Release Of Carbon Dioxide Research Articles

The Statutory Interpretation of Renewable Energy Based on Syllogism of British Government Constitutional Forms towards Sustainable Development Goals

The current production for energy consumption generates harmful impacts of carbon dioxide to the environment causing instability to sustainable development goals. The constitutional reforms of British Government serve to be an important means of resolving any encountered incompatibilities to political environment. This study aims to evaluate green economy using developed equation for renewable energy towards political polarization of corporate governance. The Kano Model Assessment is used to measure the equivalency of 1970 Patents Act to UK Intellectual Property tabulating the criteria for the fulfillment of sustainable development goals in respect to the environment, artificial intelligence, and dynamic dichotomy of administrative agencies and presidential restriction, as statutory interpretation development to renewable energy. The constitutional forms of British government satisfy the sustainable development goals needed to fight climate change, advocate healthy ecosystem, promote leadership of magnates, and delegate responsibilities towards green economy. The presidential partisanship must be observed to delineate parties of concerns and execute the government prescriptions in equivalence to the dichotomous relationship of technology and the environment in fulfilling the rights and privileges of all citizens. Hence, the political elites can execute corporate governance towards sustainable development of renewable energy promoting environmental parks and zero emission target of carbon dioxide discharges. The economic theory developed in statutory interpretation for renewable energy serves as a tool to reduce detrimental impacts of carbon dioxide to the environment, mitigate climate change, and produce artefacts of bioenergy and artificial intelligence promoting sustainable development. It is suggested to explore other vulnerabilities of artificial intelligence to prosper economic success.

Projection of Carbon Dioxide Discharge by applying ARIMA Model in Bangladesh

Projection of Carbon Dioxide Discharge by applying ARIMA Model in Bangladesh

Photocoupling multi-enzyme nanoreactor simultaneously synthesizes pentanediamine and formic acid

Global output of bio-based products continues to increase, but the release of carbon dioxide (CO2) has exacerbated the environmental crisis. The simultaneous conversion of CO2 released by bioprocesses into high-value products is increasingly gaining attention. With this in mind, a compartmentalized photocoupling multi-enzyme nanoreactor consisting of two nanocompartments was created. This nanoreactor uses a ferric tannin-gelatin (TA-Gel) coacervate to synchronously wrap nanocompartment I, which quickly sequesters the CO2 released by biodecarboxylation to prevent its loss, and nanocompartment II, which converts the sequestered CO2 into formic acid. The results indicate that nanocompartment I and II were encapsulated in the nanoreactor with high catalytic efficiency. Under the optimal conditions, the yields of pentanediamine and formic acid reached 15.7 ± 1.06 and 8.4 ± 0.07 mM, respectively. Yields of pentanediamine and formic acid by the photocoupling multi-enzyme nanoreactor were highest. The conversion efficiency of formic acid from CO2 released by biodecarboxylation by the photocoupling multi-enzyme nanoreactor, mixed nanocompartments, and free one-pot multi-enzyme system was 54.5 %, 43.8 %, and 10.0 %, respectively. The proximity effect significantly promotes the catalytic efficiency of formic acid synthesis from CO2 released by biodecarboxylation. The novel photocoupling multi-enzyme nanoreactor has important capabilites for upgrading multi-enzyme programmed catalysis.

ПИЛОТНЫЙ КАРБОНОВЫЙ ПОЛИГОН: АНАЛИЗ ЗАПАСОВ УГЛЕРОДА В ПОЧВАХ СЕЛЬХОЗУГОДИЙ

The carbon cycle in agroecosystems is determined by the balance between the absorption of carbon dioxide by terrestrial vegetation of agricultural crops to create organic matter and its release during soil respiration. The soil cover is a powerful source of carbon dioxide and serves as a reservoir accumulating soil organic carbon. Organic carbon accumulating in the humus of soils serves as a drain of carbon dioxide, methane into the atmosphere for hundreds of years. The research was carried out in order to analyze the reserves of organic carbon in the soils of agroecosystems and assess the emission of CO2 and CH4 gases. The work was carried out in 2022-2023 at the site of a pilot carbon landfill (arable land) in the Republic of Bashkortostan. In field and laboratory experiments, technologies for controlling carbon dioxide emissions on agricultural lands were developed and tested. In the field, full-profile soil sections and digs were laid in accordance with GOST R58595-2019 with the determination of morphological properties and the selection of soil samples for laboratory analysis. Agrochemical analysis of the soil for the content of organic matter, the density of addition, the content of mobile phosphorus and potassium, the pH value allowed us to estimate the carbon stock of the soil of the carbon landfill according to the methodology of the Ministry of Natural Resources of the Russian Federation. The total reserves of organic carbon of the arable horizon at the carbon-new landfill amount to 503.8 t/ha, which vary and depend on the employment of the field and the characteristics of the agricultural crop. Measurement of the destructive part of the carbon cycle using a portable LI-COR 7810 camera showed that the fields occupied by crops differ in the intensity of the release of soil carbon dioxide ‒ in the field under pure steam, CO2 emissions were 2.18 times lower than under perennial grasses. The availability of data on the spatial distribution of organic soil carbon makes it possible to introduce carbon-dependent crop rotations with a set of crops that contribute to the maximum absorption of atmospheric CO2 and other greenhouse gases into the practice of agriculture.

STUDY OF DOUGH FERMENTATION PROCESS WITH FLAX SEEDS

Flax seeds are a valuable raw material for the production of functional bakery products. The article investigates the fermentation processes in wheat dough supplemented with whole and crushed flax seeds in dry and soaked states. For a holistic understanding of the fermentation process, the regularities of the kinetics and dynamics of gas formation in the experimental samples were analyzed. It was found that during fermentation in samples with whole flax seeds in dry and soaked states, the amount of carbon dioxide released slightly increases compared to the control. In the samples with crushed dry and soaked flax seeds, the total amount of carbon dioxide released is higher than in the control sample by 16.5% and 19.0%, respectively. In the sample with crushed flax seeds, the nature of the dynamics of carbon dioxide release differs from the control sample, namely, a one-stage fermentation is observed. At the same time, the peak of carbon dioxide release was observed almost 30 minutes later than in the control sample. This may be due to the fact that soaking flaxseed products produces viscous solutions of polysaccharides, which envelop the yeast cells during dough kneading and slow down the supply of nutrients to them. Based on the analysis of the dynamics of carbon dioxide emission, it is recommended to reduce the duration of dough fermentation for the sample with whole flax seeds to 90 minutes, and for the samples with crushed seeds and soaked flax products to 60 minutes, so that the most intense carbon dioxide emission in these experimental samples occurs during the period of proofing of dough pieces. It was found that the introduction of whole and crushed flax seeds in soaked form slows down the rise of the dough due to the thickening of the dough system with water-soluble and insoluble flax dietary fiber, reducing fermentation and the formation of sugars in the dough system.

Optimal strategies for green investment, sharing contract and advertisement effort in a supply chain coordination problem

The global environment is experiencing increasingly rapid pollution due to the presence of harmful products generated by human activities, the emissions from vehicular traffic, and the release of carbon dioxide from industrial sources. To save this beautiful earth as well as human beings, it is necessary to reduce pollution by producing eco-friendly products and reducing reckless carbon emissions from industry. Furthermore, advertising serves as a very efficacious strategy for promoting sustainable green products and encouraging customer engagement. In response to the current circumstances, a supply chain model including a manufacturer, a retailer, and customers is devised, incorporating investments in green practices and advertising. This study examines the relationship between client demand and three key factors: marketing effort, the product's green level, and the selling price. In addition, a sharing contract policy between the manufacturer and the retailer on green investment costs is applied in this model. The main focus of this study is to find the optimal values of advertisement effort, the product's green level, the manufacturer's wholesale price, the retailer's selling price and the sharing percentage of green investment that maximize the profits of the retailer and manufacturer, as well as the integrated supply chain system of the proposed model. In order to demonstrate the practical significance of the concept, a numerical example is solved and then a comparative analysis is conducted. Moreover, sensitivity studies are performed to assess the impact of different model parameters on decision factors and profitability. In conclusion, this study provides management insights and offers some closing observations, along with suggestions for future research directions. The findings indicate that the implementation of a sharing contract policy yields more earnings to the participants in the supply chain compared to a decentralized situation. The centralized strategy in supply chain management (SCM) results in higher joint earnings for the manufacturer and the retailer compared to the decentralized and sharing contract policies.

Degradation of Sb-Doped SnO2 Supported IrRu-Based Electrocatalysts for PEM Water Electrolysis Via Accelerated Stress Protocols

Proton exchange membrane (PEM) water electrolyzers offer a very promising option to offset the environmental burden of conventional hydrogen production by splitting water into high purity hydrogen and oxygen without releasing carbon dioxide as by-product. However, the corrosive nature of the process makes it dependent on expensive materials, such as iridium (Ir), ruthenium (Ru) or titanium (Ti), which makes the upscaling of the technology considerably more difficult [1, 2]. To ensure industrial success of this technology, the study of the mechanisms involved in the degradation of the cell components is of great importance. Particularly, the development of accelerated stress test protocols has attracted attention in recent years, due to their potential to yield representative data pertaining degradation without incurring long testing times that would meet the typical industrial standards of 20,000 to up to 50,000 hours [3].Several strategies to investigate the various degradation mechanisms have been discussed in recent years in the literature. Particularly, Spöri pointed out the difference between transient and static operation and the degradation mechanisms triggered by each of these modes, while also investigating the intrinsic mechanisms of the catalyst via rotating disk electrode analysis [3]. Meanwhile, Frensch explored in their work the relation of cathodic fluoride release with different current density profiles and different temperatures [4]. Furthermore, attempts have been made to increase the electrochemical stability of oxygen evolution reaction (OER) electrocatalysts by adding a support material to the catalyst layer. This was described by Saveleva in their work, as they found evidence that supporting Ir on antimony-doped tin oxide (Sb-doped SnO2) resulted in a preferential dissolution of Sb and Sn, thus noticeably reducing the dissolution rate of Ir [2].In this work, the electrochemical activity and stability of newly developed IrRu OER catalysts supported on Sb-doped SnO2 is studied in a single cell setup. The catalyst and support materials were synthetized as part of the study. For the preparation of the MEAs the fabricated materials were used with membranes and ionomers which are commercially available. The prepared MEAs were analyzed using both static and dynamic current profiles with a current range of up to 4 A cm-2. To understand the different mechanisms and material dependencies at play during characterization, the MEA configuration (membrane type, material ratios, ionomer) was varied. The first screenings with different MEA configurations not only suggest a strong stability with the catalyst loading, as it was previously observed by Alia [5], but also a strong dependence on the anodic ionomer content, which reflects in the degradation rate in the first hundred hours of test.

An experimental evaluation of novel biofuel and biodiesel from Ziziphus mauritiana seeds in DICI engine

The engine community is searching for novel fuels concerning sustained availability with superior properties to traditional engine fuels. From the seeds of Ziziphus mauritiana, vegetable oil is extracted and transesterified for improvement in its properties as engine fuel. The properties of the oil qualify it for engine applications. This investigation has been carried out on a 5.2 kW, 1500 r/min, eddy current loading compression ignition engine. Engine runs at different loads on neat Ziziphus mauritiana oil biofuel and on Ziziphus mauritiana biodiesel. Both fuels developed power at all loads of the engine. Z iziphus mauritiana oil has a lesser calorific value, elevated density, viscosity, and least brake thermal efficiency, highest emissions except for NOx. Z iziphus mauritiana oil properties were improved through transesterification. At maximum load, compared to Ziziphus mauritiana oil biofuel, Ziziphus mauritiana biodiesel has a percentage variation of 2.1%, 6.0%, 24.4%, 14.5%, and 31.4% increase in brake thermal efficiency, peak pressure, heat release rate, NOx, and carbon dioxide, respectively. A percentage variation of 40%, 26.1%, 33%, and 4% reduction in ignition delay, CO, HC, and smoke is observed, respectively for Ziziphus mauritiana biodiesel operation. Compared to Ziziphus mauritiana oil biofuel, the Ziziphus mauritiana biodiesel produced better results with lesser and nearly equal diesel emissions except NOx and smoke. Therefore, Ziziphus mauritiana biodiesel fuel can be used as a replacement fuel.

Experimental Study of Compressive Strength of 8M Geopolymer Mortar for Different Combinations of Eucalyptus-ash with Ggbs(45µ)

Concrete is the material which is unstintingly used in the construction sector and the product of cement is one among the reason for global warming due to release of carbon dioxide, to minimize its effect on nature we must use artificial by- product as an indispensable material. Among artificial by- product, operation of cover ash is more. The geopolymer mortar made by the using cover- ash set sluggishly in ambient temperature and needs heat curing. To overcome this limitation, Ground Granulated Blast Furnace Sediment(GGBS) grease paint is used as a cementious material which shows considerable gain in strength. In this paper, we delved the parcels of geopolymeric binder prepared using the Ground “Granulated Blast Furnace Sediment”(GGBS) and eucalyptus ash without using conventional cement. The individual parcels of the GM for 1:3 rate, similar as compressive strength test were determined as per applicable Indian norms. cells of size (70.6x70.6x70.6) mm were casted and cured in ambient condition for molarity 8M with different rates and different temperatures. After the trials, compressive strength is increased for adding number of days of curing. Also compressive strength dropped for adding Na2SiO3/ NaOH rates and adding roaster curing temperatures

Biodegradation of aliphatic polyurethane foams in soil: Influence of amide linkages and supramolecular structure

Polyurethane (PU) foams are classified as physically nonrecyclable thermosets. The current effort of sustainable and eco-friendly production makes it essential to explore methods of better waste management, for instance by modifying the structure of these frequently used polymers to enhance their microbial degradability. The presence of ester links is known to be a crucial prerequisite for the biodegradability of PU foams. However, the impact of other hydrolysable groups (urethane, urea and amide) occurred in PU materials, as well as the supramolecular structure of the PU network and the cellular morphology of PU foams, is still relatively unexplored.In this work, fully aliphatic PU foams with and without hydrolyzable amide linkages were prepared and their aerobic biodegradation was investigated using a six-month soil burial test. Besides the variable chemical composition of the PU foams, the influence of their different supramolecular arrangement and cellular morphologies on the extent of biodegradation was also evaluated. Throughout the soil burial test, the release of carbon dioxide, and enzyme activities of proteases, esterases, and ureases were measured. At the same time, phospho-lipid fatty acids (PLFA) analysis was conducted together with an assessment of microbial community composition achieved by analysing the genetic information from the 16S rRNA gene and ITS2 region sequencing.The results revealed a mineralization rate of 30–50 % for the PU foams, indicating a significant level of degradation as well as indicating that PU foams can be utilized by soil microorganisms as a source of both energy and nutrients. Importantly, microbial biomass remained unaffected, suggesting that there was no toxicity associated with the degradation products of the PU foams. It was further confirmed that ester linkages in PU foam structure were easily enzymatically cleavable, while amide linkages were not prone to degradation by soil microorganisms. In addition, it was shown that the presence of amide linkages in PU foam leads to a change in the supramolecular network arrangement due to increased content of hard segments, which in turn reduces the biodegradability of PU foam. These findings show that it is important to consider both chemical composition and supramolecular/macroscopic structure when designing new PU materials in an effort to develop environmentally friendly alternatives.

Modelling of Carbon Dioxide Venting in Carbon Capture and Storage Studies: Design and Safety Implications

The reduction of the impact of carbon dioxide on the environment is a key driver of the energy transition, which will progressively reduce the use of fossil fuels and will promote the development of viable technologies. This process will be based on renewable energy sources to reduce, to any possible extent, the production and the release of carbon dioxide into the atmosphere. CCS (Carbon Capture and Storage) projects are more and more an ineludible stage of this process. In the last decade, a significant segment of chemical engineering research has been devoted to the management of carbon dioxide release scenarios, which can result both from an accidental loss of containment or from an emergency venting of carbon dioxide streams. This gas is asphyxiating and toxic, depending on concentration levels. Consequently, acquiring familiarity with its dispersion modelling is a key task for process and process safety engineers. On the other hand, carbon dioxide presents a very peculiar behaviour, as it is a dense gas and, below the triple point, its release can produce solid formation. The article presents a relatively simple multi-stage validated model, covering the release scenario from the source, as a heavy gas, up to the neutral Gaussian dispersion, considering also the very low temperatures possibly resulting from the JT (Joule Thomson) effect. Two case studies, carried out through the Megaris Platform, illustrate the application of the methodology. It can be useful in the design phase and in the QRA studies, to properly size and locate the venting stack and to minimize any health upsets for the operators

Investigating the thermal behavior of acyclovir

Viruses are a significant health, economic and social issue. Acyclovir (ACV) is an antiviral agent analogous to the guanine nitrogenous base that acts by interrupting the multiplication of DNA of virus in infected cells. The thermal decomposition mechanism of ACV was evaluated by thermoanalytical techniques Thermogravimetry/derivative thermogravimetry (TG/DTG), differential thermal analysis (DTA), evolved gas analysis by thermogravimetry coupled to vibrational infrared spectrometry in gas phase (TG-FTIR), differential scanning calorimetry (DSC), hot stage microscopy (HSM) and mass spectrometry (MS). TG/DTG and DTA curves were performed under N2 and air atmospheres. Under N2, four stages of mass loss were observed from the TG curve between 523-1273 K, while under air decomposition occurred in a similar way, however, the additional burning of carbonaceous material was found in air. DSC curves were obtained in heat-cool-heat mode, from 233 to 543 K, under N2 atmosphere and presented two endothermic peaks related to water loss and phase transition followed by exothermic crystallization of a new form, followed by melting associated with decomposition in agreement with HSM images. Powder X-ray diffraction (PXRD) profiles confirmed the phase transitions. From the TG-FTIR characterization, it was suggested that decomposition undergoes by release of water, 1,3-dioxolane, isocyanic acid, carbon dioxide, carbon monoxide, and ammonia. MS spectrum of the residue collected at 543 K revealed the presence of guanine free base as decomposition product in agreement with the release of dioxolane ring in gas phase.

Preparation and characterization of UiO‐66‐NH2 adsorbed triethyl phosphate: Flame retardancy and smoke suppression for epoxy resins

AbstractThe zirconium‐based metal–organic framework material (UiO‐66‐NH2) was synthesized by solvothermal method, and its excellent adsorption performance was used to combine it with the phosphorus‐based flame retardant triethyl phosphate (TEP) and to improve the flame retardant and smoke suppression properties of epoxy resin (EP). The morphology, chemical composition, and structure of the synthesized flame retardant were analyzed by scanning electron microscope, energy dispersion spectrum, Fourier transform infrared spectroscopy, and x‐ray diffractometer. The cone calorimeter measurement of EP composite materials shows that EP composite materials have good flame retardant and smoke suppression properties. Compared with EP, after the UiO‐66‐NH2 flame retardant which adsorbs TEP is added, the peak heat release rate, total heat release, peak smoke release rate, total smoke production, carbon monoxide release rate, and carbon dioxide release rate of EP composites have been reduced. From the results of thermal analysis and scanning electron microscope, it can be seen that the synthesized flame retardant can act both in the condensed phase and in the gas phase. Thereby, the combustion of the matrix and the diffusion of the toxic gas, smoke and heat generated during the combustion are inhibited, and the flame retardant and smoke suppression effects are achieved.Highlights Make full use of the excellent adsorption performance of MOF. TEP was fully adsorbed in UiO‐66‐NH2 pores. UiO‐66‐NH2 in synergy with TEP improves EP flame retardancy.

Continuous Stripping with Dense Carbon Dioxide.

The integration of flow chemistry into continuous manufacturing requires efficient, controllable, and continuous methods for the concentration of diluted solutions on relatively small scales. The design and application examples of a new continuous solvent removal process are presented. The continuous stripping method employing dense carbon dioxide is based on the formation of homogeneous mixtures of dilute organic solutions of the target molecules with a large excess of carbon dioxide at temperatures as low as 35 °C and pressures around 10 MPa. Subsequent pressure reduction results in the quick release of carbon dioxide and vaporization of a significant fraction of the organic solvent. The concentration of the solute in the separated liquid phase can be up to 40 times higher than in the feed. Among the many controllable process parameters, the most significant ones are the mass-flow rate ratio of carbon dioxide to the feed and the temperature of the phase separator. By careful setting of the operational parameters, the degree of concentration enhancement may be accurately controlled. The new apparatus-despite consisting of laboratory equipment and being built in a fume hood-could easily support pilot-scale synthetic flow chemistry, being a continuous, efficient alternative to thermal concentration methods.

Weathering of Rocks Can Release Carbon Dioxide

New research upends the notion that the weathering of rocks mainly removes CO2 from the atmosphere. Rocks can also be carbon sources, releasing as much CO2 as Earth’s volcanoes.

Solar-Powered Water Electrolysis Using Hybrid Solid Oxide Electrolyzer Cell (SOEC) for Green Hydrogen—A Review

The depletion of fossil fuels in the current world has been a major concern due to their role as a primary source of energy for many countries. As non-renewable sources continue to deplete, there is a need for more research and initiatives to reduce reliance on these sources and explore better alternatives, such as renewable energy. Hydrogen is one of the most intriguing energy sources for producing power from fuel cells and heat engines without releasing carbon dioxide or other pollutants. The production of hydrogen via the electrolysis of water using renewable energy sources, such as solar energy, is one of the possible uses for solid oxide electrolysis cells (SOECs). SOECs can be classified as either oxygen-ion conducting or proton-conducting, depending on the electrolyte materials used. This article aims to highlight broad and important aspects of the hybrid SOEC-based solar hydrogen-generating technology, which utilizes a mixed-ion conductor capable of transporting both oxygen ions and protons simultaneously. In addition to providing useful information on the technological efficiency of hydrogen production in SOEC, this review aims to make hydrogen production more efficient than any other water electrolysis system.

Respiration and carbon use efficiency characteristics of soluble protein-derived carbon by soil microorganisms: A case study at afforested sites

Soluble protein plays a significant role in the release of carbon dioxide (CO2) in soils. However, our understanding of the respiration and C use efficiency (CUE) characteristics of soluble protein-derived C by soil microorganisms is limited. To address this issue, we sampled surface soils (0−10 cm) from seven tree monocultures and examined the temporal dynamics of turnover of 14C-labelled soluble protein-derived C by soil microorganisms. Two double first-order exponential kinetic decay models were applied to analyze the mineralization data (i.e., with and without abiotic protein-surface interactions). The model incorporating the immobilization of protein on the non-living solid phase exhibited the best fit to the experimental data (R2 > 99.6%). Our results suggest that 66.1−73.9% of the soluble protein-derived C was immobilized by the non-living solid phase in soils. After uptake by the soil microbial community, 8.0−13.8% of the C was rapidly respired as CO2, while 15.0−20.8% was used in anabolic processes, resulting in a CUE of 55.1–70.2%. However, there was little effect of forest type on protein turnover rate in the soil. The C:N ratio of soil microbial biomass (C/Nmic) was positively related to the CUE of protein and exhibited less variation within a forest type. Compared with soil microbial biomass C and N, C/Nmic could serve as a better indicator of the CUE of protein by soil microorganisms. This study sheds light on the respiration and CUE characteristics of soluble protein-derived C by soil microorganisms at afforested sites and enhances our understanding of the trade-off between the metabolism of protein-derived C by soil microorganisms and its immobilization by the non-living solid phase in soils.

In-situ formation of CO2-incorportaed solid sorbent for dispersive solid phase extraction of phenolic compounds from water and wastewater samples prior to gas chromatography-flame ionization detector

BackgroundHerein, a new extraction procedure based on in-situ formation of carbon dioxide-incorporated solid sorbent was introduced for dispersive solid phase extraction of phenolic compounds from aqueous samples. In this study, incorporation of carbon dioxide into the structure of a diamine led to the formation of a solid compound in the sample solution that adsorbed the analytes. ResultsThe sample solution was mixed with isophorone diamine and placed under carbon dioxide stream. By doing so, isophorone diamine reacted with carbon dioxide and produced a carbamic acid analogue. It was dispersed into the sample solution as tiny particles that adsorbed the analytes. The adsorbed analytes were eluted by a volatile organic solvent and concentrated more by the vaporization of the eluate. The extraction procedure was done at low temperature to limit the releasing carbon dioxide from the produced compound. To obtain the reliable results, the method was validated and the obtained limits of detection and quantification were in the ranges of 0.29–41 and 0.96–1.3 ng/mL, respectively. Acceptable relative standard deviation (≤7.3%) and coefficient of determination (≥0.994) values confirmed the method repeatability and linearity. High enrichment factors (410–435) and extraction recoveries (82–87%) were attained with the introduced method. Significance and noveltyIn this work, a chemical reaction was done between isophorone diamine and carbon dioxide in solution. The produced product (sorbent) was insoluble in solution and dispersed in whole parts of the solution as tiny particles. A high contact area between the sorbent and analytes provided high extraction efficiency for the analytes. The method was successful utilized in determining target analytes in real samples and the matrix effect of the samples had no important effect on the obtained results.

From Rags to Riches: Exploiting the Calvin‐Benson‐Bassham Cycle for Biomanufacturing

AbstractIndustrial chemical production largely relies on fossil fuels, resulting in the unavoidable release of carbon dioxide (CO2) into the atmosphere. The concept of a circular carbon bioeconomy has been proposed to address this issue, wherein CO2 is captured and used as a raw material for manufacturing new chemicals. Microbial cell factories and, in particular, autotrophic microorganisms capable of utilizing CO2 as the sole carbon source, emerged as potential catalysts for upcycling CO2 to valuable products. The Calvin‐Benson‐Bassham cycle (CBBc), the best‐known CO2 fixation pathway, is widely distributed in Nature. While extensively studied, microbial engineering programmes based on the CBBc remains relatively underexplored. In this review, we discuss avenues towards biotechnological exploitation of the CBBc to engineer CO2‐utilizing microbial cell factories, with a focus on chemically‐derived electron donors. We also highlight the advantages and challenges of implementing the CBBc in heterotrophic microbial hosts and its potential to advance a true circular carbon bioeconomy. Moreover, based on the pathway's architecture, we argue about the ideal value‐added products to generate from this metabolic route. Altogether, studying and engineering the CBBc in both natural‐ and synthetic‐autotrophs will enhance our understanding on this CO2 fixation pathway, enabling further exploration of biomanufacturing avenues with CO2 as feedstock.

Effects of combined PS-Pb pollution on the calcification of Paphia undulata: Coexistence of antagonistic and synergistic effects

Similar to respiration, shellfish function as a carbon source because they release carbon dioxide during calcification which uses soluble inorganic carbon in seawater to form biological calcium deposits, such as shells, which is important for shellfish survival. Almost all filter feeding shellfish feed mainly on phytoplankton, which are the most dominant primary producers in marine ecosystems. Microplastics and Pb generally coexist in the habitat of Paphia undulata, and microplastics adsorb Pb. Both of these two matters negatively affect metabolism that affects calcification. Thus, it is speculated that the interaction between microplastics and Pb affects the calcification of P. undulata by affecting its metabolism. This hypothesis is related to the carbon cylce drived by filter feeding shellfish under combined pollution of microplastic and Pb. Nevertheless, related studies are extremely rare. To verify this hypothesis, P. undulata was exposed to PS-Pb combined pollution for 96 h, during which microplastics and Pb were represented by polystyrene (PS) with a particle size of 5.0 µm and Pb (NO3)2, respectively. Ammonia excretion was affected by PS and the interaction of PS and Pb. Not the oxygen consumption but the ratio of O/N was affected by PS, Pb and their interaction. If the concentrations of PS and Pb were 50 and 6 μg/L, respectively; the ratio of O/N of P. undulata was higher than that under the other treatments. The calcification was influenced by Pb and the interaction of PS and Pb, e.g., as the concentrations of PS and Pb were 25 and 6 μg/L, respectively, the calcification rate of P. undulata was the lowest. Moreover, the calcification rate was positively correlated with the ratio of O/N, i.e., there was a correlation between the calcification rate and metabolic substrates. PS and Pb at low concentrations had a synergistic effect on calcification, while they tended to produce antagonism at high concentrations. All these facts mean that the effect of compound pollution on calcification is not a simple addition of the effects of the two pollutants that influence calcification by affecting metabolism, and the effects of the PS-Pb combined pollution on the carbon cycle in offshore areas should be reassessed.