Search Results (157)

The aim of our work is to theoretically model the conversion of C6 and C5 carbohydrates derived from lignocellulosic biomass waste into C1–C5 carboxylic acids such as levulinic, oxalic, lactic, and formic acids. Understanding the mechanism of these processes will provide the necessary knowledge to better plan the structure of zeolite. In this article, we focus on the theoretical modeling of two carbohydrates, representing C5 and C6, namely xylose and fructose, into levulinic acid (LE) and formic acid (FA). The modeling was carried out with the participation of Na-BEA zeolite in a hierarchical form, due to the large size of the carbohydrates. The density functional theory (DFT) method (StoBe program) was used, employing non-local generalized gradient-corrected functions according to Perdew, Burke, and Ernzerhof (RPBE) to account for electron exchange and correlation and using the nudged elastic band (NEB) method to determine the structure and energy of the transition state. The modeling was performed using cluster representations of hierarchical Na-Al₂Si₁₂O₃₉H₂₃ and ideal Al₂Si₂₂O₆₄H₃₄ beta zeolite. However, to accommodate the size of the carbohydrate molecules in reaction paths, only hierarchical Na-Al₂Si₁₂O₃₉H₂₃ was used. Sodium ions were positioned above the aluminum centers within the zeolite framework. Full article

Background: Dietary patterns impact blood pressure (BP) levels, but the potential impact of replacing specific types of fats with proteins or carbohydrates, in isocaloric models, on BP remains unclear. Objective: This study evaluates the longitudinal association between the substitution of different types of fats with proteins or carbohydrates and changes in BP in a Mexican population. Methods: We analyzed data from 1448 adults (mean age at baseline: 45 years; 73.3% women) from the Health Workers Cohort Study, followed over 13 years. Trained personnel measured systolic (SBP) and diastolic (DBP) blood pressure following standard procedures and techniques at baseline and follow-up. Macronutrient intake was assessed with a validated semi-quantitative food frequency questionnaire. Generalized Estimating Equations (GEE) for hypertension and fixed-effects linear regression for BP were conducted using isocaloric substitution models. Each estimate reflects the effect of a 3% energy substitution of specific fats for carbohydrates or proteins. Results: Substituting 3% of energy intake of polyunsaturated fat (PUFA) in place of vegetable protein (β = −2.94, 95% CI: −5.02, −0.86), animal protein (β = −2.68, 95% CI: −4.73, −0.63), low glycemic index (LGI) carbohydrates (β = −2.63, 95% CI: −4.40, −0.86), and high glycemic index (HGI) carbohydrates (β = −2.52, 95% CI: −4.31, −0.74) was associated with a significant reduction in SBP. Substituting 3% of the energy intake of PUFA in place of different types of carbohydrates was associated with lower odds of hypertension. PUFA was not associated with changes in DBP. Conclusions: Our findings suggest that exchanging PUFA for carbohydrates or proteins is associated with reduced SBP and a lower risk of hypertension, highlighting the importance of macronutrient composition independent of total energy intake and other fat types, which may have a substantial impact at the population level. Full article

The genus Musa L. is one of the most important genera worldwide due to its use in food as a source of carbohydrates. A morphological characterization was performed to evaluate the potential of 100 accessions of Musa spp. from the Amazon region of Ecuador, applying 73 qualitative and quantitative descriptors in addition to the ecogeographic characterization. The multivariate analyses identified four large groups: The first is composed of the Musa AAB Simmonds ecotype “Hartón Plantain” and the “Cuerno Clone”. The second group is composed of the Musa acuminata Colla ecotype “Orito”. The third group is composed of the Musa acuminata ecotype “Malay plantain or red plantain”; and the fourth group is composed of the Musa × paradisiaca L. AAB ecotype “Barraganete” and banana or banana materials and the Musa AAB Simmonds ecotype “Plátano Dominico”. The qualitative descriptors with the highest discriminant value were the shape of the ♂ floret bud, the appearance of the rachis, and the pigmentation of the compound tepal, and the quantitative discriminant characters were the height of the pseudostem, the length of the leaf blade, the width of the leaf blade, and the weight of the raceme. The analysis with CAPFITOGEN of these 100 accessions through the ecogeographic characterization map identified 23 categories, highlighting category 20 with a coverage of 40.35%, which mainly includes the provinces of Orellana, Sucumbíos, part of Napo, Pastaza, and Morona Santiago. This category occurs within an annual temperature range between 21.6 °C and 27 °C, an apparent density of 1.25 to 1.44 g cm⁻³, and a cation exchange capacity (CEC) of 4 to 29 Cmol kg⁻¹. The morphological characterization of 100 Musa accessions revealed significant phenotypic variability, with four distinct morphological groups identified through cluster analysis. Key differences were observed in traits such as bunch weight, fruit length, and vegetative vigor. This variability highlights the potential of certain accessions for use in genetic improvement programs. The findings contribute valuable information for the efficient conservation, selection, and utilization of the Musa germplasm in Ecuadorian agroecosystems. The results demonstrate the existence of an important genetic variability in the INIAP Musa Germplasm Bank in the Ecuadorian Amazon region. Full article

The disposal of low-level and intermediate-level radioactive solid waste has aroused widespread concern. In this work, the pyrolysis characterizations of simulated radioactive solid waste, cotton gloves (CG), stain removal cloths (SRC), plastic bags (PB), shoe covers (SC), and ion exchange resins (IER), were analyzed using thermogravimetric analysis, Thermogravimetric–Fourier Transform Infrared Spectrometry–Mass Spectrometry (TG-FTIR-MS) and Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS). The main mass loss stages of CG, SRC, PB, SC, and IER were 240–500 °C, 210–500 °C, 400–550 °C, 180–610 °C, and 25–700 °C, respectively. The average activation energies calculated by three iso-conversional methods were 184.09–211.46 kJ/mol, 172.33–180.85 kJ/mol, 264.63–268.01 kJ/mol, 150.49–184.36 kJ/mol, and 150.72–151.66 kJ/mol, respectively. Pyrolysis of CG and SRC mainly produced CO₂ and oxygenated compounds. SC generated large amounts of HCl during pyrolysis. Combined with rapid pyrolysis analysis, it was shown that CG and SRC mainly produced carbohydrates, aliphatic hydrocarbons, and aromatics. The pyrolysis products of SC mainly consisted of aliphatic hydrocarbons, aromatics, and acids. The pyrolysis products of PB were mainly olefins and alcohols. IER produced large amounts of aromatics during rapid pyrolysis. Specifically, the pyrolysis of IER generated some SO₂. This work provides a theoretical basis and data support for the treatment of mixed combustible radioactive waste. Full article

Understanding the molecular mechanisms of cellobiohydrolase I (CBHI), a key enzyme in cellulase complexes, is crucial for developing efficient enzymes for the degradation of lignocellulosic biomasses (LCB). Building on our previous discovery that Chaetomium thermophilum CBHI (C-CBH) exhibits significantly higher specific activity than Trichoderma reesei CBHI (T-CBH), systematic domain-swapping experiments were conducted to elucidate the structural determinants of catalytic efficiency in CBHI. Herein, the carbohydrate-binding modules (CBM) of the CBHIs from Trichoderma reesei (T-CBH) and Chaetomium thermophilum (C-CBH) were interchanged and to obtain two chimeric mutants TC-CBH and CT-CBH. These four CBHs were expressed in T. reesei, and the enzyme properties were analyzed. Comparative characterization revealed that while module exchange preserved native temperature/pH adaptability, it significantly altered substrate specificity and catalytic performance. The CT-CBH variant was identified as the most efficient biocatalyst, exhibiting four key advantages over T-CBH: (1) protein expression levels that far exceed those of T-CBH, (2) specific activity enhanced by 2.6-fold (734.5 U/μM vs. 282.5 U/μM on MU-cellobiose), (3) superior degradation capacities for filter paper (1.6-fold) and xylan, and (4) improved binding affinity for crystalline cellulose. These findings establish cross-species domain engineering as a viable strategy for creating high-performance cellulases, providing both mechanistic insights and practical solutions for lignocellulose degradation. Full article

Fructooligosaccharides (FOSs) are carbohydrates of high nutritional value with various prebiotic properties. Optimizing their production process is of significant interest for expanding commercial-scale production. This review discusses the properties and potential applications of FOSs, addressing production challenges and providing an economic market analysis. Bibliometric analysis of data concerning the functional properties, production, purification, and applications of FOSs revealed an over 87% increase in the number of worldwide publications from 2012 to 2022, rising from 88 to 165. Furthermore, contributions from ninety-three countries were identified up to 2024, with Brazil ranking first, with 326 publications. Furthermore, Aureobasidium sp. and Aspergillus sp. have shown the best results for FOS production, with reported conversion in the order of 0.66 g FOS/g sucrose. Nevertheless, the formation of by-products or co-products requiring separation from the medium remains a challenge. Activated carbon, cation exchange resins, and zeolites are highlighted as key adsorbents, with the adsorption process achieving FOS purity exceeding 90%. Furthermore, membrane technology is identified as a more efficient and promising separation method. Addressing these limitations will facilitate the further expansion of the growing global FOS market, promoting a sustainable approach and their integration with biorefineries, which can enable the development of a wider range of value-added products. Full article

Phosphorus (P) is essential for crop growth, but its complex behavior in tropical soils necessitates alternative management strategies, such as foliar supplementation. Foliar-applied nutrients act as biostimulants, enhancing stress tolerance and plant productivity. This study assessed the physiological responses of soybean to foliar application of soluble monoammonium phosphate (MAP; at a rate of 5 kg ha⁻¹ each application) at different phenological stages (two during vegetative stages V₄ and V₆ and two during reproductive stages R₁ and R₃ or all four stages) across two growing seasons in tropical field conditions. Key parameters analyzed included leaf nutrient content, photosynthetic pigments, Rubisco activity, carbohydrate content, gas exchange (photosynthetic rate, stomatal conductance, transpiration, water use efficiency, and carboxylation efficiency), oxidative stress markers, and productivity indicators (100-grain weight and grain yield). MAP application improved all parameters, particularly at R₁ and R₃. Total chlorophyll increased by 29.2% at R₁ and 30.0% when applied at all four stages, while the net photosynthetic rate rose by 15.8% and 18.4%, respectively. Water use efficiency improved by 20.0% at R₁ and all four stages, while oxidative stress indicators, such as H₂O₂ levels, decreased. Rubisco activity increased most at R₃ (46.0%) and all four stages (59.9%). Grain yield was highest with MAP spread at all four stages (12.3% increase), though a single application at R₁ still boosted yield by 7.4%, compared to the control treatment. Full article

The use of nickel (Ni) as a fertilizer remains a topic of debate, particularly in non-legume species, as Ni is required only in trace amounts for optimal plant function. Urea application in plants, whether foliar or root-based, relies on the urease enzyme to convert urea into NH_4⁺ and CO₂, with Ni serving as an essential cofactor. In this study, we conducted an experiment using a 2 × 2 factorial design, combining two urea concentrations [4% and 8% (w/v)] with the absence or presence of Ni (0.3 g L⁻¹ supplied as NiSO₄·6H₂O). Gas exchange parameters were measured two days after fertilization. We quantified urease enzyme activity, urea content, photosynthetic pigments, carbohydrates, and other nitrogenous metabolites. The presence of Ni during foliar urea fertilization significantly increased the photosynthetic rate and photosynthetic pigments, which we attributed to improved urea assimilation. The combination of urea and Ni enhanced urease activity, leading to higher levels of various nitrogenous metabolites. Ni positively influenced foliar urea assimilation, promoting its conversion into organic compounds, such as proteins, while mitigating the toxic effects associated with urea accumulation. Full article

Background/Objectives: Our studies have provided evidence for the alteration of exercise-induced metabolic responses by the intake of anthocyanin-rich New Zealand blackcurrant (NZBC) extract. In this secondary analysis of 10 studies, we examined the relationship between the pre-intervention exercise-induced respiratory exchange ratio and the blackcurrant-induced respiratory exchange ratio and substrate utilisation during exercise. Methods: Metabolic data of seven cohort and three case studies with females (n = 46) and males (n = 71), from recreationally active to ultra-endurance trained individuals that were dosed with different intake durations (acute to two-week intake) and dosages (105 to 420 mg of anthocyanins) of NZBC extract for walking-, running-, and cycling-induced effects, were included in the secondary analysis. Results: There was a strong positive correlation between the pre-intervention and blackcurrant-induced respiratory exchange ratio for females (Pearson r: 0.7972, p < 0.0001) and males (Pearson r: 0.8674, p < 0.0001). A moderate positive correlation was obtained for the relationship between the pre-intervention respiratory exchange ratio and changes in fat oxidation for females (Pearson r: 0.5311, p = 0.0001) and males (Pearson r: 0.3136, p = 0.002). In addition, a moderate negative correlation was obtained for the relationship between the pre-intervention respiratory exchange ratio and changes in carbohydrate oxidation for females (Pearson r: −0.3017, p = 0.0393) and males (Pearson r: −0.3327, p < 0.001). There were no differences between females and males in the changes of the exercise-induced metabolic responses to the intake of New Zealand blackcurrant extract. Conclusions: Our secondary analysis of the data in studies on the effects of New Zealand blackcurrant extract suggests that the metabolic response of individuals to the intake of New Zealand blackcurrant extract depends partly on the pre-intervention respiratory exchange ratio, with the majority of individuals showing enhanced exercise-induced fat oxidation and lower exercise-induced carbohydrate oxidation. However, a divergent metabolic response seems possible such that individuals with a very low intrinsic respiratory exchange ratio may more likely experience lower fat oxidation and higher carbohydrate oxidation with the intake of New Zealand blackcurrant. Individuals with a high intrinsic respiratory exchange will more likely experience higher fat oxidation and lower carbohydrate oxidation with the intake of New Zealand blackcurrant. Future work is required to examine the factors and mechanisms for the individual variation of the response of exercise-induced substrate utilisation relative to the intake of anthocyanin-rich New Zealand blackcurrant extracts. Full article

Salt stress is an important factor affecting the growth and development of rice, and prohexadione calcium (Pro-Ca) plays an important role in alleviating rice salt stress and improving rice yield. However, there are few studies on how Pro-Ca improves rice yield under salt stress by regulating the source–sink metabolism. In this study, we used Guanghong 3 (salt-tolerant variety) and Huanghuazhan (salt-sensitive variety) as experimental materials to investigate the dynamic changes in the synthesis and partitioning of nonstructural carbohydrates among source–sink, the dynamic changes in related enzyme activities, the effects of the source–sink metabolism on yield in rice under salt stress and the effect of Pro-Ca during the filling period. The results of this study showed that Pro-Ca improved photosynthetic efficiency by increasing leaf photosynthetic gas exchange parameters and other stomatal factors on the one hand and, on the other hand, promoted sugar catabolism and reduced sugar synthesis by increasing leaf sucrose synthase activity and decreasing sucrose phosphate synthase activity, alleviating the inhibitory effect of high concentrations of sugars in the leaves on photosynthesis. Meanwhile, Pro-Ca promotes the transport of sugars from source (leaves) to sink (seeds), increases the sugar content in the seeds, and promotes starch synthesis in the seeds by increasing starch phosphorylase, which promotes seed filling, thus increasing the number of solid grains on the primary and secondary branches of the panicle in rice, increasing the 1000-grain weight, and ultimately increasing the seed setting rate and yield. These results indicated that Pro-Ca alleviated the inhibitory effect of salt stress on rice leaf photosynthesis through stomatal and non-stomatal factors. Meanwhile, Pro-Ca promotes the transport of rice sugars from source to sink under salt stress, regulates the source–sink relationship during the filling period of rice, promotes starch synthesis, and ultimately improves rice yield. Full article

Nowadays, agricultural biomass is one the most valuable sources of natural polysaccharides. In addition to primary agricultural goods, agricultural waste is abundant, diverse, and renewable and can also be utilized as raw material for the production of polysaccharides and their derivatives. The extraction and purification of agri-waste-derived polysaccharides involves multiple processes that can vary depending on the type of raw material and the specific polysaccharides targeted. This study proposes a particular pathway from corn waste to hemicellulosic polysaccharides, which involves alkaline treatment and several physicochemical separation/purification phases using precipitation and ion exchange resins (Purolite A400, Purolite A100+, Purolite C100H). The ion exchange separation stage was optimized to retain most of the acid-soluble lignin derivatives from the extraction liquors. The process parameters considered for optimization included the solid (resin) liquid (black liquor pH 4.5) ratio, contact time, and temperature. These ranged from 0.05 to 0.15 g·mL⁻¹, 30 to 180 min, and 20 to 50 °C, respectively. The chemical composition of the separated hemicelluloses varied from 44.43 to 75.28% for xylan, 2.43 to 3.93% for glucan, 1.86 to 2.44% for galactan and 8.93 to 12.68% for arabinan. The total carbohydrate content increased from 57.65 to 96.3%. Full article

Maize leaf blight (MLB), caused by the fungus Bipolaris maydis, is an important disease affecting maize production. In order to minimize the use of fungicides in agriculture, nutrient-based resistance inducers may become a promising alternative to manage MLB. The goal of this study was to investigate the potential of Semia^® (zinc (20%) complexed with a plant-derived pool of polyphenols (10%)) to hamper the infection of maize leaves by B. maydis by analyzing their photosynthetic performance and carbohydrate and antioxidative metabolism, as well as the expression of defense-related genes. Plants were sprayed with water (control) or Semia^® (referred to as induced resistance (IR) stimulus hereafter) and not inoculated or inoculated with B. maydis. The mycelial growth and conidium germination were significantly reduced by the IR stimulus in vitro. The MLB severity was significantly reduced by 76% for IR-stimulus-sprayed plants compared to plants from the control treatment. For infected and IR-stimulus-sprayed plants, the glucose, fructose, sucrose, and starch concentrations were significantly higher compared to inoculated plants from the control treatment. The activity levels of superoxide dismutase, ascorbate peroxidase, catalase, and glutathione reductase were significantly higher for the IR-stimulus-sprayed plants compared to plants from the control treatment. Less impairment on the photosynthetic apparatus (higher values for leaf gas exchange (rates of net CO₂ assimilation, stomatal conductance to water vapor, and transpiration) and chlorophyll a fluorescence (variable-to-maximum Chl a fluorescence ratio, photochemical yield, and yield for dissipation by down-regulation) parameters)) along with a preserved pool of chlorophyll a+b and carotenoids were noticed for infected and IR-stimulus-sprayed plants compared to infected plants from the control treatment. The defense-related genes IGL, CHS02, PR1, PAL3, CHI, and GLU were strongly up-regulated in the leaves of IR-stimulus-sprayed and infected plants compared to infected plants from the control treatment. These findings highlight the potential of using this IR stimulus for MLB management. Full article

The present work aimed to investigate the effect of increasing CO₂ concentration on the growth, productivity, grain quality, and biochemical changes in quinoa and amaranth plants. An experiment was conducted in open chambers (OTCs) to evaluate the responses of these species to different levels of CO₂ {a[CO₂] = 400 ± 50 μmol mol⁻¹ CO₂ for ambient CO₂ concentration, e[CO₂] = 700 ± 50 μmol mol⁻¹ CO₂ for the elevated CO₂ concentration}. Growth parameters and photosynthetic pigments reflected changes in gas exchange, saccharolytic enzymes, and carbohydrate metabolism when plants were grown under e[CO₂]. Furthermore, both species maintained most of the parameters related to gas exchange, demonstrating that the antioxidant system was efficient in supporting the primary metabolism of plants under e[CO₂] conditions. Both species were taller and had longer roots and a greater dry weight of roots and shoots when under e[CO₂]. On the other hand, the panicle was shorter under the same situation, indicating that the plants invested energy, nutrients, and all mechanisms in their growth to mitigate stress in expense of yield. This led to a reduction on panicle size and, ultimately, reducing quinoa grain yield. Although e[CO₂] altered the plant’s metabolic parameters for amaranth, the plants managed to maintain their development without affecting grain yield. Protein levels in grains were reduced in both species under e[CO₂] in the average of two harvests. Therefore, for amaranth, the increase in CO₂ mainly contributes to lowering the protein content of the grains. As for quinoa, its yield performance is also affected, in addition to its protein content. These findings provide new insights into how plants C3 (amaranth) and C4 (quinoa) respond to e[CO₂], significantly increasing photosynthesis and its growth but ultimately reducing yield for quinoa and protein content in both species. This result ultimately underscore the critical need to breed plants that can adapt to e[CO₂] as means to mitigate its negative effects and to ensure sustainable and nutritious crop production in future environmental conditions. Full article

Background: Acute and chronic pre-traumatic cigarette smoke exposure increases morbidity and mortality after trauma and hemorrhage. In mice with a genetic deletion of the H₂S-producing enzyme cystathione-γ-lyase (CSE^−/−), providing exogenous H₂S using sodium thiosulfate (Na₂S₂O₃) improved organ function after chest trauma and hemorrhagic shock. Therefore, we evaluated the effect of Na₂S₂O₃ during resuscitation from blunt chest trauma and hemorrhagic shock on CSE^−/− mice with pre-traumatic cigarette smoke (CS) exposure. Since H₂S is well established as being able to modify energy metabolism, a specific focus was placed on whole-body metabolic pathways and mitochondrial respiratory activity. Methods: Following CS exposure, the CSE^−/− mice underwent anesthesia, surgical instrumentation, blunt chest trauma, hemorrhagic shock for over 1 h (target mean arterial pressure (MAP) ≈ 35 ± 5 mmHg), and resuscitation for up to 8 h comprising lung-protective mechanical ventilation, the re-transfusion of shed blood, fluid resuscitation, and continuous i.v. noradrenaline (NoA) to maintain an MAP ≥ 55 mmHg. At the start of the resuscitation, the mice randomly received either i.v. Na₂S₂O₃ (0.45 mg/g_bodyweight; n = 14) or the vehicle (NaCl 0.9%; n = 11). In addition to the hemodynamics, lung mechanics, gas exchange, acid–base status, and organ function, we quantified the parameters of carbohydrate, lipid, and protein metabolism using a primed continuous infusion of stable, non-radioactive, isotope-labeled substrates (gas chromatography/mass spectrometry) and the post-mortem tissue mitochondrial respiratory activity (“high-resolution respirometry”). Results: While the hemodynamics and NoA infusion rates did not differ, Na₂S₂O₃ was associated with a trend towards lower static lung compliance (p = 0.071) and arterial PO₂ (p = 0.089) at the end of the experiment. The direct, aerobic glucose oxidation rate was higher (p = 0.041) in the Na₂S₂O₃-treated mice, which resulted in lower glycemia levels (p = 0.050) and a higher whole-body CO₂ production rate (p = 0.065). The mitochondrial respiration in the heart, kidney, and liver tissue did not differ. While the kidney function was comparable, the Na₂S₂O₃-treated mice showed a trend towards a shorter survival time (p = 0.068). Conclusions: During resuscitation from blunt chest trauma and hemorrhagic shock in CSE^−/− mice with pre-traumatic CS exposure, Na₂S₂O₃ was associated with increased direct, aerobic glucose oxidation, suggesting a switch in energy metabolism towards preferential carbohydrate utilization. Nevertheless, treatment with Na₂S₂O₃ coincided with a trend towards worsened lung mechanics and gas exchange, and, ultimately, shorter survival. Full article

Obligate anaerobic beer spoilage bacteria have been a menace to the brewing industry for several decades. Technological advances in the brewing process aimed at suppressing aerobic spoilers gave rise to problems with obligate anaerobes. In previous studies, the metabolic spectrum of Pectinatus and Megasphaera species has been described, but their metabolism in the beer environment remains largely unknown. We used high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GCMS) to further characterize beer spoiled by 30 different strains from six beer-spoiling species of Pectinatus and Megasphaera (P. cerevisiiphilus, P. frisingensis, P. haikarae, M. cerevisiae, M. paucivorans, and M. sueciensis). We detected differences in carbohydrate utilization and the volatile organic compounds (volatilome) produced during beer spoilage by all six species. We were able to show that glycerol, one of the basic components of beer, is the common carbon source used by all strains. It appears that this carbon source allows for anaerobic beer spoilage by Pectinatus and Megasphaera despite the spoilage-preventing intrinsic barriers of beer (iso-α-acids, ethanol, low pH, scarce nutrients); thus, extrinsic countermeasures are key for prevention. Full article