Bacteriocins of Lactic Acid Bacteria

Contributors

Foreword

Preface

Chapter I Antimicrobial Proteins: Classification, Nomenclature, Diversity, and Relationship to Bacteriocins

I. Introduction

A. Current Interest in Bacteriocins

B. Bacteriocins Defined

C. Nomenclature

D. Occurrence of Bacteriocins

II. Colicins

A. General Features

B. Mode of Action

C. Immunity

III. Killer Toxins, Yeast Antimicrobial Proteins

IV. Thionins, Plant Antimicrobial Proteins

V. Defensins, Animal Antimicrobial Proteins

VI. Conclusions

References

Chapter 2 Screening Methods for Detecting Bacteriocin Activity

I. Historical Perspective

II. Agar Diffusion Techniques

A. Introduction

B. Plating Methods

C. Media Composition and Conditions of Incubation

D. Adaptations of Agar Diffusion Methods Used with Lactic Acid Bacteria

III. Liquid Media

IV. Titration of Bacteriocins: Critical Dilution Method

V. Survivor Counts

References

Chapter 3 Biochemical Methods for Purification of Bacteriocins

I. Introduction

II. Detection and Assay of Bacteriocin Activity

III. Production of Bacteriocins

A. Production on Agar

B. Production in Broth

IV. Bacteriocin Purification

A. Biochemical Methods

B. Purified LAB Bacteriocins

V. Applications of Purified Bacteriocins

A. Biopreservation Systems

B. Characterization of Physical Properties

C. Immunological Studies

D. Protein Sequence Determinations and "Reverse Genetics"

VI. Summary

References

Chapter 4 Applications and Interactions of Bacteriocins from Lactic Acid Bacteria in Foods and Beverages

I. Introduction

II. Using Bacteriocinogenic Lactic Acid Bacteria and Bacteriocins to Control Food-Borne Pathogens

A. Sensitivity of Listeria monocytogenes to LAB Bacteriocins

B. Sensitivity of Clostridium botulinum to LAB Bacteriocins

III. Using Bacteriocinogenic Lactic Acid Bacteria and Bacteriocins to Direct Food and Beverage Fermentations

IV. Factors Affecting the Efficacy of Bacteriocins in Foods and Beverages

A. Interactions with Food Components

B. Enhancement of Bacteriocin Activity

C. Resistance of Target Microorganisms to Bacteriocins

V. Assays for Bacteriocins in Foods

VI. Regulatory (United States) and Safety Considerations

References

Chapter 5 The Molecular Biology of Nisin and Its Structural Analogues

I. An Historical Perspective of Nisin

II. Significance of Posttranslationally Modified Peptides

III. Lantibiotics Could be Adapted to Multiple Purposes

IV. A Dilemma Posed by Nisin Resistance

V. The Molecular Biology of Nisin Biosynthesis is of Unknown Complexity

VI. Cloning of the Genes for the Nisin and Subtilin Precursor Peptides

VII. Evolutionary and Functional Relationships between Nisin and Subtilin Implied by Comparison of Their Structural Genes

VIII. Expression of the Genes for Nisin and Subtilin and Characterization of Their Transcripts

IX. The Ability to Produce Subtilin Can be Transferred among Strains of Bacillus subtilis

X. The Ability to Produce Nisin Can be Transferred between Strains of Lactococcus lactis

XI. What is Known about the Organization of Genes Associated with Nisin Biosynthesis

XII. What is Known about the Organization of Genes Associated with Subtilin Biosynthesis

XIII. Strategies and Systems to Express the Structural Genes for Nisin and Other Lantibiotics

XIV. Processing of Chimeric Precursor Peptides

XV. Production of Natural and Engineered Nisin Analogues in Bacillus subtilis

XVI. Structural and Functional Analysis of Lantibiotic Analogues: The Dehydro Residues Provide a Window through Which the Chemical State of Nisin and Subtilin Can be Observed

XVII. Conclusions and Future Prospects

References

Chapter 6 Nonnisin Bacteriocins in Lactococci: Biochemistry, Genetics, and Mode of Action

I. Summary

II. Introduction

III. Nomenclature

IV. Diplococcin

A. Identification and Purification of Diplococcin

B. Effects of Diplococcin on Bacterial Cells

C. Plasmids and Diplococcin Production

V. Lactostrepcins

A. Identification and Definition of Lactostrepcin

B. Purification and Mode of Action of Lactostrepcin 5

C. Plasmid Curing and Loss of Las 5 Production

VI. Lactococcins

A. Genetics of Lactococcins

B. The Lactococcin A Secretion Machinery

C. Biochemistry of Lactococcin A

D. Mode of Action of Lactococcin A

VII. Conclusions and Future Prospects

References

Chapter 7 Molecular Biology of Bacteriocins Produced by Lactobacillus

I. Introduction

II. Evidence and Roles

III. Classification and Biochemical Characteristics

IV. Genetic Organization of Bacteriocin Operons

A. Helveticin J

B. Lactacin F

V. Common Processing Sites in Peptide Bacteriocins

VI. Perspectives and Conclusions

References

Chapter 8 Pediocins

I. Introduction

II. Description of the Genus Pediococcus

III. Bacteriocin Activity in Pediococci

IV. Pediocin AcH

A. Properties

B. Toxicity

C. Mode of Action

D. Influence of Growth Conditions on Production of Pediocin AcH

E. Genetics

F. Antibacterial Effectiveness of Pediocin AcH

G. Pediocin AcH in Foods

V. Additional Studies of Pediocins in Meat Systems

VI. Other Potential Applications for Pediocins

References

Chapter 9 Bacteriocins from Carnobacterium and Leuconostoc

I. Description of the Genera Carnobacterium and Leuconostoc

II. Habitats and Sources of Carnobacterium and Leuconostoc Species

III. Bacteriocins Produced by Carnobacterium and Leuconostoc Species

A. Bacteriocins Produced by Carnobacterium Species

B. Bacteriocins Produced by Leuconostoc Species

IV. Chemical Characterization of Leuconostoc and Carnobacterium Bacteriocins

V. Potential for Application of Carnobacteriocins or Leucocin A in Meat Preservation

References

Chapter 10 Bacteriocins from Dairy Propionibacteria and Inducible Bacteriocins of Lactic Acid Bacteria

I. Bacteriocins from Dairy Propionibacteria

A. Introduction to the Propionibacteria

B. Nonbacteriocin Inhibitors Produced by the Propionibacteria

C. Propionibacteria Bacteriocins

D. Genetics of Propionibacteria and Their Bacteriocins

II. Inducible Bacteriocins of Lactic Acid Bacteria

References

Chapter 11 Regulatory Aspects of Bacteriocin Use

I. Introduction

II. Characteristics of Bacteriocins

III. Potential Uses of Bacteriocins or Bacteriocin-Producing Organisms in Foods and Pharmaceuticals

A. Food Preservatives

B. Health Care Products

C. Starter Cultures

D. Genetically Engineered Starter Cultures

E. Probiotic Organisms

F. Markers for Food-Grade Cloning Vector Construction

IV. Factors Affecting Regulatory Approval of Bacteriocins as Food Ingredients

A. Are Bacteriocins Food Additives or GRAS Ingredients?

B. Data Required by FDA

V. Factors Affecting Regulatory Approval of Naturally Occurring Bacteriocin-Producing Strains

VI. Factors Affecting Regulatory Approval of Genetically Engineered Bacteriocin-Producing Strains

VII. Players in the Regulatory Arena

A. U.S. Food and Drug Administration

B. The International Food Biotechnology Council

C. Individual States

D. The President's Council on Competitiveness

E. Others

VIII. Future Challenges

A. Consumer Acceptance

B. Competition in the Marketplace

C. Labeling of Biotechnology-Derived Foods

IX. Conclusion

References

Chapter 12 Future Prospects for Research and Applications of Nisin and Other Bacteriocins

I. From Past to Present

II. Research Approaches and Incentives

III. Genetic Engineering

IV. Traditional and Molecular Screening

V. Protein Engineering

VI. Concluding Remarks

References

Index