Search Results (8,259)

Na⁺,K⁺-ATPase possesses a highly conserved glycine (G358 in the α3 isoform) that—together with a nearby isoleucine (I363 in α3)—is targeted by mutations causing some of the most severe neurological phenotypes of the clinical spectrum of α3-Na⁺,K⁺-ATPase mutations. The disease mutations α3-G358V and α3-I363N affect Na⁺ and K⁺ transport to an extent incompatible with cell growth. However, alanine replacement of the corresponding glycine G363 in the α1 isoform is compatible with cell growth, allowing the effects on Na⁺,K⁺-ATPase function to be addressed using enzymatic assays on plasma membranes isolated from transfected cells. Occlusion of Na⁺ appears to be defective in mutant G363A, resulting in a reduced rate of phosphorylation from ATP. Furthermore, the mutation displaces the major conformational equilibrium of Na⁺,K⁺-ATPase such that the K⁺-occluded state is destabilized and occluded K⁺ is released faster, thereby leading to accumulation of a non-productive state without bound Na⁺ or K⁺. The critical function of the glycine can be ascribed to a strategic location at the bending point between an α helix and a β strand, where it connects the catalytic ATP hydrolysis site in the cytoplasmic P domain with the ion-binding region in the membrane and coordinates important intramolecular domain movements during the Na⁺,K⁺-ATPase transport cycle. Full article

Research on hydrogen production by chemical methods has focused on combining metals to carry out the hydrolysis reaction under ambient conditions. In particular, aluminum and lithium metals were considered, with lithium used at low concentrations in order to activate aluminum. Under these conditions, the metals can react with water to obtain the maximum hydrogen yield. The main objective of this work was to prepare the lithium−aluminum alloy by mechanical milling and its chemical reaction with water to produce hydrogen under laboratory conditions. A high–energy Spex mill was used for material preparation and the time scheduled for alloys preparation was relatively short. Several techniques were used for its characterization, such as X–ray diffraction, scanning electron microscopy, gas chromatography, and low-temperature physical adsorption. According to the results, two phases were produced during the milling process when using 5% lithium. The volume of hydrogen generated was measured using a graduated burette. Depending on the volume obtained, the aluminum reacted to generate hydrogen with an efficiency of 95.24%. No additives or catalysts were used in material synthesis or hydrogen production. According to these results, the hydrogen does not require any purification because it is clean hydrogen and can therefore be used directly in fuel cells. Full article

The microbial valorization of agro-industrial residues is a promising strategy for sustainable bioprocesses and the development of a circular bioeconomy. In this study, mixed fruit peel waste was anaerobically fermented in a stirred-tank bioreactor using Wickerhamomyces sp. UFFS-CE-3.1.2 to produce organic acids and a multifunctional enzymatic bioproduct. During fermentation, sugars decreased from 6.51 to 0.22 g L⁻¹, leading to the formation of citric acid (7.65 g L⁻¹), ethanol (3.77 g L⁻¹), glycerol (0.53 g L⁻¹), and acetic acid (0.37 g L⁻¹). The accumulation of organic acids likely imposed metabolic stress on the yeast, triggering physiological responses that mitigate oxidative stress. Consequently, the resulting enzymatic extract exhibited high lipase activity (185.63 U mL⁻¹), late catalase induction (520.97 U mL⁻¹), and stable superoxide dismutase activity (50 U mL⁻¹). This enzymatic profile indicates the formation of a stress-adapted microbial system with potential applicability in processes involving lipid hydrolysis and oxidative mechanisms. The process was conducted without supplementation of synthetic medium and operated stably in a stirred-tank bioreactor. Overall, these results suggest a feasible microbial strategy for converting fruit waste into value-added bioproducts, contributing to the development of sustainable biotechnological processes. Full article

The identification of novel natural sources of bioactive peptides with multifunctional health-promoting properties remains a major challenge for the development of nutraceutical and therapeutic agents. Prosopis laevigata (mesquite), a plant of economic, medicinal, and nutritional relevance in Mexico, has been poorly explored as a source of protein-derived bioactive molecules. Therefore, this study evaluated the antioxidant, antimicrobial, cytotoxic, and enzymatic inhibitory activities of peptides obtained from the enzymatic hydrolysis of P. laevigata cotyledon proteins. The resulting hydrolysates exhibited significant antioxidant activity, for peptide fractions smaller and larger than 5 kDa, in the ABTS and FRAP assays. Cytotoxic activity against HepG2 liver cancer cells was observed at high peptide concentrations (8 mg/mL). Additionally, the peptides inhibited the growth of Staphylococcus aureus but showed no activity against Escherichia coli. The peptides also displayed partial inhibition of α-amylase activity, with peptides <5 kDa exhibiting competitive inhibition and peptides >5 kDa showing a mixed inhibition pattern. Overall, these findings highlight P. laevigata seeds as a promising source of multifunctional bioactive peptides with potential applications in functional foods and health-related biotechnological developments. Full article

Oxidative stress generates oxidized phospholipids (OxPLs) that alter membrane structure and inflammatory lipid signaling, yet the underlying biophysical mechanisms remain poorly understood. Here, we examine how two structurally distinct truncated oxidized phosphatidylcholines (OxPCs), 1-palmitoyl-2-(5′-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC) and 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphocholine (PGPC), remodel membrane lateral organization and regulate secretory phospholipase A₂ (sPLA₂) activity. Large unilamellar vesicles composed of sphingomyelin, cholesterol, and either monounsaturated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or polyunsaturated 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (PDPC) were used to reconstitute the liquid-ordered/liquid-disordered (L_o/L_d) phase coexistence characteristic of eukaryotic plasma membranes. Fluorescence spectroscopy revealed that OxPLs modulate lipid packing and nanodomain organization in a structure- and composition-dependent manner. POVPC promoted pronounced membrane ordering and L_o domain stabilization compared with PGPC, particularly in monounsaturated membranes with low cholesterol content. In contrast, PDPC-containing membranes, especially at elevated cholesterol, exhibited enhanced structural resilience to OxPL-induced perturbations. These biophysical changes were associated with distinct functional outcomes. Notably, the relationship between membrane structural parameters and sPLA₂ activity was not linear, indicating a decoupling between bulk membrane properties and enzymatic response. sPLA₂ activity was linked to membrane lateral organization: the size of L_o domains modulate hydrolysis by influencing the physicochemical properties of L_o/L_d interfaces, which may represent preferential sites for enzyme activation. Consistent with this, POVPC reduced sPLA₂ activity through stabilization of ordered domains at both low and high cholesterol, while PGPC enhanced hydrolysis at high cholesterol. Importantly, PDPC-containing membranes attenuated sPLA₂ activity and exhibited a protective effect against OxPC-induced enzymatic activation. Together, these findings identify membrane lateral organization as a key regulator of sPLA₂ function and provide mechanistic insight into how oxidative stress can differentially modulate inflammatory lipid signaling depending on membrane composition. This work highlights membrane organization as an active determinant of enzyme activity and a potential target in pathologies associated with oxidative stress, including atherosclerosis, neuroinflammation, and metabolic disease. Full article

The rapid expansion of edible insect production has focused primarily on rearing, processing efficiency, safety, and nutritional composition, while the slaughter of insects has received comparatively little scientific and ethical scrutiny. This narrative review examines insect slaughter as a critical control point linking bioethics, physiology, and ingredient quality. The review synthesizes evidence from neurobiology, food science, and processing studies to evaluate how commonly used slaughter methods interact with biological aspects of insects. Existing literature shows that slaughter techniques influence protein stability and hydrolysis, lipid oxidation, antioxidant retention, techno-functional properties such as emulsification and gelation, as well as sensory attributes and consumer acceptance. Available evidence suggests that methods designed to rapidly suppress metabolic activity may be associated with improved preservation of certain nutritional and functional parameters, although findings remain species- and context-dependent. The review further highlights major knowledge gaps, including the lack of species- and life-stage-specific welfare indicators and standardized assessment protocols. Overall, the findings support the need to reconceptualize insect slaughter as a strategic upstream decision rather than a neutral processing step. Integrating ethical considerations with nutritional, functional, and regulatory perspectives is essential for establishing science-based standards and ensuring the responsible development of edible insect-based food and feed systems. Full article

The present study aimed to investigate the migration of potentially hazardous compounds from plastic food packaging into edible oils, bottled water and soft drinks available on the market in the Republic of Moldova. GC–MS screening was applied to identify plastic additives and unintentionally added substances (NIAS). The influence of key extraction parameters, including solvent type, extraction time, pH, alcohol content and sugar concentration, was systematically investigated. The optimized procedure demonstrated satisfactory analytical performances, with recoveries ranging from 81 to 96%, repeatability below 5% and detection limits between 0.006 and 0.01 mg/L. To allow a comprehensive assessment of total phthalate contamination, an additional analytical approach based on the hydrolysis of phthalate esters and the determination of o-phthalic acid using capillary electrophoresis with spectrophotometric detection was proposed. The method showed a linearity range of 0.1–5.0 mg/L and a limit of quantification of 0.07 mg/L. The combined chromatographic and hydrolysis-capillary electrophoresis approaches provide a reliable tool for the integrated determination and evaluation of phthalate residues in aqueous-alcoholic systems and beverages, accessible to laboratories performing food quality control. Full article

Anaerobic digestion (AD) plays an important role in the circular bioeconomy by converting organic waste into renewable methane and nutrient-rich fertilizer. However, consistent, high-quality biomethane production is hindered by four main factors: hydrolysis limitations, fluctuating feedstock quality, microbial instability, and the high cost/energy demand of purification. This review explores three key areas that improve biomethane production: (i) process intensification (pretreatments and advanced reactors), (ii) microbial regulation through additives, and (iii) biogas upgrading for pipeline use. Anaerobic digestion can be greatly improved by combining thermal or hybrid pretreatments, staged digestion, high-solids technology, and electrochemical systems. These methods speed up hydrolysis and help the system handle higher amounts of organic material more effectively. However, actual performance benefits depend on specific substrate characteristics, heat integration, and control complexity. Optimizing the C:N ratio, buffering capacity, and trace-element supplementation, while simultaneously diluting toxic inhibitors, makes co-digestion an effective and adaptable approach to enhancing anaerobic digestion processes. Additives like carbon, iron nanoparticles, enzymes, and buffers can optimize digestion, but their performance is highly dependent on dosage and substrate. Additionally, they lack validation in long-term, industrial-scale applications. Conventional physicochemical techniques continue to be standard for generating high-quality biomethane, but biological methanation and microalgal systems are playing a growing role in integrating Power-to-Gas technology and using CO₂ efficiently. Critical research needs to focus on four areas: (1) standardized reporting metrics, (2) AI-enabled monitoring and control, (3) coupled techno-economic and life-cycle analysis (TEA-LCA), and (4) long-term pilot or full-scale validation. Overall, comprehensive optimization of the entire flow is more effective than improving isolated parts. Full article

The enzymatic saccharification of cellulose remains a key step in biomass conversion processes, often influenced by enzyme stability, distribution, and accessibility at solid–liquid interfaces. Immobilization of cellulolytic enzymes on nanostructured supports has been proposed as a strategy to modulate catalytic behavior; however, the relationship between enzyme loading and catalytic response remains insufficiently understood. In this study, CuO-based nanobiocatalysts were prepared through controlled cellulase immobilization and systematically evaluated under defined experimental conditions. Structural and physicochemical characterization was performed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and integrated thermal analysis (TGA–DTG–DSC), enabling a comparative assessment of the analyzed systems. SEM analysis showed that the average particle diameter increased from 39.5 ± 14.8 nm (CuO nanoparticles) to 95.6 ± 21.8 nm (NPI10), 106.6 ± 27.7 nm (NPI15), and 113.5 ± 23.1 nm (NPI20), indicating progressive variations in particle organization with increasing enzyme loading. Catalytic performance was evaluated through enzymatic hydrolysis of cellulose filter paper as a model substrate, with products quantified by HPLC at a representative reaction time. The system prepared at lower enzyme loading (NPI10) exhibited product formation comparable to that of the free enzyme, with apparent average glucose formation values of 1.054 and 1.047 mg·mL⁻¹·h⁻¹, respectively. In contrast, higher immobilization levels were associated with reduced catalytic output. Across all systems, glucose was the predominant product, with negligible accumulation of intermediate oligomers under the evaluated conditions. These results indicate that increasing enzyme loading does not correspond to proportional increases in product formation and highlight the influence of enzyme distribution and accessibility within the system. The combined structural and catalytic observations provide a controlled framework for evaluating how immobilization conditions influence system behavior in nanobiocatalytic systems. Full article

Lubricants are essential for water-based drilling fluids. Catechol-based lubricants provide improved lubrication performance owing to their strong adhesion ability through the formation of coordination bonds inspired by mussel adhesion. However, the conventional synthetic ester and amide lubricants suffer from loss of adhesive capability due to hydrolysis and autoxidation. Inspired by mussels and melanin biosynthesis, a biomimetic strategy was developed to synthesize a high-adhesion lubricant with good stability via thiol-quinone Michael addition to restore and stabilize the catechol moiety. Bisphenol A was oxidized to the corresponding quinone using 2-iodoxybenzoic acid. Subsequent Michael addition reaction with 1-octadecanethiol produced a thiol-functionalized lubricant containing catechol moieties and long alkyl chains through an S-catecholyl linkage. Biomimetic principles were incorporated into both the molecular structure and the synthetic route, emulating the structural and functional features of mussel adhesion and melanin biosynthesis. Octadecanethiol provided sulfur-containing extreme-pressure functionality and contributed to strong adsorption on metal surfaces. The molecular structure was confirmed by FTIR, ¹H NMR, and ¹³C NMR. The thiol-functionalized lubricant formed strong coordination with Fe³⁺ and Fe²⁺ ions across a wide pH range, with an apparent complexation stoichiometry of 1:1 and conditional stability constants of 4.09 and 5.02, respectively. Bis-coordination formed a cross-linking network. It exhibited good resistance toward autoxidation and thermal stability up to 350 °C. In bentonite-based drilling fluids, the extreme pressure lubrication coefficient and adhesion coefficient at a 1% addition were 0.06 and 0.07, respectively. The coefficient of friction and wear scar diameter were 0.09 and 0.63 mm, respectively. The increased contact angle confirmed strong adsorption of the lubricant on metal surfaces. The lubricant combined strong adhesion, high stability, and excellent compatibility with drilling fluids, highlighting its potential as an advanced biomimetic lubricant. This biomimetic thiol-quinone addition strategy provides an effective approach to overcome the instability of conventional catechol-based lubricants. Full article

The efficient resource utilization of duck manure and agricultural/forestry wastes (AFW) plays a significant role in environmental protection and promoting the sustainable development of the economy and society. This study examined the effects of hydrochar derived from AFW in the anaerobic digestion (AD) process, determining the optimal addition ratio. This research systematically investigated the impact of hydrochar on methane yield, as well as changes of short-chain fatty acids, microbial community dynamics, and metabolic pathways during AD of duck manure. The underlying mechanisms were clarified by metagenomic and metabolomic analyses. This experiment used duck manure as substrate and added hydrochar of four different dosage levels. Laboratory batch tests ran for 32 days at 37 ± 0.5 °C, with three parallel samples for each group. The results indicated that hydrochar additive significantly improved methane yield (p < 0.05), with a maximum increase of 27.13% at an optimal dosage of 10.91 g·L⁻¹. This amendment enhanced the abundance of Firmicutes, Bacteroidota, Chloroflexota, Halobacteriota, and Methanosarcina significantly. Compared to the control group, the abundances of functional genes involved in hydrolysis, acidogenesis, and acetogenesis pathways increased by 28–254% in the optimal treatment group, with methanogenesis-related genes showing a 16–155% enhancement (p < 0.05). Full article

Brewer’s spent grain (BSG) is an abundant lignocellulosic by-product whose valorization can support circular bioeconomy strategies. This study evaluated BSG bioconversion by Aspergillus oryzae ATCC 10124 under solid-state fermentation (SSF) to produce lignocellulolytic enzymes and release second-generation (2G) sugars relevant to biorefinery applications. SSF was monitored over 0–10 days, and FPase, endo-cellulase, β-glucosidase, xylanase, mannanase, amylase, and ligninolytic enzyme activities were quantified. Enzymatic crude extracts were further assessed in SDS-PAGE analysis. Glucose, cellobiose, xylose and arabinose release and consumption were tracked throughout fermentation, and substrate transformation was supported by FTIR. The secretome exhibited a predominantly hydrolytic profile, with maximal hemicellulolytic and cellulolytic activity around days 2–4, as well as sustained amylase activity. Ligninolytic activity was not detected. Sugar profiles indicated rapid early hydrolysis of glucose, followed by progressive pentose release. The stabilization and decline were consistent with fungal uptake. Changes in the carbohydrate fingerprint and SDS–PAGE banding supported structural polysaccharide remodeling and hydrolytic protein secretion. Thus, this SSF platform confirmed certain potential for low-cost cellulolytic and hemicellulolytic enzyme generation. However, because sugar accumulation was temporary and followed by consumption, this system is best interpreted as a biological pretreatment and enzyme-generation step that supports subsequent downstream valorization. Full article

Traditional chemical hair dyes are associated with potential health risks, while botanical alternatives are often hampered by poor stability and limited color longevity. In this study, discarded squid ink was used to prepare bionic hair colorants of high performance. By synergizing ultrasound disruption with enzymatic hydrolysis, the crude ink aggregates were transformed into highly uniform squid ink melanin nanoparticles (SIMNPs) with size and zeta potential of ~174 nm and −37.5 mV, respectively. This effectively improved the solubility but reduced the steric limitation of natural melanin. To overcome the weak affinity between melanin and human hair, a biomimetic interface where Fe(III) ions act as supramolecular bridges was further engineered to stably bind the SIMNPs to hair keratin. Under optimized conditions (pH 8.0, 45 °C, and 80 min), the dyed hair achieved a natural deep black with a total color difference (ΔE*) of 68.79 ± 0.29, which was maintained at 63.19 ± 0.27 even after 13 consecutive water washing cycles. Unlike destructive oxidative dyes, this SIMNP dyeing system assisted by coordination-driven assembly preserved the native α-helical architecture and disulfide bond networks of hair keratin. Furthermore, the deposited SIMNP layer effectively protected hair fibers from ultraviolet (UV) damage due to its powerful UV-shielding capacity. Crucially, in vitro and in vivo evaluations confirmed the exceptional biosafety of this formulation, demonstrating robust cellular tolerance and absence of murine skin irritation. The work demonstrates a green, low-damage paradigm for the development of bio-based hair colorants of high performance and presents a promising pathway for the high-value utilization of marine by-products. Full article

To develop cosmetic film-forming agents that combine sustainability with functionality, this study synthesized a series of bio-based polyols using epoxidized soybean oil (ESO) as raw material through acid-catalyzed ring-opening reactions. These polyols partially replaced petroleum-based polyols and reacted with isophorone diisocyanate (IPDI). By incorporating β-cyclodextrin (β-CD), a water-based polyurethane (CPS-ESO) was successfully developed that combines degradability with active ingredient delivery capability. Experiments demonstrated that the resulting CPS-M film exhibits excellent water repellency (contact angle 66.7°), mechanical properties (tensile strength 14.21 MPa, elongation at break 229.42%), adhesion (Level 0), and breathability, while displaying controllable degradation behavior under both enzymatic and alkaline hydrolysis conditions. Due to the cavity structure of β-cyclodextrin, this material efficiently loaded resveratrol (RES) at a loading rate of 0.16%. Formulated into a setting spray (F1), the product demonstrated outstanding makeup longevity (lowest ΔE value after water/sweat immersion), anti-friction performance (ΔE value after friction only one-third of the control group), and antioxidant activity (DPPH scavenging rate of 86.25%), with RES remaining stable under high-temperature storage conditions. This study provides new insights for designing green multifunctional cosmetic film-forming agents. Full article

Nepetalactone (NL) is a volatile iridoid monoterpene widely used in biopesticidal and repellent applications, yet its toxicokinetic behavior and metabolic fate as a pure compound remain poorly characterized. This study aimed to provide an integrated toxicokinetic evaluation of NL by combining in silico absorption, distribution, metabolism, excretion and toxicity (ADMET) modeling with in vitro metabolism assays using rat and human liver microsomes, supported by UHPLC–MS/MS analysis for metabolite identification. The in silico biotransformation predicted extensive phase I oxidation followed by phase II conjugation, while ADMET predictions indicated low systemic persistence and limited toxicological concern for most metabolites. The performed in vitro microsomal assays confirmed the in silico prediction by a rapid and time-dependent NL metabolism via both oxidative (86% reduction in NL concentration after 120 min) and conjugative (89% reduction in NL concentration after 120 min) pathways in rat and human systems, with comparable depletion kinetics between species. UHPLC–MS/MS enabled the identification of multiple phase I and phase II metabolites, pointing to pronounced interspecies differences in conjugative metabolism. In this sense, while oxidoreduction and hydrolysis reactions were consistent with previously reported iridoid metabolism. This study suggests the possible formation of previously unreported amino acid-related derivatives, although these require further confirmation. Overall, these findings advance the understanding of NL biotransformation, propose a new, previously unknown, metabolic pathway for iridoids, and provide relevant data to support human health and environmental risk assessment frameworks. Full article