Search Results (80)

Rye regeneration in anther cultures is problematic and affected by albino plants. DNA methylation changes linked to Cu²⁺ ions in the induction medium affect reprogramming microspores from gametophytic to sporophytic path. Alternations in S-adenosyl-L-methionine (SAM), glutathione (GSH), or β-glucans and changes in DNA methylation in regenerants obtained under different in vitro culture conditions suggest a crucial role of biochemical pathways. Thus, understanding epigenetic and biochemical changes arising from the action of Cu²⁺ and Zn²⁺ that participate in enzymatic complexes may stimulate progress in rye doubled haploid plant regeneration. The Methylation-Sensitive Amplified Fragment Length Polymorphism approach was implemented to identify markers related to DNA methylation and sequence changes following the quantification of variation types, including symmetric and asymmetric sequence contexts. Reverse-Phase High-Pressure Liquid Chromatography (RP-HPLC) connected with mass spectrometry was utilized to determine SAM, GSH, and glutathione disulfide, as well as phytohormones, and RP-HPLC with a fluorescence detector to study polyamines changes originating in rye regenerants due to Cu²⁺ or Zn²⁺ presence in the induction medium. Multivariate and regression analysis revealed that regenerants derived from two lines treated with Cu²⁺ and those treated with Zn²⁺ formed distinct groups based on DNA sequence and methylation markers. Zn²⁺ treated and control samples formed separate groups. Also, Cu²⁺ discriminated between controls and treated samples, but the separation was less apparent. Principal coordinate analysis explained 85% of the total variance based on sequence variation and 69% of the variance based on DNA methylation changes. Significant differences in DNA methylation characteristics were confirmed, with demethylation in the CG context explaining up to 89% of the variance across genotypes. Biochemical profiles also demonstrated differences between controls and treated samples. The changes had different effects on green and albino plant regeneration efficiency, with cadaverine (Cad) and SAM affecting regeneration parameters the most. Analyses of the enzymes depend on the Cu²⁺ or Zn²⁺ ions and are implemented in the synthesis of Cad, or SAM, which showed that some of them could be candidates for genome editing. Alternatively, manipulating SAM, GSH, and Cad may improve green plant regeneration efficiency in rye. Full article

Flavonoids, widely present in Artemisia argyi (AA), offer potential health benefits but are limited in food applications because of their bitter taste, inadequate absorption, and stability. Casein micelles encapsulation can enhance the flavonoid absorption, stability, and bioactivity. In this study, Artemisia argyi flavonoids (AAFs) were extracted using ultrasound-assisted extraction (UAE) to optimize the process. The glycosylation reaction between casein (CN) micelles and oat β-glucan (OBG) was employed to improve AAF’s emulsifying stability, sustained release during digestion, and cellular uptake. The maximum glycosylation degree of 32.33% was achieved at a CN-to-OBG ratio of 1:2, 120 min browning time, and 95 °C temperature. This glycosylated delivery system enhanced the emulsifying properties of the AAFs, digestive sustained release, and cellular uptake, showing potential as a cross-linking material for fat-soluble substances and medicines. Full article

Sporothrix schenckii is a pathogenic fungus of worldwide distribution and one of the etiological agents of sporotrichosis. The cell wall is the first point of contact with host cells; therefore, its composition has been widely studied. It has a cell wall composed of chitin, β-glucans, and glycoproteins modified with N-linked and O-linked glycans. Protein O-linked glycosylation is mediated by two gene families, PMT and MNT. Therefore, we evaluated the relevance of protein O-linked glycosylation during the interaction of S. schenckii with the host. Independent silencing of the MNT1 and PMT2 was accomplished by interference RNA. Morphological analyses revealed defects in cell morphology in both yeast and mycelial cells; however, these defects differed between MNT1 and PMT2 silencing. Subsequently, the cell wall was characterized, and the silencing of these genes markedly changed cell wall organization. When the silenced strains interacted with human peripheral blood mononuclear cells, a reduced ability to stimulate the proinflammatory cytokines IL-6 and TNFα was found. However, the PMT2-silenced mutants also stimulated higher levels of IL-10 and IL-1β. Interaction with macrophages and neutrophils was also altered, with increased phagocytosis and decreased extracellular trap formation in both sets of silenced strains. Survival assays in Galleria mellonella larvae showed that silencing of any of these genes reduced the ability of S. schenckii to kill the host. In addition, the mutant strains showed defects in the adhesion to extracellular matrix proteins. These data indicate that MNT1 and PMT2 are relevant for cell wall synthesis and interaction with the host. Full article

Different dietary fibers have distinct structures, leading to significant variations in their laxative effects. To explore how these structural differences impact constipation intervention, a 14-day study was conducted on loperamide-induced constipated mice using five dietary fibers: soluble dietary fiber from steamed sweet potato (SDF-S), oat β-glucan (OB), polydextrose (PD), arabinogalactan (AG), and inulin (IN). The results showed that four fibers, excluding PD, significantly improved gastrointestinal (GI) transit rate (p < 0.05), although PD had the highest fecal moisture, it was significantly different from the lowest IN (p < 0.05). AG and IN resulted in higher 6 h fecal weights compared to other fibers. SDF-S and OB were more effective in modulating serum levels of gastrointestinal hormones. The different monosaccharide compositions and glycosidic bonds of these fibers led to distinct changes in gut microbiota composition and SCFA profiles. Galactose and arabinose in AG were linked to increased abundance of Lachnospiraceae_UCG-006, Bacteroides, and Odoribacter, promoting butyrate fermentation, which is positively correlated with GI transit rate. Glucose in SDF-S, OB, and PD favored acetate fermentation positively correlated with fecal moisture. Fructose in IN encouraged the proliferation of Muribaculaceae_unclassified and Ruminococcus, associated with butyrate fermentation and increased 6 h stool weight, respectively. The β-glycosidic bonds in OB may lead to high butyrate production through the selective proliferation of Lachnospiraceae_unclassified. Minor components like fucose, rhamnose, and ribose were positively correlated with the abundance of Oscillospiraceae_unclassified, Anaerotignum, and Lachnospiraceae_unclassified. In conclusion, the unique monosaccharide compositions and glycosidic bond differences in dietary fibers selectively promote the proliferation of fiber-degrading and butyrate-producing bacteria, resulting in varied effects on constipation relief. Full article

This study was aimed at extracting, characterizing, and exploring the detoxification activity of the peptide-containing polysaccharide from Agaricus balchaschensis. An anion adsorption fraction was acquired through hot water extraction. Its structure was analyzed, and the potential protective effect against cadmium-intoxicated mice was explored. Structural analysis revealed that the principal component of the peptide-containing polysaccharide of A. balchaschensis (ABPCP) is polysaccharide, which consists of glucose, mannose, galactose, and xylose, containing (1 → 4)-linked α-D-glucan, (1 → 3)-linked β-D-Glcp, (1 → 4)-linked β-D-Glcp, (1 → 6)-linked β-D-Glcp, (1 → 6)-linked β-D-Manp, (1 → 3)-linked β-D-Galp, (1 → 6)-linked β-D-Galp, and (1 → 4)-linked β-D-xylan. The amino acid content of ABPCP is 11.747 mg/g. Threonine, serine, glutamate, glycine, alanine, cysteine, valine, methionine, lysine, and arginine were detected in ABPCP, among which the content of glutamate was the highest. The alleviating effect of ABPCP on cadmium poisoning in mice was investigated. ABPCP significantly reduced the cadmium content in serum and the heart, kidneys, and liver, which indicates that ABPCP could promote cadmium discharge. ABPCP also significantly decreased serum nitric oxide, endothelin-1, urea, uric acid, and serum creatinine, alleviating kidney and liver damage caused by cadmium. All these results manifest that ABPCP can lower the cadmium content in organs and alleviate the damage to kidneys and livers damaged by Cd. Full article

In this study, we report the molecular and enzymatic characterisation of Spg103, a novel bifunctional β-glucanase from the marine bacterium Streptomyces sp. J103. Recombinant Spg103 (rSpg103) functioned optimally at 60 °C and pH 6. Notably, Spg103 exhibited distinct stability properties, with increased activity in the presence of Na+ and EDTA. Spg103 displays both lichenase and cellobiohydrolase activity. Despite possessing a GH5 cellulase domain, FN3 and CBM3 domains characteristic of cellulases and CBHs, biochemical assays showed that rSpg103 exhibited higher activity towards mixed β-1,3-1,4-glucan such as barley β-glucan and lichenan than towards beta-1,4-linkages. The endolytic activity of the enzyme was confirmed by TLC and UPLC-MS analyses, which identified cellotriose as the main hydrolysis product. In addition, Spg103 exhibited an exo-type activity, selectively releasing cellobiose units from cellooligosaccharides, which is characteristic of cellobiohydrolases. These results demonstrate the potential of Spg103 for a variety of biotechnological applications, particularly those requiring tailor-made enzymatic degradation of mixed-linked β-glucans. This study provides a basis for further structural and functional investigations of the bifunctional enzyme and highlights Spg103 as a promising candidate for industrial applications. Full article

Background/Objective: Amphibian skin is a valuable source of host defense peptides (HDPs). This study aimed to identify HDPs with novel amino acid sequences from the skin of Rana tagoi yakushimensis and analyze their functions. Methods: cDNAs encoding HDP precursors were cloned and sequenced using RT-PCR and 3′-RACE. The novel HDPs were synthesized to evaluate their antimicrobial activity, antioxidant activity, and cytotoxicity. Antimicrobial activity was evaluated by way of broth microdilution and endotoxin- and β-glucan-binding capacity using an enzyme-linked endotoxin binding assay (ELEBA) and a modified ELEBA, respectively. Results: Nine cDNAs encoding precursors for various HDP families, including temporin, ranatuerin-2, brevinin-1, amurin-9, and a novel yakushimin peptide, were identified. Brevinin-1TYa exhibited antibacterial activity against Staphylococcus aureus, and brevinin-1TYa and amurin-9TYa induced morphological changes in Escherichia coli and S. aureus. Yakushimin-TYa, amurin-9TYa, and brevinin-1TYa showed concentration-dependent antibacterial effects against the plant pathogens Xanthomonas oryzae pv. oryzae and Clavibacter michiganensis subsp. michiganensis. Amurin-9TYa demonstrated strong binding affinity to lipopolysaccharide, lipoteichoic acid, and β-glucan, exhibited antioxidant activity, and lacked cytotoxicity, making it a promising therapeutic candidate. Moreover, brevinin-1TYa showed strong cytotoxicity, whereas yakushimin-TYa exhibited weak cytotoxicity. Conclusions: These findings highlight the potential of these peptides, particularly amurin-9TYa, for future applications as antimicrobial and therapeutic agents. Full article

Candida auris, an emerging multidrug-resistant fungal pathogen, poses significant challenges in healthcare settings due to its high misidentification rate and resilience to treatments. Despite advancements in diagnostic tools, a gap remains in rapid, cost-effective identification methods that can differentiate C. auris from other Candida species, particularly on non-standard culture media. We used Raman spectroscopy to characterize C. auris grown on modified Dixon’s agar (mDixon) and differentiated it from Candida albicans and Candida parapsilosis. Key Raman spectral markers at 1171 cm⁻¹ and 1452 cm⁻¹, linked to mannan and β-glucan composition, differentiated C. auris into two subgroups, A and B. Despite the spectral similarities of groups A and B with C. albicans and C. parapsilosis, respectively, all Candida species were distinguishable through principal component analysis (PCA). Additionally, this study is the first to demonstrate the distinct spectral signature of mDixon agar, achieved through spatially offset Raman spectroscopy (SORS), which enables accurate discrimination between the culture medium and fungal samples. The observed inter-individual variability within C. auris, coupled with the spectral overlap between C. auris subgroups and other Candida species, highlights a major challenge in differentiating closely related fungi due to their similar molecular composition. Enhancements in spectral resolution and further fluorescence minimization from the culture medium are needed to reliably detect the subtle biochemical differences within these species. Despite these challenges, the results underscore the potential of Raman spectroscopy as a real-time, non-destructive, and complementary tool for fungal pathogen identification. Full article

Terroir refers to the combination of environmental factors, such as climate, soil, and agricultural practices, that shape the characteristics of a crop, contributing to the unique qualities of the final product. The concept has been traditionally linked to wine, but some recent findings suggest that it also holds importance for distilled spirits. The expanding Irish distilling sector is shifting towards local raw materials such as wheat and rye, driven by regulatory changes, economic benefits, and consumer demand for sustainable local products. This research examines the effects of wheat variety, geographical location, and harvest year on grain composition and volatile composition of the new make spirit. For this study, twenty lab-scale wheat whiskey samples were produced from five different wheat varieties grown at two different locations in Ireland over two consecutive years. The wheat samples were analysed for grain composition and the volatile profiling of new make spirit samples by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography–mass spectrometry (GC-MS). A total of fifty-one volatile compounds were detected, with ethanol, ethyl acetate, phenyl ethyl alcohol, and 3-methyl-1-butanol being predominant. Principal component analysis revealed that both the harvest year and geographical location moderately influenced the volatile compound distribution of the new make spirit, which is explained by a 43.25% variance. ANOVA analysis revealed that grain composition was significantly influenced by harvest year, location, and wheat variety. The 2020 samples showed higher protein and β-glucan content, whereas samples from the location Tipperary had higher starch content. This study indicates that terroir—specifically seasons (year) and geography (location)—affects the characteristics of wheat-based Irish whiskey, highlighting opportunities for distillers to differentiate their products by leveraging local environmental factors. Full article

Background: The consumption of nutraceuticals or food supplements has increased crucially, aiming to address nutrient deficits and enhance immune system function. To develop safe food products with unique nutritional and functional benefits, new production methods of these nutraceuticals such as the fermentative process have been gaining prominence for industrial applications. Bionutri-AR1^® is a nutraceutical produced via this bioprocess, featuring a complex composition, that has been used to improve the immune systems of debilitated people. Objectives: Considering the various biological properties attributed to glucans, one of its main components, this study aims to structurally characterize and evaluate, in vitro, the antioxidant and immunomodulatory potential of the polymers from this nutraceutical to assess whether these polymers contribute to the product’s reported biological effects. Methods/Results: Unlike previous reports, this study characterized by NMR, GC-MS, and Congo Red assay techniques two main glucans: a water-insoluble linear α-D-glucan with glycosidic bonds (1→4) and a soluble branched (1→3)- and (1→6)-linked β-glucan with a triple helix. Both glucans showed significant antioxidant activity, measured by their capacity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. They were also capable of inducing the secretion of cytokines such as tumoral necrosis factor-alpha (TNF-α), interleukin 10 (IL-10), and interleukin 6 (IL-6), determined through capture enzyme-linked immunosorbent assay (ELISA), especially when co-stimulated with lipopolysaccharide (LPS). Conclusions: This suggests a dual action of these glucans in both proinflammatory and regulatory pathways. Future studies will describe the mechanisms by which these glucans, especially the insoluble ones, enhance immune system function, highlighting their potential use in immunotherapy. Full article

Lanostene-derived triterpenoids and β-glucans are important metabolites in Ganoderma mushrooms associated with benefits to human health. The medicinal value of the Australian Ganoderma species remains unclear, with no data on triterpenoid distribution or glucan content. In the present study, 22 Australian Ganoderma specimens were analyzed for triterpenoid and glucan contents. Thirty-two triterpenoids were identified in the fruiting bodies of 19 of the specimens. Distinct patterns in triterpenoid distribution between laccate and matte fruiting bodies were observed, leading to the classification of four groups of Ganoderma. Most of the glucans in the Ganoderma fruiting bodies were β-glucans (~99%), with a nominal α-glucan content (~1%). The β-glucan content ranged from 19.5 to 43.5% (w/w). A range of antioxidant activities was observed for methanol extracts using the ABTS (1.8 to 8.4 mg GAE.g⁻¹), DPPH (1.7 to 9.4 mg GAE/g⁻¹) and FRAP (24.7 to 111.6 mmol FeSO₄.g⁻¹) assays, with four specimens presenting relatively high radical scavenging and reducing activities. For the first time, we demonstrated that Australian Ganoderma mushrooms contain medicinal triterpenoids, including ganoderic acid A, and we established a link between its distribution and the fruiting body morphology. However, further research is required to isolate diploid clones and determine factors that impact triterpenoid and glucan synthesis in these strains. Full article

The gut microbiota, a complex ecosystem of microorganisms in the human gastrointestinal tract (GI), plays a crucial role in maintaining metabolic health and influencing disease susceptibility. Dysbiosis, or an imbalance in gut microbiota, has been linked to the development of type 2 diabetes mellitus (T2DM) through mechanisms such as reduced glucose tolerance and increased insulin resistance. A balanced gut microbiota, or eubiosis, is associated with improved glucose metabolism and insulin sensitivity, potentially reducing the risk of diabetes-related complications. Various strategies, including the use of prebiotics like inulin, fructooligosaccharides, galactooligosaccharides, resistant starch, pectic oligosaccharides, polyphenols, β-glucan, and Dendrobium officinale have been shown to improve gut microbial composition and support glycemic control in T2DM patients. These prebiotics can directly impact blood sugar levels while promoting the growth of beneficial bacteria, thus enhancing glycemic control. Studies have shown that T2DM patients often exhibit a decrease in beneficial butyrate-producing bacteria, like Roseburia and Faecalibacterium, and an increase in harmful bacteria, such as Escherichia and Prevotella. This review aims to explore the effects of different prebiotics on T2DM, their impact on gut microbiota composition, and the potential for personalized dietary interventions to optimize diabetes management and improve overall health outcomes. Full article

A Leuconostoc mesenteroides strain (SJC113) isolated from cheese curd was found to produce large amounts of a mucoid exopolysaccharide (EPS). An analysis revealed the glucan nature of the EPS with 84.5% (1→6)-linked α-d-glucose units and 5.6% (1,3→6)-linked α-d-glucose units as branching points. The EPS showed 52% dextranase resistance and a yield of 7.4 ± 0.9 g/L from MRS medium supplemented with 10% sucrose within 48 h. Ln. mesenteroides SJC113 was also characterized and tested for the production of EPS as a fat substitute in fresh cheese. Strain SJC113 showed high tolerance to a wide range of NaCl concentrations (2, 5 and 10%), high β-galactosidase activity (2368 ± 24 Miller units), cholesterol-reducing ability (14.8 ± 4.1%), free radical scavenging activity (11.7 ± 0.7%) and hydroxyl scavenging activity (15.7 ± 0.4%). The strain had no virulence genes and was sensitive to clinically important antibiotics such as ampicillin, tetracycline and chloramphenicol. Ln. mesenteroides SJC113 produced highly viscous EPS during storage at 8 °C in skim milk with 5% sucrose. Therefore, these conditions were used for EPS production in skim milk before incorporation into fresh cheese. Four types of fresh cheese were produced: full-fat cheese (FF) made from pasteurized whole milk, non-fat cheese (NF) made from pasteurized skim milk, non-fat cheese made from skim milk fermented with Ln. mesenteroides without added sugar (NFLn0) and non-fat cheese made from skim milk fermented with Ln. mesenteroides with 5% sucrose (NFLn5). While the NF cheeses had the highest viscosity and hardness, the NFLn5 cheeses showed lower firmness and viscosity, higher water-holding capacity and lower weight loss during storage. Overall, the NFLn5 cheeses had similar rheological properties to full-fat cheeses with a low degree of syneresis. It was thus shown that the glucan-type EPS produced by Ln. mesenteroides SJC113 can successfully replace fat without altering the texture of fresh cheese. Full article

An alkali-soluble β-glucan (AHEP-A-b, 20 kDa) purified from Hericium erinaceus fruiting bodies, was structurally characterized and examined for antioxidant activity. Methylation analysis and NMR spectroscopy show that the backbone of AHEP-A-b is composed of (1→6)-linked-D-β-glucopyran residues, branched at O-3 of glucopyranose (Glcp) residues with [→3)-β-D-Glcp-(1→] oligosaccharides or single unit of β-Glcp. Periodate oxidation analysis and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) indicate that the degree of polymerization (DP) of [→3)-β-D-Glcp-(1→] side chains is 2 to 8. Functionally, AHEP-A-b is a relatively strong antioxidant as demonstrated by using 2, 2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical (ABTS^·+), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and hydroxyl radicals scavenging assays. The present study lays the foundation for further studies into structure-activity relationships of polysaccharides from H. erinaceus. Full article

Callose, found in the cell walls of higher plants such as β-1,3-glucan with β-1,6 branches, is pivotal for both plant development and responses to biotic and abiotic stressors. Plasmodesmata (PD), membranous channels linking the cytoplasm, plasma membrane, and endoplasmic reticulum of adjacent cells, facilitate molecular transport, crucial for developmental and physiological processes. The regulation of both the structural and transport functions of PD is intricate. The accumulation of callose in the PD neck is particularly significant for the regulation of PD permeability. This callose deposition, occurring at a specific site of pathogenic incursion, decelerates the invasion and proliferation of pathogens by reducing the PD pore size. Scholarly investigations over the past two decades have illuminated pathogen-induced callose deposition and the ensuing PD regulation. This gradual understanding reveals the complex regulatory interactions governing defense-related callose accumulation and protein-mediated PD regulation, underscoring its role in plant defense. This review systematically outlines callose accumulation mechanisms and enzymatic regulation in plant defense and discusses PD’s varied participation against viral, fungal, and bacterial infestations. It scrutinizes callose-induced structural changes in PD, highlighting their implications for plant immunity. This review emphasizes dynamic callose calibration in PD constrictions and elucidates the implications and potential challenges of this intricate defense mechanism, integral to the plant’s immune system. Full article