The history of antibiotics may weIl have begun with the ancient Sudanese-Nubian civilization (see Chapter 1, Historical Introduction ), but this volume reflects a more contemporary appraisal of the antibiotic era. We have compiled a comprehensive review of the tetracyclines which includes all the major sub divisions of these chemically important and clinically useful antibiotics. There can be little doubt about the contribution of antibiotics to both the increase in human life span and the alleviation of much human suffering. The tetracyclines are still playing an important role in these areas and will continue to do so in the foreseeable future. We hope this volume will be an important contribution to a better under standing of the chemistry, biochemistry, and medical aspects of tetracycline antibiotics. We are indebted to the individual authors who have given so much of their time and effort in the preparation of the chapters. Pearl River, NY J OSEPH J. HLA VKA Ocean Gate, NJ JAMES H. BOOTHE Contents CHAPTER 1 Historical Introduction. J. H. BOOTHE and J. J. HLAVKA References. 3 CHAPTER 2 Fermentation and Mutational Development of the Tetracyclines J. J. GOODMAN A. Introduction 5 B. The Producing Microorganisms . 6 I. Morphology and Ultrastructure 6 11. Mutation and Strain Selection 8 111. Cosynthesis. 13 The Fermentation Process 14 C. I. Inoculum 14 11. Contamination 16 Complex Media. 18 111. IV. Synthetic Media. 27 V. Stimulators and Inhibitors 30 Directed Fermentations 32 VI.