Search Results (10,906)

Given the therapeutic potential of bioactive cordycepin in medical and healthcare products, precision fermentation using an engineered strain of Aspergillus oryzae was performed to enhance cordycepin production. To understand and predict the dynamics of cell growth and cordycepin production in this fungal strain, mathematical modeling of submerged fermentation was applied. The effects of different nitrogen sources (yeast extract, peptone, (NH₄)₂SO₄, NH₄Cl, NaNO₃, and KNO₃) and carbon sources (glucose and cassava starch hydrolysate, CSH) on cell growth and cordycepin production were evaluated under submerged fermentation conditions. The results showed that organic nitrogen sources significantly enhanced biomass formation and cordycepin production compared with inorganic nitrogen sources. Among them, yeast extract provided the best performance, yielding the highest biomass (13.63–15.99 g/L) and cordycepin titer (1.24–1.72 g/L). In contrast, nitrate-based nitrogen sources supported cell growth but resulted in negligible cordycepin production. Under optimized conditions in a bioreactor, both glucose and CSH supported fungal growth, although CSH promoted higher biomass formation while glucose favored cordycepin biosynthesis. The kinetic model demonstrated that the growth of engineered A. oryzae was well described by the logistic growth model (R² > 0.88). The cordycepin production profiles were well fitted by the Luedeking–Piret model (R² > 0.99), indicating a mixed growth-associated product with kinetic constants α and β representing growth-associated and non-growth-associated production, respectively. Overall, the developed kinetic model provides a quantitative framework for describing cell growth, substrate utilization, and cordycepin formation, offering guidance for process optimization and scale-up of cordycepin production in engineered fungal systems. Full article

Filamentous fungal infections of breast implants remain underrecognized compared with infections caused by Candida species and bacteria, despite their potential to induce significant inflammatory pathology. This commentary highlights the distinctive ability of filamentous fungal biofilms to penetrate deeply into the implant capsule, a feature that may contribute to distinct pathogenic behaviour compared with bacterial or yeast biofilms. We discuss how this invasive behavior may contribute to the perception that reported cases represent the first documented breast implant-associated fungal infections, when in fact such infections may be under-recognised and under-investigated. By drawing attention to these mechanisms and their clinical implications, this commentary aims to stimulate greater awareness and further investigation within the fields of infectious diseases and pathogen research. Full article

Solid-state fermentation (SSF) is a long-established biotechnological approach gaining renewed interest for its ability to enhance nutrient availability and improve the functional properties of agro-industrial by-products. This strategy is particularly relevant for early post-weaning piglets, which are highly susceptible to weaning stress due to an immature digestive system and a gut microbiota not yet adapted to solid feed. In this study, the fermentation parameters of flaxseed cake were optimized using a Plackett–Burman experimental design. Protease activity was selected as the response variable due to its relevance for improving protein degradation and potential digestibility in fermented feed ingredients. Accordingly, based on the statistical analysis, the conditions selected for the in vivo trial were 1% molasses, 0.5% yeast extract, 0.05% CaCl₂, 0.5% NaCl, 7.5% inoculum (4.12 × 10⁹ CFU/mL), 60% moisture, and 72 h fermentation. Fermentation time was identified as the main factor positively influencing protease production, while higher CaCl₂ concentrations and inoculum levels negatively affected enzyme activity. Optimization increased protease activity, microbial viability and free amino acid content. In addition, SSF reorganizes the carbohydrate profile by reducing structural fiber fractions, with neutral detergent fiber and acid detergent fiber decreasing by 27% and 29%, respectively, while simultaneously increasing soluble carbohydrates by 14.67%. Phytic acid content being also reduced by 23.81%. A pilot nutritional trial on post-weaned piglets (35 days old) showed that including 8% fermented flaxseed cakes (FFSC group) improved body weight, average daily gain, feed conversion ratio, and diarrhea score, without affecting average daily feed intake, compared with 8% unfermented flaxseed cakes (FSC group). These performance improvements were accompanied by changes in fermentation metabolites and gut microbial composition. Lower isovalerate concentrations suggested reduced proteolysis, while higher propionate levels may contribute to increased blood glucose availability in the FFSC group. These changes coincided with a shift in microbial composition, characterized by a reduced abundance of methanogenic archaea and increased abundances of taxa such as Lactobacillus, Enterococcus, and members of the Lachnospiraceae and Eubacteriaceae families. Full article

Yeast models are widely used to study molecular chaperones from diverse organisms, including plants, because of their well-characterized genetics and the conservation of the protein-folding machinery among eukaryotes. Cross-species complementation studies in yeast have yielded valuable insights into conserved biochemical activity and molecular functions that manage protein folding, assembly, and repair during stress. This study evaluated the functional capacity of three potato StBiP isoforms (StBiP1, StBiP2, and StBiP3) to complement the kar2 deletion (kar2Δ) strain under a range of environmental and ER stress conditions. All three StBiPs partially restored colony growth under normal conditions, demonstrating that they are functional orthologs of yeast KAR2 and can support core ER housekeeping functions. Under severe stress, however, the isoforms diverged: StBiP3 most effectively complemented the kar2Δ strain during heat- and chemically induced ER stress, whereas StBiP1 and StBiP2 provided weaker protection. Unfolded protein response (UPR) activation, monitored via HAC1 mRNA splicing, further highlighted isoform-specific differences in how the StBiPs support IRE1-HAC1 signaling under ER stress and oxidative stress. A conserved cysteine in the nucleotide-binding domain, previously implicated in Kar2 redox control, was also critical for StBiP3-mediated protection in yeast, although the same mutation led to different consequences in plant tissues. Together, these findings provide evidence of subfunctionalization among potato BiP isoforms, with StBiP3 emerging as a stress-specialized chaperone that is a promising target for improving ER stress resilience in solanaceous crops. Full article

RipP1 is a well-characterized avirulence effector that induces a hypersensitive response (HR) in three tobacco species. However, the molecular mechanisms by which host proteins recognize RipP1 to activate a defense response and modulate host–pathogen interactions remain largely unknown. In this study, we screened a Nicotiana benthamiana cDNA library via yeast two-hybrid assay and identified FRIGIDA-like protein 4a (FRL4a) as a host protein interacting with RipP1. Secondary structure analysis of FRL4a and construction of serial mutants revealed that the ClyA-like domain of FRL4a is the key region mediating its interaction with RipP1. Using virus-induced gene silencing (VIGS) and quantitative real-time PCR (qPCR) analysis, we found that the ability of RipP1 to induce HR was significantly attenuated in FRL4a-silenced plants, and RipP1 no longer suppressed the ethylene signaling pathway. Pathogenicity tests by inoculating R. solanacearum on N. benthamiana with different FRL4a expression levels showed enhanced bacterial wilt resistance in FRL4a-silenced plants but increased susceptibility in FRL4a-overexpressing plants. Collectively, these findings demonstrate that RipP1 suppresses the ethylene pathway through its interaction with FRL4a, and FRL4a acts as a negative regulator of tobacco resistance to bacterial wilt. Full article

Despite the importance of surface microbiota in postharvest quality, the effects of mechanical damage on microbial succession in Hypsizygus marmoreus during refrigerated storage remain insufficiently understood. In this study, 16S rRNA gene and ITS amplicon sequencing were used to characterize the bacterial and fungal communities on intact and mechanically damaged H. marmoreus during 15 days of storage at 4 °C. Storage time, rather than mechanical damage, was the main driver of whole-community variation, although mechanical damage accelerated visible spoilage assessed qualitatively. Bacterial communities showed pronounced temporal turnover, shifting from early Firmicutes-rich assemblages to late-stage Proteobacteria-dominated communities, especially Pseudomonas. In contrast, fungal communities remained largely dominated by Ascomycota throughout storage, although mechanically damaged mushrooms showed a greater late-stage occurrence of opportunistic yeasts such as Candida. Predicted functional and phenotypic analyses further suggested late-stage increases in Gram-negative, aerobic, biofilm-forming, stress-tolerant, and potentially pathogenic bacterial traits. Because these traits were inferred from 16S rRNA gene-based prediction rather than measured directly, they should be interpreted cautiously. Overall, the results suggest that maintaining the physical integrity of H. marmoreus during postharvest handling may help preserve quality and delay the emergence of spoilage-associated microbial traits during refrigerated storage. Full article

Red yeast rice (RYR), a traditional fermented product obtained via rice fermentation with Monascus purpureus, has a millennia-long history of culinary and medicinal use in East Asia and has gained global attention as a prominent functional food ingredient for its well-recognized cholesterol-lowering properties. This review is driven by one core question: How can the dual challenges of standardizing key bioactive constituents, particularly monacolin K (MK), while eliminating the mycotoxin citrinin be addressed through biotechnological and analytical advances? This narrative review consolidates the latest research progress on RYR-derived bioactive compounds, with a specific focus on their production optimization, multifaceted health-promoting potentials, safety regulation, and application prospects in health food development. We elaborate on key advances in fermentation biotechnology and strain engineering for enhancing the yield of the core lipid-lowering component MK while eliminating the nephrotoxic mycotoxin citrinin, and comprehensively summarize the synergistic bioactivities of RYR metabolites beyond MK. The current applications of RYR in functional foods, dietary supplements, and traditional fermented products are detailed, alongside a comparison of the divergent regulatory frameworks for RYR across major global markets. Finally, we identify critical bottlenecks restricting RYR industrialization, including extreme inter-product heterogeneity and global regulatory fragmentation, and propose evidence-based future research directions to facilitate the development of safe, standardized, and effective RYR-based health foods. Full article

Ethnopharmacological relevance. Withania somnifera (L.) Dunal, widely used in traditional medical systems such as Ayurveda, Unani, and Middle Eastern folk medicine, is valued for its adaptogenic, anti-inflammatory, neuroprotective, antimicrobial, and anticancer properties. These activities are primarily attributed to withanolides, with Withaferin A recognized as one of the most bioactive constituents. Although traditional preparations often rely on the root, leaf use provides a more sustainable alternative and may yield significant quantities of active metabolites. Identifying efficient, modern extraction technologies that can enhance the recovery of bioactive compounds from leaves is essential for developing effective, standardized ethnopharmacological formulations. Materials and methods. Plants of W. somnifera grown from seeds were subjected to different environmental conditions (control, drought, cold, yeast extract treatment). Leaves were extracted using Pressurized Cyclic Solid–Liquid Extraction (PCSLE) with hydroalcoholic solvents and compared with conventional infusion of dried leaves. Extracts were fractionated with solvents of varying polarity and analyzed by TLC, HPLC, and NMR for quantification of Withaferin A. Expression levels of key withanolide-biosynthetic genes (CAS, SMT1, DWARF1, CYP71, CYP76) were assessed using qRT-PCR. Antimicrobial activity of pure Withaferin A, aqueous extract, and hydroalcoholic PCSLE extract was evaluated through MIC and MBC assays against Gram-positive and Gram-negative strains. Cytotoxic activity was measured via MTT assays in six human cancer cell lines after 3, 6, and 24 h of treatment. Results. PCSLE yielded substantially higher levels of Withaferin A than traditional infusion, especially in medium-polarity fractions (chloroform and ethyl acetate), with concentrations reaching 0.70% in fresh leaf mass (4.8% dry weight), compared to 0.11% obtained by infusion. Gene expression analysis revealed that 24-week-old plants exhibited the highest transcription of withanolide-biosynthetic genes, and drought stress significantly upregulated CAS, SMT1, DWARF1, CYP71, and CYP716, indicating enhanced metabolic flux toward withanolide production. Hydroalcoholic PCSLE extracts showed broad-spectrum antimicrobial activity, with MIC and MBC values comparable to pure Withaferin A and demonstrating bactericidal effects against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes. The aqueous extract showed activity only against Gram-positive strains. Cytotoxicity assays demonstrated an optimistic, dose-dependent reduction in cell viability across all tumour cell lines treated with the hydroalcoholic PCSLE extract, closely mirroring the activity of pure Withaferin A and consistently exceeding the effect of the aqueous extract. IC50 values confirmed the high bioactive content of PCSLE extracts and suggested mechanisms like those known for Withaferin A. Conclusions. PCSLE proved to be a highly efficient extraction technology for obtaining leaf extracts rich in Withaferin A, outperforming conventional extraction methods while exploiting sustainable plant tissue. Developmental stage and drought stress significantly modulated the expression of genes involved in withanolide biosynthesis, highlighting agronomic strategies capable of enhancing metabolite production. Hydroalcoholic PCSLE extracts exhibited antimicrobial and cytotoxic activities comparable to pure Withaferin A, supporting their relevance as promising therapeutic candidates. These findings advocate for the use of W. somnifera leaves as a sustainable source of bioactive compounds and demonstrate that advanced extraction technologies can contribute to the development of innovative ethnopharmacological preparations for antimicrobial and anticancer applications. Full article

Soil salinization has become a major global constraint threatening ecosystem stability and agricultural production. As a prominent salt-tolerant turfgrass, Paspalum vaginatum (seashore paspalum) serves as an excellent material for exploring salt tolerance mechanisms. In this study, PvHAK12, a high-affinity K⁺ transporter (HAK) family gene isolated from seashore paspalum, was functionally characterized. PvHAK12 encodes a 788 amino acid protein with 13 transmembrane domains, belonging to the plasma membrane-localized ion transporters. It exhibits high sequence conservation with other HAK transporters and is predominantly expressed in roots and stems, with distinct tissue- and time-specific induction under salt stress. Yeast complementation assays revealed that PvHAK12 has no obvious K⁺ transport capacity but may mediate Na⁺ transport. Overexpression of PvHAK12 in Arabidopsis thaliana significantly reduced salt tolerance at germination, seedling and rosette stages, as reflected by lower germination rate, fresh weight, survival rate, the maximum quantum yield of photosystem II (Fv/Fm) value and chlorophyll content, accompanied by higher ion leakage. Under salt stress, transgenic plants accumulated more Na⁺ and less K⁺, leading to an elevated Na⁺/K⁺ ratio. Moreover, transgenic lines displayed weaker antioxidant enzyme activities and higher reactive oxygen species (ROS) accumulation. Transcript analysis further demonstrated that PvHAK12 overexpression suppressed the induction of multiple ion-transport and stress-responsive genes under salt conditions. These results indicate that PvHAK12 negatively regulates plant salt tolerance by disrupting ion homeostasis, antioxidant capacity and stress-related gene expression. Full article

Alchemilla alpina L. (Rosaceae), belongs to a genus well recognized in traditional medicine for treating gynecological disorders and hormonal imbalance; however, the specific bioactivity of A. alpina itself remains poorly characterized. This study aimed to elucidate the phenolic composition and the biological potential of the methanolic (MeOH) extract of A. alpina. LC–MS/MS analysis identified 39 phenolic compounds, with rutin, catechin, kaempferol-3-O-glucoside, and caffeic acid being the dominant constituents. The extract exhibited high total phenolic and flavonoid contents, consistent with strong antioxidant capacities. It demonstrated notable α-glucosidase and acetylcholinesterase inhibitory activities, indicating its potential relevance for metabolic and neurodegenerative disorders. The extract effectively reduced AAPH-induced ROS levels in MRC-5 fibroblasts, indicating cytoprotective and antioxidative effects. The cytotoxicity toward cervical cancer cells HeLa and ovarian cancer cells A2780 was moderate and concentration dependent. A yeast-based fluorescent screen revealed a strong and selective binding affinity toward estrogen receptor α (ERα) and selective inhibition of human recombinant AKR1C3 (59.5%), without affecting AKR1C4. Additionally, high COX-1/COX-2 inhibition (>70%) supported its anti-inflammatory potential. Collectively, these findings provide the first integrated evidence of A. alpina’s phenolic richness and multifunctional bioactivity, scientifically supporting its potential in managing hormone-dependent and oxidative stress-related disorders. Full article

Flower senescence is a key physiological constraint on the ornamental and commercial longevity of cut roses. Although abscisic acid (ABA) is recognized as a promoter of this process, the molecular circuitry through which ABA operates, particularly the specific contributions of MYB transcription factors, remains largely unexplored. In this study, we identify RcMYB002 as a negative regulator of rose flower senescence. Transient overexpression of RcMYB002 significantly delays senescence, preserves anthocyanin accumulation, and modulates antioxidant enzyme activities in a time-dependent manner, consequently attenuating ABA-triggered oxidative stress. In contrast, silencing RcMYB002 accelerates senescence-associated phenotypes. At the molecular level, ABA suppresses RcMYB002 transcript accumulation, while yeast one-hybrid (Y1H) assays indicate that RcMYB002 interacts with the promoter regions of senescence-associated genes SAG12 and SAG21, consistent with a role in their transcriptional regulation. Taken together, our results support a model in which ABA promotes flower senescence by downregulating RcMYB002, thereby derepressing downstream senescence-executing genes. This work provides a molecular basis for understanding flower senescence and offers a potential target for extending rose vase life. Full article

Oxidative stress contributes to reproductive disorders, immune dysfunction, and reduced productivity in livestock during periods of high metabolic demand and environmental challenge. Selenium supports antioxidant defense systems because it is incorporated as selenocysteine into selenoproteins, including glutathione peroxidases and thioredoxin reductases that detoxify peroxides and sustain redox balance. The review summarizes selenium occurrence and chemical forms in feeds, as well as its absorption, transportation, and storage. The review also outlines the major features of selenoprotein biosynthesis and its prioritized allocation, with an emphasis on cattle, pigs, sheep, and goats. Evidence from multiple sources indicates that selenium status and supplementation interacts with antioxidant capacity, immune competence, thyroid hormone metabolism, reproductive performance, and the transfer of selenium to milk and offspring. In ruminants, rumen microbial transformations can reduce the bioavailability of inorganic selenium salts, and organic sources, such as selenium-enriched yeast, hydroxy-selenomethionine, and selenitetriglycerides, often increase blood and milk selenium more effectively. In pigs, organic selenium is commonly associated with enhanced antioxidant and immune indices in sows and piglets during late gestation, lactation, and weaning, whereas effects on growth performance are inconsistent. The review emphasizes the narrow margin between adequacy and excess and outlines practical considerations for supplementation and monitoring, alongside research needs for emerging selenium forms and functional biomarkers. Full article

Salt stress inhibits plant growth, requiring salt-tolerant genes for the development of resilient plants. A key tolerance mechanism is potassium/sodium homeostasis, governed by Shaker K⁺ channels. Given that Shaker K⁺ channels from salt-sensitive species have been extensively studied while their counterparts in salt-tolerant plants remain largely unexplored, this study investigates the evolution and function of these channels in salt-tolerant bermudagrass to address this knowledge gap. Genomic analysis identified 25 Shaker K⁺ channel genes, an expanded family relative to other species. Phylogenetics placed them into five groups (I–V), with groups I, II, III, and V expanded via segmental duplication. Salt stress response screening revealed that only CdKAT1.1 was rapidly upregulated. Functional assays in yeast demonstrated that both CdKAT1.1 and its closest homolog CdKAT1.2 improve potassium uptake and salt tolerance, but the enhancement from CdKAT1.1 was significantly greater. This work elucidates the expansion and functional divergence of Shaker K⁺ channels in bermudagrass. CdKAT1.1 emerges as a superior regulator of potassium efficiency and salt tolerance, making it a prime candidate for molecular breeding to improve plant resilience in saline-alkaline soils. Full article

The Rot1 protein is a chaperone involved in glycosylation, dolichol phosphorylation, cell wall synthesis, and protein folding in the yeast Saccharomyces cerevisiae. Available information on cell wall defects in the S. cerevisiae rot1-1 mutant and the association of Rot1 with protein glycosylation suggest that in the case of Candida albicans, Rot1 may be involved in pathogenesis, since both cell wall synthesis and protein glycosylation are closely related to the formation of pathogenic structures in C. albicans. As Rot1 has not been found in humans, it seems particularly attractive for study in the context of C. albicans pathogenicity. This protein takes on additional significance because deletion of the gene that encodes Rot1 is lethal for yeast. In this study, we cloned and analyzed the function of the candidate protein CaRot1 from C. albicans in the S. cerevisiae rot1Δ/ROT1 mutant. Furthermore, we investigated the consequences of restricted CaROT1 expression in C. albicans. We have shown that a low amount of Rot1 limits the transfer of oligosaccharide to protein, inhibits the activity of the first steps of oligosaccharide formation on dolichyl diphosphate, changes the composition of the cell wall, limits the protection of C. albicans against ER and abiotic stress, and finally prevents filamentation, which is an invasive structure of C. albicans. Full article

Sigma factors (SIGs) are nuclear-encoded regulators of chloroplast gene transcription. We conducted a genome-wide analysis in Brassica napus, identifying 23 SIG genes that were phylogenetically classified into six distinct subfamilies. Characterization of gene structure, conserved motifs, and chromosomal locations indicated family expansion primarily through segmental duplication under purifying selection. Promoter analysis identified cold-responsive elements enriched in BnSIG5A. Expression profiling showed that BnSIG5 subfamily members, particularly BnSIG5A, are strongly induced by cold stress. Analysis of Arabidopsis SIG5 mutants confirmed previously reported roles of AtSIG5 in cold tolerance. Heterologous expression in yeast, and the strong cold induction of BnSIG5A together with its chloroplast localization, suggest that BnSIG5A may play a conserved role, providing a foundation for future functional studies in B. napus. This work establishes a genomic framework for the SIG family in rapeseed and identifies BnSIG5A as a high-priority candidate for further investigation. Subcellular localization confirmed chloroplast targeting of BnSIG5A. Heterologous expression in yeast and analysis of Arabidopsis SIG5 mutants suggest conserved functions in cold tolerance, providing a foundation for future functional studies in B. napus. This work establishes a genomic framework for understanding SIG-mediated stress responses in rapeseed and identifies BnSIG5A as a promising candidate for further investigation. Full article