John Postgate

Microbes are everywhere. Normally invisible, they are abundant in the air we breathe, in soil, in water, on our skin and hair, in our mouths and intestines, on and in the food we eat. They make the soil fertile; they clean up the environment; they change, often improve, our food; some protect us from less desirable microbes. Yet most people are scarcely aware that they exist - except when they become ill. Microbes, as 'germs', are widely regarded as nasty, unpopular because a few can cause disease and a few can spoil food. Yet collectively microbes present a fascinating world of miniscule creatures, who together encompass all the processes of which terrestrial life is capable: creatures who have profound effects on our lives and surroundings. In this up-dated edition, the extraordinary impact which the microbial community has on our everyday lives is described in an accessible and easy to read style.

The fixation of nitrogen - the conversion of atmospheric nitrogen to a form which plants can use - is fundamental to the productivity of the biosphere and therefore to the ability of the expanding human population to feed itself. Although the existence and importance of the process of biological nitrogen fixation has been recognised for more than a century, scientific advances over the last few decades have altered radically our understanding of its nature and mechanisms. This book provides an introductory-level survey of biological nitrogen fixation, covering the role of the process in the global nitrogen cycle as well as its biochemistry, physiology, genetics, ecology, general biology and prospects for its future exploitation. This new edition has been fully updated to include the most recent developments in the field, so providing an up-to-date and accessible account of this key biological process.