The increasing worldwide demand for energy, combined with diminishing fossil fuel reserves and concerns about climate change, have stimulated intense research into the development of renewable energy sources, in particular, microbial biofuels. For a biofuel to be commercially viable, the production processes, yield, and titer have to be optimized, which can be achieved through the use of microbial cell factories. Using multidisciplinary research approaches, and through the application of diverse biotechnologies (such as enzyme engineering, metabolic engineering, systems biology, and synthetic biology), microbial cell factories have begun to yield some very encouraging data and microbial biofuels have a very promising future. In this book, a panel of international experts review the most important hot-topics in this area to provide a timely overview. The production of different biofuel molecules is comprehensively covered, including hydrogen, methane, ethanol, butanol, higher chain alcohols, isoprenoids, and fatty acid derivatives from genetically engineered microbes. To enhance biofuel production, special focus is given to the use of metabolic engineering of microbes, including bacteria, yeast, and microalgae. In addition, the book's contributors discuss the current research progress, technical challenges, and future development trends for biofuel production. Essential reading for research scientists, graduate students, and other specialists interested in microbial biofuels, the book is also recommended reading for environmental microbiologists, chemists, and engineers.