The fifth edition of this highly successful book provides students with an essential introduction to the molecular genetics of bacteria covering the basic concepts and the latest developments. It is comprehensive, easy to use and well structured with clear two-colour diagrams throughout. Specific changes to the new edition include: More detail on sigma factors, anti-sigma factors and anti-anti sigma factors, and the difference in the frequency of sigma factors in bacteria Expand material on integrons as these are becoming increasingly important in antibiotic resistance Enhanced treatment of molecular phylogeny Complete revision and updating of the final chapter on Gene Mapping and Genomics Two-colour illustrations throughout. The focus of the book remains firmly on bacteria and will be invaluable to students studying microbiology, biotechnology, molecular biology, biochemistry, genetics and related biomedical sciences.