This book provides a comprehensive and authoritative review of cyanobacteria and their applications as solar cell factories. Cyanobacteria are able to perform oxygenic photosynthesis and they are utilized in many different bioprocesses. The book covers two major aspects of a cyano-based bioprocess: the biological whole-cell catalyst and the technical environment in which the catalyst is applied. In the biocatalyst itself electron and carbon flow play an essential role for the performance of the cell and need to be tackled likewise for successful biocatalyst development. In the first chapters of this volume, cyanobacterial biotechnology and the fundamentals of cyanobacterial bioenergetics are introduced followed by an overview on tools and strategies for cyanobacteria engineering. Further on, examples of applications, engineering and production of different industrially relevant compounds in these organisms are provided, and finally process technology specific for cyanobacteria is covered.
In this book, particular attention is given to topics such as cyanobacterial bioenergetics, metabolic engineering design strategies, utilizing cyanobacteria in biophotovoltaics, and production of pigments as well as photobiohydrogen in cyanobacteria, among others.
This book will provide interested students and researchers in the area of photo-biotechnology with a deeper understanding of the cyanobacterial cell-factory, including the latest innovations and persistent challenges in the field.
Author(s): Katja Bühler, Pia Lindberg
Series: Advances in Biochemical Engineering/Biotechnology, 183
Publisher: Springer
Year: 2023
Language: English
Pages: 358
City: Cham
Preface
Editorial Letter
The Hour of Parting
Changes
Contents
Introduction to Cyanobacteria
1 Introduction
2 Microbiological Perspective on Cyanobacteria and Their Role in Nature and Technology
3 Cyanobacteria as Industrial Workhorses
4 Model Strains and Genetic Engineering
5 Target Products
6 Engineering Strategies
7 Engineering Photosynthetic Efficiency
8 Engineering Carbon Fixation
9 Comparison to Heterotrophic Production Hosts
10 Optimizing the Growth Environment
11 Conclusions
References
Cyanobacterial Bioenergetics in Relation to Cellular Growth and Productivity
1 Introduction
2 Energy Production Mechanisms of Cyanobacteria
2.1 Membrane Bioenergetics
2.1.1 Cytoplasmic Membrane (CM) Bioenergetics
2.1.2 Thylakoid Membrane Bioenergetics
2.2 Photochemical Charge Separation
2.2.1 Light-Harvesting
Phycobilisomes
Chlorophyll Antenna
2.2.2 Photosystem II
2.2.3 PSI and the Production of a Strong Reductant
2.2.4 Cytochrome b6/f
2.2.5 Type-1 Complexes
2.3 Cyclic Electron Transfer, Energy Balancing, and Photoprotection
2.3.1 Cyclic Electron Flow (CEF)
2.3.2 Control of Light Harvesting and Energy Transfer
2.3.3 Regulation of Photosynthetic Electron Flow for Photoprotection
2.3.4 Protection of PSI as Key to Photoacclimation
2.4 Energy Charge and Redox Poise
3 Integration of Bioenergetic Mechanisms into Cellular Metabolism and Growth
3.1 Source-Sink Relationships: Bioengineered Product Synthesis Can Alleviate Potentially Dangerous Bioenergetic Overflows
3.2 Fast-Growing Cyanobacteria and Productivity
References
The Molecular Toolset and Techniques Required to Build Cyanobacterial Cell Factories
1 Introduction
2 Molecular Tools and Approaches to Genetically Modify Cyanobacteria
2.1 Integration of Genetic Information into Neutral Sites of the Host DNA via Homologous Recombination
2.2 Introduction and Maintenance of Genes via Replicative Plasmids
2.3 Modifications Based on CRISPR/Cas
2.4 Marker-Based and Marker-Free Selection of Recombinant Strains
3 Customized Biological Parts to Control the Expression of Introduced Genes
3.1 Promoters
3.1.1 Homologous Promoters Derived from Cyanobacteria
3.1.2 Heterologous Promoters Derived from Other Sources
3.2 Transcription Terminators
3.3 Ribosome Binding Sites
3.4 Regulatory RNAs
3.4.1 Small RNAs
3.4.2 Riboswitches
3.5 Knockdown via CRISPR Interference
4 Post-Translational Control of Proteins and Their Activities
4.1 Protein Degradation Tags and Heterologous Proteases
5 Assembly of Biological Parts
6 Conclusion and Future Perspectives
References
Metabolic Engineering Design Strategies for Increasing Carbon Fluxes Relevant for Biosynthesis in Cyanobacteria
1 Introduction
2 Increasing Carbon Flux Toward Acetyl-CoA and Its Derivatives
2.1 Dark Anoxic Cultivation Increases Acetyl-CoA Flux by Degrading Carbon Storage Compounds
2.2 Enhancing Upstream Enzyme Activity Increases Acetyl-CoA Flux for Biosynthesis
2.3 Reducing Competing Pathway Activities Concentrates Acetyl-CoA Flux Toward Targeted Bioproducts
2.4 Constructing Metabolic Bypasses for Enhancing Carbon Flux to Acetyl-CoA
3 Strategies to Increase Flux of Pyruvate
3.1 Elimination of Glycogen Biosynthesis and Mimic Nitrogen Starvation
3.2 Improve Flux from 3-Phosphoglycerate Toward Pyruvate
3.3 Partitioning Flux from TCA Cycle to Pyruvate
3.4 Reducing Native Pyruvate Consumption Fluxes
4 Strategies to Increase Flux of Malonyl-CoA
4.1 Overexpression of Acetyl-CoA Carboxylase
4.2 Inhibiting Downstream Fatty Acid Biosynthesis
5 Strategies to Drive Flux Toward TCA Cycle
6 Increasing Carbon Flux Toward Aromatic Amino Acid and Its Derivatives
7 Increasing Reducing Cofactor Availability Drives Carbon Flux for Biosynthesis
7.1 Adopting NADPH-Dependent Enzymes for Biosynthesis
7.2 Manipulating Intracellular Reducing Cofactor Availability
8 Engineered Mixotrophy for Increased Biosynthetic Fluxes
8.1 Glucose
8.2 Xylose
8.3 Sucrose
8.4 Glycerol
8.5 Acetate
9 Conclusion
References
Production of Fatty Acids and Derivatives Using Cyanobacteria
1 Introduction
2 Fatty Acids, Fatty Acid Derivatives, and Their Importance
3 Fatty Acid Metabolism in Cyanobacteria
4 The Use of Metabolic Engineering to Implement Pathways for Fatty Acid Derivatives
4.1 Fatty Aldehydes
4.2 Fatty Alcohols
4.3 Hydrocarbons
4.4 Fatty Acid Methyl Esters
4.5 Hydroxy Fatty Acids
5 Metabolic Engineering Strategies for Enhancing Bioproduction of Fatty Acids and Fatty Acid Derivatives in Cyanobacteria
5.1 Knocking Out Acyl-ACP Synthetase (aas) Gene
5.2 Expression of Genes Involved in Fatty Acids Biosynthesis (FAB)
5.3 Enhance Cellular Productivity
5.4 Alleviation of Free Fatty Acid Toxicity
5.5 Manipulation of the Transcriptional Regulators
5.6 Increasing Free Fatty Acid Secretion
5.7 Free Fatty Acid Recovery from Lipid Membrane
5.8 Increasing the Precursor Pool
5.9 Optimization of Metabolic Engineering
5.10 Protein Engineering
6 Commercial Opportunities to Manufacture Fatty Acids and Derivatives Thereof
7 Conclusion
References
Sustainable Production of Pigments from Cyanobacteria
1 Introduction
2 Cyanobacterial Pigments
2.1 Phycobiliproteins
2.2 Chlorophylls
2.3 Carotenoids
2.4 Scytonemin
3 Applications
3.1 Food and Nutraceuticals
3.2 Cosmetics
3.3 Pharmaceuticals and Diagnostics
4 Pigment Production in Cyanobacteria
4.1 Cultivation Parameters and Their Impact on Biomass and Pigment Yields
4.1.1 Carbon and Energy Supply
4.1.2 Key Macro- and Micronutrients Optimisation
4.2 Mass Cultivation Systems and Process Management
4.2.1 Open Systems
4.2.2 Closed Systems (Photobioreactors)
4.2.3 Performance Comparison, Transfer of Scale and Process Control
4.2.4 Light Supply and Optimisation
4.2.5 Salinity and pH
4.2.6 Temperature
4.2.7 Mixing and Shear Sensitivity
5 Downstream Processing
5.1 Biomass Harvesting
5.2 Product Release via Cell Disruption or Pre-Treatment
5.2.1 Mechanical Pre-Treatment Methods
5.2.2 Physical Pre-Treatment Methods
5.2.3 Chemical Pre-Treatment Methods
5.3 Product Recovery via Pigment Extraction
5.3.1 Conventional Organic Solvent Extraction
5.3.2 Accelerated Organic Solvent Extraction
5.3.3 Ionic Liquid Extraction
5.3.4 Supercritical Carbon Dioxide Extraction
5.4 Pigment Purification
6 Pigment Bioprocessing Challenges
7 Commercial Pigment Production Technologies
7.1 Patents and Technology Transfer
7.2 Techno-Economic Analysis and Life-Cycle Analysis: CAPEX/OPEX and Price Points
8 Global Pigment Market Analysis: Opportunities and Challenges
9 Future Perspectives
References
Photobiohydrogen Production and Strategies for H2 Yield Improvements in Cyanobacteria
1 Introduction
2 Biophotolysis and H2 Metabolism in Cyanobacteria
3 H2-Catalyzing Enzymes in Cyanobacteria
4 Strategies for H2 Yield Improvements in Cyanobacteria
4.1 Metabolic Manipulation Approaches
4.1.1 Physiochemical Parameters Affecting H2 Production
4.1.2 Cell Immobilization for Reduced O2 and Cell-Stacking Effects
4.2 Genetic Engineering Approaches
4.2.1 Eliminating of Electron Competing Pathways for Promoting H2 Metabolism
4.2.2 Modifying Heterocyst Frequency for Increased H2 Production
4.2.3 Inactivation of Uptake (Hup) Hydrogenase Function for Enhanced H2 Production
4.2.4 Introduction of Non-native Hydrogenase for Enhanced H2 Productivity
5 Conclusions and Perspectives
References
Utilizing Cyanobacteria in Biophotovoltaics: An Emerging Field in Bioelectrochemistry
1 Introduction: Biophotovoltaic and Other Light Harvesting Bioelectrochemical Systems
2 Cyanobacterial Electron Transfer Pathways and Exoelectrogenesis
3 State of the Art of BPV
4 Unraveling the EET Pathways
5 Outlook
References
Process Technologies of Cyanobacteria
1 Introduction
2 Genome-Based Screening for Potential New Bioactive Substances
3 Strain Conservation of Cyanobacteria
3.1 Cryopreservation of Cyanobacteria
3.2 Alternative Conservation Approaches for Cyanobacteria
3.2.1 Lyophilization
3.2.2 Immobilization
3.2.3 Commonly Used Pre-Culture Technologies in Algae Biotechnology
4 Characterization of Cyanobacteria
4.1 Cell Vitality
4.1.1 In Vivo Growth Fluorometry
4.1.2 Resazurin Assay
4.1.3 Vitality Determination by pO2 Measurements
4.1.4 Spectral Domain Optical Coherence Tomography (sdOCT) and Pulse Amplitude Modulated (PAM)-Fluorometry
4.2 Cell Viability
4.2.1 Staining Methods
5 Photobioreactors
5.1 Closed Photobioreactors (PBRs)
5.2 Attached (Biofilm) Cultivation of Cyanobacteria
5.3 (Partly-)Submerged Biofilm PBRs
5.3.1 Dynamic Systems
5.3.2 Stationary Systems
5.4 Air-Exposed Biofilm PBRs
6 Cultivation Modes of Cyanobacteria
7 Conclusion
References
