Bacterial Polysaccharide Function of Bacterial and Viral Polysaccharides Dr. Lianchun Wang Overview General structure of bacterial cell walls Peptidoglycan (murein).

1. Bacterial Polysaccharides An Overview
2. Bacterial Polysaccharides Depolymerized

Author by: Joanna B. Goldberg Language: en Publisher by: CRC Press Format Available: PDF, ePub, Mobi Total Read: 77 Total Download: 805 File Size: 52,5 Mb Description: Bacterial surface or secreted polysaccharides are molecules that can function as barriers to protect bacterial cells against environmental stresses, as well as act as adhesins or recognition molecules. In some cases, these molecules are immunodominant antigens eliciting a vigorous immune response, while in other cases the expression of polysaccharides camouflages the bacteria from the immune system. Until recently, most studies on the enzymatic steps and regulation of these molecules were performed on the enteric gram negative bacteria Escherichia coli and Salmonella typhimurium.

With the advent of modern bacterial genetics, techniques such as construction and characterization of polysaccharide mutants, cloning of genes and complementation of these mutations, and expression of polysaccharides in heterologous bacterial hosts has prompted investigations into the roles and functions of these molecules for many different bacteria. Here, we present the genetic analysis of polysaccharides from a number of bacteria pathogenic to humans and one symbiotic with plants in hopes that similarities in the experimental approaches as well as finding s from such investigations may lead to a general understanding of polysaccharide synthesis and regulation in various bacteria.

1. Bacterial Polysaccharides: An Overview Swati Misra, Varsha Sharma* and Ashok Kumar Srivastava Department of Biochemical Engineering and Biotechnology, Indian.
2. Bacterial Polysaccharide Function of Bacterial and Viral Polysaccharides Dr. Lianchun Wang Overview General structure of bacterial cell walls Peptidoglycan (murein).

Author by: Matthias Ullrich Language: en Publisher by: Horizon Scientific Press Format Available: PDF, ePub, Mobi Total Read: 57 Total Download: 492 File Size: 48,9 Mb Description: Bacterial polysaccharides represent a diverse range of macromolecules that include peptidoglycan, lipopolysaccharides, capsules, and exopolysaccharides - compounds whose functions range from structural cell-wall components (e.g. Peptidoglycan) - and important virulence factors (e.g. Poly-N-acetylglucosamine in S. Aureus) to permitting the bacterium to survive in harsh environments (e.g.

Pseudomonas aeruginosa in the human lung). Polysaccharide biosynthesis is a tightly-regulated, energy-intensive process. Understanding the subtle interplay between the regulation and energy conservation, the polymer modification and synthesis, and the external ecological functions is a huge area of research. The potential benefits are enormous and should enable, for example, the development of novel antibacterial strategies (e.g. New antibiotics and vaccines) and the commercial exploitation to develop novel applications. In this timely book, experienced and authoritative experts review the most important innovations in the research and biotechnological applications of bacterial polysaccharides. The book takes an interdisciplinary view that examines this fascinating subject area in detail from molecular biology, genome-, transcriptome-, and proteome-wide perspectives, and looks at the ecological aspects and systems biology approaches.

It provides a sound basis for future research directions, including high efficiency applications of bacterial polysaccharides in medicine, the food industry, and renewable energy production. Topics include: peptidoglycan, lipopolysaccharide, arabinogalactan, capsule gene expression in Escherichia coli, immune response to polysaccharides, polysaccharides from periodontopathic bacteria, role in dental plaque, biofilms, levan, amylovoran, and much more. Author by: Language: en Publisher by: ScholarlyEditions Format Available: PDF, ePub, Mobi Total Read: 32 Total Download: 689 File Size: 43,9 Mb Description: Bacterial Polysaccharides—Advances in Research and Application: 2013 Edition is a ScholarlyBrief™ that delivers timely, authoritative, comprehensive, and specialized information about Lipopolysaccharides in a concise format. The editors have built Bacterial Polysaccharides—Advances in Research and Application: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Lipopolysaccharides in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant.

The content of Bacterial Polysaccharides—Advances in Research and Application: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/. Author by: Severian Dumitriu Language: en Publisher by: Routledge Format Available: PDF, ePub, Mobi Total Read: 29 Total Download: 925 File Size: 52,8 Mb Description: Integrates the latest advances in polysaccharide chemistry and structure analysis, with the practical applications of polysaccharides in medicine and pharmacy, highlighting the role of glycoconjugates in basic biological processes and immunology. It also presents recent developments in glycobiology and glycopathology. The work covers bacterial, fungal and cell-wall polysaccharides, microbial and bacterial exopolysaccharides, industrial gums, the biosynthesis of bacterial polysaccharides, and the production of microbial polysaccharides.

Author by: Severian Dumitriu Language: en Publisher by: CRC Press Format Available: PDF, ePub, Mobi Total Read: 9 Total Download: 642 File Size: 43,9 Mb Description: Completely revised and expanded to reflect the latest advancements in the field, Polysaccharides: Structural Diversity and Functional Versatility, Second Edition outlines fundamental concepts in the structure, function, chemistry, and stability of polysaccharides and reveals new analytical techniques and applications currently impacting the cosmetic, medicinal, chemical, and biochemical industries. The authoritative book discusses polysaccharides utilized in medical applications such as polysaccharide-based hydrogels, polysialic acids, proteoglycans, glycolipids, and anticoagulant polysaccharides; renewable resources for the production of various industrial chemicals and engineering plastics polysaccharides; and more. Author by: Gerald O. Aspinall Language: en Publisher by: Academic Press Format Available: PDF, ePub, Mobi Total Read: 42 Total Download: 478 File Size: 41,5 Mb Description: The Polysaccharides, Volume 2 is a seven-chapter text that presents the status of polysaccharide chemistry and related aspects of biochemistry.

The opening chapter is concerned with the major classifications of polysaccharides, such as homoglycans and diheteroglycans. The succeeding five chapters discuss the occurrence, usage, structural studies, conformation, and derivatives of specific carbohydrate group, including cellulose, plant, algal, bacterial, and fungal polysaccharides. The last chapter deals with the industrial application and economic aspects of polysaccharides. This book will prove useful to chemists and biochemists working on polysaccharides and other complex carbohydrates.

Is a linear of mainly linked with α(1→4) bonds. It can be made of several thousands of glucose units.

It is one of the two components of, the other being. Polysaccharides are molecules composed of long chains of units bound together by, and on give the constituent. They range in structure from linear to highly branched.

Examples include storage polysaccharides such as and, and structural polysaccharides such as and. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit.

Depending on the structure, these can have distinct properties from their monosaccharide building blocks. They may be or even in water. When all the monosaccharides in a polysaccharide are the same type, the polysaccharide is called a homopolysaccharide or homoglycan, but when more than one type of monosaccharide is present they are called heteropolysaccharides or heteroglycans. Natural saccharides are generally of simple carbohydrates called with general formula (CH 2O) n where n is three or more. Examples of monosaccharides are, and. Polysaccharides, meanwhile, have a general formula of C x(H 2O) y where x is usually a large number between 200 and 2500. When the repeating units in the polymer backbone are six-carbon monosaccharides, as is often the case, the general formula simplifies to (C 6H 10O 5) n, where typically 40≤n≤3000.

As a rule of thumb, polysaccharides contain more than ten monosaccharide units, whereas contain three to ten monosaccharide units; but the precise cutoff varies somewhat according to convention. Polysaccharides are an important class of.

Their in living organisms is usually either structure- or storage-related. (a polymer of glucose) is used as a storage polysaccharide in plants, being found in the form of both and the branched. In animals, the structurally similar glucose polymer is the more densely branched, sometimes called 'animal starch'. Glycogen's properties allow it to be metabolized more quickly, which suits the active lives of moving animals.

And are examples of structural polysaccharides. Cellulose is used in the of plants and other organisms, and is said to be the most abundant on Earth. It has many uses such as a significant role in the paper and textile industries, and is used as a feedstock for the production of rayon (via the process), cellulose acetate, celluloid, and nitrocellulose. Chitin has a similar structure, but has -containing side branches, increasing its strength.

It is found in and in the cell walls of some. It also has multiple uses, including. Polysaccharides also include or, and. Contents. Function Structure Nutrition polysaccharides are common sources of energy. Many organisms can easily break down starches into glucose; however, most organisms cannot metabolize cellulose or other polysaccharides like and. These carbohydrate types can be metabolized by some bacteria and protists.

And, for example, use microorganisms to process. Even though these complex polysaccharides are not very digestible, they provide important dietary elements for humans.

Called, these carbohydrates enhance digestion among other benefits. The main action of dietary fiber is to change the nature of the contents of the, and to change how other nutrients and chemicals are absorbed.

Soluble fiber binds to in the small intestine, making them less likely to enter the body; this in turn lowers levels in the blood. Soluble fiber also attenuates the absorption of sugar, reduces sugar response after eating, normalizes blood lipid levels and, once fermented in the colon, produces as byproducts with wide-ranging physiological activities (discussion below). Although insoluble fiber is associated with reduced diabetes risk, the mechanism by which this occurs is unknown. Not yet formally proposed as an essential macronutrient (as of 2005), dietary fiber is nevertheless regarded as important for the diet, with regulatory authorities in many developed countries recommending increases in fiber intake. Storage polysaccharides Starch is a polymer in which units are bonded by alpha-linkages. It is made up of a mixture of (15–20%) and (80–85%). Amylose consists of a linear chain of several hundred glucose molecules and Amylopectin is a branched molecule made of several thousand glucose units (every chain of 24–30 glucose units is one unit of Amylopectin).

Starches are in. They can be digested by breaking the alpha-linkages (glycosidic bonds). Both humans and animals have amylases, so they can digest starches., and are major sources of starch in the human diet. The formations of starches are the ways that plants store. Glycogen Glycogen serves as the secondary long-term energy storage in and cells, with the primary energy stores being held in. Glycogen is made primarily by the and the, but can also be made by within the and.

Bacterial Polysaccharides An Overview

Glycogen is analogous to, a glucose polymer in, and is sometimes referred to as animal starch, having a similar structure to but more extensively branched and compact than starch. Glycogen is a polymer of α(1→4) glycosidic bonds linked, with α(1→6)-linked branches. Glycogen is found in the form of granules in the /cytoplasm in many types, and plays an important role in the. Glycogen forms an reserve that can be quickly mobilized to meet a sudden need for glucose, but one that is less compact and more immediately available as an energy reserve than (lipids). In the liver, glycogen can compose up to eight percent (100–120 g in an adult) of the fresh weight soon after a meal. Only the glycogen stored in the liver can be made accessible to other organs.

In the, glycogen is found in a low of one to two percent of the muscle mass. The amount of glycogen stored in the body—especially within the, and —varies with physical activity, and eating habits such as. Small amounts of glycogen are found in the, and even smaller amounts in certain cells in the and. The uterus also stores glycogen during pregnancy, to nourish the embryo.

Glycogen is composed of a branched chain of glucose residues. It is stored in liver and muscles. It is an energy reserve for animals.

It is the chief form of carbohydrate stored in animal body. It is insoluble in water. It turns brown-red when mixed with iodine. It also yields glucose on. A view of the structure of a single branched strand of units in a glycogen.

Structural polysaccharides Arabinoxylans are found in both the primary and secondary cell walls of plants and are the copolymers of two sugars: and. Cellulose The structural component of are formed primarily from. Wood is largely cellulose and, while and are nearly pure cellulose. Cellulose is a made with repeated glucose units bonded together by beta-linkages. Humans and many animals lack an enzyme to break the beta-linkages, so they do not digest cellulose.

Certain animals such as can digest cellulose, because bacteria possessing the enzyme are present in their gut. Cellulose is insoluble in water. It does not change color when mixed with iodine. On hydrolysis, it yields glucose. It is the most abundant carbohydrate in nature.

Chitin is one of many naturally occurring. It forms a structural component of many animals, such as. Over time it is bio-degradable in the natural environment. Its breakdown may be catalyzed by called, secreted by microorganisms such as and, and produced by some plants. Some of these microorganisms have to simple from the decomposition of chitin.

If chitin is detected, they then produce to digest it by cleaving the in order to convert it to simple sugars and. Chemically, chitin is closely related to (a more water-soluble derivative of chitin). It is also closely related to in that it is a long unbranched chain of derivatives. Both materials contribute structure and strength, protecting the organism. Pectins are a family of complex polysaccharides that contain 1,4-linked α-D-galactosyl uronic acid residues. They are present in most primary cell walls and in the non-woody parts of terrestrial plants.

Acidic polysaccharides Acidic polysaccharides are polysaccharides that contain, phosphate groups and/or groups. Bacterial capsular polysaccharides commonly produce a thick, mucous-like, layer of polysaccharide. This 'capsule' cloaks on the bacterial surface that would otherwise provoke an immune response and thereby lead to the destruction of the bacteria. Capsular polysaccharides are water-soluble, commonly acidic, and have on the order of 100–2000. They are linear and consist of regularly repeating subunits of one to six. There is enormous structural diversity; nearly two hundred different polysaccharides are produced by alone.

Mixtures of capsular polysaccharides, either or native are used as. Bacteria and many other microbes, including and, often secrete polysaccharides to help them adhere to surfaces and to prevent them from drying out.

Humans have developed some of these polysaccharides into useful products, including, diutan gum and. Most of these polysaccharides exhibit useful properties when dissolved in water at very low levels. This makes various liquids used in everyday life, such as some foods, lotions, cleaners, and paints, viscous when stationary, but much more free-flowing when even slight shear is applied by stirring or shaking, pouring, wiping, or brushing. This property is named pseudoplasticity or; the study of such matters is called. Shear Rate (rpm) Viscosity (cP) 0.3 23,330 0.5 16,000 1 11,000 2 5500 4 3250 5 29 20 900 50 520 100 310 Aqueous solutions of the polysaccharide alone have a curious behavior when stirred: after stirring ceases, the solution initially continues to swirl due to momentum, then slows to a standstill due to viscosity and reverses direction briefly before stopping. This recoil is due to the elastic effect of the polysaccharide chains, previously stretched in solution, returning to their relaxed state. Cell-surface polysaccharides play diverse roles in bacterial and.

They serve as a barrier between the and the environment, mediate host-pathogen interactions, and form structural components of. These polysaccharides are synthesized from -activated precursors (called ) and, in most cases, all the enzymes necessary for biosynthesis, assembly and transport of the completed polymer are encoded by genes organized in dedicated clusters within the genome of the. Is one of the most important cell-surface polysaccharides, as it plays a key structural role in outer membrane integrity, as well as being an important mediator of host-pathogen interactions. The enzymes that make the A-band (homopolymeric) and B-band (heteropolymeric) O-antigens have been identified and the defined. The exopolysaccharide alginate is a linear copolymer of β-1,4-linked D-mannuronic acid and L-guluronic acid residues, and is responsible for the mucoid phenotype of late-stage cystic fibrosis disease. The pel and psl loci are two recently discovered gene clusters that also encode found to be important for biofilm formation.

Is a biosurfactant whose production is tightly regulated at the level, but the precise role that it plays in disease is not well understood at present. Protein, particularly of and, became a focus of research by several groups from about 2007, and has been shown to be important for adhesion and invasion during bacterial infection. Chemical identification tests for polysaccharides Periodic acid-Schiff stain (PAS). This section does not any.

Unsourced material may be challenged and. (March 2013) Polysaccharides with unprotected or amino sugars (i.e. Some OH groups replaced with amine) give a positive (PAS). The list of polysaccharides that stain with PAS is long. Although of epithelial origins stain with PAS, mucins of connective tissue origin have so many acidic substitutions that they do not have enough glycol or amino-alcohol groups left to react with PAS.

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Bacterial Polysaccharides Depolymerized

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McArdle, Frank I. Katch, Victor L. Katch, Edition: 6, illustrated, Published by Lippincott Williams & Wilkins, 2006, 1068 pages. Viscosity of Welan Gum vs. Concentration in Water. Guo H, Yi W, Song JK, Wang PG (2008).

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