This book is an unparalleled, very comprehensive survey of methods for monitoring of specific microorganisms in the environment, with great usefulness for those working in either the assessment of risks of released GMMs or with monitoring of released microorganisms in e.g. soil bioremediation or biocontrol. The aim is to provide a background in different techniques for monitoring of specific microorganisms in environmental samples along with examples of applications of these approaches. The examples include work done in laboratory model systems (microcosms) as well as documentation from actual field releases of genetically modified microorganisms. The regulatory aspects of risk assessment of genetically modified microorganisms targeted for release are also included. Therefore, this book is unique in dealing with different aspects of monitoring of GMMs and should be useful for regulatory agencies that require a summary of existing techniques and information as well as scientists that require a review of the "state-of the art" of modern methods for monitoring specific microorganisms in nature.