Large-scale Production Of Chemicals Research Articles

Recursive identification of kernel-based hammerstein model for online energy efficiency estimation of large-scale chemical plants

Accurate energy efficiency prediction is crucial for decision-making in large-scale chemical production, especially considering energy management and environmental concerns. The complexity of chemical processes, characterized by strong nonlinearities, dynamics, and uncertainties, challenges traditional prediction methods. This paper introduces KHSM (Kernel-based Hammerstein Subspace Model), which models nonlinear static and linear dynamic processes in series by embedding kernel function-based nonlinear mapping into subspace modeling for energy efficiency estimation. KHSM identifies nonlinear process models without explicit nonlinear mapping functions, constructing dynamic models that encompass both energy input and product output variables. An adaptive KHSM variant dynamically updates the energy efficiency model, improving accuracy by iteratively selecting and excluding samples. Comparative analysis shows KHSM outperforms existing methods, achieving a coefficient of determination (R2) closest to 1 and reducing the root-mean-square error (RMSE) by up to an order of magnitude, with the smallest mean and standard deviation. Additionally, modeling efficiency increases by an order of magnitude. The developed model enables ongoing energy efficiency estimation and proactive identification of efficiency trends. Validation through mathematical and real-world ethylene process cases demonstrates KHSM's efficacy and applicability. These estimates facilitate informed adjustments to energy management strategies and optimization of production approaches in energy-intensive chemical processes.

Sustainable One-Pot Production and Scale-Up of the New Platform Chemical Diformylxylose (DFX) from Agricultural Biomass.

The large-scale production of platform chemicals from biomass requires efficient, cost-effective, and sustainable methods. Here, we present three one-pot synthesis routes for producing diformylxylose (DFX), a sugar-based solvent and platform chemical, using d-xylose or corncobs as feedstocks. With yields of approximately 80%, these routes were seamlessly scaled from lab to kilogram-scale in a 15 L batch reactor. Techno-economic assessment demonstrates the competitiveness of the proposed methods against fossil- and biobased analogues. Life-cycle analysis shows the potential of these processes to reduce environmental and societal impacts from cradle to gate. At the "end of life", DFX is demonstrated to be inherently biodegradable. Overall, we present a compelling case study of scaling a novel platform chemical guided by techno-economic and environmental concerns leading to balanced cost-competitiveness and life-cycle sustainability.

Harnessing elastic instabilities for enhanced mixing and reaction kinetics in porous media

Turbulent flows have been used for millennia to mix solutes; a familiar example is stirring cream into coffee. However, many energy, environmental, and industrial processes rely on the mixing of solutes in porous media where confinement suppresses inertial turbulence. As a result, mixing is drastically hindered, requiring fluid to permeate long distances for appreciable mixing and introducing additional steps to drive mixing that can be expensive and environmentally harmful. Here, we demonstrate that this limitation can be overcome just by adding dilute amounts of flexible polymers to the fluid. Flow-driven stretching of the polymers generates an elastic instability, driving turbulent-like chaotic flow fluctuations, despite the pore-scale confinement that prohibits typical inertial turbulence. Using in situ imaging, we show that these fluctuations stretch and fold the fluid within the pores along thin layers ("lamellae") characterized by sharp solute concentration gradients, driving mixing by diffusion in the pores. This process results in a [Formula: see text] reduction in the required mixing length, a [Formula: see text] increase in solute transverse dispersivity, and can be harnessed to increase the rate at which chemical compounds react by [Formula: see text]-enhancements that we rationalize using turbulence-inspired modeling of the underlying transport processes. Our work thereby establishes a simple, robust, versatile, and predictive way to mix solutes in porous media, with potential applications ranging from large-scale chemical production to environmental remediation.

From Charge to Spin: An In-Depth Exploration of Electron Transfer in Energy Electrocatalysis.

Catalytic materials play crucial roles in various energy-related processes, ranging from large-scale chemical production to advancements in renewable energy technologies. Despite a century of dedicated research, major enduring challenges associated with enhancing catalyst efficiency and durability, particularly in green energy-related electrochemical reactions, remain. Focusing only on either the crystal structure or electronic structure of a catalyst is deemed insufficient to break the linear scaling relationship (LSR), which is the golden rule for the design of advanced catalysts. The discourse in this review intricately outlines the essence of heterogeneous catalysis reactions by highlighting the vital roles played by electron properties. The physical and electrochemical properties of electron charge and spin that govern catalysis efficiencies are analyzed. Emphasis is placed on the pronounced influence of external fields in perturbing the LSR, underscoring the vital role that electron spin plays in advancing high-performance catalyst design. The review culminates by proffering insights into the potential applications of spin catalysis, concluding with a discussion of extant challenges and inherent limitations.

Isotopically non-stationary 13 C metabolic flux analysis of two closely related fast-growing cyanobacteria Synechococcus elongatus PCC 11801 and 11802.

Synechococcus elongatus PCC 11801 and 11802 are closely related cyanobacterial strains that are fast-growing and tolerant to high light and temperature. These strains hold significant promise as chassis for photosynthetic production of chemicals from carbon dioxide. A detailed quantitative understanding of the central carbon pathways would be a reference for future metabolic engineering studies with these strains. We have used isotopic non-stationary 13 C-metabolic flux analysis (INST-MFA) to quantitively assess the metabolic potential of these two strains. This study highlights key similarities and differences in the central carbon flux distribution between these and other model/non-model strains. The two strains demonstrated a higher Calvin-Benson-Bassham (CBB) cycle flux coupled with negligible flux through the oxidative pentose phosphate (OPP), photorespiratory pathway, and lower anaplerosis fluxes under photoautotrophic conditions. Interestingly, PCC 11802 shows the highest CBB cycle and pyruvate kinase (PK) flux values among those reported in cyanobacteria. The unique tricarboxylic acid (TCA) cycle diversion in PCC 11801 makes it ideal for the large-scale production of TCA cycle-derived chemicals. Additionally, dynamic labeling transients were measured for intermediates of amino acid, nucleotide, and nucleotide-sugar metabolism. Overall, this study provides the first detailed metabolic flux maps of S. elongatus PCC 11801 and 11802 that may aid metabolic engineering efforts in these strains.

Synthetic Multienzyme Assemblies for Natural Product Biosynthesis.

In nature, enzymes that catalyze sequential reactions are often assembled as clusters or complexes. The formation of multienzyme complexes, or metabolons, brings the enzyme active sites into proximity to promote intermediate transfer, decrease intermediate leakage, and streamline the metabolic flux towards the desired products. We and others have developed synthetic versions of metabolons through various strategies to enhance the catalytic rates for synthesizing valuable chemicals inside microbes. Synthetic multienzyme complexes range from static enzyme nanostructures to dynamic enzyme coacervates. Enzyme complexation optimizes the metabolic fluxes inside microbes, increases the product titer, and supplies the field with high-yield microbe strains that are amenable to large-scale fermentation. Enzyme complexes constructed inside microbial cells can be separated as independent entities and catalyze biosynthetic reactions ex vivo; such a feature gains these complexes another name, "synthetic organelles" - new subcellular entities with independent structures and functions. Still, the field is seeking new strategies to better balance dynamicity and confinement and to achieve finer control of local compartmentalization in the cells, as the natural multienzyme complexes do. Industrial applications of synthetic multienzyme complexes for the large-scale production of valuable chemicals are yet to be realized. This review focuses on synthetic multienzyme complexes that are constructed and function inside microbial cells.

Direct Conversion of Cellulose into 5-HMF by Transition-Metal Doped Montmorillonite Catalyst in Water

AbstractCatalysts are very important in the use of cellulose, the main component of biomass, as a raw material for the large-scale production of liquid fuels and chemicals. 5-Hydroxymethylfurfural (HMF) is an extremely important intermediate in the fine chemical industry. HMF can be synthesized by acid-catalyzed dehydration of fructose, glucose, cellulose, or sucrose. The conversion of cellulose to HMF is challenging due to its chemical structure. The objective of the present study was to devise a more facile synthesis method using transition metal-doped montmorillonite catalysts (10Cr-Mnt, 10Cu-Mnt, 10Fe-Mnt, and 10Zn-Mnt) by wet impregnation. Samples were characterized by X-ray powder diffraction, specific surface area, and NH3-TPD analyses. The synthesized catalysts were used for the conversion of cellulose to 5-HMF in an aqueous medium. Among the metals studied, Cr showed the greatest catalytic activity. With the use of this catalyst, efficient conversion of cellulose to 5-HMF was achieved, affording a conversion yield of 93.47% and 5-HMF yield of 9.07% within 6 h at 200°C. The study described here could be useful for the efficient conversion of cellulose into 5-HMF, as well as into other biomass-derived chemicals.

Recent Advances in the Synthesis, Characterization, and Application of Carbon Nanomaterials for the Removal of Endocrine-Disrupting Chemicals: A Review.

The large-scale production and frequent use of endocrine-disrupting chemicals (EDCs) have led to the continuous release and wide distribution of these pollutions in the natural environment. At low levels, EDC exposure may cause metabolic disorders, sexual development, and reproductive disorders in aquatic animals and humans. Adsorption treatment, particularly using nanocomposites, may represent a promising and sustainable method for EDC removal from wastewater. EDCs could be effectively removed from wastewater using various carbon-based nanomaterials, such as carbon nanofiber, carbon nanotubes, graphene, magnetic carbon nanomaterials, carbon membranes, carbon dots, carbon sponges, etc. Important applications of carbon nanocomposites for the removal of different kinds of EDCs and the theory of adsorption are discussed, as well as recent advances in carbon nanocomposite synthesis technology and characterization technology. Furthermore, the factors affecting the use of carbon nanocomposites and comparisons with other adsorbents for EDC removal are reviewed. This review is significant because it helps to promote the development of nanocomposites for the decontamination of wastewater.

Combinatorial Metabolic Engineering Strategies for the Enhanced Production of Free Fatty Acids in Escherichia coli.

In this study, we evaluated the effects of several metabolic engineering strategies in a systematic and combinatorial manner to enhance the free fatty acid (FFA) production in Escherichia coli. The strategies included (i) overexpression of mutant thioesterase I ('TesAR64C) to efficiently release the FFAs from fatty acyl-ACP; (ii) coexpression of global regulatory protein FadR; (iii) heterologous expression of methylmalonyl-CoA carboxyltransferase and phosphoenolpyruvate carboxylase to synthesize fatty acid precursor molecule malonyl-CoA; and (iv) disruption of genes associated with membrane proteins (GusC, MdlA, and EnvR) to improve the cellular state and export the FFAs outside the cell. The synergistic effects of these genetic modifications in strain SBF50 yielded 7.2 ± 0.11 g/L FFAs at the shake flask level. In fed-batch cultivation under nitrogen-limiting conditions, strain SBF50 produced 33.6 ± 0.02 g/L FFAs with a productivity of 0.7 g/L/h from glucose, which is the maximum titer reported in E. coli to date. Combinatorial metabolic engineering approaches can prove to be highly useful for the large-scale production of FA-derived chemicals and fuels.

Technology for processing phosphogypsum into a fluorescent dye based on calcium sulfide

Objectives. There is considerable economic demand for products obtained by processing phosphogypsum. In particular, calcium sulfide-based materials having luminescent properties are the object of intensive study due to the wide range of possibilities for their use. The alloying of the structure of calcium sulfide with cations of rare earth elements leads to the appearance of a glow having various colors. However, the high cost of such phosphorescent materials is due to the high chemical purity of the reagents required for their synthesis. The development of efficient methods for obtaining calcium sulfide-based luminescent materials from phosphogypsum is part of an integrated approach to solving the problem of synthesizing economically demanded materials from production waste.Methods. The synthesized materials were studied using X-ray phase analysis and scanning electron microscopy. Photos of the samples were taken under illumination with an incandescent lamp or a fluorescent ultraviolet lamp.Results. According to X-ray phase analysis, phosphogypsum is mainly comprised of calcium sulfate dihydrate and calcium sulfate hemihydrate. Heat treatment of a phosphogypsum sample at a temperature of 1073 K is accompanied by the formation of anhydrous calcium sulfate. In the presence of a reducing agent, a composite material is formed containing a phase of anhydrous calcium sulfate and calcium sulfide. Due to the calcium sulfide content, phosphogypsum has luminescent properties when heat-treated in the presence of various reducing agents, including activated carbon, wood charcoal, vegetable oil, citric acid, starch, and sucrose.Conclusions. Optimal technological conditions for obtaining a composite material exhibiting luminescent properties are revealed. The successful synthesis of phosphor from without nonpretreated phosphogypsum is demonstrated. Optimal technological conditions for obtaining a composite material exhibiting luminescent properties are as follows: heat treatment temperature is 1073–1173 K; isothermal holding time is 60 min; reducing agent quantity is 37–50% (mol). The study results are widely applicable to processing wastes obtained from large-scale chemical production involving the production of a highly demanded inorganic product.

Substrate-inducible and antibiotic-free high-level 4-hydroxyvaleric acid production in engineered Escherichia coli

In this study, we developed a levulinic acid (LA)-inducible and antibiotic-free plasmid system mediated by HpdR/P hpdH and infA-complementation to produce 4-hydroxyvaleric acid (4-HV) from LA in an engineered Escherichia coli strain. The system was efficiently induced by the addition of the LA substrate and resulted in tight dose-dependent control and fine-tuning of gene expression. By engineering the 5′ untranslated region (UTR) of hpdR mRNA, the gene expression of green fluorescent protein (GFP) increased by at least two-fold under the hpdH promoter. Furthermore, by evaluating the robustness and plasmid stability of the proposed system, the engineered strain, IRV750f, expressing the engineered 3-hydroxybutyrate dehydrogenase (3HBDH∗) and formate dehydrogenase (CbFDH), produced 82 g/L of 4-HV from LA, with a productivity of 3.4 g/L/h and molar conversion of 92% in the fed-batch cultivation (5 L fermenter) without the addition of antibiotics or external inducers. Overall, the reported system was highly beneficial for the large-scale and cost-effective microbial production of value-added products and bulk chemicals from the renewable substrate, LA.

High zirconium loads in Zr-SBA-15 mesoporous materials prepared by direct-synthesis and pH-adjusting approaches

SBA-15 is a material with interesting characteristics associated with the size, order, uniformity, and pores distribution. However, the absence of acidity in SBA-15 restricts its applications as a potential acid catalyst in the industry for the large-scale production of fuels and chemicals. Mesoporous SBA-15 modified by the incorporation of heteroatomic species can be a good strategy to include acidity and prepare an efficient catalyst. In this work, we present a comparative study in the preparation of SBA-15 and Zr-SBA-15 mesoporous materials with high zirconium loads (Si/Zr ​= ​10, 5, and 2) using direct-synthesis and pH-adjusting approaches with a low crystallization temperature of 60 ​°C. The materials were characterized using XRPD, HRTEM, ICP, SEM-EDS, XPS, DRS UV-VIS, FT-IR, NH3-TPD, in situ FT-IR with pyridine probe, and N2-physisorption. Characterization by ICP and SEM-EDS indicated that the Si/Zr molar ratio of Zr-materials prepared by the pH adjustment better matched the nominal values. N2-physisorption showed that the mesoporosity of the materials was preserved even at the high Zr load. XRPD and HRTEM pointed out that Zr-SBA-15 materials prepared by the pH adjustment showed a higher level of ordering in the porous network. Regardless of the synthesis approach, the presence of a higher Zr load caused a loss in the structural ordering. It must be highlighted that the high-resolution XPS spectra of Zr 3d suggested the formation of Si–O–Zr bonds giving some indication of Zr incorporation into the SBA-15 framework. The formation of Si–O–Zr linkage in the Zr-materials was also corroborated by DRS UV-VIS due to the presence of a blue shift in the absorption edge for both series of the Zr-SBA-15 materials. NH3-TPD and in-situ FT-IR spectroscopy with pyridine probe showed that the presence of Zr species introduces acidity in the SBA-15 and at higher Zr load the Brønsted acidity increased particularly for the Zr-materials prepared by pH adjustment. In conclusion, this study evidences that the pH-adjusting approach improves structural, textural, morphological, and acidic properties in SBA-15 and Zr-SBA-15 materials compared to the direct-synthesis approach.

Polyhydroxyalkanoate (PHA) Biopolyesters - Emerging and Major Products of Industrial Biotechnology

Abstract Background: Industrial Biotechnology (“White Biotechnology”) is the large-scale production of materials and chemicals using renewable raw materials along with biocatalysts like enzymes derived from microorganisms or by using microorganisms themselves (“whole cell biocatalysis”). While the production of ethanol has existed for several millennia and can be considered a product of Industrial Biotechnology, the application of complex and engineered biocatalysts to produce industrial scale products with acceptable economics is only a few decades old. Bioethanol as fuel, lactic acid as food and PolyHydroxyAlkanoates (PHA) as a processible material are some examples of products derived from Industrial Biotechnology. Purpose and Scope: Industrial Biotechnology is the sector of biotechnology that holds the most promise in reducing our dependence on fossil fuels and mitigating environmental degradation caused by pollution, since all products that are made today from fossil carbon feedstocks could be manufactured using Industrial Biotechnology – renewable carbon feedstocks and biocatalysts. To match the economics of fossil-based bulk products, Industrial Biotechnology-based processes must be sufficiently robust. This aspect continues to evolve with increased technological capabilities to engineer biocatalysts (including microorganisms) and the decreasing relative price difference between renewable and fossil carbon feedstocks. While there have been major successes in manufacturing products from Industrial Biotechnology, challenges exist, although its promise is real. Here, PHA biopolymers are a class of product that is fulfilling this promise. Summary and Conclusion: The authors illustrate the benefits and challenges of Industrial Biotechnology, the circularity and sustainability of such processes, its role in reducing supply chain issues, and alleviating societal problems like poverty and hunger. With increasing awareness among the general public and policy makers of the dangers posed by climate change, pollution and persistent societal issues, Industrial Biotechnology holds the promise of solving these major problems and is poised for a transformative upswing in the manufacture of bulk chemicals and materials from renewable feedstocks and biocatalysts.

Plant cell cultures: An enzymatic tool for polyphenolic and flavonoid transformations

BackgroundIn the pharmaceutical sector, tissue culture techniques for large-scale production of natural chemicals can be a less expensive alternative to large-scale synthesis. Although recent biotransformation research have used plant cell cultures to target a wide range of bioactive compounds, more compiled information and synopses are needed to better understand metabolic pathways and improve biotransformation efficiencies. PurposeThis report reviews the biochemical transformation of phenolic natural products by plant cell cultures in order to identify potential novel biotechnological approaches for ensuring more homogeneous and stable phenolic production year-round under controlled environmental conditions. MethodsArticles on the use of plant cell culture for polyphenolic and flavonoid transformations (1988 – 2021) were retrieved from SciFinder, PubMed, Scopus, and Web of Science through electronic and manual search in English. Following that, the authors chose the required papers based on the criteria they defined. The following keywords were used for the online search: biotransformation, Plant cell cultures, flavonoids, phenolics, and pharmaceutical products. ResultsThe initial search found a total of 96 articles. However, only 70 of them were selected as they met the inclusion criteria defined by the authors. The analysis of these studies revealed that plant tissue culture is applicable for the large-scale production of plant secondary metabolites including the phenolics, which have high therapeutic value. ConclusionPlant tissue cultures could be employed as an efficient technique for producing secondary metabolites including phenolics. Phenolics possess a wide range of therapeutic benefits, as anti-oxidant, anti-cancer, and anti-inflammatory properties. Callus culture, suspension cultures, transformation, and other procedures have been used to improve the synthesis of phenolics. Their production on a large scale is now achievable. More breakthroughs will lead to newer insights and, without a doubt, to a new era of phenolics-based pharmacological agents for the treatment of a variety of infectious and degenerative disorders.

Iridium- and Palladium-Based Catalysts in the Pharmaceutical Industry

Transition metal catalysts play a vital role in a wide range of industrial organic processes. The large-scale production of chemicals relying on catalyzed organic reactions represents a sustainable approach to supply society with end products for many daily life applications. Homogeneous (mainly for academic uses) and heterogeneous (crucial in industrial processes) metal-based catalysts have been developed for a plethora of organic reactions. The search for more sustainable strategies has led to the development of a countless number of metal-supported catalysts, nanosystems, and electrochemical and photochemical catalysts. In this work, although a vast number of transition metals can be used in this context, special attention is devoted to Ir- and Pd-based catalysts in the industrial manufacture of pharmaceutical drugs. Pd is by far the most widely used and versatile catalyst not only in academia but also in industry. Moreover, Ir-based complexes have emerged as attractive catalysts, particularly in asymmetric hydrogenation reactions. Ir- and Pd-based asymmetric reductions, aminations, cross-coupling reactions, and C–H activation are covered herein in the production of biologically active compounds or precursors; adaptation to bulk conditions is particularly highlighted.

Bimetallic Co-Rh Systems as a Prospective Base for Design of CH4 Reforming Catalysts to Produce Syngas with a Controllable Composition

Dry and bireforming (CO2-H2O) of methane are the most environmentally friendly routes involving two main greenhouse gases to produce syngas—an important building block for large-scale production of various commodity chemicals. The main drawback preventing their industrial application is the coke formation. Developing catalysts that do not favour or are resistant to coke formation is the only way to improve the catalyst stability. Designing an economically viable catalyst may be achieved by exploiting the synergic effects of combining noble (expensive but coke-resistant) and non-noble (cheap but prone to carbonisation) metals to form highly effective catalysts. This work deals with development of highly active and stable bimetallic Co-containing catalysts modified with small amount of Rh, 0.1–0.5 mass %. The catalysts were characterised by BET, XRD, TEM, SEM, XPS, and TPR-H2 methods and tested in dry, bi-, and for comparison in steam reforming of methane. It was revealed that the bimetallic Co-Rh systems is much more effective than monometallic ones due to Co-Rh interaction accompanied with increasing dispersion and reducibility of Co. The extents of CH4 and CO2 conversion over the 5%Co-Rh/Al2O3 are varied within 85–99%. Syngas with variable H2/CO = 0.9–3.9 was formed. No loss of activity was observed for 100 h of long-term stability test.

Discovering and Demonstrating a Novel High-Performing 2D-Patterned Electrode for Proton-Exchange Membrane Water Electrolysis Devices.

Proton-exchange membrane water electrolysis (PEMWE) produces hydrogen with high efficiency and purity but uses high-loading platinum-group metal (PGM) catalysts. Such concerns call for the development of novel electrode architectures to improve catalyst utilization and mass activity, thus promoting PEMWE cost competitiveness for large-scale implementation. In this study, we demonstrated, for the first time, a novel two-dimensional (2D)-patterned electrode with edge effects to address these challenges. The edge effect was induced by membrane properties, potential distribution, and counter electrode coverage and could be optimized by tuning the catalyst layer dimensions. To achieve identical PEMWE performance, the optimal pattern saved the 21% anode PGM catalyst compared with the conventional catalyst fully covered electrode. The PGM catalyst could be further reduced by 61% to boost mass activity with no significant performance loss. The results also indicated that the electrode uniformity in PEMWE cells might not be as critical as that in PEM fuel cells. The novel 2D-patterned electrode could effectively reduce PGM catalyst loading, accelerating affordable and large-scale production of hydrogen and other value-added chemicals via electrolysis.

A Secure Block Chain Based Contract Manufacturing System for Pharma Industries Using Imperative Ant Loop Optimization Algorithm

Manufacturers that work under contract for another firm may make their goods under their own brand or label. Using their own or their clients' designs, formulas, and needs as a guide, contract manufacturers perform this service. The pharmaceutical industry relies heavily on contract manufacturing. Due to a lack of capital, some companies are unable to obtain the required equipment for large-scale mass production of certain chemicals. In order to create the final product, they can work with a third-party chemical manufacturer to obtain the necessary chemicals and combine them with their own resources. An organization should carefully assess the benefits and drawbacks of contract manufacturing before committing to this strategy. There may be advantages to contract manufacturing, if the company works with the right service provider capable of delivering high-quality products. The contract manufacturing system proposed in this study is a blockchain-based solution for the pharmaceutical business. Initially, the customer uploads the order details that are preprocessed using normalization method. The preprocessed data is authenticated using the crypto smart contracts before being stored in the blockchain ledger. Then the stored data can be encrypted for security purpose by using the triple MD5 algorithm. Finally, the trust of the order data is evaluated using the proposed Imperative Ant loop optimization algorithm. In order to demonstrate the effectiveness of our system, we use the MATLAB simulation programme to compare it to other approaches.

The development of luminescent solar concentrator-based photomicroreactors: a cheap reactor enabling efficient solar-powered photochemistry

Sunlight strikes our planet every day with more energy than we consume in an entire year. Therefore, many researchers have explored ways to efficiently harvest and use sunlight energy for the activation of organic molecules. However, implementation of this energy source in the large-scale production of fine chemicals has been mostly neglected. The use of solar energy for chemical transformations suffers from potential drawbacks including scattering, reflections, cloud shading and poor matches between the solar emission and absorption characteristics of the photochemical reaction. In this account, we provide an overview of our efforts to overcome these issues through the development of Luminescent Solar Concentrator-based PhotoMicroreactors (LSC-PM). Such reactors can efficiently convert solar energy with a broad spectral distribution to concentrated and wavelength-shifted irradiation which matches the absorption maximum of the photocatalyst. Hence, the use of these conceptually new photomicroreactors provides an increased solar light harvesting capacity, enabling efficient solar-powered photochemistry.Graphical abstract

Improving succinate production by engineering oxygen-dependent dynamic pathway regulation in Escherichia coli

Succinate is an important building block for chemical synthesis. However, during the fermentation process, excessive osmotic stress and byproduct accumulation substantively impair the performance of the microbial cell factory. To this end, two strategies were proposed. First, an osmo-tolerant mutant, Escherichia coli FMME-N-2, was screened by combined mutagenesis (ARTP and 60Co-γ irradiation) to produce 51.8 g L−1 succinate with a productivity of 0.81 g L−1 h−1. Second, an oxygen-dependent bifunctional switch (OBS) was developed with promoter PfnrF8-based activation and tobacco etch virus protease-based inhibition functions. With ribosomal binding site (RBS) and degron optimization of OBS, the optimal strain E. coli FMME-N-30 achieved a succinate titer and productivity of 119 g L−1 and 1.65 g L−1 h−1, respectively, in a 30-L fermentor, while only 7.1 g L−1 acetate and no formate or lactate were detected. Compared to the wild-type strain E. coli FMME-N, the succinate titer was increased by 3.3-fold. These results highlight the applicability of OBS for the large-scale production of value-added chemicals.