Carbon Dioxide Fixation Research Articles

Evaluation of agricultural soil health after applying atrazine in maize-planted fields based on the response of soil microbes

Soil health is closely linked to the sustainable development of agriculture, and soil microorganisms are the fundamental and pivotal components in maintaining soil health. Atrazine (ATZ) is a triazine herbicide widely used worldwide, and its ecotoxicity to soil microorganisms has been widely studied. However, previous studies have focused on investigating the ecotoxicity of ATZ active ingredients under laboratory conditions. The damage caused by ATZ formulations to soil health in the actual field environment cannot be ignored. Herein, the toxicity of ATZ formulations (1140 and 1710 g hm−2) in maize fields after 1, 28, and 72 d of exposure was investigated in terms of soil microbial abundance, community structure, soil enzyme activities, functional gene abundance, and ATZ residues. The results showed that ATZ disturbed the microbial functions that maintain soil health by disturbing soil nutrient and carbon cycling as well as enhancing pollution degradation. The promotion of both urease activity and AOB-amoA gene abundance indicated that ATZ accelerated the loss of nitrogen from soil, which was detrimental to soil nitrogen cycling. The abundances of the Pontibacter genus and the cbbLG gene were inhibited, indicating that the ability of soil carbon dioxide fixation was hindered. The abundance of Lysobacter, which helps to degrade pollutants, increased. The integrated biomarker response indicated that the comprehensive toxicity of ATZ to soil microorganisms increased with dose. Additionally, the DT50 of ATZ in agricultural soil was 5.4–5.7 d, and the residual level of ATZ in crop grains was in line with the maximum residue limit recommended by the European Union and China. The findings of the present study reflect the effects of ATZ formulation on soil microbes in the actual agricultural environment and provide insights into the mechanisms of soil health regulation mediated by microorganisms.

Strain-resolved metagenomics approaches applied to biogas upgrading

Genetic heterogeneity is a common trait in microbial populations, caused by de novo mutations and changes in variant frequencies over time. Microbes can thus differ genetically within the same species and acquire different phenotypes. For instance, performance and stability of anaerobic reactors are linked to the composition of the microbiome involved in the digestion process and to the environmental parameters imposing selective pressure on the metagenome, shaping its evolution. Changes at the strain level have the potential to determine variations in microbial functions, and their characterization could provide new insight into ecological and evolutionary processes driving anaerobic digestion. In this work, single nucleotide variant dynamics were studied in two time-course biogas upgrading experiments, testing alternative carbon sources and the response to exogenous hydrogen addition. A cumulative total of 76,229 and 64,289 high-confidence single nucleotide variants were discerned in the experiments related to carbon substrate availability and hydrogen addition, respectively. By combining complementary bioinformatic approaches, the study reconstructed the precise strain count—two for both hydrogenotrophic archaea—and tracked their abundance over time, while also characterizing tens of genes under strong selection. Results in the dominant archaea revealed the presence of nearly 100 variants within genes encoding enzymes involved in hydrogenotrophic methanogenesis. In the bacterial counterparts, 119 mutations were identified across 23 genes associated with the Wood-Ljungdahl pathway, suggesting a possible impact on the syntrophic acetate-oxidation process. Strain replacement events took place in both experiments, confirming the trends suggested by the variants trajectories and providing a comprehensive understanding of the biogas upgrading microbiome at the strain level. Overall, this resolution level allowed us to reveal fine-scale evolutionary mechanisms, functional dynamics, and strain-level metabolic variation that could contribute to the selection of key species actively involved in the carbon dioxide fixation process.

Methylacidiphilum caldifontis gen. nov., sp. nov., a thermoacidophilic methane-oxidizing bacterium from an acidic geothermal environment, and descriptions of the family Methylacidiphilaceae fam. nov. and order Methylacidiphilales ord. nov.

Strain IT6T, a thermoacidophilic and facultative methane-oxidizing bacterium, was isolated from a mud-water mixture collected from Pisciarelli hot spring in Pozzuoli, Italy. The novel strain is white when grown in liquid or solid media and forms Gram-negative rod-shaped, non-flagellated, non-motile cells. It conserves energy by aerobically oxidizing methane and hydrogen while deriving carbon from carbon dioxide fixation. Strain IT6T had three complete pmoCAB operons encoding particulate methane monooxygenase and genes encoding group 1d and 3b [NiFe] hydrogenases. Simple carbon-carbon substrates such as ethanol, 2-propanol, acetone, acetol and propane-1,2-diol were used as alternative electron donors and carbon sources. Optimal growth occurred at 50-55°C and between pH 2.0-3.0. The major fatty acids were C18 : 0, C15 : 0 anteiso, C14 : 0 iso, C16 : 0 and C14 : 0, and the main polar lipids were phosphatidylethanolamine, aminophospholipid, phosphatidylglycerol, diphosphatidylglycerol, some unidentified phospholipids and glycolipids, and other unknown polar lipids. Strain IT6T has a genome size of 2.19 Mbp and a G+C content of 40.70 mol%. Relative evolutionary divergence using 120 conserved single-copy marker genes (bac120) and phylogenetic analyses based on bac120 and 16S rRNA gene sequences showed that strain IT6T is affiliated with members of the proposed order 'Methylacidiphilales' of the class Verrucomicrobiia in the phylum Verrucomicrobiota. It shared a 16S rRNA gene sequence identity of >96 % with cultivated isolates in the genus 'Methylacidiphilum' of the family 'Methylacidiphilaceae', which are thermoacidophilic methane-oxidizing bacteria. 'Methylacidiphilum sp.' Phi (100 %), 'Methylacidiphilum infernorum' V4 (99.02 %) and 'Methylacidiphilum sp.' RTK17.1 (99.02 %) were its closest relatives. Its physiological and genomic properties were consistent with those of other isolated 'Methylacidiphilum' species. Based on these results, we propose the name Methylacidiphilum caldifontis gen. nov., sp. nov. to accommodate strain IT6T (=KCTC 92103T=JCM 39288T). We also formally propose that the names Methylacidiphilaceae fam. nov. and Methylacidiphilales ord. nov. to accommodate the genus Methylacidiphilum gen. nov.

Optimization of Long-Chain Fatty Acid Synthesis from CO 2 Using Response Surface Methodology

A microbial electrosynthesis cell (MES) is an electrochemical technique in which electrolithoautotrophic electroactive microbes fix carbon dioxide (CO2) to longer-chain volatile fatty acids (VFAs). The synthesis of VFAs from CO2 requires optimization to improve the MES performance for industrial feasibility. This work studied the effect of different parameters, such as pH, headspace gas pressure, ethanol concentration, electrolyte, and trace element concentrations, on VFA synthesis from CO2 that used mixed anaerobic consortia in serum bottles. The operational parameters were varied according to a central composite design (CCD) and response surface methodology (RSM). A global optimum for the response variables was determined. The optimum values of different operating factors to maximize VFA production that was obtained from the optimizations were 1.12 × 105 Pa pressure, pH 7.149, ethanol = 2,318.7 mg/L, three times the standard Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ) 300 electrolyte concentration and five times the standard DSMZ 300 trace elements concentration. The experimental study was validated in triplicate, which considered the optimal values. The rate of total VFA production that was obtained from the operational parameters experimental study was 43.7 ± 5.9 mg/L/day under this optimized condition, which agreed with the predicted value of 30.39 mg/L/day. For the media optimization, validation of the experimental study was conducted at the optimal values, and their experimental response was 79.75 ± 19.26 mg/L/day, and the predicted response was 75.89 mg/L/day for total VFA production rates.

Hierarchically porous bimetallic oxide derived from a metal-organic framework for the promotion of catalytic CO2 chemical fixation

Chemical carbon dioxide (CO2) fixation over heterogenous catalysts under more realistic conditions enables the acceleration of the global carbon cycle. Despite the recent advances, many catalysts often suffer from chemical lability, mass transfer resistance, as well as single catalytic species. To this end, this work demonstrates a metal-organic framework (MOF)-templated thermolysis to give bimetallic oxides, CuxZny-BMOs, featuring hierarchically porous structures. By varying the initial molar ratio of Cu/Zn, the local coordination environment can be adjusted, thus regulating the type and quantity of active species. Together with its abundant active sites and appropriate pore size, the optimized Cu1Zn2-BMO not only achieves a high activity (98% yield) for the coupling of CO2 and epichlorohydrin under solvent-free mild conditions, but also promotes the N-formylation of CO2 with amines. Worthy to note, the decent chemical stability endows Cu1Zn2-BMO with almost unchanged performance even after long exposure to humidity. Our study offers a reliable strategy for the structure regulation of catalysts to enhance practical CO2 catalytic conversion.

Poly(ionic liquid)-coated hydroxy-functionalized carbon nanotube nanoarchitectures with boosted catalytic performance for carbon dioxide cycloaddition

Poly(ionic liquid)s (PILs) bearing high ionic densities are promising candidates for carbon dioxide (CO2) fixation. However, efficient and metal-free methods for boosting the catalytic efficiencies of PILs are still challenging. In this study, a novel family of poly(ionic liquid)-coated carbon nanotube nanoarchitectures (CNTs@PIL) were facilely prepared via a noncovalent and in-situ polymerization method. The effects of different carbon nanotubes (CNTs) and PILs on the structure, properties, and catalytic performance of the composite catalysts were systematically investigated. Characterizations and experimental results showed that hybridization of PIL with hydroxyl- or carboxyl-functionalized CNTs (CNT-OH, CNT-COOH) endows the composite catalyst with increased porosity, CO2 capture capacity, swelling ability and diffusion rate with respect to individual PIL, and allows the CNTs@PIL to provide H-bond donors for the synergistic activation of epoxides at the interfacial layer. Benefiting from these merits, the optimal composite catalyst (CNT-OH@PIL) delivered a super catalytic efficiency in the cycloaddition of CO2 to propylene oxide, which was over 4.5 times that of control PIL under metal- and co-catalyst free conditions. Additionally, CNT-OH@PIL showed high carbon dioxide/nitrogen (CO2/N2) adsorptive selectivity and could smoothly catalyze the cycloaddition reaction with a simulated flue gas (15% CO2 and 85% N2). Furthermore, the CNT-OH@PIL exhibited broad substrate tolerance and could be readily recycled and efficiently reused at least 12 times. Hybridization of PIL with functionalized CNTs provides a feasible approach for boosting the catalytic performance of PIL-based solid catalysts for CO2 fixation.

Forest management plan based on TOPSIS analysis method

Climate change poses a huge threat to life, especially climate change caused by greenhouse gas emissions. Positive actions should be taken to reduce greenhouse gas emissions. But simply reducing emissions is not enough. It is necessary to increase carbon dioxide reserves through biosphere or mechanical means. Forests in the biosphere can store carbon dioxide. Moderate deforestation can increase the amount of fixed carbon dioxide and have little impact on society. For this issue, this article selects Saihanba Forest Farm as the research object. By establishing a mathematical model, the impact of different forest management schemes on the carbon dioxide absorption capacity of Saihanba Forest Farm was analyzed. This paper selected four main variables to reflect their impact: forest coverage, forest volume, forest volume at different ages, and water conservation. The entropy method and TOPSIS comprehensive evaluation method are used for the data in the variables. The results showed that near mature and mature forests contributed the most to carbon dioxide absorption, while over mature trees contributed the least to carbon dioxide absorption. Based on the results, this paper presents the optimal forest management plan, and suggests that managers should appropriately cut down over mature forests to increase the stock of near mature and mature forests.

Kinetics study comparing bacterial growth and iron oxidation kinetics over a range of temperatures 5–45 °C

This comprehensive study summarizes kinetic data from experiments performed over a wide temperature range that overlaps the physiological operating temperature windows for most mesophilic Fe-oxidizers. Three acidophilic autotrophic bacterial strains Acidithiobacillus (At.) ferrivorans, At. ferrooxidans and Leptospirillum (L.) ferriphilum were investigated in this work in order to compare their growth and iron oxidation kinetics over a temperature range of 5–45 °C. On-line gas analysis was applied to determine the O2 and CO2 consumption rates during the culture incubation. Despite the genotypic differences these three strains share many common physiological traits. At t = 30 °C, the specific growth rate (μ) at all three species reached 0.11 h−1 which is equivalent to generation time 6.5 h. Maximum ferrous‑iron oxidation rate per unit of biomass was achieved with L. ferriphilum at t = 40 °C and approached 10 mmol Fe2+ (C-mmol) h−1. The temperature of incubation had a profound effect on the specific rates, while the kinetic parameter Ks/Ki at the Acidithiobacilli strains remained unaffected. Cultures with Leptospirillum incubated at temperatures >35 °C were capable of iron oxidation at redox potentials close to +950 mV and kept constant specific rates until Fe2+ depletion. The parameter Ks/Ki at L. ferriphilum was two order of magnitude lower than for the Acidithiobacilli. However, this feature disappears at temperatures below 30 °C, where Ks/Ki has a value comparable to Acidithiobacilli, which suggests that L. ferriphillum uses different Fe oxidation systems depending on temperature conditions. Strong correlation was observed between ferrous iron oxidation, and carbon dioxide fixation in the exponentially growing cultures with the yield coefficient (YSX) approaching 14 μmol C fixed per mmol Fe2+ oxidized. The kinetic parameters differed significantly between bacterial strains under “extreme” temperatures (t < 10 °C; t > 35 °C). All three bacterial strains were capable of oxidizing iron over the entire range (5–45 °C) of incubation temperatures. Neither At. ferrivorans nor At. ferrooxidans showed exponential growth at the temperature 40 °C. Bacterial iron oxidation not associated with growth was observed during incubation at 5 °C. At. ferrivorans, was the only species that can grow exponentially at a temperature of 5 °C. Moreover, it differed from the other species by greater sensitivity to low pH which seems to be more pronounced at temperatures t < 10 °C, with minimum of pH 1.9 for growth.

Ferredoxin as a Physiological Electron Donor for Carbon Dioxide Fixation to Formate in a Bacterial Carbon Dioxide Reductase

Ferredoxin as a Physiological Electron Donor for Carbon Dioxide Fixation to Formate in a Bacterial Carbon Dioxide Reductase

Halide-free squaramide–phenolate organocatalyst for the cycloaddition of CO2 into epoxides

The cycloaddition of CO2 into epoxide (CCE) reaction was the few routes viable industrially in catalytic fixation of carbon dioxide into value-added chemicals in which cocatalyst halide was predominant. To obviate the harmful corrosion of halide anions to steel reactors, and to alleviate the environmental burden of halogen waste, halide-free catalyst was desirable. We propose a category of one-component H-bond donor (HBD) and nucleophilic anion (HBD–anion) bifunctional organocatalyst as representative halide-free catalyst in CCE reactions. Squaramide (Sq) in conjugation with phenolate constitutes a typical HBD–anion catalyst featured with the squaramide as the HBD moiety and the phenolate as the nucleophilic anion moiety. Series of pre-catalyst in structure of squaramide–phenol (Sq–PhOH) was designed and the active catalyst Sq–phenolate (Sq–PhO) was generated from the corresponding Sq–PhOH by deprotonating of the weakly acidic hydroxyl of the phenol by super strong Brønsted base. In an optimal N-benzyl squaramide para-phenol (Sq–PhOH-p) and P2 phosphazene (t-BuP2) combination, CCE reactions proceed under mild conditions of 120 °C, and atmospheric pressure of 0.1 MPa, by 2.5 mol % loading of catalyst Sq–PhOH-p/t-BuP2. Terminal epoxides were transformed with excellent conversions (86–99 %) and high selectivity (85–97 %) in 8 h. Bifunctional activations mechanisms were proposed and validated. 1H and 13C NMR titrations certified the coordination of H-bond donor squaramide to epoxide, and FT-IR spectra observed formation of phenyl carbonate anion from phenolate and carbon dioxide, these suggested unprecedent CCE reaction composed capture of CO2 in carbonate anion followed by its intramolecular nucleophilic attack on the HBD coordinated epoxide as the key catalytic steps. The squaramide–phenolate catalytic dyad exemplified halide-free HBD–anion organocatalyst of wide scope for carbon dioxide activation and fixation.

A Review of the Harvesting Techniques of Microalgae

Algae are an important group of photosynthetic autotrophs and are commonly found in different types of water bodies, including paddy fields. The algal group possesses distinctive characteristics and ranges from prokaryotic cyanobacteria to eukaryotic algae. Within these, microalgae are unicellular microorganisms widely distributed in saltwater as well as freshwater environments. Microalgae species have been utilized in different fields, especially animal and human nutrition, medicine, bioremediation, and bio-fertilizers. Recently, numerous studies have reported the importance of microalgae in the production of biofuel. Further, microalgae have great carbon dioxide fixation efficiency during growth, so farmable land is not required for cultivating microalgae. Microalgae biomass production is a three-step process: cultivation, harvesting, and processing. Of these, the harvesting process is considered challenging due to its high cost, and it directly affects the processing step. In addition, several factors influence the harvesting process, including the size of microalgae cells (&lt;30 µm), cultural conditions of microalgae, electronegative property of cell membrane, growth rate, etc. The harvesting of microalgae is an elaborate process that involves different chemical or mechanical approaches. A number of harvesting techniques have been utilized to recover algal biomass, such as membrane filtration, chemical and bio-flocculation, flotation centrifugation, sedimentation, and coagulation. In this context, this review aims to discuss various types of techniques used for harvesting microalgae. This review could be useful for selecting appropriate harvesting technology for enhancing the yield of microalgae biomass.

Facile synthesis of InIII-salen complexes from indium metal and their use as catalysts for the chemical fixation of carbon dioxide in mild conditions

An alternative, very simple and improved route to obtain indium(III) tetrahaloindate salts of tetrabutylammonium (TBA)[InX4] – 1a (X = Cl), 1b (X = Br) and 1c (X = I) – in high yields (74 – 82%) was developed. Indium(III) tetrahaloindates were then used as starting materials for the synthesis of In(salen)X complexes 2a (X = Cl, 88%), 2b (X = Br, 94%) and 2c (X = I, 88%). Compounds 2a-c were characterized by FT-IR, Raman, and 1H and 13C NMR spectroscopies. The In-salen complexes were able to promote the CO2 cycloaddition reaction with styrene oxide in mild and solvent-free conditions; complex 2a presented the best performance in the initial screening, achieving quantitative conversion (>99%). The parameters of the catalytic system were optimized, and a series of epoxides were tested as substrates for the production of cyclic carbonates with conversions varying from 38% to quantitative. The present study provides a simple method to cheaply and easily prepare indium(III) complexes and employ them to produce value-added chemicals from CO2.

A Short Review on Prickly Pear Fruit Opuntia spp

In India, a significant portion of the population has settled in dry rain-fed areas that need perennial vegetation to protect them from erosion. The use of drought tolerant and economically viable plants appears to be an option to sustain livelihoods, reduce poverty and create employment opportunities. Prickly pear is drought tolerant due to its carbon dioxide fixation pathway (CAM), well suited to dry zones where it can be used as an alternative food and fodder as well as a hedge to protect agricultural fields. In the seventh century, the British introduced cacti to India to produce cochineal dye, but these plantations gradually disappeared due to pests and flooding of the areas. Recent attempts to introduce the cultivated cactus pear began in the late 1980s. In addition to the adaptation trials, some other aspects have been studied in the country: plant productivity, nutritional aspects, salinity tolerance, fruit quality, etc., which are briefly described in this article.

Assessment of Green Chemistry Metrics for Carbon Dioxide Fixation into Cyclic Carbonates Using Eutectic Mixtures as Catalyst: Comprehensive Evaluation on the Example of a Tannic Acid-Derived System

Assessment of Green Chemistry Metrics for Carbon Dioxide Fixation into Cyclic Carbonates Using Eutectic Mixtures as Catalyst: Comprehensive Evaluation on the Example of a Tannic Acid-Derived System

Phytoplankton Producer Species and Transformation of Released Compounds over Time Define Bacterial Communities following Phytoplankton Dissolved Organic Matter Pulses.

Phytoplankton-bacterium interactions are mediated, in part, by phytoplankton-released dissolved organic matter (DOMp). Two factors that shape the bacterial community accompanying phytoplankton are (i) the phytoplankton producer species, defining the initial composition of released DOMp, and (ii) the DOMp transformation over time. We added phytoplankton DOMp from the diatom Skeletonema marinoi and the cyanobacterium Prochlorococcus marinus MIT9312 to natural bacterial communities from the eastern Mediterranean and determined the bacterial responses over a time course of 72 h in terms of cell numbers, bacterial production, alkaline phosphatase activity, and changes in active bacterial community composition based on rRNA amplicon sequencing. Both DOMp types were demonstrated to serve the bacterial community as carbon and, potentially, phosphorus sources. Bacterial communities in diatom-derived DOM treatments maintained higher Shannon diversities throughout the experiment and yielded higher bacterial production and lower alkaline phosphatase activity compared to cyanobacterium-derived DOM after 24 h of incubation (but not after 48 and 72 h), indicating greater bacterial usability of diatom-derived DOM. Bacterial communities significantly differed between DOMp types as well as between different incubation times, pointing to a certain bacterial specificity for the DOMp producer as well as a successive utilization of phytoplankton DOM by different bacterial taxa over time. The highest differences in bacterial community composition with DOMp types occurred shortly after DOMp additions, suggesting a high specificity toward highly bioavailable DOMp compounds. We conclude that phytoplankton-associated bacterial communities are strongly shaped by the phytoplankton producer as well as the transformation of its released DOMp over time. IMPORTANCE Phytoplankton-bacterium interactions influence biogeochemical cycles of global importance. Phytoplankton photosynthetically fix carbon dioxide and subsequently release the synthesized compounds as dissolved organic matter (DOMp), which becomes processed and recycled by heterotrophic bacteria. Yet the importance of phytoplankton producers in combination with the time-dependent transformation of DOMp compounds on the accompanying bacterial community has not been explored in detail. The diatom Skeletonema marinoi and the cyanobacterium Prochlorococcus marinus MIT9312 belong to globally important phytoplankton genera, and our study revealed that DOMp of both species was selectively incorporated by the bacterial community. The producer species had the highest impact shortly after DOMp appropriation, and its effect diminished over time. Our results improve the understanding of the dynamics of organic matter produced by phytoplankton in the oceans as it is utilized and modified by cooccurring bacteria.

Economic analysis of global microalgae biomass energy potential

With the increasing demand for renewable energy, microalgae, as a renewable biomass energy, can fix carbon dioxide and have broad application prospects in alleviating the energy crisis and improving the environment. In this paper, the potential biomass of global microalgae is calculated based on the mathematical growth model of microalgae proposed by predecessors. Based on this, this study further uses Newton's gravity model as the basic model of economic analysis and calculates the economic potential coefficient of microalgae production in various regions of the world by using the data of the world's top 20 cities in terms of urban population and urban GDP in 2020. The study has obtained the current global unused land with the high economic value of large-scale microalgae production areas, such as western North America, northern Africa, and northwest China, etc., which can provide guidance for the future site selection and development of microalgae biomass energy.

Chemical Fixation of Carbon Dioxide into Cyclic Carbonates Catalyzed by Porous Materials

AbstractThe reaction of carbon dioxide (CO2) with epoxide to generate cyclic carbonates is one of the most effective chemical fixation methods. The catalytic system significantly affects the carbon fixation efficiency of the reaction. Among the reported catalytic systems, porous materials as heterogeneous catalysts have attracted significant attention. This study aimed to summarize porous materials that catalyzed the conversion of CO2 into cyclic carbonates, including metal organic frameworks, covalent organic frameworks, poly(ionic) liquids, hyper crosslinked polymers, conjugated porous polymers and others. The study analyzed the catalytic properties of these materials and outlined future research directions.

Microalgae-material hybrid for enhanced photosynthetic energy conversion: a promising path towards carbon neutrality.

Photosynthetic energy conversion for high-energy chemicals generation is one of the most viable solutions in the quest for sustainable energy towards carbon neutrality. Microalgae are fascinating photosynthetic organisms, which can directly convert solar energy into chemical energy and electrical energy. However, microalgal photosynthetic energy has not yet been applied on a large scale due to the limitation of their own characteristics. Researchers have been inspired to couple microalgae with synthetic materials via biomimetic assembly and the resulting microalgae-material hybrids have become more robust and even perform new functions. In the past decade, great progress has been made in microalgae-material hybrids, such as photosynthetic carbon dioxide fixation, photosynthetic hydrogen production, photoelectrochemical energy conversion and even biochemical energy conversion for biomedical therapy. The microalgae-material hybrid offers opportunities to promote artificially enhanced photosynthesis research and synchronously inspires investigation of biotic-abiotic interface manipulation. This review summarizes current construction methods of microalgae-material hybrids and highlights their implication in energy and health. Moreover, we discuss the current problems and future challenges for microalgae-material hybrids and the outlook for their development and applications. This review will provide inspiration for the rational design of the microalgae-based semi-natural biohybrid and further promote the disciplinary fusion of material science and biological science.

Prussian blue analogs as catalysts for the fixation of CO2 to glycidol to produce glycerol carbonate and multibranched polycarbonate polyols

A series of Prussian blue analogs (PBAs) having a range of crystal structures and compositions was investigated as heterogeneous catalysts for the fixation of carbon dioxide (CO2) to glycidol. The morphology of PBAs was modified, as confirmed by structural characterization, by varying the precipitation method. Of the prepared catalysts, the cubic Zn(II)-Co(III) PBA exhibited the highest catalytic activity (turn-over frequency up to 763 h−1), selectivity (up to 94%), and recyclability for the cycloaddition of CO2 to glycidol. In addition, branched polycarbonate polyols having tunable branching degree (0.15–0.61) and linear polycarbonates of relatively high carbonate content (up to 64.2%) were produced via ring-opening (multibranching) copolymerization of CO2 and various epoxides using a highly amorphous Zn(II)-Co(III) double metal cyanide catalyst. Mechanistic pathways have been proposed by combining experimental results with computational studies.

In Vivo Detection of Low Molecular Weight Platform Chemicals and Environmental Contaminants by Genetically Encoded Biosensors.

Genetically encoded biosensor systems operating in living cells are versatile, cheap, and transferable tools for the detection and quantification of a broad range of small molecules. This review presents state-of-the-art biosensor designs and assemblies, featuring transcription factor-, riboswitch-, and enzyme-coupled devices, highly engineered fluorescent probes, and emerging two-component systems. Importantly, (bioinformatic-assisted) strategies to resolve contextual issues, which cause biosensors to miss performance criteria in vivo, are highlighted. The optimized biosensing circuits can be used to monitor chemicals of low molecular mass (<200 g mol-1) and physicochemical properties that challenge conventional chromatographical methods with high sensitivity. Examples herein include but are not limited to formaldehyde, formate, and pyruvate as immediate products from (synthetic) pathways for the fixation of carbon dioxide (CO2), industrially important derivatives like small- and medium-chain fatty acids and biofuels, as well as environmental toxins such as heavy metals or reactive oxygen and nitrogen species. Lastly, this review showcases biosensors capable of assessing the biosynthesis of platform chemicals from renewable resources, the enzymatic degradation of plastic waste, or the bioadsorption of highly toxic chemicals from the environment. These applications offer new biosensor-based manufacturing, recycling, and remediation strategies to tackle current and future environmental and socioeconomic challenges including the wastage of fossil fuels, the emission of greenhouse gases like CO2, and the pollution imposed on ecosystems and human health.