Rehm Alginates: Biology and Applications

1. Auflage 2009
ISBN: 978-3-540-92679-5
Verlag: Springer Berlin Heidelberg
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 13, 266 Seiten

Reihe: Microbiology Monographs

'Alginates: Biology and Applications' provides an overview of the state of art of alginate material properties, genetics and the molecular mechanisms underlying alginate biosynthesis as well as applications of tailor-made alginates in medicine, food and biotechnology. Topics treated are: material properties of alginates, alginate production: precursor biosynthesis, polymerization and secretion, bacterial system for alginate uptake and degradation, enzymatic alginate modification, alginate gene regulation, role of alginate in bacterial biofilms, microbial production of alginates: physiology and process aspects, alginate-based blends and nano/microbeads, applications of alginates in food, alginate and its comonomer mannuronic acid: medical relevance as drugs.

Autoren/Hrsg.

Rehm, Bernd H. A.

Inhaltsverzeichnis

1;Preface;6
1.1;References;7
2;Contents;8
3;Material Properties of Alginates;10
3.1;1 Sources and Applications;11
3.2;2 Chemical Structure and Sequence;12
3.2.1;2.1 Chemical Composition;13
3.2.2;2.2 Comonomer Sequence;14
3.2.3;2.3 Natural Substituents;19
3.2.4;2.4 Alginate as a Polyelectrolyte;21
3.2.5;2.5 Conformational Properties of the Alginate Chain;24
3.3;3 Molecular Weight and Stability ;26
3.3.1;3.1 Molecular Weight and Molecular Weight Distribution of Native Alginates;26
3.3.2;3.2 Chain Degradation;27
3.3.3;3.3 Chemical Modifications of Alginate;29
3.4;4 Alginate Solutions ;30
3.4.1;4.1 Thermodynamic Properties;30
3.4.2;4.2 Nonequilibrium Properties;32
3.5;5 Ion-Binding Properties;35
3.6;6 Alginate Gels;39
3.6.1;6.1 Gel Formation Properties;39
3.6.2;6.2 Hydrogel Stability;44
3.6.3;6.3 Mechanical Properties;46
3.6.4;6.4 Diffusion Properties;54
3.7;References;55
4;Alginate Production: Precursor Biosynthesis, Polymerization and Secretion;63
4.1;1 Introduction;64
4.2;2 Alginate Precursor Biosynthesis;65
4.2.1;2.1 Alginate Biosynthesis Genes;66
4.2.2;2.2 GDP-Mannuronic Acid Biosynthesis;67
4.3;3 Alginate Polymerization and Secretion;69
4.3.1;3.1 Alginate Polymerization;69
4.3.2;3.2 Alginate Export;73
4.4;4 Conclusion and Future Perspectives;75
4.5;References;75
5;Bacterial System for Alginate Uptake and Degradation;80
5.1;1 Introduction;81
5.2;2 Alginate-Assimilating Bacterium;82
5.2.1;2.1 Pit Formation on the Cell Surface;82
5.2.2;2.2 Genome Sequence;84
5.3;3 Alginate Uptake;84
5.3.1;3.1 Cell Surface Receptors;86
5.3.2;3.2 Outer-Membrane Transporters;87
5.3.3;3.3 Periplasmic Binding Proteins;88
5.3.4;3.4 Inner-Membrane ABC Importer;90
5.4;4 Alginate Degradation;91
5.4.1;4.1 Endotype Alginate Lyases;91
5.4.2;4.2 Exotype Alginate Lyases;93
5.5;5 Concluding Remarks and Future Perspectives;94
5.5.1;5.1 Superchannel as Alginate Uptake System;94
5.5.2;5.2 Molecular Transplantation of Superchannel;95
5.5.3;5.3 Application of the Alginate Degradation System;97
5.6;References;98
6;Enzymatic Alginate Modification;102
6.1;1 Introduction;103
6.2;2 Mannuronan C-5-Epimerases;105
6.2.1;2.1 Early Studies on the Secreted Mannuronan C-5-Epimerase from A. vinelandii;105
6.2.2;2.2 Cloning and Characterization of the Mannuronan C-5-Epimerases from A. vinelandii;107
6.2.3;2.3 Cloning and Characterization of the Bacterial Periplasmic Mannuronan C- 5- Epimerases;109
6.2.4;2.4 Mannuronan C-5-Epimerases from Algae;110
6.2.5;2.5 Structure of the Mannuronan C-5-Epimerases;110
6.2.6;2.6 Mode of Action of the Secreted Mannuronan C- 5- Epimerases;111
6.2.7;2.7 Enzyme Specificity; Epimerization of Nonnatural Uronans and Poly( guluronic acid);113
6.2.8;2.8 In Vitro Epimerization with AlgE Epimerases;114
6.3;3 Alginate Lyases;115
6.3.1;3.1 Alginate Lyases as Tools To Determine Alginate Structure;115
6.3.2;3.2 An Alginate Lyase Is Needed To Remove Aberrantly Localized Alginate;115
6.4;4 Alginate Acetylation;116
6.5;5 Use of Alginate-Modifying Enzymes for Biotechnological Purposes;116
6.6;References;117
7;Alginate Gene Regulation;123
7.1;1 Introduction;124
7.2;2 Hierarchical Regulation of the Alginate Operon;124
7.3;3 AlgR, a Two-Component Regulator;125
7.4;4 AlgB, an NtrC-Family Two-Component Regulator;127
7.5;5 AmrZ, an Arc-Like DNA-Binding Protein;128
7.6;6 Ancillary Regulators of the algD Operon;129
7.7;7 Alternative Sigma Factor, s 22;129
7.8;8 Role of s 22 -MucAB and Regulated Proteolysisin a Cell Wall Stress Response;131
7.9;9 Conclusions;134
7.10;References;134
8;Role of Alginate in Bacterial Biofilms;140
8.1;1 Introduction;141
8.2;2 Bacterial Exopolysaccharides;141
8.3;3 Alginate Structure and Properties;142
8.4;4 Regulation of Alginate Biosynthesis;143
8.5;5 Role of Alginate in Biofilm Formation;145
8.6;6 Alginate Creates a Hydrated Biofilm Microenvironment;146
8.7;7 Alginate Production in the CF Lung;148
8.8;8 Alginate Protects Cells from Antimicrobial Agents;149
8.9;9 Alginate in Phytopathogenic Interactions;150
8.10;10 Concluding Remarks and Future Perspectives;152
8.11;References;152
9;Microbial Production of Alginates: Physiology and Process Aspects;157
9.1;1 Introduction;158
9.2;2 Commercial Production of Alginate;158
9.3;3 Biological Role of Alginate Production in Bacteria;160
9.3.1;3.1 Azotobacter vinelandii;160
9.3.2;3.2 Pseudomonads;163
9.4;4 Optimal Conditions for Microbial Alginate Production ;166
9.4.1;4.1 Fermentation Conditions for Optimal AlginateProduction in A. vinelandii;166
9.4.2;4.2 Alginate Production by P. aeruginosa;168
9.4.3;4.3 Kinetics of Alginate Production;169
9.4.4;4.4 Non-Newtonian Alginate Fluids and the Role of Fermentor Hydrodynamics;170
9.5;5 Conclusion;172
9.6;References;172
10;Alginate-Based Blends and Nano/Microbeads;178
10.1;1 Introduction;179
10.2;2 Alginate Blends;180
10.2.1;2.1 General Methods for the Preparation of Alginate Blends;180
10.2.2;2.2 Applications of Alginate Blends;181
10.3;3 Alginate Microbeads and Nanobeads;186
10.3.1;3.1 Methods for Preparation of the Beads;186
10.3.2;3.2 Application of Alginate Beads;191
10.4;4 Conclusion;206
10.5;References;206
11;Applications of Alginates in Food;214
11.1;1 Introduction;215
11.2;2 Gelling Agents;216
11.3;3 Thickening, Stabilising and Emulsifying Agents;217
11.4;4 Encapsulation and Immobilisation;218
11.5;5 Food Coating;220
11.6;6 Physiological Effects of Dietary Alginates;221
11.6.1;6.1 Alginate Safety;221
11.6.2;6.2 Effect on Colonic Microflora;221
11.6.3;6.3 Reduction of Toxicity of Colonic Luminal Contents;222
11.6.4;6.4 Effect of Alginate on Satiety;223
11.6.5;6.5 Effect on Intestinal Absorption Rates;223
11.6.6;6.6 Effect on Plasma Cholesterol;224
11.6.7;6.7 Effect on Glycaemic and Insulinaemic Responses;225
11.7;7 Summary;225
11.8;References;226
12;Alginate and Its Comonomer Mannuronic Acid: Medical Relevance as Drugs;232
12.1;1 Introduction;233
12.2;2 Therapeutic Effects of Alginate on Experimental Acute Ulcerative Colitis;234
12.3;3 Treatment of Experimental Chronic Ulcerative Colitis with Sodium Alginate;239
12.4;4 Treatment of Experimental Immune Complex Glomerulonephritis by Sodium Alginate;240
12.5;5 Therapeutic Effects of M2000 on an Experimental Model of Rheumatoid Arthritis;245
12.6;6 Immunosuppressive Effect of M2000 in Experimental Multiple Sclerosis;247
12.7;7 Treatment of Experimental Nephrotic Syndrome with M2000;251
12.8;8 Therapeutic Effects of M2000 in Experimental Immune Complex Glomerulonephritis;255
12.9;9 Tolerability and Pharmacotoxicology of M2000;258
12.10;10 Outlook;261
12.11;References;261
13;Index;264