This book ‘Extremophiles: Wastewater and Algal Biorefinery’ explores the potential of extremophiles/extremotolerant organisms in wastewater treatment, biorefining of algal biomass and in the treatment of industrial waste effluent. The book provides a holistic overview about the current status of extremophiles in waste water treatment and various industrial processes. The chapters comprehensively cover the scientific and research findings on various industrial applications of extremophiles such as biofuels, extremozymes, electricity generation, biofilms, microbial corrosion and waste water treatment etc. This book is an integrated source of literature for the scientists, engineers, academicians, and students working in the area of extremophiles, microbial technology and biorefinery.