so the process remains as much art as engineering.
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