Search Results (1,799)

Harnessing nature’s ingenuity with microorganisms for industrial production is an attractive solution to today’s climate concerns. Nature’s innate diversity allows the production of many value-added chemicals and can be expanded on through genetic engineering. Although the use of microbial cell factories (MCFs) has been extremely successful at lab scale, the numbers of successful bioprocesses remain limited. High cell densities and long cultivation times lead to reductions in productivity over the course of the cultivation through the effects of genetic and expression instability of the strain. This instability leads to population diversification. In this review, we explore the roots of genetic instability in microorganisms, focusing on prokaryotic bioprocesses, and how organisms cope with this instability. We spotlight single-cell detection methods capable of monitoring populations within the bioprocess both in- and on-line. We also examine different approaches to minimizing population diversification, both through strain development and bioprocess engineering. With this review, we highlight the fact that population-averaged metrics overlook the single-cell stresses driving genetic and functional instability, leading to an overestimation of microbial bioprocess robustness. High-throughput single-cell monitoring in industry-like conditions remains essential to identify and select truly stable microbial cell factories and bioprocesses. Full article

This study developed a two-step conversion strategy for the efficient conversion of bamboo waste into 5-hydroxymethylfurfural (HMF). First, ultrasonic-assisted formic acid pretreatment was used at 80 °C for 3 h, removing approximately 83.7% of hemicellulose and 76.5% of lignin from the biomass, with a cellulose recovery of 93.5%. The ultrasonic step significantly enhanced the chemical action of formic acid through cavitation, allowing formic acid to penetrate deeper into the biomass, thereby more effectively removing hemicellulose and lignin. Subsequently, glucose was obtained through an enzymatic hydrolysis. In the second step of HMF preparation, citric acid in the hydrolysate was combined with ChCl to form an acidic deep eutectic solvent (DES), and metal chlorides were added as Lewis acid catalysts. Experiments results showed that when the ChCl–citric acid ratio was 2:1, and the Ca²⁺ concentration was 100 mM, an HMF yield of 51.9% was obtained at 220 °C for 1.5 h. This study provides an efficient, mild, and environmentally friendly method for the high-value valorization of waste bamboo. Full article

Pellets produced from raw or torrefied shredded logging residues have been investigated in the study. The research material came from pine and spruce stands in Poland, Slovakia, Czechia and Hungary. Torrefaction temperatures (T_t) of 250, 300, and 400 °C were applied. Before pressure agglomeration, 3% wheat flour was added to the torrefaction material as a binding agent. Pellets with a diameter of 8 mm were produced at constant humidity, compaction pressure (P) of 140 or 180 MPa and agglomeration temperature (T_a) of 100, 120 or 140 °C. The produced pellets were assessed for their physicomechanical parameters (density, radial compressive strength, compression ratio, modulus of elasticity), chemical parameters (extractive compounds, cellulose, lignin) and energy parameters (ash content, elemental composition, calorific value). The results were subjected to basic statistical analysis and multi-way ANOVA. The produced pellets varied in physical, mechanical, chemical and energy properties. A significant effect of torrefaction temperature, agglomeration temperature and compaction pressure on the results was observed. In terms of physicomechanical parameters, the best pellets were produced from the raw material, while in terms of energy parameters, those produced from the torrefied material were superior. Pellets of satisfactory quality produced from torrefied logging residues could be obtained at T_t = 250 °C, T_a = 120 °C and P = 180 MPa. Pellets with specific density of approximately 1.1 g·cm⁻³, radial compressive strength of 3–3.5 MPa, modulus of elasticity of 60–80 MPa and calorific value of 20.3–23.8 MJ·kg⁻¹ were produced in the process. Full article

Electrochemical CO₂ reduction (CO₂RR) is a promising route to transform a major greenhouse gas into value-added fuels and chemicals. However, its deployment is still hindered by the sluggish activation of CO₂, poor selectivity toward multielectron products, and competition with the hydrogen evolution reaction (HER). Single-atom catalysts (SACs) have emerged as powerful materials to address these challenges because they combine maximal metal utilization with well-defined coordination environments whose electronic structure can be precisely tuned through metal–support interactions. This minireview summarizes current understanding of how structural, electronic, and chemical features of SAC supports (e.g., porosity, heteroatom doping, vacancies, and surface functionalization) govern the adsorption and conversion of key CO₂RR intermediates and thus control product distributions from CO to CH₄, CH₃OH and C₂⁺ species. Particular emphasis is placed on selectivity descriptors (e.g., coordination number, d-band position, binding energies of *COOH and *OCHO) and on rational design strategies that exploit curvature, microenvironment engineering, and electronic metal–support interactions to direct the reaction along desired pathways. Representative SAC systems based primarily on N-doped carbons, complemented by selected examples on oxides and MXenes are discussed in terms of Faradaic efficiency (FE), current density and operational stability under practically relevant conditions. Finally, the review highlights remaining bottlenecks and outlines future directions, including operando spectroscopy and data-driven analysis of dynamic single-site ensembles, machine-learning-assisted DFT screening, scalable mechanochemical synthesis, and integration of SACs into industrially viable electrolyzers for carbon-neutral chemical production. Full article

Current management strategies for sorghum aphids heavily rely on indiscriminate chemical application, leading to severe environmental consequences and impacting food safety. While precision spraying offers a viable remediation for pesticide overuse, its effectiveness depends on accurately locating and classifying pests. To address the critical challenge of segmenting small, swarming aphids in complex field environments, we propose FESW-UNet, a dual-domain attention network that integrates Fourier-enhanced attention, spatial attention, and wavelet-based downsampling into a UNet backbone. We introduce an efficient multi-scale attention (EMA) module between the encoder and decoder to enhance global context perception, enabling the model to capture more accurate relationships between global and local features in the field. In the feature extraction stage, we embed a simple attention module (SimAM) to target key infestation regions while suppressing background noise, thereby enhancing pixel-level discrimination. Furthermore, we replace conventional downsampling with Haar wavelet downsampling (HWD) to reduce resolution while preserving structural edge details. Finally, a Fourier-enhanced attention module (FEAM) is added to the skip-connection layers. By using complex-valued weights to regulate frequency-domain features, FEAM effectively fuses global low-frequency structures with local high-frequency details, thereby enhancing feature representation diversity. Experiments on the Aphid Cluster Segmentation dataset demonstrate that FESW-UNet outperforms other models, achieving an mIoU of 68.76%, mPA of 78.19%, and mF1 of 79.01%. The model also demonstrated strong adaptability on the AphidSeg-Sorghum dataset, achieving an mIoU of 81.22%, mPA of 87.97%, and mF1 of 88.60%. The proposed method offers an efficient and feasible technical solution for monitoring and controlling sorghum aphids through image segmentation, demonstrating broad application potential. Full article

With the escalating challenges of global warming and the energy crisis, electrocatalytic CO₂ reduction reaction (CO₂RR) has emerged as a promising strategy to mitigate atmospheric CO₂ concentrations while converting it into high-value-added chemicals. Among various CO₂RR catalysts, copper-based materials exhibit unique capabilities for C-C coupling, yet their practical application remains constrained by several limitations: Low selectivity for C₂₊ products (typically <60%); Catalyst instability due to dynamic reconfiguration of active sites under high overpotentials; poor energy efficiency caused by competing hydrogen evolution reactions (HERs), etc. Recent studies demonstrate that nonmetallic heteroatom doping or functionalized ligand incorporation can effectively modulate the electronic structure and surface microenvironment of Cu-based catalysts, thereby enhancing CO₂RR performance. In this review, we comprehensively summarize recent advances in such strategies. We first systematically elucidate the unique advantages of copper-based catalysts as benchmark materials for multi-carbon (C₂₊) product synthesis, along with the current challenges they face. Subsequently, we highlight recent advances in modulating copper-based catalysts through the incorporation of diverse nonmetallic heteroatoms (e.g., N, S, B, P, halogens) or the introduction of functionalized ligands, with a particular focus on mechanistic insights and characterization methods aimed at enhancing C-C coupling efficiency and improving C₂₊ product selectivity. Finally, we present perspectives on the remaining opportunities and challenges in this research field. Full article

Waste valorization is a necessary activity for the development of the circular economy. Pyrolysis as a waste valorization pathway has been extensively studied, as it allows for obtaining different fractions with diverse and valuable applications. The joint analysis of results generated by thermogravimetry (TGA) and analytical pyrolysis (Py-GC/MS) allows for the characterization of waste materials and the assessment of their potential as sources of energy, value-added chemicals and biochar, as well as providing awareness for avoiding potential harmful emissions if the process is performed without proper control or management. In the present study, these techniques were employed on three greenhouse plant residues (broccoli, tomato, and zucchini). Analytical pyrolysis was conducted at eight temperatures ranging from 100 to 800 °C, investigating the evolution of compounds grouped by their functional groups, as well as the predominant compounds of each biomass. It was concluded that the decomposition of biomass initiates between 300–400 °C, with the highest generation of volatiles occurring around 500–600 °C, where pyrolytic compounds span a wide range of molecular weights. The production of organic acids, ketones, alcohols, and furan derivatives peaks around 500 °C, whereas alkanes, alkenes, benzene derivatives, phenols, pyrroles, pyridines, and other nitrogenous compounds increase with temperature up to 700–800 °C. The broccoli biomass exhibited a higher yield of alcohols and furan derivatives, while zucchini and tomato plants, compared to broccoli, were notable for their nitrogen-containing groups (pyridines, pyrroles, and other nitrogenous compounds). Full article

The conversion of CO₂ into value-added chemicals exemplifies an innovative and eco-friendly approach to addressing carbon emissions. In this study, shape-specific CeO₂ nanocrystals (nanorods, nanocubes, and nanoparticles) were successfully synthesized and employed as catalysts to study the structure-dependent behavior and reaction mechanism for one-step CO₂ conversion to diethyl carbonate (DEC). Among the three catalysts, CeO₂ nanorods (Ce-NR) exhibited the best catalytic activity in the synthesis of DEC from CO₂ compared with CeO₂ nanocubes (Ce-NC) and nanoparticles (Ce-NP), which achieved the DEC production of 1.32 mmol_DEC/g_cat at 423 K and 5 MPa for 4 h. Comprehensive characterization further confirmed the enhanced activity of Ce-NR originated from the morphology effect, particularly the promotion of oxygen vacancies and Ce³⁺ species, which promoted reaction activity. Furthermore, the Ce-NR catalyst almost retained 1.32 mmol_DEC/g_cat DEC production of its initial activity after four cycles, underscoring its exceptional stability and promising industrial scalability. These findings provide fundamental insights to guide the rational design of efficient catalysts for CO₂ activation and other critical transformations. Full article

Ammonia, as an essential chemical, plays an indispensable role in both industry and agriculture. However, the traditional Haber–Bosch technique for ammonia synthesis suffers from high energy consumption and significant CO₂ emissions. Therefore, developing an energy-efficient and eco-friendly method for ammonia production is imperative. Photoelectrochemical (PEC) nitrate reduction to ammonia has emerged as a promising green alternative, which utilizes renewable solar energy to convert nitrate into valuable ammonia, thereby contributing to nitrogen recycling and wastewater remediation. This review systematically summarizes recent advances in PEC nitrate reduction to ammonia, focusing on the rational design of efficient photocathodes with the development of semiconductor materials, cocatalysts, p–n junction and heterostructure strategies. Furthermore, the integration of photocathodes with photoanodes enables the assembly of bias-free PEC systems capable of simultaneously producing ammonia and value-added chemicals, demonstrating the potential for scalable solar-driven ammonia synthesis. The mechanistic studies and future research directions are also discussed. The review aims to offer valuable insights and promote the further development of PEC nitrate reduction to ammonia. Full article

This study evaluated the effects of tamarind pulp addition at different processing stages and concentrations on the physicochemical, volatile, bioactive, and sensory characteristics of Saison-style beers. The experiment was conducted in two stages. First, tamarind pulp (15 g/L) was added during fermentation or maturation, with maturation resulting in superior sensory scores and higher purchase intention (75%). In the second stage, tamarind pulp was added during maturation at 20, 40, and 60 g/L. The beers presented alcohol contents between 7.1 and 7.6% (v/v), bitterness values of 29–31 IBU, and color typical of the Saison style. Sensory analysis showed that the beer with 20 g/L of tamarind pulp achieved the best balance of acidity, aroma, and flavor, with acceptability indices above 70%, while higher concentrations increased residual acidity and reduced flavor acceptance. Chromatographic analyses indicated increased levels of esters and terpenes, particularly ethyl octanoate, phenethyl acetate, citronellol, and linalool, contributing fruity, floral, and citrus notes. Overall, tamarind pulp addition during maturation, especially at 20 g/L, improved the sensory and chemical profile of Saison beers, supporting its use as a craft beer adjunct. Full article

Growing concern about the environmental impact of traditional packaging has driven the development of biodegradable edible films made from natural and functional biopolymers. Various by-products generated during harvesting can be subjected to valorization. Potato, a tuber with high starch content, and carrot, rich in β-carotene, represent important sources of polymeric matrix and bioactive compounds, respectively. Similarly, the use of biodegradable plasticizers such as pectin and polysaccharides derived from nopal mucilage is a viable alternative. This study assessed the physical and chemical properties of edible films composed of potato starch (PS), cactus mucilage (NM), carrot extract (CJ), citrus pectin (P), and glycerin (G). The films were produced by means of casting, with three mixtures prepared that had different proportions of CJ, P, and PS. The experiments were adjusted to a simple mixture design, and the data were analyzed in triplicate, using Pareto and Tukey diagrams at 5% significance. Results showed that adding CJ (between 5 to 6%), P (between 42 to 44%) and PS (between 43 to 45%) significantly affects all of the evaluated physical and chemical properties, resulting in films with luminosity values greater than 88.65, opacity ranging from 0.20 to 0.54 abs/mm, β-carotene content up to 26.11 μg/100 g, acidity between 0.22 and 0.31% and high solubility with a significant difference between treatments (p-value < 0.05) and low water activity (around of 0.47) (p-value > 0.05). These characteristics provide tensile strength up to 5.7 MPa and a suitable permeability of 1.6 × 10⁻² g·mm/h·m²·Pa (p-value < 0.05), which ensures low diffusivity through the film. Similarly, increasing the CJ addition enables the functional groups of the other components to interact. Using carrot extract and potato starch is a promising approach for producing edible films with good functional qualities but with high permeability. Full article

The transition to a circular economy and the pursuit of environmental sustainability are driving humanity to develop alternative technologies for producing a range of bioproducts. In this context, microbial-mediated fermentation processes have gained prominence. Although yeasts are well known for their ability to produce alcohols, they can also generate a wide range of value-added bioproducts. At the same time, microalgae emerge as an advantageous unconventional raw material, as their cultivation does not require arable land, thus avoiding competition with food production. To meet this demand, this study aimed to produce biocomposites through submerged fermentation using biomass from the microalgae Chlorella sp. Enzymatic hydrolysis was optimized using a 2² Central Composite Rotational Design (CCRD), with algal biomass and enzyme mass as independent variables. This step was followed by fermentation with the yeast Wickerhamomyces sp. UFFS-CE-3.1.2. The enzyme alpha amylase employed is of commercial origin, commonly used in the brewing industry, characterized by its easy accessibility and lower environmental impact compared to chemical hydrolysis methods. The results demonstrated that the combination of microalgae biomass with the enzyme preparation led to the production of several compounds of interest, such as highly active enzymes, mainly protease (560 U/mL), catalase (3381 U/mL), and peroxidase (277 U/mL), as well as other compounds, such as glycerol (32.5 g/L) and acetic acid (22.8 g/L). These products have wide industrial applications and a strong market demand, reinforcing the potential of the yeast–microalgae synergy for the sustainable production of high-value biocompounds, which represents a matrix of environmentally friendly products. Full article

Gastrodin is a bioactive component of traditional Chinese medicine, exhibiting anti-cancer, anti-inflammatory, antioxidant and neuroprotective properties. It has broad application prospects in health foods, pharmaceuticals and cosmetics. In recent years, the conversion of biomass-derived aldehydes into high-value-added chemicals has garnered widespread attention. In this study, gastrodin was biosynthesized via a dual-enzyme coupling system consisting of UGT_BL1-Δ60 and KpADH. Specifically, lignin-derived p-hydroxybenzaldehyde was used as the substrate. First, the glycosylation of p-hydroxybenzaldehyde by UGT_BL1-Δ60 yielded p-hydroxybenzaldehyde β-glucoside, generating the glycosylation reaction solution. Subsequently, bioreduction of the glycosylation product by KpADH produced gastrodin. Under the optimal reaction conditions (0.05 g/mL KpADH whole cells, 50 mM glucose, pH 7.5 and 30 °C) a gastrodin yield of 82.8% was achieved within 12 h. Moreover, both UGT_BL1-Δ60 and KpADH retained high catalytic activity after multiple reaction cycles. This study establishes a green and efficient biocatalytic approach for gastrodin synthesis, and also provides new insights into the high-value utilization of lignin. Full article

The commitment to the Sustainable Development Goals and the need for increasing the circularity of industrial processes call for the exploitation of byproducts to generate value-added chemicals in cost- and energy-advantageous processes. In this process simulation-based research, two technologies were evaluated for the synthesis of isoamyl acetate from fusel oil: (A) an indirect process, and (B) a direct process using reactive distillation. Aspen Hysys v14.0 was used for simulation. A sensitivity analysis was performed to identify the influence of operating parameters on product purity, isoamyl acetate recovery and productivity, and energy consumption. Technology B was found to be the most favorable, obtaining 22.27 kg/h of isoamyl acetate with a purity of 98%. The total consumption values of cooling water and heating were 24.33 kW and 24.50 kW, respectively. Based on the best conditions, a technical–economic analysis was performed that demonstrated the viability of the process, obtaining a net present value (NPV) of US$3,587,110/year, an internal rate of return (IRR) of 38.95% and a payback period (PP) of 5.05 years. If acid recirculation is considered in the process, an NPV of US$7,232,950, an IRR of 56.34%, and a PP of 3.56 years are obtained. Full article

Reducing CO₂ emissions from cement production is currently one of the major challenges faced by the cement industry. One approach to lowering these emissions is to reduce the clinker factor by incorporating alternative mineral additives into cement. Consequently, there is a growing interest in the use of copper slags (CSs) as supplementary cementitious materials. Therefore, this study investigates the properties of cements containing substantial amounts of copper slag (up to 60%) and, for comparison, the same proportions of granulated blast furnace slag. The inclusion of substantial amounts of CS results both from the lack of studies in this area and from the potential benefits associated with the utilization of larger quantities of copper slag. The chemical, phase, and particle size composition of CS and granulated blast furnace slag added to CEM I 42.5 cement from the Odra cement plant in amounts of 20%, 40%, and 60% by weight were compared. The pozzolanic activity index of the copper slag and the hydraulic activity index of the blast furnace slag were determined. The high pozzolanic activity of the CS was attributed to its high degree of vitrification (nearly 100%). In contrast, the lower hydraulic activity of the blast furnace slag was explained by its lower glass phase content (about 90% by mass). A gradual decrease in the total heat of hydration released within the first two days was observed with increasing slag content in the cement, slightly more pronounced for copper slags. However, at later stages (2–28 days), XRD analysis indicated higher hydration activity in cements containing copper slag, resulting from its strong pozzolanic reactivity. Cements with copper slag also showed slightly lower water demand compared to those with blast furnace slag. An increase in setting time was observed with higher slag content, more noticeable for blast furnace slag. The type and amount of slag in cement reduce both yield stress and plastic viscosity. Greater reductions were observed at higher slag content. Moreover, copper slag caused greater paste fluidity, attributed to the lower amount of fine particles fraction. The addition of slag decreased flexural and compressive strength in the early period (up to 7 days), this reduction being proportional to slag content. After 90 days, mortars containing 20% and 40% copper slag achieved strength values exceeding that of the reference mortar by 4%. In contrast, at a 60% CS content, a 5% decrease was observed, while for cement with 60% BFS the decrease was 11%. This indicates that a lower copper slag content in the cement (40%) is more favorable in terms of strength. Full article