This is supposed to be the most up-to-date book on 'biosurfactants'. Moreover, the enormous commercial and healthcare potentials of biosurfactants and the current market demand for cost competitive and environment friendly alternatives to synthetic surfactants, particularly when an impending petroleum crisis is looming large all over the world, have encouraged me to undertake the challenge of editing this book on 'Biosurfactants'. We endeavor not only to highlight the tremendous progress made by the scientific community in this field of research, but also to critically analyze the lacunae to improve the commercial prospects of these wonder biomolecules by resorting to novel screening methods, metabolic pathway engineering, and innovative process development and application strategies. I do fervently hope that the book will be able to cater to the needs of the research scientists and technologists at large. We will be very happy if our sincere efforts enhance the reader's understanding of the new developments in this subject area.