Chapter 1 _Introduction to Microbial Quorum Sensing.- Chapter 1.1. Introduction to microbial quorum sensing molecules and biofilm formation.- Chapter 1.2 . Intra and inter-species communications in microbes: Living with complex and sociable neighbours.- Chapter 1.3 . Relationship between Quorum Sensing Systems and Persister Cells.- Chapter 1.4 . Microbial Social Interactions in Biofilm.- Chapter 2 . Functional Aspects of Quorum Sensing in Microbes.- Chapter 2.1. Quorum sensing and swarming migration in bacteria.- Chapter 2.2. Quorum Sensing and Paradigms of microbial Pathogenic relationships. - Chapter 2.3. Cellular signalling in bacterial biofilms. - Chapter 2.4. Quorum sensing in bacterial pathogenesis and virulence.- Chapter 2.5. Quorum sensing in Bacteria-Plant interactions .- Chapter 2.6. Microbes living together: Exploiting the art for making biosurfactants and biofilms.- Chapter 2.7. Quorum sensing and their role in regulation of Antibiotics Synthesis - Chapter 3. Quorum Sensing regulated behaviors in Fungi .- Chapter 3.1. Role of Quorum Sensing on Morphogenesis and Biofilm formation in fungi.- Chapter 3.2. Perspective of Quorum sensing mechanism in Candida albicans .- Chapter 4 . Quorum Sensing regulated behaviours in Gram-negative bacteria.- Chapter 4.1. Vibrio fischeri synchronizes bioluminescence in marine invertebrates via Quorum sensing mechanism.- Chapter 4.2. Quorum sensing system regulates virulence and pathogenicity genes in Vibrio harveyi .- Chapter 4.3. Simplifying the complexity of quorum sensing signalling of the gut Enterobacteria: Escherichia coli and Salmonella enterica .- Chapter 4.4. Quorum-sensing mechanism in Rhizobium sp: Revealing the complexity in a dialogue.- Chapter 4.5. Quorum Sensing and Its role in Agrobacterium Mediated Gene Transfer.- Chapter 4.6. Quorum sensing and Biofilm formation in Helicobacter pylori .- Chapter 4.7. Quorum sensing and biofilm disassembly process in Pseudomonas aeruginosa , Staphylococcus aureus and Xanthomonas campestris : A comparative study.- Chapter 5. QS-regulated behaviours in Gram- Positive bacteria.- Chapter 5.1. Quorum sensing mechanisms in Gram Positive Bacteria.- Chapter 5.2. Novel insights on Bacillus Quorum sensing mechanism: Its role in competence, virulence, sporulation and biofilm formation.- Chapter 5.3. Quorum sensing in Mycobacterium tuberculosis : Its role in virulence and pathogenesis.- Chapter 5.4. Quorum sensing in Streptococcus pyogenes and their role in establishment of disease.