This book reviews the potential of unconventional production organisms in biotechnology, emphasizing their role in enhancing bioprocess efficiency and sustainability. By focusing on a diverse range of microorganisms, such as the archaea Methanothermobacter thermautotrophicus and the fast-growing bacterium Vibrio natriegens, the book highlights the opportunities and needs for integrating these organisms into biotechnological applications.The chapters cover topics such as the utilization of alternative substrates like CO2 and methane, adaptation to unusual process conditions, and the exploitation of microbial diversity for enhanced biofilm growth and electron transport systems. Each chapter begins with an overview of the microbiological and biochemical characteristics of the organisms, followed by discussions on their biotechnological applications. Readers will also find expert analysis of the current challenges and future trends in the application of these organisms, making the book a must-read for anyone interested in advancing bioprocess technologies.Given its breadth, this book is an invaluable resource for researchers, scholars, and practitioners in biotechnology and related fields. It provides cutting-edge insights into the development of processes based on alternative organisms, and their role in shaping the future of biotechnology.