Biofilms are predominant mode of life for microbes under natural conditions. The three-dimensional structure of the biofilm provides enhanced protection from physical, chemical and biological stress conditions to associated microbial communities. These complex and highly structured microbial communities play a vital role in maintaining the health of plants, soils and waters. Biofilm associated with plants may be pathogenic or beneficial based on the nature of their interactions. Pathogenic or undesirable biofilm requires control in many situations, including soil, plants, food and water.

Written by leading experts from around the world, Biofilms in Plant and Soil Health provides an up-to-date review on various aspects of microbial biofilms, and suggests future and emerging trends in biofilms in plant and soil health.

Issues are addressed in four sub areas:

I) The fundamentals and significance of biofilm in plant and soil health, and the concept of mono and mixed biofilms by PGPR and fungal biofilms.

II) Biochemical and molecular mechanisms in biofilm studies in plant associated bacteria, and techniques in studying biofilms and their characterization, gene expression and enhanced antimicrobial resistance in biofilms, as well as biotic and biotic factors affecting biofilm in vitro.

III) The ecological significance of soil associated biofilms and stress management and bioremediation of contaminated soils and degraded ecosystems.

IV) Pathogenic biofilm associated with plant and food and its control measures.

This book is recommended for students and researchers working in agricultural and environmental microbiology, biotechnology, soil sciences, soil and plant health and plant protection. Researchers working in the area of quorum sensing, biofilm applications, and understanding microbiome of soil and plants will also find it useful.

Autorentext

About the Editors

Iqbal Ahmad is a Professor in the Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, India and former visiting Professor, Department of Biology, Umm Al-Qura University, Makkah, Saudia Arabia.

Fohad Mabood Husain is a Post-doctoral Researcher in the Department of Food Science and Nutrition, King Saud University, Saudi Arabia.

Inhalt

Preface xviii

List of Contributors xx

1 Biofilms: An Overview of Their Significance in Plant and Soil Health 1
Iqbal Ahmad, Mohammad Shavez Khan, Mohd Musheer Altaf, Faizan Abul Qais, Firoz Ahmad Ansari and Kendra P. Rumbaugh

1.1 Introduction 1

1.2 Biofilm Associated with Plants 3

1.3 Biofilm Formation Mechanisms: Recent Update on Key Factors 4

1.4 Biofilm in Soil and Rhizospheres 7

1.5 Genetic Exchange in Biofilms 7

1.6 Diversity and Function of Soil Biofilms 8

1.7 The Role of Biofilms in Competitive Colonization by PGPR 8

1.8 Biofilm Synergy in Soil and Environmental Microbes 9

1.9 Biofilms in Drought Stress Management 10

1.10 Plant Health and Biofilm 10

1.11 How Microbial Biofilms Influence Plant Health? 10

1.12 Soil Health and Biofilms 12

1.13 How to Assess Soil Health? 13

1.14 Impact of Biofilms on Soil Health 14

1.15 Biofilm EPS in Soil Health 14

1.16 Conclusions and Future Directions 15

References 15

2 Role of PGPR in Biofilm Formations and Its Importance in Plant Health 27
Govind Gupta, Sunil Kumar Snehi and Vinod Singh

2.1 Introduction 27

2.2 Rhizosphere: A Unique Source of Microorganisms for Plant Growth Promotion 27

2.3 Plant GrowthPromoting Rhizobacteria 28

2.4 Biofilm Producing Plant GrowthPromoting Rhizobacteria 34

2.5 Role of PGPR in Biofilm Formations 35

2.6 Future Research and Development Strategies for Biofilm Producing Sustainable Technology 35

2.7 Conclusions 36

Acknowledgments 36

References 36

3 Concept of Mono and Mixed Biofilms and Their Role in Soil and in Plant Association 43
Janaína J. de V. Cavalcante, Alexander M. Cardoso and Vânia L. Muniz de Pádua

3.1 Introduction 43

3.2 Soil- and Plant-Associated Biofilms 45

3.3 Microbial Signaling, Regulation, and Quorum Sensing 46

3.4 Biotechnology 48

3.5 Outlook 49

Acknowledgments 49

References 49

4 Bacillus Biofilms and Their Role in Plant Health 55
Mohd Musheer Altaf, Iqbal Ahmad, Mohd Sajjad Ahmad Khan and Elisabeth Grohmann

4.1 Introduction 55

4.2 Interaction of Bacillus within Plant Rhizosphere and Biofilm Development 57

4.3 Multispecies Biofilms and Their Significance 59

4.4 Biofilm Detection and Characterization 60

4.5 Bacillus Biofilm and Plant Health Promotion 60

4.6 Conclusion and Future Prospects 62

References 63

5 Biofilm Formation by Pseudomonas spp. and Their Significance as a Biocontrol Agent 69
Zaki A. Siddiqui and Masudulla Khan

5.1 Introduction 69

5.2 Biofilms 79

5.3 Mechanisms of Biofilm Formation 81

5.4 Metabolites Affecting Biofilm Formation 84

5.5 Biofilm Formation and Biological Control of Plant Diseases 84

5.6 Conclusion 85

References 86

6 Quorum Sensing Mechanisms in Rhizosphere Biofilms 99
Jorge Barriuso

6.1 Background 99

6.2 QS in Biofilms Formation 101

6.3 Conclusions 106

References 107

7 Biofilm Formation and Quorum Sensing in Rhizosphere 111
Kusum Harjai and Neha Sabharwal

7.1 Introduction 111

7.2 Importance of Rhizosphere 111

7.3 Constituents of Rhizosphere 112

7.4 Communication in Rhizosphere 113

7.5 Quorum Sensing in Rhizobia 115

7.6 Quorum Sensing in Pseudomonads 118

7.7 Biofilm Formation in Rhizosphere 120

7.8 Conclusions 124

References 124

8 The Significance of Fungal Biofilms in Association with Plants and Soils 131
Michael W. Harding, Lyriam L.R. Marques, Bryon Shore and G.C. Daniels 8.1 Introduction...