Contents
List of contributing authors
Preface
1 Cyanobacterial design cell for the production of hydrogen from water
1.1 Introduction: Why hydrogen producing cells?
1.2 Antenna size reduction
1.3 Partial uncoupling of ATP synthesis
1.4 Re-directing electron flow at PS1-acceptor side
1.5 Hydrogenase design strategies
1.6 Photobioreactor design and continuous cultivation for optimization of design cell performance
1.7 Outlook and biotechnological potential
2 Analysis and assessment of current photobio reactor systems for photobiological hydrogen production
2.1 Introduction
2.2 Methodological approach
2.3 System description
2.4 Sunlight-dependent hydrogen production rates
2.5 System assessment
2.5.1 Life cycle inventory analysis
2.5.2 Life cycle impact analysis
2.5.3 Benchmark
2.6 Summary
3 Catalytic properties and maturation of [FeFe]-hydrogenases
3.1 Introduction
3.2 The three major structure types of [FeFe]-hydrogenases
3.3 The H-cluster, the catalytic center of [FeFe]-hydrogenases
3.4 The catalytic cycle, a working hypothesis
3.5 The interplay between H-cluster and protein environment
3.6 Oxygen induced H-cluster degradation
3.7 The native H-cluster maturation system
3.8 Spontaneous in vitro maturation of the H-cluster
4 Oxygen-tolerant hydrogenases and their biotechnological potential
4.1 Introduction
4.2 O2-tolerant membrane-bound hydrogenases
4.2.1 Physiological function of O2-tolerant MBHs
4.2.2 Structure and cofactor composition of O2-tolerant MBHs
4.2.3 Mechanism of O2 tolerance in certain MBHs
4.2.4 Proton reduction capacity of O2-tolerant MBHs
4.3 O2-tolerant, NAD+-reducing hydrogenases
4.3.1 Physiological function of NAD+-reducing hydrogenases
4.3.2 Structure and reactivity of cofactors in NAD+-reducing hydrogenase
4.3.3 Mechanism of O2 tolerance in NAD+-reducing hydrogenase
4.3.4 Proton reduction capacity of NAD+-reducing hydrogenases
4.4 O2-insensitive regulatory hydrogenases
4.4.1 Genetic organization of hydrogenase genes and hydrogenase biosynthesis
4.4.2 Role of the regulatory hydrogenase in H2-responsive signaling
4.4.3 Unique features of regulatory hydrogenases
4.4.4 The O2-insensitive regulatory hydrogenase as a major player in the O2- sensitive H2 signaling pathway
4.5 O2-insensitive actinobacterial hydrogenases
4.5.1 Physiological function of AHs
4.5.2 Genetic organization of the AH operons
4.5.3 AH cofactor composition and mechanism of O2 insensitivity
4.6 Biotechnological application of O2-tolerant hydrogenases
4.6.1 H2 oxidation
4.6.2 H2 production
5 Metal centers in hydrogenase enzymes studied by X-ray spectroscopy
5.1 Introduction
5.2 X-ray spectroscopy results on hydrogenase proteins
5.2.1 [Fe]-hydrogenases
5.2.2 [FeFe]-hydrogenases
5.2.3 [NiFe]-hydrogenases
5.2.4 [NiFeSe]-hydrogenase
5.3 Key questions in H2 chemistry and advanced X-ray techniques
6 Structure and function of [Fe]-hydrogenase and biosynthesis of the FeGP cofactor
6.1 Introduction
6.2 Physiological function
6.2.1 Hydrogenases in methanogenesis
6.2.2 Nickel limitation
6.3 Structure of [Fe]-hydrogenase
6.3.1 Protein structure
6.3.2 Structure of the FeGP cofactor
6.4 Catalytic properties
6.4.1 Reactions catalyzed
6.4.2 Inhibitors
6.4.3 Catalytic mechanism
6.5 Biosynthesis of the FeGP cofactor
6.5.1 Stable-isotope labeling
6.5.2 Hcg proteins involved in FeGP cofactor biosynthesis
6.6 Potential application of [Fe]-hydrogenase and the FeGP cofactor
7 Hydrogenase evolution and function in eukaryotic algae
7.1 Introduction
7.2 Hydrogen production in green algae
7.3 Hydrogen utilization pathways in green algae
7.4 Hydrogenase activity, anaerobic metabolism and evolution
7.5 Core anaerobic metabolisms in eukaryotes
7.6 Fermentative H2 production in algae
7.7 Disruption of fermentative enzymes in Chlamydomonas reinhardtii
7.8 Hydrogenase isoforms
7.9 [FeFe]-hydrogenase assembly
7.10 Algal hydrogenase diversity
7.11 Hydrogenases in saltwater organisms
7.12 Outlook
8 Engineering of cyanobacteria for increased hydrogen production
8.1 Native cyanobacteria, hydrogen production and hydrogen uptake
8.2 Genetic engineering, synthetic biology
8.3 Genetic engineering of cyanobacteria for enhanced hydrogen production
8.3.1 Engineering of nitrogenases and hydrogenases for enhanced hydrogen production
8.3.2 Genetic engineering of metabolic pathways for enhanced hydrogen production
8.4 Future perspectives
9 Semi-artificial photosynthetic Z-scheme for hydrogen production from water
9.1 Nature-inspired approaches for hydrogen production
9.2 Bio-photoelectrochemical half-cells based on photosynthetic proteins
9.2.1 PS2-based photoanodes
9.2.2 PS1-based photoelectrodes
9.3 PS1-catalyst nanoconstructs for hydrogen evolution
9.3.1 Platinum โ PS1
9.3.2 PS1-molecular wire-nanoparticle bioconjugates
9.3.3 PS1-molecular wire-H2ase nanoconstructs
9.3.4 PS1-H2ase hybrid complexes
9.4 Electron transfer rates of PS1 in bio-photoelectrochemical devices and PS1-catalyst hybrids vs. natural photosynthesis
9.5 Semi-artificial Z-scheme
9.5.1 Realizing and exploiting a photosynthetic Z-scheme mimic for electrical energy production
9.5.2 Improving the efficiency of a semi-artificial Z-scheme by adjusting the formal potential of the hydrogels
9.6 Outlook โ PS2-PS1-H2 catalyst
10 Photosynthesis and hydrogen metabolism revisited. On the potential of light-driven hydrogen production in vitro
10.1 Introduction
10.2 Photosynthesis and redox balance
10.2.1 Basic principles of photosynthetic electron transport
10.2.2 Molecular structure of PSI and interaction with ferredoxin
10.2.3 Light-driven hydrogen evolution
10.3 Hydrogenases are the natural model of hydrogen catalysis
10.3.1 The active site of [NiFe]- and [FeFe]-hydrogenases
10.3.2 The structure of [NiFe]- and [FeFe]-hydrogenases
10.4 Exploiting the modules of light-driven hydrogen production in vitro
10.4.1 Nobel metal catalysis with PSI as photosensitizer
10.4.2 Cluster-to-cluster electron wiring from PSI to hydrogenase
10.4.3 Reconstitution of the PSI stromal ridge by a hydrogenase construct
10.5 Outlook
11 Re-routing redox chains for directed photocatalysis
11.1 Making hydrogen with sunlight โ an alchemic approach
11.2 Re-routing redox chains: Biological approaches
11.2.1 Coating PSI with platinum
11.2.2 Engineering PSI to interact with non-natural species
11.2.3 Fusion constructs
11.3 Re-routing redox chains: Synthetic approaches
11.3.1 Artificial photosynthesis
11.3.2 Hydrogenase active site mimics and alternative H2 production catalysts
11.3.3 Chimeras
11.4 Future directions and implications
12 Energy and entropy engineering on sunlight conversion to hydrogen using photosynthetic bacteria
12.1 Introduction
12.1.1 Enthalpy to entropy
12.1.2 The appropriate steps to the use of renewable energy
12.2 Biological energy conversion methods as stabilizing elements of power grids
12.2.1 Dark-fermentation in renewable energy systems
12.2.2 Photo-fermentation in renewable energy systems
12.3 Discussion
12.3.1 How to overcome the entropic difficulties of renewable energy sources by using biological functions
12.3.2 Possible applications of biohydrogen in tropical regions
Index