Structure And Function Of Biofilms

Structure and Function of Biofilms W.G. Characklis P.A. Wilderer Editors Biofilms, the accumulation of microorganisms at surfaces (e.g. a rock, a heat exchanger tube, an oil droplet, a tooth, or a medical implant) play an important role in nature and have recently received increasing attention in science as well as in technology. This volume contains a summary of the current state of knowledge concerning the behavior of microorganisms in a biofilm and their physical, chemical, and biological interactions with each other and with the environment at both the biofilm—substratum and the biofilm—bulk liquid interfaces. New techniques to investigate biofilms and to predict the performance of biofilm systems are presented and future research needs are identified. An excellent source of information for microbiologists, medical scientists and engineers is provided.

Biofilms are of great practical importance for beneficial technologies such as water and wastewater treatment and bioremediation of groundwater and soil. In other settings biofilms cause severe problems, for example in 65% of bacterial infections currently treated by clinicians (particularly those associated with prosthetics and implants), accelerated corrosion in industrial systems, oil souring and biofouling. Until recently, the structure and function of biofilms could only be inferred from gross measures of biomass and metabolic activity. This limitation meant that investigators involved in biofilm research and application had only a crude understanding of the microbial ecology, physical structure and chemical characteristics of biofilms. Consequently, opportunities for the exploitation and control of biofilms were very limited. The past decade has witnessed the development of several new techniques to elucidate the structure and function of biofilms. Examples include: the use of molecular probes that identify different microbes in complex communities as well as their metabolic functions; the use of microsensors that show concentration gradients of key nutrients and chemicals; the use of confocal laser scanning microscopy to describe the physical structure of biofilms and the development of a new generation of mathematical models that allow for the prediction of biofilm structure and function. However, much progress remains to be made in efforts to understand, control and exploit biofilms. This timely book will introduce its readers to the structure and function of biofilms at a fundamental level as determined during the past decade of research, including: Extracellular polymers as the biofilm matrix; Biofilm phenotype (differential gene expression, interspecies signalling); Biofilm ecology; Biofilm monitoring; Resistance of biofilms to antimicrobial agents and Biofilm abatement. Biofilms in Medicine, Industry and Environmental Technology offers a holistic and multi-disciplinary description of the topic, including biofilm formation and composition, but also biofilm monitoring, disinfection and control. All these aspects are presented from three points of views: medical, industrial and environmental biotechnological in a compact, easy to read format.

The study of biofilm considers the close association of micro-organisms with each other at interfaces and is relevant to a variety of disciplines, including medicine, dentistry, bioremediation, biofouling, water technology, engineering and food science. Although the habitats studied differ widely, some common elements exist such as method of attachment, coadhesion and regulation of biofilm phenotype and architecture. This book aims to distil the common principles of biofilm physiology and growth for all interested disciplines.

An examination of the research and translational application to prevent and treat biofilm-associated diseases In the decade since the first edition of Microbial Biofilms was published, the interest in this field has expanded, spurring breakthrough research that has advanced the treatment of biofilm-associated diseases. This second edition takes the reader on an exciting, extensive review of bacterial and fungal biofilms, ranging from basic molecular interactions to innovative therapies, with particular emphasis on the division of labor in biofilms, new approaches to combat the threat of microbial biofilms, and how biofilms evade the host defense. Chapters written by established investigators cover recent findings, and contributions from investigators new to the field provide unique and fresh insights. Specifically, Microbial Biofilms provides state-of-the-art research in the field of bacterial and fungal biofilms detailed descriptions of the in vitro and in vivo models available to evaluate microbial biofilms future areas of research and their translational and clinical applications Microbial Biofilms is a useful reference for researchers and clinicians. It will also provide insight in the dynamic field of microbial biofilms for graduate and postgraduate students.

Microbial extracellular polymeric substances (EPS) are the key components for the aggregation of microorganisms in biofilms, flocs and sludge. They are composed of polysaccharides, proteins, nucleic acids, lipids and other biological macromolecules. EPS provide a highly hydrated gel matrix in which microbial cells can establish stable synergistic consortia. Cohesion and adhesion as well as morphology, structure, biological function and other properties such as mechanical stability, diffusion, sorption and optical properties of microbial aggregates are determined by the EPS matrix. Also, the protection of biofilm organisms against biocides is attributed to the EPS. Their matrix allows phase separation in biofiltration and is also important for the degradation of particulate material which is of great importance for the self purification processes in surface waters and for waste water treatment.

Throughout the biological world, bacteria thrive predominantly in surface-attached, matrix-enclosed, multicellular communities or biofilms, as opposed to isolated planktonic cells. This choice of lifestyle is not trivial, as it involves major shifts in the use of genetic information and cellular energy, and has profound consequences for bacterial physiology and survival. Growth within a biofilm can thwart immune function and antibiotic therapy and thereby complicate the treatment of infectious diseases, especially chronic and foreign device-associated infections. Modern studies of many important biofilms have advanced well beyond the descriptive stage, and have begun to provide molecular details of the structural, biochemical, and genetic processes that drive biofilm formation and its dispersion. There is much diversity in the details of biofilm development among various species, but there are also commonalities. In most species, environmental and nutritional conditions greatly influence biofilm development. Similar kinds of adhesive molecules often promote biofilm formation in diverse species. Signaling and regulatory processes that drive biofilm development are often conserved, especially among related bacteria. Knowledge of such processes holds great promise for efforts to control biofilm growth and combat biofilm-associated infections. This volume focuses on the biology of biofilms that affect human disease, although it is by no means comprehensive. It opens with chapters that provide the reader with current perspectives on biofilm development, physiology, environmental, and regulatory effects, the role of quorum sensing, and resistance/phenotypic persistence to antimicrobial agents during biofilm growth.

Bacterial biofilm is a complex structure with diverse bacterial cells in a highly organized and ordered group within a matrix of extracellular polymeric substances they produce. Microbes attach to surfaces to develop biofilms, a sophisticated process regulated by factors such as nutritional status and biotic/abiotic surface features. An established biofilm structure mainly comprises bacterial cells, proteins, nucleic acid, and exo-polysaccharides that are extracellular macromolecules excreted as tightly bound layers in microbes, providing a perfect niche for bacteria to exchange genetic material between cells. In addition, bacterial cells in the matrix also communicate via quorum sensing, which greatly impacts biofilm processes. Under clinical circumstances, bacterial biofilm shows great resistance to antibiotics, disinfectants, and body defense systems, making it difficult for clinicians to eradicate and facilitate many infectious disease processes, leading to chronic infections of patients with long-term hospitalization and high mortality rates. Therefore, it is very important to understand the recent advances in forming, regulating, and eradicating biofilms in human infections to better prevent, control, and treat biofilm infections in humans. Written by an international team of basic and clinical researchers, the chapters of this book provide novel insights and advanced knowledge for life science researchers, clinical researchers, doctors, and other interested readers on some of the latest developments in biofilms.

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.