Peptidoglycan Structure and Dynamics in Gram Positive Bacteria - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Peptidoglycan Structure and Dynamics in Gram Positive Bacteria write by Emma Hayhurst. This book was released on 2006. Peptidoglycan Structure and Dynamics in Gram Positive Bacteria available in PDF, EPUB and Kindle.
Bacterial Cell Wall
Bacterial Cell Wall - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Bacterial Cell Wall write by J.-M. Ghuysen. This book was released on 1994-02-09. Bacterial Cell Wall available in PDF, EPUB and Kindle. Studies of the bacterial cell wall emerged as a new field of research in the early 1950s, and has flourished in a multitude of directions. This excellent book provides an integrated collection of contributions forming a fundamental reference for researchers and of general use to teachers, advanced students in the life sciences, and all scientists in bacterial cell wall research. Chapters include topics such as: Peptidoglycan, an essential constituent of bacterial endospores; Teichoic and teichuronic acids, lipoteichoic acids, lipoglycans, neural complex polysaccharides and several specialized proteins are frequently unique wall-associated components of Gram-positive bacteria; Bacterial cells evolving signal transduction pathways; Underlying mechanisms of bacterial resistance to antibiotics.
Bacterial Cell Wall Structure and Dynamics
Bacterial Cell Wall Structure and Dynamics - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Bacterial Cell Wall Structure and Dynamics write by Tobias Dörr. This book was released on 2019-12-27. Bacterial Cell Wall Structure and Dynamics available in PDF, EPUB and Kindle. Bacterial cells are encased in a cell wall, which is required to maintain cell shape and to confer physical strength to the cell. The cell wall allows bacteria to cope with osmotic and environmental challenges and to secure cell integrity during all stages of bacterial growth and propagation, and thus has to be sufficiently rigid. Moreover, to accommodate growth processes, the cell wall at the same time has to be a highly dynamic structure: During cell enlargement, division, and differentiation, bacteria continuously remodel, degrade, and resynthesize their cell wall, but pivotally need to assure cell integrity during these processes. Finally, the cell wall is also adjusted according to both environmental constraints and metabolic requirements. However, how exactly this is achieved is not fully understood. The major structural component of the bacterial cell wall is peptidoglycan (PG), a mesh-like polymer of glycan chains interlinked by short-chain peptides, constituting a net-like macromolecular structure that has historically also termed murein or murein sacculus. Although the basic structure of PG is conserved among bacteria, considerable variations occur regarding cross-bridging, modifications, and attachments. Moreover, different structural arrangements of the cell envelope exist within bacteria: a thin PG layer sandwiched between an inner and outer membrane is present in Gram-negative bacteria, and a thick PG layer decorated with secondary glycopolymers including teichoic acids, is present in Gram-positive bacteria. Furthermore, even more complex envelope structures exist, such as those found in mycobacteria. Crucially, all bacteria possess a multitude of often redundant lytic enzymes, termed “autolysins”, and other cell wall modifying and synthesizing enzymes, allowing to degrade and rebuild the various structures covering the cells. However, how cell wall turnover and cell wall biosynthesis are coordinated during different stages of bacterial growth is currently unclear. The mechanisms that prevent cell lysis during these processes are also unclear. This Research Topic focuses on the dynamics of the bacterial cell wall, its modifications, and structural rearrangements during cell growth and differentiation. It pays particular attention to the turnover of PG, its breakdown and recycling, as well as the regulation of these processes. Other structures, for example, secondary polymers such as teichoic acids, which are dynamically changed during bacterial growth and differentiation, are also covered. In recent years, our view on the bacterial cell envelope has undergone a dramatic change that challenged old models of cell wall structure, biosynthesis, and turnover. This collection of articles aims to contribute to new understandings of bacterial cell wall structure and dynamics.
Peptidoglycan Architecture and Dynamics in Gram-positive Bacteria
Peptidoglycan Architecture and Dynamics in Gram-positive Bacteria - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Peptidoglycan Architecture and Dynamics in Gram-positive Bacteria write by Richard Wheeler. This book was released on 2012. Peptidoglycan Architecture and Dynamics in Gram-positive Bacteria available in PDF, EPUB and Kindle. The major structural determinant of most bacterial cells is the peptidoglycan layer, a network (the sacculus) of glycan strands cross-linked by short peptide stems which encompasses the entire bacterium. However the architecture of peptidoglycan, which must accommodate both the structural requirements of the cell and the dynamic processes of growth and division, is poorly understood. Most architectural studies have addressed the peptidoglycan of rod-shaped bacteria. The architecture in Gram-positive cocci and ovococci is largely uncharacterised, In this study, atomic force microscopy (AFM) of purified sacculi of three species of ovococcus was combined with biochemical analysis and super resolution fluorescence microscopy. A model was developed in which incorporation of long glycan strands from a single mid-cell focus results in preferential orientation, parallel to the short axis of the cell. AFM and fluorescence microscopy of the coccoid bacterium Staphylococcus aureus revealed a dynamic peptidoglycan architecture of rings and knobbles, growth by peptidoglycan maturation, and a system of heritable peptidoglycan ribs. Ribs may provide a structural mechanism for coordinating orthogonal division on three planes. We hypothesised cell wall growth occurs via the activity of N-acetyl-[beta]-D-glucosaminidases. Four putative glucosaminidases were identified, with SagB found to have a major role in glycan strand length determination. Hydrolysis of the septal cross-wall by glucosaminidase activity was required for spherical shape, suggesting a novel mechanism of growth by hydrolysis. My work has highlighted diverse and elegant peptidoglycan architectures, adapted to meet the unique mechanical requirements of bacteria with different morphologies and strategies for growth and division.
Extracellular Sugar-Based Biopolymers Matrices
Extracellular Sugar-Based Biopolymers Matrices - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Extracellular Sugar-Based Biopolymers Matrices write by Ephraim Cohen. This book was released on 2019-07-02. Extracellular Sugar-Based Biopolymers Matrices available in PDF, EPUB and Kindle. The extracellular matrix (ECM) is an acellular three-dimensional network composed of proteins, glycoproteins, proteoglycans and exopolysaccharides. It primarily serves as a structural component in the tissues and organs of plants and animals, or forms biofilms in which bacterial cells are embedded. ECMs are highly dynamic structures that undergo continuous remodeling, and disruptions are frequently the result of pathological processes associated with severe diseases such as arteriosclerosis, neurodegenerative illness or cancer. In turn, bacterial biofilms are a source of concern for human health, as they are associated with resistance to antibiotics. Although exopolysaccharides are crucial for ECM formation and function, they have received considerably little attention to date. The respective chapters of this book comprehensively address such issues, and provide reviews on the structural, biochemical, molecular and biophysical properties of exopolysaccharides. These components are abundantly produced by virtually all taxa including bacteria, algae, plants, fungi, invertebrates and vertebrates. They include long unbranched homopolymers (cellulose, chitin/chitosan), linear copolymers (alginate, agarose), peptoglycans such as murein, heteropolymers like a variety of glycosaminoglycans (hyaluronan, dermatan, keratin, heparin, Pel), and branched heteropolymers such as pectin and hemicellulose. A separate chapter is dedicated to modern industrial and biomedical applications of exopolysaccharides and polysaccharide-based biocomposites. Their unique chemical, physical and mechanical properties have attracted considerable interest, inspired basic and applied research, and have already been harnessed to form structural biocomposite hybrids for tailor-made applications in regenerative medicine, bioengineering and biosensor design. Given its scope, this book provides a substantial source of basic and applied information for a wide range of scientists, as well as valuable textbook for graduate and advanced undergraduate students.
