The bioactive compounds of plants have world—wide applications in pharmaceutical, nutraceutical and food industry with a huge market. In this book, a group of active researchers have addressed on the most recent advances in plant cell and organ cultures for the production of biomass and bioactive compounds using bioreactors. Tremendous efforts have been made to commercialize the production of plant metabolites by employing plant cell and organ cultures in bioreactors. This book emphasizes on the fundamental topics like designing of bioreactors for plant cell and organ cultures, various types of bioreactors including stirred tank, airlift, photo—bioreactor, disposable bioreactor used for plant cell and organ cultures and the advantages and disadvantages of bioreactor cultures. Various strategies for biomass production and metabolite accumulation have been discussed in different plant systems including Korean/Chinese ginseng, Siberian ginseng, Indian ginseng, Echinacea, St. John’s wort, Noni, Chinese licorice, Caterpillar fungus and microalgae. Researches on the industrial application of plant cells and organs with future prospects as well as the biosafety of biomass produced in bioreactors are also described. The topics covered in this book, such as plant cell and organ cultures, hairy roots, bioreactors, bioprocess techniques, will be a valuable reference for plant biotechnologists, plant biologists, pharmacologists, pharmacists, food technologists, nutritionists, research investigators of healthcare industry, academia, faculty and students of biology and biomedical sciences. The multiple examples of large—scale applications of cell and organ cultures will be useful and significant to industrial transformation and real commercialization.