The genus Aspergillus has a worldwide distribution and is one of the most common of all groups of fungi. They are possibly the greatest contami nants of natural and man-made organic products, and a few species can cause infections in man and animals. The aspergilli are also one of the most important mycotoxin-producing groups of fungi when growing as contaminants of cereals, oil seeds, and other foods. Not all aspergilli are viewed as troublesome contaminants, however, as several species have had their metabolic capabilities harnessed for commercial use. The aspergilli have long been associated in the Far East with the koji stage of several food fermentations, particularly soy sauce and miso, and subsequently as a source of useful enzymes. The ability of these fungi to produce several organic acids, especially citric acid, has created major industrial complexes worldwide. Traditional methods of strain develop ment have been extensively studied with the industrial strains, while more recently, recombinant DNA technology has been applied to the aspergilli with emphasis on heterologous protein production. In compiling this book, I have been fortunate to have the full enthu siastic involvement of the authors, and to them I extend my very grateful thanks for mostly being on time and for producing such readable and authoritative chapters. Collectively, we hope that our efforts will strengthen the scientific understanding of this intriguing group of filamentous fungi and further their use in the field of biotechnology.
Inhaltsverzeichnis
1 Taxonomy Current Concepts of Aspergillus Systematics.- 1. Introduction.- 2. Criteria for Classification and Identification.- 3. Nomenclature.- 4. Current Taxonomic Scheme.- References.- 2 Physiology of Aspergillus.- 1. Introduction.- 2. Water Availability (aw).- 3. Temperature ..- 4. pH.- 5. Gas Composition.- 6. Mycotoxin Production.- 6.1. Fungal Factors.- 6.2. Environmental Factors.- 7. Summary.- References.- 3 Improvement of Industrial Aspergillus Fungi.- 1. Breeding by Protoplast Fusion of Koji Mold, Aspergillus sojae.- 2. Improvement of Enzyme Productivities through Mutation or Haploidization of Heterozygous Diploids Obtained by Protoplast Fusion of Aspergillus sojae.- 3. Interspecific Protoplast Fusion between Aspergillus oryzae and Aspergillus sojae.- 4. Interspecific Electrofusion between Protoplasts of Aspergillus oryzae and Aspergillus sojae.- 5. Interspecific Hybridization of Aspergillus awamori and Aspergillus oryzae by Protoplast Fusion.- 6. Intraspecific Protoplast Fusion of Aspergillus niger.- References.- 4 Molecular Genetics and Expression of Foreign Proteins in the Genus Aspergillus.- 1. Introduction.- 2. Methodology.- 3. Expression of Foreign Proteins.- References.- 5 Solid-State Fermentations of the Genus Aspergillus.- 1. Introduction.- 2. Fungal Growth Characteristics in a Solid-State Medium.- 3. Dynamic and Thermodynamic Properties of a Solid-State Medium.- 4. Influence of Physicochemical Parameters of the Medium in Solid-State Fermentation.- 5. Aspergillus Products.- References.- 6 Liquid Fermentation Systems and Product Recovery of Aspergillus.- 1. Introduction.- 2. Submerged Cultivation.- 3. Current Technology.- 4. Citric Acid Production.- 5. Enzyme Production.- 6. Heterologous Protein Production.- 7. Downstream Processing.- 8. OverallConclusions.- References.- 7 Enzymes of the Genus Aspergillus.- 1. Introduction.- 2. Production and Recovery of Enzymes.- 3. Downstream Processing and Recovery.- 4. Amylolytic Enzymes of Aspergillus Species.- 5. Pectinolytic Enzymes.- 6. Cellulases.- 7. Xylanases.- 8. Lipases.- 9. Glucose-Transforming Enzymes.- 10. Proteinases.- 11. Miscellaneous Enzymes.- 12. Conclusions.- References.- 8 Health-Related Aspects of the Genus Aspergillus.- 1. Introduction.- 2. Aspergillosis.- 3. Mycotoxicosis.- 4. Epidemiology, Host Susceptibility, and High-Risk Groups ..- 5. Other Medical Aspects.- 6. Conclusions.- References.
