This book aims to present as broad a perspective as possible to the subject matter. In the construction of the chapters, much has been left to the individual contributors. Some chapters have been written essentially up to the minute reviews of an application or use of continuous culture whilst other have used data obtained in the author's own laboratory to illustrate the use of continuous culture as a problem-solving tool. Yet others have concentrated on specific topics and cited a few key ways in which continuous culture can be useful. The approach was left solely up to the contributor.