Explores the possible contributions of microbes to the next generation of fuels. Provides thorough explanations of the current knowledge and future areas for research on microbial energy conversions. Includes chapters on ethanol production from cellulosic feedstocks, which is more sustainable than ethanol production from corn. Also presents explanations of the status of energy sources that are in various stages of development, including methane, methanol, hydrogen, electricity, and butanol. Examines possible areas for new research that may contribute to future breakthroughs on alternative fuels.