IX International Congress for Microbiology discusses the genetic regulation of microbial metabolism. This book presents the recommendations and suggestions on the nomenclature and classification of viruses. Organized into eight parts encompassing 72 chapters, this compilation of papers starts with an overview of the genetic code, which expresses the relationship between nucleotide triplets in messenger RNA and amino acids in proteins. This text then discusses the two aspects of the regulation of the physiology of Escherichia coli. Other chapters explore the ergot alkaloids and examine the problem of ergot alkaloid production and biosynthesis. This book discusses as well the antibiotic inhibitors of protein synthesis that are major clinical drugs, including chloramphenicol, tetracycline, streptomycin, erythromycin, and other aminoglycosides. The final chapter deals with karyological investigation of the cells during transformation by Rous virus (RSV), which shows that these cells retain a diploid character. This book is a valuable resource for epidemiologists, microbiologists, and experts in infectious diseases.