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Chemical structure of quinones involved in this study. a Phylloquinone native to the organism; b plastoquinone-9 that incorporates in the A1A/A1B- sites when the biosynthesis of phylloquinone is interrupted; c thiolated quinone wire used to tether PS I to the H2ase
Source publication
Photosystem I complexes from the menB deletion mutant of Synechocystis sp. PCC 6803 were previously wired to a Pt nanoparticle via a molecular wire consisting of 15-(3-methyl-1,4-naphthoquinone-2-yl)]pentadecyl sulfide. In the presence of a sacrificial electron donor and an electron transport mediator, the PS I-NQ(CH2)15S-Pt nanoconstruct generated...
Citations
... Integrating abiotic components with RCs or introducing novel chemical bonds to channel electrons span approaches involving platinum nanoparticles deposited on reaction centers directly such as photosystem I (PSI) to generate molecular hydrogen (Evans et al., 2004) or by directly wiring hydrogenase (H 2 ase) to PSI's iron-iron cluster (Fe-Fe) (Gorka and Golbeck, 2020). Photosystem II has also been covalently bound to an electrode by an amide linkage allowing for a more controlled orientation and distance electrons would need to be transported or tunneled through (Kato et al., 2012). ...
Combining proteins and abiotic substances such as electrodes and nanomaterials is as attractive as it is challenging. Photosynthetic reaction centers (RCs) convert light energy of a single photon to cause a charge separation resulting in an excited electron, typically with a high quantum yield, making them among the most attractive proteins to harness for energy capture. RCs from purple bacteria provide a unique combination of visible and near-infrared light utilization with long term stability. This chapter will consider not only RC structure and function, but also of RC density on the chosen electrode, the electrode material itself, as well as addressing overall efficiency and long-term stability. The overlap between multiple fields spanning biochemistry, biophysics, nano-material science, and chemical engineering inspired the authors to systematically review literature from these perspectives to highlight the interplay of photon energy reception, energy conversion, as well as electron and mass transport. Nanoparticles (NPs) similar in dimensions to natural antenna and RCs, that are all much shorter than the wavelength of light they interact with, provide a valuable insight into not only interfacing strategies, but also ease of synthesis and perhaps into RCs function, as well. Nanoparticle incorporation into plants is also reviewed. Multiple examples of common practices within the fields of electrochemistry, chemical preparation of biological, and nanomaterials, to include scale up challenges, are discussed. Past and current efforts in engineering of photovoltaic devices based on purple bacterial RCs are reviewed and compared based on current density in micro amps per square centimeter (µA cm−2). Lastly, several opportunities are identified for the future of reaction center- electrode interfacial design.
... The artificial quinone has a typical headgroup as the native phylloquinone with a long tail of 15carbons ended with a thiol. The thiol tail is bound to an [FeFe]-hydrogenase variant from C. acetobutylicum that contains an iron on the distal [4Fe-4S] cluster afforded by mutating the surface exposed Cys97 residue to Gly [122]. 14.6.5 Fabrication of PsaD-hoxYH complex Hydrogen production during photosynthesis through PSIÀPsaD-H2ase fusion within a cell is highlighted. ...
... The successful results obtained via in vitro experiments pave the way for constructing a PSI-NQ(CH2)15S-[FeFe]H2ase nanocomplex in vivo in the menB mutants of Synechocystis sp. PCC 6803[122]. ...
In recent decades, exploring new energy resources is a key challenge for urban development and political stability. Since consuming fossil fuels is accompanied by high environmental pollution, biohydrogen fuel is being introduced as one of the most efficient renewable sources. Several new articles have been published annually to establish convenient strategies for converting solar light energy into biohydrogen. Highlighting the principal mechanism of photobiohydrogen production by microalgae is discussed in this chapter, showing the recent approaches for photosynthetic apparatus and types of algal hydrogenases. The developments in modern algal cultivation technologies for scaling up biohydrogen production in microalgae are shown. Recent genetic engineering applications within microalgae for improving photosynthetic electron transport efficiency, overexpression of bacterial hydrogenases within microalgal cells, establishing links between photosynthetic apparatus and hydrogenases, enhancing photocurrent production, and developing semiartificial devices are the most recent successful attempts for biohydrogen production in microalgae, and they are discussed in depth in this chapter.
Engineering living microorganisms to enhance green biomanufacturing for the development of sustainable and carbon‐neutral energy strategies has attracted the interest of researchers from a wide range of scientific communities. In this study, we develop a method to achieve photosynthesis‐mediated biomineralization of gold nanoparticles (AuNPs) inside Chlorella cells, where the photosynthesis‐dominated reduction of Au ³⁺ to Au ⁰ allows the formed AuNPs to locate preferentially around the thylakoid membrane domain. In particular, we reveal that the electrons generated by the localized surface plasmon resonance of AuNPs could greatly augment hypoxic photosynthesis, which then promotes the generation and transferring of photoelectrons throughout the photosynthetic chain for augmented hydrogen production under sunlight. We demonstrate that the electrons from AuNPs could be directly transferred to hydrogenase, giving rise to an 8.3‐fold enhancement of Chlorella cells hydrogen production independent of the cellular photosynthetic process under monochromatic 560 nm light irradiation. Overall, the photosynthesis‐mediated intracellular biomineralization of AuNPs could contribute to a novel paradigm for functionalizing Chlorella cells to augment biomanufacturing.
Engineering living microorganisms to enhance green biomanufacturing for the development of sustainable and carbon‐neutral energy strategies has attracted the interest of researchers from a wide range of scientific communities. In this study, we develop a method to achieve photosynthesis‐mediated biomineralization of gold nanoparticles (AuNPs) inside Chlorella cells, where the photosynthesis‐dominated reduction of Au³⁺ to Au⁰ allows the formed AuNPs to locate preferentially around the thylakoid membrane domain. In particular, we reveal that the electrons generated by the localized surface plasmon resonance of AuNPs could greatly augment hypoxic photosynthesis, which then promotes the generation and transferring of photoelectrons throughout the photosynthetic chain for augmented hydrogen production under sunlight. We demonstrate that the electrons from AuNPs could be directly transferred to hydrogenase, giving rise to an 8.3‐fold enhancement of Chlorella cells hydrogen production independent of the cellular photosynthetic process under monochromatic 560 nm light irradiation. Overall, the photosynthesis‐mediated intracellular biomineralization of AuNPs could contribute to a novel paradigm for functionalizing Chlorella cells to augment biomanufacturing.
Nature has evolved an intricate process called “photosynthesis” that depicts a brilliant example of solar energy conversion into fuels (energy-rich compounds), by extracting electrons from water employing solar radiation (light) as the only energy source. In this process, a huge amount of energy is stored in the form of chemical bonds (e .g. carbohydrates, etc.). These chemical transformations are facilitated by enzymes at an outstanding rate. Inspired by this biological photosynthesis process, an enormous interest has grown to mimic this process, to produce a renewable energy vector-hydrogen. There has been multifaceted development over last few decades, on the design of fuel forming photocatalysts, water oxidation catalyst, optimization of light-harvesting unit, and integration of all these to design artificial photosynthesis systems. The catalysts ranging from molecular mimics of naturally occurring enzyme activities, nanostructured semiconducting photocatalyst, cocatalysts (metal nanocrystals, etc.), and their electroactive coupling (to have seamless electron transfer across) with sensitizers ranging from organic dyes to semiconducting nanoparticles have been designed to produce hydrogen. In this chapter, the progress made in the chemistry front of designing such bio-mimetic catalysts, their integration with light-harvesting components, and the state of the art of artificial photosynthesis systems has been explicitly discussed. The focus currently lies largely on the chemistry in designing these artificial fuel forming systems and has been elaborated herein. Further, to get an overall insight into the solar H2 generation, the underlying fundamental phenomena are also comprehensively discussed.
The ubiquity, structural variation, and functional diversity of iron-sulfur (Fe-S) clusters in biological environments has long fascinated scientists. In nature, Fe-S clusters form a variety of shapes and sizes, from the simple [Fe2S2] rhombic cluster to the complex [Fe8S7] fused di-cubane ‘P-cluster’, among others. Fe-S clusters perform critical tasks, including electron transfer, catalysis, sulfur donation, and sensing, in many essential biological processes, such as cellular respiration, gene expression, nitrogen fixation, DNA repair, cofactor biosynthesis, and more. To further understand Fe-S clusters, they have been synthesized outside of their protein environments with various monodentate, bidentate, and tridentate ligands. In addition to providing insight into their biological properties, synthetic small molecule models of Fe-S clusters have yielded oxidation states and structures beyond those observed in biology as well as led to the development of many small molecule catalysts. More recently, Fe-S clusters have been utilized in an expanding array of applications, including maquettes and artificial proteins, biomimetic materials, and therapeutic development. The high degree of utility of Fe-S clusters outside of their biological roles suggests exciting possibilities for future uses of these earth-abundant, redox-active, and structurally and functionally diverse clusters. This review provides an overview of Fe-S clusters in and beyond biology to highlight the growing versatile uses of these clusters. Our discussion is divided into sections that describe the structure–function relationship of Fe-S clusters in five research areas: biology, synthetic small molecules, maquettes and artificial proteins, biomimetic materials, and therapeutic development. We also tracked the number of publications in each research area by year to identify trends in Fe-S cluster research, and we conclude by describing the overarching connections between each of the research areas. Overall, this review summarizes the application areas of Fe-S cluster research and highlights connections between the areas based on the structure–function relationship of Fe-S clusters and their ligands.
Im Hinblick auf die Entwicklung verbesserter biophotovoltaischer Anordnungen für die Umwandlung von Sonnenenergie ermöglicht eine gemischte Monoschicht aus Trimeren und Monomeren des Photosystems I die Herstellung hocheffizienter Biophotoelektroden, indem elektronische Kurzschlussprozesse minimiert werden und gleichzeitig eine hohe Dichte photoaktiver Moleküle pro Flächeneinheit gewährleistet wird.
Abstract
Eine definierte Assemblierung von photosynthetischen Proteinkomplexen ist für eine optimale Leistung von semiartifiziellen Energieumwandlungssystemen erforderlich, die in der Lage sind, einen unidirektionalen Elektronenfluss zu liefern, wenn lichtsammelnde Proteine mit Elektrodenoberflächen verbunden werden. Wir stellen gemischte Photosystem‐I (PSI)‐Monoschichten vor, die aus nativen cyanobakteriellen PSI‐Trimeren in Kombination mit isolierten PSI‐Monomeren aus demselben Organismus bestehen. Die sich daraus ergebende kompakte Anordnung gewährleistet eine hohe Dichte an photoaktiven Proteinkomplexen pro Flächeneinheit und bildet die Grundlage für eine wirksame Minimierung von Kurzschlussprozessen, die die Leistung von PSI‐basierten Bioelektroden typischerweise einschränken. Die PSI‐Schicht ist darüber hinaus mit Redoxpolymeren für einen optimalen Elektronentransfer verbunden, was eine hocheffiziente lichtinduzierte Photostromerzeugung ermöglicht. Die Kopplung der Photokathode mit einer [NiFeSe]‐Hydrogenase ermöglicht lichtinduzierte H2‐Entwicklung.
Well‐defined assemblies of photosynthetic protein complexes are required for an optimal performance of semi‐artificial energy conversion devices, capable of providing unidirectional electron flow when light‐harvesting proteins are interfaced with electrode surfaces. We present mixed photosystem I (PSI) monolayers constituted of native cyanobacterial PSI trimers in combination with isolated PSI monomers from the same organism. The resulting compact arrangement ensures a high density of photoactive protein complexes per unit area, providing the basis to effectively minimize short‐circuiting processes that typically limit the performance of PSI‐based bioelectrodes. The PSI film is further interfaced with redox polymers for optimal electron transfer, enabling highly efficient light‐induced photocurrent generation. Coupling of the photocathode with a [NiFeSe]‐hydrogenase confirms the possibility to realize light‐induced H2 evolution.
