A diverse range of biological material are produced by multicellular organisms. In some cases, such as with cellulose, there are naturally-occurring microbes that can be harnessed to produce this material on or off Earth. In others, such as spider silk, microbes have been–or will be–engineered to produce these compounds. B. subtilis spore image courtesy of the 2015 Stanford-Brown iGEM team (http://2015.igem.org/Team:Stanford-Brown/BioHYDRA).