Search Results (1,075)

Older adults and patients with masticatory and deglutition disorders often experience difficulties consuming tough, fibrous vegetables. The enzymatic and liposomal conditions for softening garlic scapes were optimized while simultaneously enhancing their nutritional value through vitamin E fortification. Enzymes (Plantase UF and Plantase PT) were applied at varying concentrations and incubation times to determine optimal tenderization conditions, followed by the application of vitamin E-loaded liposomes. The physicochemical, microstructural, and color characteristics of the scapes and liposomal systems were evaluated. Enzymatic treatment significantly (p < 0.05) decreased hardness and increased adhesiveness, indicating effective cell wall disruption. Plantase PT hydrolyzes pectin in the middle lamella, promoting cell separation and softening, and maintains higher activity than Plantase UF, confirming its suitability for the consistent tenderization of fibrous vegetables. Its stability ensures reliable and uniform softening for real-world fibrous vegetable processing. Enzyme–vitamin E co-encapsulation balanced texture and nutrition by enlarging particles and lowering the ζ-potential (p < 0.05). Liposomal encapsulation preserved enzyme activity during processing and enabled sustained vitamin E delivery to scape tissues. Compared with untreated control, vitamin E liposomes provided controlled softening and improved nutrient stability. This highlights the potential of enzyme–liposome systems in developing tenderized older adult-friendly diets using fibrous plants. Full article

Under global climate change, the response of mountain forest soil carbon pools to elevation is central to carbon cycle research, and Pinus yunnanensis stands, which span a wide elevation range, serve as a typical subject for studying how soil properties in mountain ecosystems respond to elevation gradients. To reveal the variation patterns and underlying regulatory mechanisms of soil nutrients and organic carbon components in Pinus yunnanensis stands across different altitudinal gradients, this study took Pinus yunnanensis stands at three altitude gradients (1604 m, 2377 m, 3206 m) within Yunnan Province as research objects, collected stratified soil samples, and determined soil chemical properties, organic carbon components, enzyme activity, and microbial biomass. The results showed that changes in elevation significantly influence soil nutrient content: soil pH gradually decreases with increasing elevation; soil organic carbon, total nitrogen, alkali-hydrolyzable nitrogen, available phosphorus, and readily available potassium first increase then decrease with elevation, reaching their highest levels at Jin’an Town (JA); total phosphorus and total potassium gradually increase with elevation, peaking at Xiaozhongdian Town (XZD); particulate organic carbon, mineral-bound organic carbon, and microbial biomass carbon follow similar patterns to organic carbon, all showing enrichment in the surface layer; JA exhibits the highest carbon cycle enzyme activity and bacterial biomass, while XZD shows dominant fungal biomass. Partial Least Squares Path Modeling (PLS-PM) analysis indicates that elevation strongly positively drives microbial biomass, indirectly regulating enzyme activity and chemical properties, ultimately jointly influencing organic carbon components. In conclusion, soil properties varied markedly, and under stable precipitation, the thermal gradient emerged as the primary driver; the mid-elevation site (2377 m) showed optimal soil functioning, with peak nutrient and carbon stocks linked to heightened microbial and enzymatic activity, and path modeling confirmed that temperature, via microbial mediation, is the key regulator of soil organic carbon dynamics in these pine forests. Full article

Selenium-enriched oyster proteins were hydrolyzed using trypsin to obtain peptides with angiotensin-I-converting enzyme (ACE) inhibitory activity. The hydrolysate was purified by ultrafiltration and two-step reversed-phase high-performance liquid chromatography (RP-HPLC), yielding the most active fraction M4-2 (selenium content: 37.00 ± 0.56 mg/kg; IC₅₀: 0.774 mg/mL, significantly lower than the IC₅₀ of the crude hydrolysate, 2.801 mg/mL). This fraction was further analyzed by LC-MS/MS and molecular docking, leading to the identification of 91 selenium-containing peptide sequences. Two novel peptides, SeMFRTSSK and QASeMNEATGGK, showing strong binding affinities (−9.8 and −9.0 kcal/mol, respectively), were selected. Molecular docking revealed that SeMFRTSSK bound to key residues in the ACE active pocket via hydrogen bonds, whereas QASeMNEATGGK interacted with the Zn²⁺ active center. Cellular assays using EA.hy926 cells demonstrated that both peptides were non-cytotoxic at concentrations up to 0.25 mg/mL. At 0.025 mg/mL, SeMFRTSSK and QASeMNEATGGK enhanced cellular NO release by 202.65% and 273.45%, respectively, while suppressing Endothelin-1 (ET-1) secretion by 18.03% and 27.86%, compared to the blank control group. Notably, these peptides induced higher levels of NO release and greater suppression of ET-1 secretion than those in the captopril-treated positive control group. These findings support selenium-enriched oyster-derived peptides as potential natural antihypertensive ingredients. Full article

Celiac disease (CD) is an autoimmune disorder triggered by pepsin-resistant, gluten-derived immunogenic peptides (GIPs) in genetically predisposed individuals. Enzyme therapy targeting GIPs has been suggested as a complementary practice to a gluten-free diet to help reduce the symptoms of CD. Here, we present the crystal structure of RmuAP1, a pepsin-like aspartic protease from Rhodotorula mucilaginosa, which effectively degrades the toxic 33-mer and 26-mer GIPs under postprandial gastric conditions (pH 3.0–6.0). RmuAP1 has a canonical fold characteristic of the aspartic protease subfamily A1; however, it features a distinct flap and a flexible loop structure. Compared to pepsin, RmuAP1 accommodates the tetrapeptides PQQP and PQPQ, motifs frequently repeated on GIPs, via an adaptable binding cleft. Molecular dynamics (MD) simulations have shown that RmuAP1 stably engages these ligands, maintaining both the catalytic water in position and a closed flap conformation, primarily through ligand-induced remodeling of the S1′ pocket. In contrast, pepsin neither binds these ligands effectively nor achieves a catalytically competent conformation. Structural comparisons and dihedral analysis further support an induced-fit mechanism underlying RmuAP1’s pocket remodeling. Together, this study clarifies the structural basis for RmuAP1 to hydrolyze GIPs, emphasizing the potential of RmuAP1 as a platform for developing enhanced oral peptidase for CD patients through protein engineering approaches. Full article

This study aimed to investigate the effects of varying organic fertilizer substitution ratios on soil nutrients, organic matter, enzyme activities, and microbial communities, with the goal of optimizing fertilization strategies, enhancing soil fertility, and promoting sustainable agricultural development. Experimental Design: A three-year consecutive field experiment was conducted using an equal nitrogen application design with the following treatments: no fertilizer control (CK), conventional farmer fertilization (CF), and organic fertilizer substitutions at 10% (SF1), 20% (SF2), 30% (SF3), 40% (SF4), and 50% (SF5) of chemical fertilizer. Key soil parameters were analyzed, including available nutrients (alkali-hydrolyzable nitrogen, available phosphorus, and available potassium), organic matter content, enzyme activities (e.g., urease and phosphatase), and microbial community structure (bacterial and fungal diversity and abundance). Results: Partial substitution with organic fertilizer significantly enhanced soil available nutrient content and organic matter levels, with the 30–50% substitution treatments (SF3–SF5) demonstrating particularly pronounced effects. Moreover, organic fertilizer amendments markedly improved soil enzyme activities and altered microbial community composition, notably increasing the abundance of beneficial taxa such as Gemmatimonadota. These modifications further facilitated soil nutrient cycling and utilization efficiency. Conclusions: The findings demonstrate that appropriate organic fertilizer substitution not only improves soil fertility but also enhances microbial activity, thereby creating a healthier soil environment for crop growth. This study provides critical theoretical and practical insights for optimizing fertilization regimes, reducing chemical fertilizer reliance, and improving soil ecosystem functionality. Full article

Helicobacter pylori urease (HpU) plays a central role in bacterial survival and virulence by hydrolyzing urea into ammonia and carbon dioxide, neutralizing gastric acidity, and facilitating host colonization. The increasing prevalence of antibiotic resistance underscores the need for alternative strategies targeting essential bacterial enzymes such as urease. In this study, a multistage computational pipeline integrating pharmacophore modeling, machine learning (ML), ensemble docking, and enhanced molecular dynamics simulations were applied to identify novel triazole-based HpU inhibitors. Starting from over seven million compounds in the ZINC15 database, pharmacophore- and ML-based filters progressively reduced the chemical space to 7062 candidates. Ensemble docking across 25 conformational frames of HpU, followed by quantum-polarized ligand docking (QPLD), identified seven promising ligands exhibiting strong binding energies and stable metal coordination. Molecular dynamics (MD) simulations under progressively relaxed restraints revealed three highly stable complexes (CA1, CA3, and CA6). Subsequent well-tempered metadynamics (WT-MetaD) simulations reconstructed free-energy landscapes showing deep, localized basins for CA3 and CA6, comparable to the potent reference inhibitor DJM, supporting their potential as strong urease binders. Finally, unsupervised chemical space mapping using the UMAP algorithm positioned these candidates within molecular regions associated with potent urease inhibitors, further validating their structural coherence and pharmacophoric relevance. An ADMET assessment confirmed that the selected candidates exhibit physicochemical and early safety properties compatible with subsequent in vitro evaluation. This multilevel screening strategy demonstrates the power of combining ML-driven classification, ensemble docking, and enhanced sampling simulations to discover non-hydroxamic urease inhibitors. Although the current findings are computational, they provide a rational foundation for future in vitro validation and for expanding the discovery of triazole-based scaffolds targeting ureolytic enzymes. Full article

Substituting chemical fertilizers with organic fertilizers is a significant agricultural practice that can enhance crop yield while influencing soil activity. To investigate the effects of biochar-based organic fertilizer on rice yield, quality, and soil physicochemical properties and activity, this study conducted a field experiment with three treatments: chemical fertilizer only (CK), 30% of chemical nitrogen substituted with conventional organic fertilizer (CF), and 30% of chemical nitrogen substituted with biochar-based organic fertilizer (BF). Compared with chemical fertilizer alone (CK), both CF and BF treatments significantly increased rice yield by 8.9% and 14.2%, respectively, with BF showing a further increase over CF, primarily attributed to an 18.7% increase in panicle number. Both organic fertilizer treatments significantly improved grain quality, reducing amylose content by 4.6% and 13.1%, and increasing taste value by 3.3% and 3.6%, respectively. Dry matter accumulation throughout the growth period was significantly enhanced, with BF increasing total dry weight by 11.2% at maturity compared to CK. Root morphology was markedly improved, with BF increasing root volume by 146.1% at the grain-filling stage. Soil nutrient content was significantly elevated, showing maximum increases under BF of 118.9% for alkali-hydrolyzable nitrogen, 51.7% for ammonium nitrogen, 30.6% for available phosphorus, and 177.6% for available potassium. Soil enzyme activity analysis revealed significant enhancements in urease, acid phosphatase, and sucrase activities, with maximum increases of 91.5%, 105.6%, and 104.2%, respectively, under BF. These findings demonstrate that organic fertilizers, particularly biochar-based organic fertilizer, can synergistically enhance rice yield and quality by promoting root growth, strengthening soil microbial activity and enzymatic reactions, and optimizing nutrient supply. Biochar-based organic fertilizer exhibits significant advantages in improving soil biological fertility and maintaining stable nutrient supply during the late growth stages of rice. Full article

This study evaluated the bioactive potential of Thai silkworms (Bombyx mori) at three developmental stages—mature silkworm (MS), A-silking silkworm (AS), and pupae (PP)—as alternative protein sources for functional hydrolysates. Silkworm powders were hydrolyzed with Alcalase^® (5% w/w, 1 h, 60 °C) to obtain MS hydrolysate powder (MSHP), AS hydrolysate powder (ASHP), and PP hydrolysate powder (PPHP). AS contained the highest protein content (72.13%), followed by MS (70.20%) and PP (56.70%). Amino acid profiling revealed stage-specific and hydrolysis-dependent variations, MS was enriched in phenylalanine and histidine, AS in threonine, valine, and tyrosine, and PP in lysine, leucine, and arginine. Hydrolysates showed markedly increased amino acid levels across all samples, indicating enhanced peptide release and improved nutritional quality. The hydrolysates achieved yields of 61–64% and protein recoveries of approximately 46%. MSHP and ASHP exhibited higher degrees of hydrolysis than PPHP. Among the biological activities, MSHP demonstrated the strongest angiotensin-converting enzyme (ACE) inhibition (88.46%), whereas PPHP exhibited the greatest antioxidant capacity (DPPH, ABTS, FRAP). Overall, Alcalase^® hydrolysis effectively enhanced silkworm bioactivity, supporting their potential as multifunctional ingredients for functional foods and nutraceuticals targeting cardiovascular and oxidative stress-related disorders. Full article

Acetylcholinesterase (AChE) is a key enzyme responsible for terminating cholinergic neurotransmission by hydrolyzing acetylcholine. While clinically approved AChE inhibitors such as donepezil, rivastigmine, and galantamine are used in the symptomatic treatment of Alzheimer’s disease and related dementias, little is known about the modulatory effects of common dietary compounds on AChE activity. In this study, we investigated the influence of creatine (CR) and taurine (TA)—two widely consumed nutritional supplements with reported neuroprotective and cognitive-enhancing properties—on AChE. Enzyme kinetics were evaluated using a modified Ellman’s method, and Lineweaver–Burk analyses revealed that both CR and TA act as competitive inhibitors. Calculated parameters (Km, Vmax), inhibition constants (Ki), and half maximal inhibitory concentrations (IC₅₀) consistently indicated stronger potency for CR (IC₅₀ = 0.0056 ± 0.00018 mM) compared to TA (IC50 = 0.0097 ± 0.00035 mM). To complement the experimental data, molecular docking was performed using two crystal structures of human AChE. Docking confirmed that both ligands preferentially occupy the active-site region in a manner consistent with competitive inhibition, with CR showing more favorable binding scores than TA. Although markedly weaker than clinical drugs, these findings provide the first biochemical and in silico evidence that CR and TA directly interact with AChE, suggesting subtle cholinergic modulation relevant to cognitive function and neuroprotection. Full article

Straw returning is a critical practice with profound strategic importance for sustainable agricultural development. However, within a comprehensive soil health evaluation framework, research analyzing the impact of tobacco straw returning on soil ecosystem health from the perspectives of microbial taxa and functional genes remains insufficient. To investigate the effects of tobacco straw returning on virulence factor genes (VFGs), methane-cycling genes (MCGs), nitrogen-cycling genes (NCGs), carbohydrate-active enzyme genes (CAZyGs), antibiotic resistance genes (ARGs), and their host microorganisms in soil, this study collected soil samples from a long-term tobacco-rice rotation field with continuous tobacco straw incorporation in Shaowu City, Fujian Province. Metagenomic high-throughput sequencing was performed on the samples. The results demonstrated that long-term tobacco straw returning influenced the diversity of soil VFGs, MCGs, NCGs, CAZyGs, ARGs, and their host microorganisms, with richness significantly increasing compared to the CK treatment (p < 0.05). In the microbially mediated methane cycle, long-term tobacco straw returning resulted in a significant decrease in the abundance of the key methanogenesis gene mttB and the methanogenic archaeon Methanosarcina, along with a reduced mtaB/pmoA functional gene abundance ratio compared to CK. This suggests enhanced CH₄ oxidation in the tobacco-rice rotation field under straw returning. Notably, the abundance of plant pathogens increased significantly under tobacco straw returning. Furthermore, a significantly higher norB/nosZ functional gene abundance ratio was observed, indicating a reduced capacity of soil microorganisms to convert N₂O in the tobacco-rice rotation field under straw amendment. Based on the observation that the full-rate tobacco straw returning treatment (JT2) resulted in the lowest abundances of functional genes prkC, stkP, mttB, and the highest abundances of nirK, norB, malZ, and bglX, it can be concluded that shifts in soil physicochemical properties and energy substrates drove a transition in microbial metabolic strategies. This transition is characterized by a decreased pathogenic potential of soil bacteria, alongside an enhanced potential for microbial denitrification and cellulose degradation. Non-parametric analysis of matrix correlations revealed that soil organic carbon, dissolved organic carbon, alkaline-hydrolyzable nitrogen, available phosphorus, and available potassium were significantly correlated with the composition of soil functional groups (p < 0.05). In conclusion, long-term tobacco straw returning may increase the risk of soil-borne diseases in tobacco-rice rotation systems while potentially elevating N₂O and reducing CH₄ greenhouse gas emission rates. Analysis of functional gene abundance changes identified the full-rate tobacco straw returning treatment as the most effective among all treatments. Full article

Recently, we found that combining various antimicrobial polypeptides (AMPs) with enzymes exhibiting lactonase activity results in an antifungal agent with significantly enhanced stability and antimicrobial action efficiency. In this context, this study aims to investigate the catalytic and antifungal activity and physical-chemical properties of antifungal enzyme combinations hydrolyzing fungal cell wall components with various AMPs, comparing them with enzymes exhibiting lactonase activity (capable of hydrolyzing lactones by ring opening). Additionally, combinations of enzymes targeting the fungal cell wall and/or hydrolyzing fungal lactone-containing Quorum-sensing molecules with polyamino acids (PAAs) supplemented with fungicides (PAAF) were studied for comparison with AMP-containing combinations. Interaction models for these antifungal enzyme combinations were simulated in silico using the molecular docking method. The most promising variants, which were predicted to possess high catalytic activity, were selected, and their catalytic and physical-chemical characteristics were further evaluated in vitro. The antifungal activity of the selected combinations of enzymes with AMPs or PAAF was assessed against a number of fungi, leading to the identification of several combinations as potential candidates for inclusion in antifungals. Unexpectedly, antifungal enzyme combinations with lactonase activity were, in most cases, more effective than those with fungal-cell-wall-degrading enzymes. Full article

A novel xylanase gene (RuXyn854) was identified from the rumen metagenome and was heterologously expressed in Escherichia coli to produce xylo-oligosaccharides (XOSs) as a prebiotic in this study. RuXyn854, a member of glycosyl hydrolase family 10, demonstrated peak enzymatic activity at pH 7.0 and 50 °C. RuXyn854 retains more than 50% of its activity after treatment at 100 °C for 10 min, highlighting the enzyme’s excellent heat resistance. RuXyn854 showed a preferential hydrolyzation of xylan, especially rice straw xylan. RuXyn854 activity was significantly increased in the presence of 15 mM Mn²⁺, 0.25% Tween-20, and 0.25% Triton X-100 (125%, 20%, and 26%, respectively). The reaction temperature (30, 40, and 50 °C), dosage (0.20, 0.27, and 0.34 U), and time (90, 120, and 150 min) of RuXyn854 affected the XOS yield and composition, with a higher yield at 0.27 U, 50 °C, and 120–150 min. Xylobiose, xylotriose, and xylotetraose were characterized as the predominant XOS products resulting from the enzymatic hydrolysis of wheat straw xylan by RuXyn854, with xylose present at a mere 0.49% of the total yield. The prebiotic potential of XOSs was assessed through in vitro fermentation with established probiotic strains of Bifidobacterium bifidum and Lactobacillus brevis. The results showed that, regardless of incubation time, XOSs stimulated the growth and xylanolytic enzyme secretion of the two probiotics compared to the controls. These results demonstrate that the feature of RuXyn854 to withstand temperatures up to 100 °C is impressive, and its ability to hydrolyze wheat xylan into XOSs promotes the growth of probiotics. Full article

Background: Obesity is a highly prevalent chronic disease characterized by excessive weight gain and fat accumulation. There is growing evidence that Lactiplantibacillus plantarum strains with bile salt hydrolase (BSH) activity are effective in preventing and alleviating obesity. Methods: Initially, we screened bacterial strains with high hydrolytic activity against glycochenodeoxycholic acid (GDCA), and constructed an isogenic bsh1 knockout mutant. Subsequently, male C57BL/6J mice fed a high-fat diet (HFD) were randomly assigned to receive daily gavage of either the wild-type Lp20 (Lp20-WT) or the bsh1-deficient mutant (Lp20-Δbsh1) for 8 weeks. Serum cholesterol levels and histopathological changes in liver sections were monitored. Hepatic gene expression was quantified by RT-qPCR, and fecal bacterial communities were analyzed via 16S rRNA gene sequencing. These comprehensive assessments aimed to evaluate metabolic improvements and uncover the potential mechanisms behind the observed effects. Results:L. plantarum Lp20 hydrolyzed 91.62% of GDCA, exhibiting the highest bile-salt hydrolase (BSH) activity among tested isolates. Whole-genome sequencing and in-silico analyses mapped this activity to bsh1; gene deletion of bsh1 confirmed the role of bsh1 in GDCA hydrolysis. Daily gavage of the wild-type strain (Lp20-WT) to diet-induced obese mice markedly attenuated weight gain, reduced inguinal white adipose tissue and mesenteric fat mass, and lowered serum TC and LDL-C by 20.8% and 33.3%, respectively, while decreasing ALT and AST levels and reversing hepatic steatosis. In contrast, the bsh1-null mutant (Lp20-Δbsh1) failed to elicit any measurable metabolic benefit. Mechanistically, Lp20-WT upregulated rate-limiting bile-acid synthetic enzymes CYP7A1 and CYP27A1, thereby accelerating the catabolism of cholesterol into bile acids. Concurrently, it activated hepatic TGR5 and FXR signaling axes to modulate hepatic metabolism. Moreover, Lp20-WT restructured the gut microbiota by notably enhancing the abundance of beneficial bacteria such as norank_f__Muribaculaceae, Akkermansia, and Alistipes, while reducing the abundance of potentially harmful taxa, including norank_f__Desulfovibrionaceae, Dubosiella, and Mucispirillum. Conclusions: This study provides direct evidence of BSH’s anti-obesity effects through gene deletion. Specifically, BSH lowers cholesterol by modulating hepatic bile-acid metabolism-related gene expression and altering the gut microbiota composition. However, the study is limited by a small sample size (n = 6), the use of male mice only, and its preclinical stage, indicating a need for further validation across diverse strains and human populations. Full article

Extracellular glutathione (GSH) is degraded on the cell surface, in which the γ-glutamyl residue is removed to generate cysteine–glycine (Cys–Gly) dipeptides that are subsequently transported to the cytoplasm. Carnosine dipeptidase 2 (CNDP2) is a cytoplasmic enzyme that hydrolyzes Cys–Gly and plays an important role in maintaining intracellular cysteine (Cys) homeostasis. CNDP2-mediated hydrolysis of Cys–Gly promotes Cys mobilization and contributes to the replenishment of intracellular GSH levels. CNDP2 is frequently overexpressed in various cancers and has been implicated in tumor cell proliferation and progression. This mechanism may enhance cancer cell survival by causing resistance to oxidative stress, which indicates that CNDP2 is a potential therapeutic target for cancer treatment. Although bestatin (BES) has been identified as a CNDP2 inhibitor, its limited specificity and suboptimal drug-like properties have limited its therapeutic potential. In this study, we performed an in silico screen of a small-molecule compound library and identified KKL-35 as a novel CNDP2-binding molecule. Molecular dynamics (MD) simulations suggested that KKL-35 interacts within the catalytic pocket. Biochemical assays confirmed that it inhibits CNDP2 enzymatic activity, albeit with lower potency compared with BES. Despite its modest intrinsic activity, KKL-35 exhibits favorable physicochemical and pharmacokinetic properties, which are characterized by a low topological polar surface area (TPSA), reduced molecular flexibility, and well-balanced lipophilicity. This positions it as an attractive and tractable starting point for lead optimization. Taken together, these findings establish KKL-35 as a validated CNDP2 inhibitor and a promising lead compound for the development of more selective therapeutics targeting CNDP2-mediated cancer cell metabolism. Full article

Modern diets are high in fructans, which may lead to abdominal discomfort, particularly in sensitive individuals. Microbial inulinase, an enzyme that hydrolyzes inulin into fructose and fructo-oligosaccharides (FOS), has significant prebiotic potential and may contribute to the prevention of metabolic disorders by enhancing fructan digestion. This study investigates inulinase production by the Aspergillus niger ICCF 92 strain under various growth conditions. Three carbon sources (inulin, molasses, and carob pod decoction), the time required for biosynthesis processes, and stirring speed were evaluated for their influence on inulinase activity. Nitrogen sources included yeast extract, ammonium nitrate, and ammonium phosphate. Process monitoring included pH measurement, protein quantification via the Bradford assay, and inulinase activity assessment using the 3,5-dinitrosalicylic acid method. The highest inulinase production (38.29 U/mL) and protein concentration (0.7548 mg/mL) were achieved after 14 days of static fermentation with carob pod decoction as the carbon source. Full article