Preface
Since van Leeuwenhoek’s descriptions of the microbial world up to few decades ago,
bacteria were considered as deaf-mute individual cells designed to proliferate but unable
to communicate and interact with each other. The first evidence of bacterial social behaviors
can be traced back to 1965, when Alexander Tomasz reported that the ability of aStrepto-
coccus pneumoniaepopulation to enter the competence state is governed by a self-produced
extracellular factor. With a remarkable and inspired intuition, Tomasz stated: “Since the
activator—a cell-produced chemical—seems to impose a high degree of physiological
homogeneity in a pneumococcal population with respect to competence, one is forced to
conclude that in this case a bacterial population can behave as a biological unit with
considerable coordination among its members. One wonders whether this kind of control
may not be operative in some other microbial phenomena also” [1].
Few years later, Kenneth H. Nealson, Terry Platt, and J. Woodland Hastings unraveled
the population density dependency of light emission in the bioluminescent marine bacte-
riumVibrio fischeri[2], thus paving the way for the identification of the first autoinducer
used by bacteria to coordinate gene expression at the population level [3].
These pioneer works suggested that certain bacteria coordinate behaviors at the popu-
lation level in response to variations in cell density and that this phenomenon is mediated by
self-produced chemical signals. It is now acknowledged that this communication system,
which has been named quorum sensing by Clay Fuqua, Stephen C. Winans, and E. Peter
Greenberg in 1994 [4], is widespread in eubacteria, archaea and fungi rather than a curiosity
restricted to few bacterial species. In the last decades, a rich vocabulary of quorum sensing
signals belonging to distinct chemical classes has been compiled, by which microorganisms
exploit complex beneficial or competitive interactions at the intraspecies, interspecies, and
interkingdom levels. In this context, it is not surprising that sociomicrobiology has recently
emerged as a fascinating research topic involving a growing community of scientists
worldwide.
The aim of this book is to provide scientists interested in quorum sensing with a broad
spectrum of methods and protocols useful for studying bacterial communication processes
at the chemico-physical, molecular, and physiological level. In addition to wet-lab
approaches, the book also contains bioinformatic methods and a discursive description of
mathematical models (Chapter20) to investigate quorum sensing.
The book is structured in three main parts: (1) Detection and quantification of quorum
sensing signal molecules; (2) Methods for the studying of quorum sensing at the molecular,
physiological, and population level; (3) Identification and characterization of anti-quorum
sensing agents.
Overall, we think that this book could be helpful for a broad community of scientists
interested in quorum sensing, ranging from biochemists to microbial ecologists, including
molecular microbiologists, biotechnologists, bioinformaticians, and synthetic biologists.
Our first thanks go to Kendra Rumbaugh, the editor of the previous book “Quorum
Sensing: Methods and Protocols” (Springer, 2010) [5]. We acknowledge her outstanding
work by maintaining the original organization in three main parts, since we could not find a
better rationale to follow, and by including some chapters present in the previous edition.
Indeed, some of the methods and protocols reported in the book edited by Kendra can be
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