Can spider silk and grasshopper rubber, brewed by vats of genetically modified microbes, wean us off our addiction to oil-based plastics?Manuela Saragosa explores what sounds like an environmentalist sci-fi utopia. She speaks to Daniel Meyer, head of corporate planning at Spiber, a Japanese company that is already trying to commercialise clothes and car parts made of synthetic spider silk. Meanwhile Christophe Schilling, chief executive of California-based Genomatica, is using a similar biotechnology to manufacture good old-fashioned nylon.But there is one potential problem: The microbes that make these fantastic new materials need to be fed lots and lots of sugar - but where will it all come from? Agnieszka Brandt-Talbot of Imperial College in London thinks she has an answer, and it involves that most sugary of substances - wood.Producer: Laurence Knight(Picture: Close up of a Furrow Spider on its web in a Pennsylvania meadow in summer; Credit: Cwieders/Getty Images)