The Bacteriocins

In recent years bacteriocins, especially colicins, have become widely known to molecular biologists as proteins with peculiar ways of killing bacteria. These same bacteriocins have been known for a long time to bacteriology for their unusual activity spectra and enormous variety. In this monograph I have attempted to bring together our detailed knowledge of those few bacteriocins which have already re­ ceived attention from molecular biologists, and our less detailed hut extensive knowledge of the variety of bacteriocins which exist. The field has been reviewed in whole or in part, by several authors [FREDERICQ, 1957, 1964, 1965 (2); IVANOVICS, 1962; HAMON, 1965; REEVES, 1965 (2)]. These reviews have been very useful to the author, and readers will find further references in them, and sometimes alternative viewpoints. We have already referred to bacteriocins as proteins, and in doing so have ex­ cluded many more complex antibacterial agents which resemble bacteriophages or their tails. In the author's view, these phage-like particles are probably not bacterio­ cins, but many authors include them within the definition; the more restrictive de­ finition used here has meant omitting discussion of some excellent studies on what the present author would term defective bacteriophages. In the first chapter we look at the discovery of bacteriocins and an outline of their classification. With this background we can discuss in Chapters 2 to 6 the chemistry, genetics and mode of action of the more intensively studied bacteriocins.

Contenu

1 The Colicins and Other Bacteriocins.- The Discovery and Classification of Colicins.- Specific Receptors in Colicin Classification.- Terminology.- Subcategories of Colicin Types.- Colicins as Bacteriocins and Other Groups of Bacteriocins.- 2 The Chemistry.- Chemical Studies on Colicins and Related Bacteriocins.- The First Observations.- Colicin K-K235.- Colicins V-K357, A-CA31 and SG710.- Colicins of Type E.- Colicins of Type I.- Cloacin DF13.- Morganocin MB336.- Other Colicins.- The Colicins Compared.- Pyocins A2-P1-III and A3-P1-III.- Bacteriocins of Gram-positive Bacteria.- Megacin A-216.- Megacin KP-337.- Staphylococcin 1262.- Enterococcin E1.- Defective Bacteriophages.- Other Observations on Chemistry of Bacteriocins.- Conclusions.- 3 Inheritance of Bacteriocinogeny.- to Bacterial Genetics.- The Fertility System of E. coli K12.- The Sex Pilus.- The Epichromosomes.- C-Factors.- The Epichromosome E1-K30.- Nomenclature of C-Factors.- The Epichromosome I-P9.- The Epichromosomes VB-K260 and VI-K94.- The Inheritance of Other Bacteriocins.- Intergeneric Transfer.- The Autonomous Nature of C-Factors.- The Types of C-Factor.- Transduction of Colicinogeny.- Physical Nature of C-Factors.- Conclusions.- 4 The Properties of C-Factors.- Regulation of Colicin Synthesis and C-Factor Replication.- The Production of Bacteriocins.- Induction of Colicin Production.- Lethal Biosynthesis of Bacteriocins.- The Induction of the E1-K30 C-Factor and Its Colicin.- The Role of C-Factor Proteins in Induction.- The Role of the E. coli Rec Gene in Induction.- The Nature of E1-K30 Induction.- Regulation of the I-P9 C-Factor.- Classification of C-Factors.- The Specificity of the Sex-Pilus.- Repressors of Promoter Activity.- The Rec Gene and Induction of Various C-Factors.- Incompatibility between Epichromosomes and Entry Exclusion.- Immunity to Bacteriocins.- Stability and Elimination of Epichromosomes.- Conclusions.- 5 Mode of Action - The Adsorption of Bacteriocins.- How Bacteriocins Kill.- The Colicin Receptor.- The Quantitation and Specificity of Colicin Adsorption.- Specific Adsorption of Colicin by Sensitive Bacteria.- The Quantitation of Adsorption.- The Single-Hit Hypothesis.- The Multi-Hit Hypothesis.- The Lethal Unit.- The Amount of Colicin Adsorbed per Cell at Saturation.- Number of Molecules per Lethal Unit.- The Reaction between Colicin and Receptor.- The Role of the Colicin Receptor.- The Nature of the Receptor.- Cross-Resistance between Colicins and Bacteriophages.- The Bacterial Cell Wall and Its Receptors.- Bacteriophage Receptors.- Colicin Receptors.- Conclusions and Summary.- 6 Mode of Action - The Biochemical Lesion.- Bacteriocins Which Affect Energy Flux.- Colicins of Types E1 and K.- Colicins of Types A and I.- Pyocin P10.- Bacteriocins Which Affect DNA Metabolism.- Colicins of Type E2.- Megacins C-C4 and KP-337.- Pesticin.- Bacteriocins Which Affect Protein Synthesis.- Colicins of Type E3.- Cloacin DF13 and Pneumocins S6 and S8.- A Bacteriocin Affecting Protein and RNA Synthesis.- Pneumocin G196.- Mediation of the Bacteriocin Effect.- Immunity of Colicinogenic Bacteria.- The Effect of Specific Inhibition on the Effect of Bacteriocins.- Is Energy Necessary?.- Is Protein or RNA Synthesis Necessary?.- Is DNA Synthesis Necessary?.- Colicin-Tolerant Mutants.- The Tol VIII Class or Tol C Gene.- The Tol VII or Ref II Gene.- The Tol I to VI Mutants.- Cross-Resistance between Colicins B, I and V.- General Conclusions on the Action of Colicins.- Bacteriocins Causing Membrane Damage.- Megacin A-216.- Enterococcin 1-X14.- The Bacteriocin-like Effects of Phage Adsorption.- Summary and Conclusions.- 7 The Bacteriocins in Nature.- Evolutionary Origins of Bacteriocins and Their Role in Ecology.- Relationship of Bacteriocins to Bacteriophages.- Paramecium and Paramecin.- The Killer Characteristic in Yeast.- Appendix A Catalogue of Bacteriocins.- Bacteriocins of the Enterobacteriaceae.- Alveicins.- Arizonacins.- Caratovoricins.- Cloacins.- Marcescins.- Pneumocins.- Miracins, Morganocins and Provicins.- Colicins.- Colicins - Activity Spectra.- The Colicinogenic Bacteria.- Sensitivity of Different Genera to Colicins.- Problems of Classifying the Bacteriocins of the Enterobacteriaceae.- Relationships between Bacteriocins of the Enterobacteriaceae.- The Pseudomonadaceae.- Pyocins.- Fluocins.- Vibriocins.- Other Gram-negative Bacteria.- The Pesticins.- Convexins.- Columnaricins.- Meningocins.- Bacteriocins of Gram-positive Bacteria.- Staphylococcins.- Enterococcins.- Lactocins.- Monocins.- Megacins.- Cerecins.- Subtilicins.- Perfringocins.- Types of Bacteriocins.