Quorum sensing (QS) describes a chemical communication behavior that is nearly universal among bacteria. Individual cells release a diffusible small molecule (an autoinducer) into their environment. A high concentration of this autoinducer serves as a signal of high population density, triggering new patterns of gene expression throughout the population. However QS is often much more complex than this simple census-taking behavior. Many QS bacteria produce and detect multiple autoinducers, which generate quorum signal cross talk with each other and with other bacterial species. QS gene regulatory networks respond to a range of physiological and environmental inputs in addition to autoinducer signals. While a host of individual QS systems have been characterized in great molecular and chemical detail, quorum communication raises many fundamental quantitative problems which are increasingly attracting the attention of physical scientists and mathematicians. Key questions include: What kinds of information can a bacterium gather about its environment through QS? What physical principles ultimately constrain the efficacy of diffusion-based communication? How do QS regulatory networks maximize information throughput while minimizing undesirable noise and cross talk? How does QS function in complex, spatially structured environments such as biofilms? Previous books and reviews have focused on the microbiology and biochemistry of QS. With contributions by leading scientists and mathematicians working in the field of physical biology, this volume examines the interplay of diffusion and signaling, collective and coupled dynamics of gene regulation, and spatiotemporal QS phenomena. Chapters will describe experimental studies of QS in natural and engineered or microfabricated bacterial environments, as well as modeling of QS on length scales spanning from the molecular to macroscopic. The book aims to educate physical scientists and quantitative-oriented biologists on the application of physics-based experiment and analysis, together with appropriate modeling, in the understanding and interpretation of the pervasive phenomenon of microbial quorum communication.

Many bacterial diseases are caused by organisms growing together as communities or biofilms. These microorganisms have the capacity to coordinately regulate specific sets of genes by sensing and communicating amongst themselves utilizing a variety of signals. This book examines the mechanisms of quorum sensing and cell-to-cell communication in bacteria and the roles that these processes play in regulating virulence, bacterial interactions with host tissues, and microbial development. Recent studies suggest that microbial cell-to-cell communication plays an important role in the pathogenesis of a variety of disease processes. Furthermore, some bacterial signal molecules may possess immunomodulatory activity. Thus, understanding the mechanisms and outcomes of bacterial cell-to-cell communication has important implications for appreciating host-pathogen interactions and ultimately may provide new targets for antimicrobial therapies that block or interfere with these communication networks.

This book illustrates the importance and significance of Quorum sensing (QS), it’s critical roles in regulating diverse cellular functions in microbes, including bioluminescence, virulence, pathogenesis, gene expression, biofilm formation and antibiotic resistance. Microbes can coordinate population behavior with small molecules called autoinducers (AHL) which serves as a signal of cellular population density, triggering new patterns of gene expression for mounting virulence and pathogenesis. Therefore, these microbes have the competence to coordinate and regulate explicit sets of genes by sensing and communicating amongst themselves utilizing variety of signals. This book descry emphasizes on how bacteria can coordinate an activity and synchronize their response to external signals and regulate gene expression. The chapters of the book provide the recent advancements on various functional aspects of QS systems in different gram positive and gram negative organisms. Finally, the book also elucidates a comprehensive yet a representative description of a large number of challenges associated with quorum sensing signal molecules viz. virulence, pathogenesis, antibiotic synthesis, biosurfactants production, persister cells, cell signaling and biofilms, intra and inter-species communications, host-pathogen interactions, social interactions & swarming migration in biofilms.

The new field of physical biology fuses biology and physics. New technologies have allowed researchers to observe the inner workings of the living cell, one cell at a time. With an abundance of new data collected on individual cells, including observations of individual molecules and their interactions, researchers are developing a quantitative, physics-based understanding of life at the molecular level. They are building detailed models of how cells use molecular circuits to gather and process information, signal to each other, manage noise and variability, and adapt to their environment. This book narrows down the scope of physical biology by focusing on the microbial cell. It explores the physical phenomena of noise, feedback, and variability that arise in the cellular information-processing circuits used by bacteria. It looks at the microbe from a physics perspective, to ask how the cell optimizes its function to live within the constraints of physics. It introduces a physical and information based -- as opposed to microbiological -- perspective on communication and signaling between microbes. The book is aimed at non-expert scientists who wish to understand some of the most important emerging themes of physical biology, and to see how they help us to understand the most basic forms of life.

Microorganisms (bacteria, archaea, microeukaryotes) in marine environments secrete a diverse array of exopolymeric substances that facilitate attachment to surfaces, the formation of organic colloids and larger aggregations of cells (marine snow), and that can influence many ocean, as well as global, processes. The aim of this Research Topic is to highlight recent advances in the sources, chemistry and function of these microbial-produced macromolecules. We encouraged original research and reviews on exopolymeric substances, from their sources, chemico-physiological properties, functions and ecosystem effects, and including their role in the Gulf of Mexico following the Deepwater Horizon oil spill disaster.

Modern thought is characterized by a dichotomy of meaningful culture and unmeaning nature. Signs in the Dust uses medieval semiotics to develop a new theory of nature and culture that resists this familiar picture of things. Through readings of Thomas Aquinas, Nicholas of Cusa, and John Poinsot (John of St. Thomas), it offers a semiotic analysis of human culture in both its anthropological breadth as an enterprise of creaturely sign-making, and its theological height as a finite participation in the Trinity, which can be understood as an absolute 'cultural nature'. Signs in the Dust then extends this account of human culture backwards into the natural depth of biological and physical nature. It puts the biosemiotics of its medieval sources, along with Félix Ravaisson's philosophy of habit, into dialogue with the Extended Evolutionary Synthesis that is emerging in contemporary biology, to show how all living things participate in semiosis, so that that a cultural dimension is present through the whole order of nature and the whole of natural history. It also retrieves Aquinas' doctrine of intentions in the medium to show how signification can be attributed in a diminished way to even inanimate nature, with the ontological implication that being as such should be reconceived in semiotic terms. The phenomena of human culture are therefore to be understood not as breaks with a meaningless nature, but instead as heightenings and deepenings of natural movements of meaning that long precede and far exceed us. Against the modern divorce of nature and culture, Signs in the Dust argues that culture is natural and nature is cultural, through and through.

Kin Recognition in Protists and Other Microbes is the first volume dedicated entirely to the genetics, evolution and behavior of cells capable of discriminating and recognizing taxa (other species), clones (other cell lines) and kin (as per gradual genetic proximity). It covers the advent of microbial models in the field of kin recognition; the polymorphisms of green-beard genes in social amebas, yeast and soil bacteria; the potential that unicells have to learn phenotypic cues for recognition; the role of clonality and kinship in pathogenicity (dysentery, malaria, sleeping sickness and Chagas); the social and spatial structure of microbes and their biogeography; and the relevance of unicells’ cooperation, sociality and cheating for our understanding of the origins of multicellularity. Offering over 200 figures and diagrams, this work will appeal to a broad audience, including researchers in academia, postdoctoral fellows, graduate students and research undergraduates. Science writers and college educators will also find it informative and practical for teaching.