Search Results (1,092)

The novel strain TD-94 with higher ammonia degradation efficiency was isolated from the activated sludge of SINOPEC and belongs to the family of Alcaligenes faecalis (A. faecalis) based on its 16sRNA sequence and physio-biochemical characteristics. It is a Gram-negative, highly heterotrophic aerobic ammoxidation bacterium that is capable of effectively treating ammonia-nitrogen wastewater. The genome size of strain TD-94 was 4,361,949 bp with a GC content of 56.47% and a total of 4101 genes, which accounted for 89.54% of the total genome length. Analysis of various databases showed that 649 genes were annotated in the GO database; a total of 2712, 4095 and 12 genes were annotated in the KEGG, COG, and ADRB databases, respectively; and there were 24 types of cytochrome P450, 477 signal peptides, and eight secondary metabolites. All these data provide a theoretical basis for the mechanism of action of the strain TD-94. Based on the whole-genome sequencing results, functional genes related to nitrogen metabolism in A. faecalis TD-94, including aerobic ammonia oxidation (AOB), hydroxylamine oxidoreductase (HAO), and pyruvic oxime dioxygenase (POD) were identified. Through growth curve analysis and the identification of functional genes, the nitrogen metabolism pathway of A. faecalis TD-94 was proposed, demonstrating that the strain TD-94 has good denitrification capabilities and a novel degradative pathway. Full article

Rice grain yield and drought tolerance are critical for global food security. So far, only a few genes have been reported to regulate both traits simultaneously. Here, we characterize OsFLO1, a previously unreported FAD-linked oxidoreductase, as a dual regulator of grain development and drought stress tolerance in rice. Genome-wide association studies (GWAS) revealed natural variation in OsFLO1, with haplotypes showing geographic adaptation to local rainfall. Functional analysis demonstrated that overexpression (OX) lines exhibited larger grains and improved panicle traits, while knockout (CR) lines showed reduced grain size and yield components despite increased tiller number. Regarding drought tolerance, OX lines of OsFLO1 enhanced drought tolerance, as evidenced by increased root length and antioxidant activities, whereas knockout (CR) lines displayed impaired stress responses. We further show that OsWRKY53 directly binds the OsFLO1 promoter, thereby activating its expression and coordinating both grain development and stress responses. Together, these results suggest that OsFLO1 functions as a key regulator coordinating grain development and drought tolerance, making it a promising target for improving rice productivity. Full article

Renal ischemia–reperfusion injury (IRI) is a major cause of acute kidney injury. Estradiol (E2) and the selective estrogen receptor modulator raloxifene (RAL) reduce organ dysfunction, potentially via heme oxygenase-1 (HO-1)–mediated antioxidant and anti-inflammatory effects. This study examined whether E2 and RAL protect against IRI through G protein-coupled estrogen receptor (GPER)–dependent activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/HO-1 pathway in ovariectomized (OVX) mice; OVX IRI mice were pretreated for four weeks with E2, RAL, RAL + ML385 (Nrf2 inhibitor), or RAL + G15 (GPER antagonist). Renal histology, inflammatory and oxidative markers, and nuclear Nrf2 levels were assessed; OVX IRI increased interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and malondialdehyde (MDA) and decreased superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH); nuclear Nrf2 was low in sham and OVX IRI groups. E2 and RAL improved renal function and histology, reduced inflammation and oxidative stress, restored GPER expression, increased nuclear Nrf2, and upregulated HO-1 and NAD(P)H:quinone oxidoreductase 1 (NQO1). Co-treatment with ML385 or G15 reversed RAL’s benefits, reduced nuclear Nrf2, and worsened injury; E2 and RAL exert renoprotective effects against OVX-related renal IRI in a manner consistent with GPER-dependent Nrf2 nuclear translocation, which suggests involvement of the downstream antioxidant gene activation pathway. Full article

Complex I (NADH:quinone oxidoreductase, CI) is central to cellular aerobic energy metabolism. The L-shaped structure of CI is unique, where the hydrophilic arm is responsible for the electron transfer function and the membrane arm operates proton pumping. These two functional sites are spatially far apart yet functionally connected. This basic core subunit architecture is highly conserved from bacterial to mammalian CI. Here, to gain detailed mechanistic insight into the role of the membrane subunit ND2 in the coupling mechanism, we mutated several highly conserved residues in the middle of the membrane axis of NuoN, the E. coli CI homolog of ND2. To more precisely investigate the consequences of mutational effects on highly conserved residues, we purified each mutant CI and compared the mutational effects on electron transfer and proton pumping activity using our instant membrane reconstitution method with E. coli double knockout (DKO) membrane vesicles lacking both CI and alternative NADH dehydrogenase (NDH-2). Thre results were corroborated by conventional proteoliposome reconstitution experiments. We found that Lys247 and Lys395 are absolutely essential for both electron transfer and proton pumping activities, while about 50% reduction of NADH oxidase activity but no reduction in proton pumping activity was observed in Lys217, and no significant decrease was detected in Glu133. Furthermore, unexpectedly, we were able to purify an NuoN knockout (ΔNuoN) mutant, which contained stoichiometric peripheral subunits NuoB, NuoCD, NuoE, NuoF, NuoG, and NuoI; and a substoichiometric amount of NuoH and a reduced amount of quinone. However, surprisingly, this isolated ΔNuoN CI showed CI activities (~30% of the WT) after being reconstituted into DKO membranes but not into proteoliposomes. Later, we confirmed by blue native PAGE that the wild-type CI was partially formed from ΔNuoN CI by recruiting its missing membrane subunits that existed in DKO membranes. Our data strongly suggest that ND2/NuoN plays an essential role in the coupling mechanism in CI. CI is the entry respiratory chain enzyme and is central to cellular energy metabolism. Two highly conserved lysine residues in the center of the antiporter-like membrane subunit ND2 are essential for the coupling mechanism between electron transfer and proton translocation. Full article

Background: Metabolic disorder-associated fatty liver disease (MASLD) is closely related to obesity and type 2 diabetes. Its pathogenesis involves many factors, including mitochondrial dysfunction, endoplasmic reticulum stress and intestinal flora disorders. Notoginsenoside R1 (NGR1) is a key bioactive component of Panax notoginseng. The purpose of this study was to investigate the therapeutic effect of notoginsenoside R1 (NGR1) on metabolic disorder-associated steatohepatitis (MASH) and its potential mechanism. Methods: Mice were fed a choline-deficient, L-amino acid-defined high-fat diet (CDAHFD) for 6 weeks and received NGR1 (50/100 mg/kg/day) in the last 3 weeks. The role of NGR1 was evaluated by developing metabolomics, proteomics and functional analysis. In addition, the effects of NGR1 on lipid droplet content, mitochondrial function and fatty acid oxidation in hepatocytes were also verified. Results: NGR1 improved MASH progression in CDAHFD-fed mice, significantly reduced liver triglyceride content from 31.2 ± 5.1 mmol/g to 20.5 ± 4.8 mg/g (p < 0.001), free fatty acid from 0.12 ± 0.03 mmol/g prot to 0.06 ± 0.028 mg/g (p < 0.001), TNF-α (p < 0.01), IL-1β (p < 0.001), α-SMA (p < 0.05) and Collagen1A1 levels (p < 0.01), as well as serum ALT and AST concentrations (p < 0.001), and alleviated hepatomegaly and lipid droplet accumulation. Metabolomics and proteomics analysis showed that NGR1 normalized liver metabolism in MASH mice and upregulated mitochondrial OXPHOS components, including NADH: ubiquinone oxidoreductase core subunit S2 (NDUFS2), and effectively reversed CDAHFD-induced mitochondrial dysfunction. Mitochondrial membrane potential and ATP production were restored. Conclusions: This study confirmed that NGR1 has significant therapeutic potential for MASH and improves mitochondrial function by upregulating NDUFS2. This study provides new insights for the future clinical treatment of MASH. Full article

Oxidative stress in intestinal epithelial cells has been increasingly recognized as a key factor in various intestinal disorders. Gastrodia elata polysaccharide-2 (GEP-2), a water-soluble polysaccharide known for its antioxidant properties, has shown potential against intestinal injury. However, its effects on intestinal epithelial cells and the molecular mechanisms involved are not yet fully understood. In this study, we established a hydrogen peroxide (H₂O₂)-induced oxidative stress model using human colonic epithelial cells (NCM460) to evaluate the protective effects of GEP-2. We assessed cell viability, antioxidant enzyme activities, reactive oxygen species (ROS) levels, and mitochondrial membrane potential (MMP). The results demonstrated that GEP-2 pretreatment significantly improved the viability of NCM460 cells subjected to H₂O₂ damage. Additionally, it could enhance the antioxidant defense, reduce the levels of ROS, malondialdehyde (MDA), and maintain the MMP. Transcriptomic analysis identified 169 differentially expressed genes upregulated in the glutathione metabolism. JAK-STAT pathway and downregulated in inflammation. Furthermore, it was shown that GEP-2 treatment activated the Nuclear factor erythroid 2-related factor 2 (Nrf2)/quinone oxidoreductase 1 (NQO1)-mediated antioxidant response and promoted the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway. Therefore, GEP-2 exerts multi-targeted cell protection by coordinating the Nrf2/NQO1 antioxidant axis and the JAK/STAT survival signaling pathway, providing a theoretical basis for the development of novel antioxidants. Full article

Green-synthesized metal nanoparticles are increasingly investigated for their antioxidative, antimicrobial, and stress-protective properties as eco-friendly and cost-effective alternatives to conventional chemical synthesis. Although agri-food wastes represent biomolecule-rich and sustainable resources, they remain less explored as biological matrices for green metal nanoparticle synthesis compared with plant and microbial extracts. The aim of this study was to optimize the synthesis and evaluate the bioactivity of silver nanoparticles derived from bergamot pomace, a polyphenol-rich agri-food waste. Synthesis parameters, including extract concentration, pH, extract-to-metal ratio, temperature, and reaction time, were optimized, and the nanoparticles were characterized by UV–Vis spectroscopy, dynamic light scattering, zeta potential analysis, and electron microscopy (TEM, STEM). ATR-FTIR and proteomic analyses were employed to investigate the molecular mechanisms involved in nanoparticle reduction, capping, and stabilization. The bergamot pomace-based silver nanoparticles exhibited a surface plasmon resonance peak at 430 nm, spherical morphology, good colloidal stability, and average diameters of 15–20 nm, without irreversible aggregation. A putative synthesis mechanism was proposed, involving Ag⁺ bioreduction mediated by polyphenols, ascorbic acid, and oxidoreductase-associated proteins, followed by stabilization through protein corona formation. Seed nanopriming assays on tomato and lettuce, together with in vitro antimicrobial tests against Pseudomonas syringae pv. tomato and Xanthomonas campestris pv. vesicatoria, demonstrated phytostimulatory and antimicrobial effects at very low nanoparticle concentrations. Overall, this study highlights bergamot pomace as a valuable resource for green silver nanoparticle synthesis, supporting its applicability in sustainable agriculture. Full article

Fusarium graminaerum causes Fusarium Head Blight (FHB) on wheat, reduces yield, and contaminates food and feed. It is therefore of paramount importance to control its growth or convert its harmful mycotoxins. This study aimed to find yeasts with biocontrol activity against F. graminearum, and to identify genes with potential detoxifying activities, using microbiological, molecular methods and bioinformatics. Co-cultivation tests showed that Schizosaccharomyces japonicus was able to inhibit the growth of F. graminearum. Transcriptomic analysis of the yeast cells co-cultured with F. graminearum highlighted differentially expressed genes (DEGs) encoding various enzymes, such as oxidoreductases, transferases, hydrolases, or genes involved in transmembrane transport. Three trichothecene-3-O-acetyltransferase homologous genes, which can convert trichothecenes to less toxic forms, were also among them. A database search showed that several yeast species contained this gene, including S. japonicus, which unexpectedly had seven copies. Real-time PCR analysis and mycotoxin tolerance tests confirmed that some of these genes could be induced by deoxynivalenol (DON), and S. japonicus had stronger DON tolerance than the related S. pombe, whose genome did not contain such a gene. This study is the first to report the biocontrol efficacy of S. japonicus against F. graminearum and the identification of its potential detoxification genes, offering promising new avenues for biotechnological applications in food safety. Full article

Enzyme immobilization onto solid supports enhances their stability, reusability, and efficiency. This work investigates the physical immobilization of laccase (Lac) from Trametes versicolor (purchased, EC 1.10.3.2, ≥0.5 U/mg) onto two carbon-based materials: activated carbon (AC) and biochar (BC), obtained from spent brewery grains (SBGs) through microwave pyrolysis (with and without chemical activation, respectively), generating SBG-AC/Lac and SBG-BC/Lac. Various immobilization conditions (pH 3.5–6.5, Lac concentration 1–10 mg/mL) were tested, with immobilization up to 80 ± 6% (for Lac 1 mg/mL, pH 5.0 in SBG-AC/Lac) and maximum activities of 5.5 ± 0.2 U/g (SBG-AC/Lac) and 4.6 ± 0.5 U/g (SBG-BC/Lac) at pH 3.5 and 40 °C. Although SBG-AC led to a higher immobilization %, SBG-BC was a greener alternative, requiring no chemical activation during production. Kinetics analysis with a typical Lac chromogenic substrate revealed higher values of K_M (Michaelis constant) for SBG-BC/Lac compared with free Lac (Lac_f) (indicating lower substrate affinity), but higher stability, retaining ~60% activity after 24 h, while Lac_f was nearly inactive. These results demonstrate the potential of SBG-BC as a sustainable support for Lac immobilization in applications such as wastewater treatment and environmental monitoring. Full article

Alfalfa (Medicago sativa L.) is a key forage crop, but its production is severely limited by water scarcity. This study evaluated the effects of exogenous abscisic acid (ABA) root application on the drought tolerance of the alfalfa cultivar “Xinmu No. 4”, focusing on water use efficiency (WUE), physiological traits, and transcriptome expression. The highest WUE was achieved at 25 μM ABA and 10% polyethylene glycol-6000 (PEG-6000). Physiological parameters, including proline (Pro), malondialdehyde (MDA), hydrogen peroxide (H₂O₂), peroxidase (POD), catalase (CAT), and methyl jasmonate (MeJA) in both leaves and roots, showed strong positive correlations with the WUE (p < 0.01), with leaf POD showing a significant correlation (p < 0.05). Regression analysis showed that 34.42 µM ABA under 10% PEG-6000 significantly optimized the WUE. Transcriptomic analysis revealed that ABA enhanced the WUE by enriching genes involved in root defense response and leaf oxidoreductase activity. These results demonstrate that root-applied ABA under drought stress significantly improves the WUE and drought tolerance in alfalfa, offering a promising strategy to enhance forage crop resilience to water scarcity. Full article

ywqN encodes a protein with an unassigned function that shares partial 3D homology with B. subtilis YhdA, Pseudomonas putida ChrR, and Escherichia coli YieF, which are NADP(H)/FMN-dependent oxidoreductases that catalyze the reduction of diverse chemical pollutants, including Cr(VI). Here, we report that a recombinant His₆-YwqN protein displays marginal chromate reductase activity but is capable of reducing synthetic azo dyes. Remarkably, His₆-YwqN exhibits a potent quinone reductase activity, catalyzing the reduction of menadione (MD) and 1,4-naphthoquinone (NQ). The individual and combined roles of YwqN and YhdA in protecting B. subtilis from ROS-promoting agents were further tested. Sensitization to the oxidizing agent H₂O₂ required the simultaneous loss of both YwqN and YhdA. In contrast, strains deficient in ywqN, either alone or in combination with yhdA, exhibited similar but higher susceptibilities to the superoxide-generating agent MD compared with the WT strain. These results indicate that YwqN and YhdA contribute to protection against the deleterious effects of ROS in B. subtilis. Further results revealed that while YwqN, but not YhdA, prevented MD-induced mutagenesis, both proteins synergistically prevented Rif^R mutations induced by H₂O₂. Furthermore, overexpression of YwqN suppressed the hypermutagenesis phenotype of a B. subtilis strain deficient in the prevention/repair oxidized guanine (GO) system, which is prone to accumulate 8-oxoGs. In summary, YwqN counteracts the cytotoxic and genotoxic effects promoted by ROS in B. subtilis and represents a potential tool for the remediation of soils and effluents contaminated with carcinogenic azo dyes. Full article

Heat stress (HS) severely impairs boar reproductive function by inducing oxidative stress and inflammatory responses, while lycopene (LYC), as a potent antioxidant, exerts a potential protective effect on the male reproductive system. This study aimed to clarify the mechanism underlying LYC-mediated alleviation of HS-induced decline in semen quality in Rongchang boars, identify the most affected tissues, and explore its regulatory role in the Nrf2 (Nuclear factor E2-related factor 2) pathway. A total of 18 Rongchang boars with an initial body weight of 15.81 ± 1.07 kg were randomly assigned to three groups (6 boars per group): the control group (CON, 26 ± 1 °C), the heat stress group (HS, exposed to 35 ± 1 °C for 8 h daily), and the heat stress + 100 mg/kg lycopene group (HS + LYC). After 28 days of adaptive feeding and 14 days of HS treatment, samples were collected for semen quality analysis, testicular histological analysis, antioxidant index detection, transcriptome analysis, Nrf2 pathway detection, and inflammatory index detection. The results showed that HS significantly increased the sperm abnormality rate (p < 0.05), damaged the testicular structure, and induced oxidative stress in serum, lung, liver, left ventricle, testis, and epididymis (caput epididymis, corpus epididymis, cauda epididymis), with varying degrees of oxidative stress observed in these samples. Among these tissues, the testis and cauda epididymis exhibited the most significant responses to HS and LYC, with the comprehensive impact magnitudes of 317% and 514%, respectively. Enrichment analysis of differentially expressed genes (DEGs) in these two tissues revealed that the pathways mediating oxidative stress response displayed distinct tissue specificity, and all of them were closely associated with the Nrf2 antioxidant signaling pathway. HS significantly downregulated the mRNA expressions of Nrf2, Quinone Oxidoreductase (NQO1), Heme Oxygenase 1 (HMOX1) and Glutamate-Cysteine Ligase Catalytic Subunit (GCLC) genes as well as the protein level of Nrf2 in the testis and cauda epididymis, increased the protein level of Keap1, and significantly elevated the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in these two tissues (p < 0.05). Compared with the HS group, dietary supplementation of LYC significantly improved sperm motility and the proportion of rapidly progressive sperm, reduced the proportion of immotile sperm and sperm abnormality rate (p < 0.05), alleviated testicular damage and oxidative stress in various tissues, upregulated the mRNA expressions of Nrf2 and HMOX1 genes in the testis as well as the mRNA expressions of Nrf2, NQO1, HMOX1 and GCLC genes in cauda epididymis (p < 0.05), significantly increased the Nrf2 protein level and decreased the Keap1 protein level in these two tissues, and simultaneously decreased the levels of the aforementioned inflammatory factors (p < 0.05). In conclusion, dietary supplementation with 100 mg/kg LYC can alleviate HS-induced decline in semen quality and testicular damage by regulating the oxidative status and inflammatory level of relevant tissues (e.g., testis and cauda epididymis) in boars, and this protective effect may be associated with the regulation of the Nrf2 signaling pathway. Full article

A new category of polyphenolic compounds, like flavonoids, phenolic acids, phenylpropanoids, terpenoids, and others, referred to as food nutrients, may counteract the harmful effects of micro- and nanoplastics (MNPs) by enhancing cellular stress resilience response and overall human health. These compounds found in functional food help mitigate the cellular damage, inflammation, and oxidative stress caused by MNP exposure, which can contribute to pathological conditions, including diabetes. Importantly, specific food nutrients are able to activate, at the minimum dose, the nuclear factor erythroid-derived 2-like 2 (Nrf2) to prevent or block MNP-induced damage. The Nfe2l2 gene encodes the Nrf2 transcription factor, acting as a master regulator of redox homeostasis by inducing antioxidant response element (ARE)-driven resilience genes, which in turn, promote the expression of detoxification enzymes like heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidoreductase 1 (NQO1), and glutathione S-transferase (GST) to scavenge reactive oxygen species (ROS) and shield cells from environmental damage and toxicity. Deregulation of the Nfe2l2 gene due to the accumulation of MNP pollutants may exacerbate the inflammatory conditions associated with diabetes and its chronic complications by rendering cells more sensitive to oxidative stress, apoptosis, and pyroptosis. Furthermore, epigenetic modifications influence gene regulation; chromatin remodeling directly impacts DNA accessibility, allowing or limiting transcription factor access to regulate gene expression. This mechanism may also play a pivotal role in the progression of oxidative stress-related diseases, as it modulates the Nrf2 pathway and the expression levels of its target genes. In contrast to the current literature, which has only addressed the pathological mechanisms induced by MNPs, this research explores, for the first time, how food nutrients interacting with the Nfe2l2 gene can combat or reverse the toxic effects of MNPs in cells, tissues, and organs. The goal is to improve health by attenuating MNP toxicity, which is influenced by individual genetic variations and cellular stress resilience. Full article

2,5-Furandicarboxylic acid (FDCA) is an important bio-based platform compound that can be synthesized through the biotransformation of 5-hydroxymethylfurfural (HMF). However, the limited availability of safe microbial strains is a major constraint in the whole-cell catalysis of HMF to FDCA. In this study, a strain capable of catalyzing the conversion of HMF to FDCA, Bacillus subtilis J8M8, was identified. Under optimized whole-cell catalytic conditions, the wild-type strain produced 33.1 mM FDCA with a yield of 41.4%. To enhance FDCA production, HMF/furfural oxidoreductase (HmfH), PQQ-dependent alcohol dehydrogenase (ADH), and aryl-alcohol oxidase (MaAAO) were co-expressed in B. subtilis J8M8. As a result, FDCA production increased to 72.3 mM, with a yield of 90.4%. Further optimization of the engineered strain improved FDCA production to 83.3 mM and yield to 92.6%, representing a 2.52-fold increase over that of the wild-type strain. This study establishes a foundation for the safe and sustainable production of FDCA from HMF. Full article

Sheep’s meat production and quality are influenced by genetic and physiological factors that affect muscle development, growth, and fat deposition metabolism. However, the breed-specific transcriptional landscapes driving these traits in Indian sheep breeds, especially in Nellore (meat-type) and Deccani (wool-meat type) breeds are remain unexplored. Therefore, this study aimed to investigate the differences in muscle growth and fat deposition between Nellore and Deccani breeds by integrating transcriptomic profiling, carcass characteristics, and histological analysis of longissimus dorsi muscle and liver tissues. Carcass assessment revealed higher Hot Carcass Weight (HCW), Cold Carcass Weight (CCW), Hot Carcass Yield (HCY) and Cold Carcass Yield (CCY), and larger myofibrillar cross-sectional area (p < 0.05), indicating enhanced musculature, which was observed in Nellore. Deccani showed elevated Intramuscular Fat (IMF) deposition (p < 0.05), indicating improved meat flavour/juiciness. Transcriptomic profiling revealed several Differentially Expressed Genes (DEGs) associated with meat quality and quantity traits. In Nellore, the genes WFIKKN2, FGFRL1, FKBP4, and IRF1 were upregulated, while the gene TAS1R2 was downregulated, leading to enhanced muscle development, superior carcass traits, thermotolerance, and immunity. While Deccani showed higher expression of lipid metabolism genes PLA2G4F, ACSL1, ACOX1, CPT1A, and PLIN1, which are linked to higher IMF content. Functional enrichment analysis revealed 46 significantly enriched GO terms for the DEGs (p < 0.05), including oxidoreductase activity, muscle development, etc. These outcomes demonstrate novel genetic markers and key biological insights into the regulation of muscle development, thermotolerance, immunity, and IMF for future validation in Indian sheep breeds. Full article