The actinomycetes are a group of bacteria well known as producers of antibiotics. With the advent of molecular biology they have become important to biotechnologists in the search for new antibiotics, vitamins, enzyme inhibitors, etc. They also play an important role in the biodegradation of wastes, and their wide (natural) distribution in soil, composts, water and elsewhere in the environment makes them important to the agricultural and waste industries. This research book presents a broad view of the current interest in actinomycetes, ranging from isolation/screening of actinomycetes, discovery of new antibiotics, a substantial contribution on genetic manipulation to actinomycetes in agriculture, forestry, and the threat of actinomycetes as pollutants in the environment.The chapters, which have been written by experts, are intended to provide a balanced view of the opportunities and problems in an expanding field of interest.