Microbial Extracellular Polymeric Substances

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.

The Perfect Slime presents the latest state of knowledge and all aspects of the Extracellular Polymeric Substances, (EPS) matrix – from the ecological and health to the antifouling perspectives. The book brings together all the current material in order to expand our understanding of the functions, properties and characteristics of the matrix as well as the possibilities to strengthen or weaken it. The EPS matrix represents the immediate environment in which biofilm organisms live. From their point of view, this matrix has paramount advantages. It allows them to stay together for extended periods and form synergistic microconsortia, it retains extracellular enzymes and turns the matrix into an external digestion system and it is a universal recycling yard, it protects them against desiccation, it allows for intense communication and represents a huge genetic archive. They can remodel their matrix, break free and eventually, they can use it as a nutrient source. The EPS matrix can be considered as one of the emergent properties of biofilms and are a major reason for the success of this form of life. Nevertheless, they have been termed the “black matter of biofilms” for good reasons. First of all: the isolation methods define the results. In most cases, only water soluble EPS components are investigated; insoluble ones such as cellulose or amyloids are much less included. In particular in environmental biofilms with many species, it is difficult to impossible isolate, separate the various EPS molecules they are encased in and to define which species produced which EPS. The regulation and the factors which trigger or inhibit EPS production are still very poorly understood. Furthermore: bacteria are not the only microorganisms to produce EPS. Archaea, Fungi and algae can also form EPS. This book investigates the questions, What is their composition, function, dynamics and regulation? What do they all have in common?

Microbial extracellular polymeric substances (EPS) provide the structural matrix for all microbial aggregates such as biofilms, flocs and sludge, and are of great technical and ecological importance. EPS provide and form the space between biofilm cells, mediating both cohesion and adhesion. They serve as a multipurpose functional matrix for microbial communities, which allows the establishment of stable microconsortia. The EPS matrix governs diffusional and convectional mass transport because it occurs in various densities, including void spaces such as pores and channels. This creates different types of physico-chemical gradients, providing habitats in which aerobic and anaerobic organisms can coexist in close proximity and largely independent of the conditions in the water phase. Major aspects of EPS include mechanical stability, as in the case of biofouling when unwanted biofilms have to be removed, and the stability of biofilms in bioreactors; interaction with substrata in bioleaching, biocorrosion, and biodeterioration; sorption capacity for dissolved and particulate substances (biosorption), representing both a sink and source of sorbed material; enhanced resistance of biofilm organisms to biocides. The 25 peer-reviewed articles selected for these proceedings provde both a starting point for newcomers to the field and a state-of-the-art survey for the more experienced. With a diversity of approaches, ranging from sophisticated microanalysis to industrial applications, these papers provide a broad understanding of EPS from the viewpoints of microbiologists, polymer scientists, chemists and engineers, and showing how EPS may be seen as the key to understanding and controlling all forms of microbial aggregates.

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. In this volume, analysis, characterization, composition, regulation, function and interactions of microbial EPS are covered.

This book cover all types of microbe based polymers and their application in diverse sectors with special emphasis on agriculture. It collates latest research, methods, opinion, perspectives, and reviews dissecting the microbial origins of polymers, their production, design, and processing at industrial level, as well as improvements for specific industrial applications. Book also discusses recent advances in biopolymer production and their modification for amplifying the value. In addition, understanding of the microbial physiology and optimal conditions for polymer production are also explained. This compilation of scientific chapters on principles and practices of microbial polymers fosters the knowledge transfer among scientific communities, industries, and microbiologist and serves students, academicians, researchers for a better understanding of the nature of microbial polymers and application procedure for sustainable ecosystem

This manual details the techniques involved in the study of plant microbe interactions (PMI). Covering a wide range of basic and advanced techniques associated with research on biological nitrogen fixation, microbe-mediated plant nutrient use efficiency, the biological control of plant diseases and pests such as nematodes, it will appeal to postgraduate students, research scholars and postdoctoral fellows, as well as teachers from various fields, including pathology, entomology and agronomy. It consists of five broad sections featuring different units. Information panels at the beginning of each unit present essential knowledge as well as advances in a particular topic. The manual can also serve as a textbook for undergraduate courses like Techniques for Plant-Microbe Interactions; Biological Control of Plant Diseases; and Nutrient Use Efficiency. Providing basic insights and working protocols from all related disciplines, this unique laboratory manual is a valuable resource for researchers interested in investigating PMI.

Aerobic Granular Sludge has recently received growing attention by researchers and technology developers, worldwide. Laboratory studies and preliminary field tests led to the conclusion that granular activated sludge can be readily established and profitably used in activated sludge plants, provided 'correct' process conditions are chosen. But what makes process conditions 'correct'? And what makes granules different from activated sludge flocs? Answers to these question are offered in Aerobic Granular Sludge. Major topics covered in this book include: Reasons and mechanism of aerobic granule formation Structure of the microbial population of aerobic granules Role, composition and physical properties of EPS Diffuse limitation and microbial activity within granules Physio-chemical characteristics Operation and application of granule reactors Scale-up aspects of granular sludge reactors, and case studies Aerobic Granular Sludge provides up-to-date information about a rapidly emerging new technology of biological treatment.

Microbial polysaccharides represent an attractive alternative to those from plants or macro algae. They can be produced from renewable sources including lignocellulosic waste streams. Their production does not depend on geographical constraints and/or seasonal limitations. Additionally the manipulation of biosynthetic pathways to enhance productivity or to influence the chemical polysaccharide composition is comparatively easy in bacteria. Microbial exopolysaccharides represents a valuable resource of biogenic and biodegradable polymers, suitable to replace petro based polymers in various technical applications. Furthermore, biocompatible exopolysaccharides are very attractive in medical applications, such as drug delivery systems, use as vaccines or nanoparticles. This research topic will depict the status quo, as well as the future needs in the field of EPS and biofilm research. Starting from the unexplored diversity of microbial polysaccharide producers to production processes and possibilities for modifications, to enhance the already high number of functionalities based on the chemical structures. An overview of the recent and future applications will be given, and the necessity in unravelling the biosynthesis of microbial exopolysaccharide producers is depicted, highlighting the future trend of tailor made polymers. Constraints in structure analysis of these highly complex biogenic polymers are described and different approaches to solve the restrictions in imaging and NMR analysis will be given. Therefore; this research topic comprises the whole process from genes to applications.