Industrial biotechnology. Renewable biomass can be used as a raw material for the production of various chemicals, fuels and materials in a cost-effective manner by employing metabolically engineered high performance microorganisms. This cover art shows production of biobutanol from renewable biomass by employing engineered clostridia (see the article by Jang et al. http://dx.doi.org/10.1002/biot.201100059). The cover picture was created by Prof. Sang Yup Lee and Dr. Yu Sin Jang at KAIST, Korea.