The rapid expansion od industry and the excessive demands made on limited natural resources have caused genuine concern at all levels of society. In the past this concern has concentrated on plants and animals and their relationships with their environments, but now attention is also turning towards microorganisms whose role is crucial to so many natural processes - from global life and mineral cycles through to the production of beer and milk products. After a brief introduction to microbiology this book concentrates on the ecological aspects of microbial life covering a wide variety of topics including structure, behaviour, growth, dispersal, interactions and how microbes act as symbionts and pathogens. Such a wide-ranging interdisciplinary approach will appeal to undergraduate and graduate students of microbiology, plant and animal ecology, agronomy, forestry and environmental sciences. Professionals working in the same fields will also find it informative as will those working in plant pathology and soil, aquatic, medical and food microbiology.