Preface

Soil is a home of various living microorganisms, such as algae, fungi, bacteria, nematodes, etc., that live and carry out their activities. A handful of soil contains billions of bacteria, fungi and other microorganisms. They play important roles in the nutrient cycle and make the availability of nutrients to plants. These microorganisms also degrade the dead and decaying parts of plants and animals that ultimately break up into minerals and make the soil healthy and fertile for crops to be grown there. These microorganisms not only interact with each other but also with the rhizosphere of the plant. The plant root exudates also influence the population of microorganisms.

Some microorganisms are found to be associated with particular plants and help those plants specifically. Microorganisms secrete chemicals or metabolites such as enzymes, which are helpful to plants and mankind in several ways. They may help plants to reduce stress and also increase the metabolic reactions to produce specific chemicals that may help for industrial purposes. These chemicals, secreted by microorganisms of plants in the presence of microorganisms, may be used by industries like pharmacy, leather, soaps, food, agriproducts, etc.

In the present volume 3 of the book, emphasis is being given to various soil microorganisms, including bacteria and mycorrhiza. The chapters contributed by eminent scientists and researchers have emphasized not only the introduction of these microorganisms but also their industrial uses as well as the effect on the plants. The chapters are written to provide information to the graduate and research students and for the scientists and academicians to get up-to-date knowledge of the subject. The authors have tried to provide the recent developments in the subject.

With positive hope, the editors of the book will be happy to receive suggestions and comments to improve the information for further editions.