This contributed volume provides a comprehensive overview of polyhydroxyalkanoates (PHAs)—a family of biodegradable and bio-based polyesters synthesized by microorganisms. Authored by leading experts in microbiology, polymer science, and biotechnology, the book devotes special attention to recent advances in metabolic and enzyme engineering, positioning microbial plastic factories as a key innovation in the development of sustainable plastic materials. In addition to discussing the physical properties, biodegradability, and industrial applications of PHAs, the book highlights the extensive research achievements of pioneering scientists and their broader contributions to the progress of the field. Strong emphasis is placed on industrial case studies, the outstanding challenges in the commercialization of microbially synthesized plastics, and future directions in sustainable materials science. This book serves as a comprehensive reference for scientists, engineers, and policymakers working on the development and practical use of biobased and biodegradable plastics.

Seiichi Taguchi, Ph.D., is a Professor Emeritus at Hokkaido University, Japan. He is a leading expert in the field of microbial polyester synthesis, metabolic engineering, and synthetic biology. His research focuses on the design of microbial cell factories for the production of biodegradable plastics, especially polyhydroxyalkanoates (PHAs), using both natural and recombinant organisms. He has authored over 210 peer-reviewed publications and has co-edited several academic books on biopolymer science. Prof. Taguchi has collaborated extensively with industry and international partners and is recognized for his contributions to the development of sustainable materials from renewable resources. As a token of his greate contributions, he received Prizes for Science and Technology, The Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology (MECST) and the other awards. 

Prof. Miwa Yamada is a Professor at Iwate University. She received her Ph.D. in engineering from Hokkaido University in 2010. Her Ph.D. thesis was on the microbial synthesis of lactic acid polyesters using recombinant Escherichia coli under the supervision of Prof. Seiichi Taguchi. Her current research focuses on the microbial synthesis of PHAs from seaweeds and the elucidation of the microbial enzymatic degradation mechanisms of biodegradable polyamides. These works have been well received and she received the Japan Society for Bioscience Biotechnology and Agrochemistry (JSBBA) Award for Women Scientists from JSBBA in 2024 and the other awards.