Search Results (96)

Aflatoxin B₁ (AFB₁) is a highly stable mycotoxin that can persist during conventional food processing and therefore poses a serious risk to food and feed safety. In this study, two enzymes (CotA and Prx) were heterologously expressed in Bacillus subtilis, purified by Ni–NTA affinity chromatography, and evaluated for their ability to degrade AFB₁. Both enzymes exhibited remarkable thermostability and distinct catalytic optima. CotA exhibited its highest activity at 80 °C with an AFB₁ removal of 38.4%, whereas Prx showed its highest activity at 90 °C with a removal of 82.6%. The optimal pH values were near neutral, with CotA performing best at pH 7.0 and Prx at pH 7.5, and both reactions approached maximal conversion within approximately 10 h. When the two enzymes were combined, a clear cooperative effect was observed. The mixed system achieved 91.0% AFB₁ removal at 80 °C after 10 h, with the best degradation activity occurring at a CotA to Prx ratio of 1:3. At 50 °C, neither enzyme alone caused appreciable AFB₁ degradation, but the addition of hydrogen peroxide markedly enhanced catalytic activity. Both enzymes also retained substantial activity after boiling and autoclaving. In a maize flour model, the mixed-enzyme system showed strong AFB₁ degradation capacity, and peroxide-assisted treatment further improved activity. These results establish a thermostable and peroxide-responsive enzymatic platform for AFB₁ degradation and support future development of enzyme-based detoxification strategies for food and feed applications. Product identification and toxicological validation will be needed to confirm the safety of the treated products. Full article

Aflatoxin B1 (AFB1) is a potent mycotoxin threatening food and feed safety. Here, we report the identification and characterization of a Bacillus safensis-derived multicopper oxidase (BsaMCO) capable of efficient AFB1 detoxification. Recombinant BsaMCO exhibited robust in vitro activity, achieving >78% degradation of AFB1 under 24 h incubation at 37 °C. Optimization experiments revealed that enzyme concentration, pH, temperature, metal ions, and electron acceptors significantly influenced degradation efficiency, defining an operational window suitable for practical applications. LC–MS profiling suggested the presence of transformation products tentatively consistent with oxidative demethylation to aflatoxin P1 (AFP1) and with the formation of AFG2a-like products through subsequent hydration- and oxidation-related transformations. Molecular docking and 100 ns all-atom molecular dynamics (MD) simulations demonstrated stable binding of AFB1 in the T1 copper pocket. Van der Waals and electrostatic interactions, together with a persistent hydrogen bond at Gly323, facilitated single-electron transfer through the intramolecular T2/T3 copper cluster. Principal component and Gibbs free energy analyses confirmed a low-energy, stable conformational ensemble. HepG2 cell assays indicated that BsaMCO-degraded products substantially reduced cytotoxicity and apoptosis compared with native AFB1. Simulated feed experiments further validated enzymatic AFB1 degradation, with approximately 53% reduction after 24 h. Collectively, these findings establish BsaMCO as a safe and effective biocatalyst for AFB1 detoxification, providing mechanistic, structural, and cellular evidence supporting its application in food and feed safety. Full article

Aflatoxin B1 (AFB1) poses a serious threat to global food and feed safety. Laccase-based enzymatic degradation represents a promising green strategy for AFB1 removal; however, its industrial application is severely limited by the rapid thermal inactivation of wild-type enzymes under high-temperature processing conditions (>70 °C). Here, we engineered the thermal stability of a laccase from Bacillus amyloliquefaciens B10 through an integrated strategy combining computational structural biology with semi-rational design. By coupling molecular dynamics (MD) simulations with folding free-energy (ΔΔG) calculations, we identified key flexible regions associated with thermal instability and subsequently implemented iterative saturation mutagenesis. The best single mutant, R196C, retained more than 96% relative activity after heat treatment at 80 °C for 10 min. Further iterative mutational stacking progressively enhanced thermostability: the R90E/R196C double mutant showed 1.25-fold higher activity at 80 °C than R196C, and the R90E/R196C/H54F triple mutant showed a further 1.16-fold increase over the double mutant. The final quadruple mutant, R90E/R196C/H54F/R253I, achieved 86.9% AFB1 degradation at 80 °C after 24 h. High-temperature MD simulations (100 ns at 353.15 K) indicated that the enhanced thermostability was associated with reduced conformational flexibility, lower radius of gyration (Rg) and solvent-accessible surface area (SASA), and a coil-to-β-sheet transition that contributed to stabilization of the protein core. In addition, efficient secretory expression of the engineered enzyme was achieved in Pichia pastoris, reaching 3.0 U/mL, while the crude enzyme maintained more than 70% activity at 80 °C. Collectively, these results provide a practical basis for the rational engineering and scalable production of thermostable biocatalysts for AFB1 detoxification-related applications of AFB1 control, and offer broader insights into the targeted enhancement of thermal stability in industrial enzymes. Full article

Aflatoxin B1 (AFB1) contamination is a significant issue for the safety of edible oils. Biodegradation of mycotoxins represents a green and efficient approach. However, enzymes exhibit low catalytic activity and stability under harsh conditions, leading to rapid deactivation in edible oils. Zeolitic imidazolate frameworks (ZIFs) possess high specific surface areas, tunable pore sizes, and excellent thermal stability. Immobilizing enzymes on ZIFs can address the problem of enzyme inactivation during application. Although the stability of the enzyme can be enhanced after immobilization, the overall enzymatic activity remains limited. To overcome the issues of low catalytic activity and poor cycling stability associated with enzymes immobilized on ZIF-8 using 2-methylimidazole (2-mIM) as the ligand, this study optimized the ZIF structure through a ligand screening strategy. Both encapsulation efficiency and cycling stability were enhanced. This research found that the activity of Lac@ZIFs(IM), which uses imidazole (IM) as the ligand, was 2.16 times that of Lac@ZIF-8. The degradation efficiency of AFB1 reached 93% within 4 h in edible oil using Lac@ZIFs(IM) as the catalyst, which was 21-fold higher than that of free laccase. Lac@ZIFs(IM) exhibited excellent activity in the continuous flow system. After 20 h of continuous reaction, the activity of Lac@ZIFs(IM) was 6.6 times that of Lac@ZIF-8. This study provides a novel approach for the efficient enzymatic degradation of mycotoxins. Full article

Mycotoxin contamination in agricultural products poses a serious challenge to food safety, severely threatening human and animal health and causing significant economic losses. This study aimed to investigate the degradation and detoxification capabilities of Trichoderma reesei GG-T40 against two representative mycotoxins—aflatoxin B₁ (AFB₁) and zearalenone (ZEN). The results showed that the degradation rates of AFB₁ and ZEN by this strain reached 98.6% and 88.4%, respectively. Using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF MS), the degradation products were systematically characterized, leading to the identification of six AFB₁ degradation products (C₁₇H₁₄O₇, AFD₁: C₁₆H₁₄O₅, C₁₁H₁₀O₄, C₁₄H₁₆O₄, C₁₅H₁₀O₄, and C₁₇H₁₄O₅) and two ZEN degradation products (α-ZOL and β-ZOL). Toxicity evaluation revealed that the key toxic structures of AFB₁ were disrupted, significantly reducing or even eliminating the toxicity of its degradation products; ZEN was mainly converted into β-ZOL (accounting for 91.5%), which has lower estrogenic activity. Further toxicological experiments in mice confirmed that the degradation products were non-toxic and non-pathogenic under actual testing conditions, demonstrating systematic verification of their safety. In conclusion, T. reesei GG-T40 can efficiently and safely degrade AFB₁ and ZEN, showing great potential for developing green control technologies for mycotoxin contamination in food and feed raw materials, with important application value for ensuring food safety. Full article

Aflatoxin B1 (AFB1) is a naturally occurring contaminant pervasively found in agricultural produce, exhibiting extremely high carcinogenicity, teratogenicity and immunotoxicity, thereby constituting a substantial menace to worldwide food security and public health. Consequently, developing green and efficient degradation strategies for AFB1 is highly important. The intestinal tract of black soldier fly (Hermetia illucens) larvae (BSFL) contains complex, functionally diverse microbial communities that function as microbial reactors to degrade emerging environmental pollutants such as pesticides, microplastics, mycotoxins, and antibiotics. This functional characteristic offers a novel approach for mitigating AFB1 contamination. In this review, we systematically summarize the currently reported AFB1 degradation methods, focusing on the biological mode of action of the intestinal microbiota of BSFL. We elaborate on the efficacy of BSFL in AFB1 detoxification in terms of the host–microorganism co-degradation mechanism and discuss the core intestinal microbiota of BSFL and the main microbial degradation pathways involved in AFB1 metabolism during degradation. Given the low cost, high efficiency, safety, and sustainability of using the BSFL as living microbial reactors in which the core gut microbiota and the larval host detoxifying enzyme system synergistically degrade AFB1, this study provides a scientific reference for managing AFB1 pollution to overcome food security issues. Full article

Due to the high toxicity and widespread distribution of aflatoxin B1 (AFB1), there is significant interest in efficient, safe, and environmentally friendly microbial degradation methods. Rhodococcus opacus PD630 cell-free supernatant (RCFS) shows excellent activity in degrading AFB1, but its active components and mechanisms remain unclear. We assessed the feasibility of ethanol precipitation to enrich active components in RCFS and characterized the ethanol precipitate (RCFSC-EP). Metabolomics and proteomics were used to elucidate the active components, mechanisms, and products of AFB1 degradation by RCFS. The results indicate that ethanol precipitation enriches over 80% of the active components for AFB1 degradation in RCFS. RCFSC-EP exhibits excellent heat resistance, and inhibitors like EDTA-2Na and proteinase K significantly inhibit its activity. Multi-omics analysis suggests that active components in RCFS metabolize AFB1 into six products through four potential pathways, three of which withstand 135 °C for 20 min. The AFB1-degrading activity of RCFS is an intrinsic, constitutive trait of R. opacus PD630 during normal growth. The active components are diverse proteins or enzymes, including glutathione S-transferases, aldo/keto reductase, peroxidases, and carbonyl reductases. This study enriches and reveals the active components, pathways, and products of AFB1 degradation by RCFS, providing a basis for developing RCFS as a biological agent for AFB1 degradation. Full article

Aflatoxin B1 (AFB1) and its metabolite aflatoxin M1 (AFM1) are stable and carcinogenic mycotoxins that are commonly found in dairy products, posing serious food safety concerns. However, conventional degradation methods face limited degradation efficiency and high energy demand. Here, we develop an innovative polyvinylidene fluoride (PVDF) composite membrane incorporating Fe/Co-based metal-organic frameworks (MOF) (Named Fe/Co-MIL-88B(NH₂)) and CaO₂ for targeted aflatoxin removal from milk. This system integrates two synergistic mechanisms: (1) hierarchical porous MOF structures enabling superior aflatoxin adsorption capacity and peroxidase-like catalytic activity, and (2) CaO₂ acts as a controllable-release H₂O₂ donor, supplying a steady flux of reactive oxygen species without the addition of exogenous H₂O₂. Moreover, the PVDF membrane with mechanical stability offers uniform immobilization of active components, which prevents the aggregation of nanozymes. As a result, the integrated membrane achieves high degradation efficiency for AFB1 and AFM1, exceeding 95% within 60 min. By eliminating external oxidant addition and minimizing collateral nutrient damage, the technology demonstrates remarkable operational stability (>10 cycles) and milk quality preservation capability. This breakthrough establishes an efficient and reusable detoxification method, providing new opportunities for mycotoxin mitigation in dairy products through spatiotemporal control of reactive oxygen species. Full article

Mycotoxin contamination represents a major risk to both human and animal health. Antioxidants can mitigate some of these effects through free radical scavenging, reduction in oxidative stress, and anti-inflammatory and immunomodulatory actions. This work investigated the potential of antioxidants derived from grapeseed and sea buckthorn to mitigate the adverse effects of aflatoxin B1 (AFB1) and ochratoxin A (OTA) in weaned piglets. An unbiased Data-Independent Acquisition (DIA) proteomic approach was used to analyse the impact of OTA- and AFB1-contaminated diets on liver and kidney cytoplasmic metabolism, particularly focusing on the conjugation phase. Our results indicate that several toxic effects of these mycotoxins were partially alleviated by dietary antioxidant supplementation. Additionally, in kidneys, some of the effects are synergistically amplified, such as proteins involved in fatty acid degradation, peroxisome, PPAR signalling, translation, the TCA cycle, and excretion pathways. Inclusion of antioxidants in the animal diet can have beneficial effects. Nevertheless, caution is advised; synergistic effects can occur with potentially more serious consequences than the effects of mycotoxins alone. Full article

Aflatoxin (AF) contamination in pistachios remains a critical food safety and trade challenge, given the potent carcinogenicity of AF-B₁ and the nut’s high susceptibility to Aspergillus infection throughout production and storage. Traditional decontamination methods such as roasting, irradiation, ozonation, and acid/alkaline treatments can reduce AF levels but often degrade sensory and nutritional quality, implying the need for more sustainable approaches. In recent years, innovative nonthermal interventions, including pulsed light, cold plasma, nanomaterial-based adsorbents, and bioactive coatings, have demonstrated significant potential to decrease fungal growth and AF accumulation while preserving product quality. Biosensing technologies such as electrochemical immunosensors, aptamer-based systems, and optical or imaging tools are advancing rapid, portable, and sensitive detection capabilities. Combining these experimental strategies with artificial intelligence (AI) and machine learning (ML) models can increasingly be applied to integrate spectral, sensor, and imaging data for predicting fungal development and AF risk in real time. This review brings together progress in nonthermal reduction strategies, biosensing innovations, and data-driven approaches, presenting a comprehensive perspective on emerging tools that could transform pistachio safety management and strengthen compliance with global regulatory standards. Full article

The major objective was to investigate the protective capabilities of endophytic bacterial strains isolated from a number of medicinal plant species towards Aspergillus spp. secured from the internal tissues of fungi-infected peanuts. Among 32 fungal isolates surveyed for mycotoxin production in various culture media (PDA, RBCA, YES, CA), 10 isolates qualitatively producing AFB₁, besides 10 OTA-producers, were assayed by HPLC for quantitative toxin production. Aspergillus spp. isolate Be 13 produced an extraordinary quantity of 1859.18 μg mL⁻¹ AFB₁, against the lowest toxin level of 280.40 μg mL⁻¹ produced by the fungus isolate IS 4. The estimated amounts of OTA were considerably lower and fell in the range 0.88–6.00 μg mL⁻¹; isolate Sa 1 was superior, while isolate Be 7 seemed inferior. Based on ITS gene sequencing, the highly toxigenic Aspergillus spp. isolates Be 13 and Sa 1 matched the description of A. novoparasiticus and A. ochraceus, respectively, ochraceus, respectively, which are present in GenBank with identity exceeding 99%. According to 16S rRNA gene sequencing, these antagonists labeled Ar6, Ma27 and So34 showed the typical characteristics of Pseudomonas aeruginosa, Bacillus subtilis and Bacillus velezensis, respectively, with similarity percentages of 99–100. The plant growth-promoting activity measurements of the identified endophytes indicated the production of 16.96–80.00 μg/100 mL culture medium of IAA. Phosphate-solubilizing capacity varied among endophytes from 2.50 to 21.38 μg/100 mL. The polysaccharide production pool of bacterial strains ranged between 2.74 and 6.57 mg mL⁻¹. P. aeruginosa Ar6 and B. velezensis successfully produced HCN, but B. subtilis failed. The in vitro mycotoxin biodegradation potential of tested bacterial endophytes indicated the superiority of B. velezensis in degrading both mycotoxins (AFB₁-OTA) with average percentage of 88.7; B. subtilis ranked thereafter (85.6%). The 30-day old peanut (cv. Giza 6) seedlings grown in gnotobiotic system severely injured due to infection with AFB₁/OTA-producing fungi, an effect expressed in significant reductions in shoot and root growth traits. Simultaneous treatment with the endophytic antagonists greatly diminished the harmful impact of the pathogens; B. velezensis was the pioneer, not P. aeruginosa Ar6. In conclusion, these findings proved that several endophytic bacterial species have the potential as alternative tools to chemical fungicides for protecting agricultural commodities against mycotoxin-producing fungi. Full article

Hepatocellular carcinoma (HCC) imposes a significant burden on global public health. Exposure to aflatoxins, potent mycotoxins produced by Aspergillus fungi contaminating staple foods, and chronic hepatitis B virus (HBV) infection are major etiological factors, especially where they co-exist. This review examines the critical role of the p53 tumor suppressor pathway as a primary target and convergence point for the carcinogenic actions of aflatoxins and HBV. Aflatoxin B₁ (AFB₁), a Group 1 carcinogen, exerts significant genotoxicity, characteristically inducing a specific hotspot mutation (R249S) in the TP53 gene via DNA adduct formation, thereby compromising p53’s critical tumor suppressor functions. This R249S mutation is considered a molecular fingerprint of aflatoxin exposure. Concurrently, the HBV X protein (HBx) functionally inactivates wild-type p53 through direct binding and by promoting its degradation. The synergistic disruption of the p53 pathway, driven by AFB₁-induced mutation and amplified by HBV-mediated functional inhibition, significantly enhances the risk of HCC development. This review addresses how aflatoxin exposure alters key aspects of p53 and how this damage interacts with HBV-mediated p53 suppression, providing crucial insights into hepatocarcinogenesis. The knowledge synthesized here underscores the importance of mitigating aflatoxin exposure alongside HBV control for effective HCC prevention and treatment strategies. Full article

To address the issue of aflatoxin contamination, which poses a significant threat to food safety and human health, we have conducted extensive research. We have isolated a strain of Myroides odoratimimus (3J2MO) from the soil that exhibited remarkable efficiency in degrading various aflatoxin types, including AFB1, AFB2, AFG1, AFG2, and AFM1. SDS-PAGE analysis confirmed the purity of the enzymes to be over 95%. Through fluorescence assays, we quantified the enzymatic activity, with an AFB1 degradation rate of 95% achieved at 37 °C and a pH of 8.0. Further analysis using HPLC-MS/MS identified the degradation intermediates, revealing the mechanisms of lactone ring cleavage and epoxy group hydrolysis. GO/COG/KEGG annotations provided insights into the functions of these enzymes, with peroxidase linked to reactive oxygen species (ROS) generation and helicase associated with ATP-dependent conformational changes. Helicase, on the other hand, hydrolyzes ATP, driving conformational changes in AFB1 and facilitating its breakdown into non-toxic metabolites. The potential industrial-scale application of this discovery could significantly mitigate aflatoxin-related economic losses while minimizing chemical residues in the food chain. Full article

With the increasing application of electrical network frequency (ENF) in forensic audio and video analysis, ENF signal detection has emerged as a critical technology. However, high-pass filtering operations commonly employed in modern communication scenarios, while effectively removing infrasound to enhance communication quality at reduced costs, result in a substantial loss of fundamental frequency information, thereby degrading the performance of existing detection methods. To tackle this issue, this paper introduces Multi-HCNet, an innovative deep learning model specifically tailored for ENF signal detection in high-pass filtered environments. Specifically, the model incorporates an array of high-order harmonic filters (AFB), which compensates for the loss of fundamental frequency by capturing high-order harmonic components. Additionally, a grouped multi-channel adaptive attention mechanism (GMCAA) is proposed to precisely distinguish between multiple frequency signals, demonstrating particular effectiveness in differentiating between 50 Hz and 60 Hz fundamental frequency signals. Furthermore, a sine activation function (SAF) is utilized to better align with the periodic nature of ENF signals, enhancing the model’s capacity to capture periodic oscillations. Experimental results indicate that after hyperparameter optimization, Multi-HCNet exhibits superior performance across various experimental conditions. Compared to existing approaches, this study not only significantly improves the detection accuracy of ENF signals in complex environments, achieving a peak accuracy of 98.84%, but also maintains an average detection accuracy exceeding 80% under high-pass filtering conditions. These findings demonstrate that even in scenarios where fundamental frequency information is lost, the model remains capable of effectively detecting ENF signals, offering a novel solution for ENF signal detection under extreme conditions of fundamental frequency absence. Moreover, this study successfully distinguishes between 50 Hz and 60 Hz fundamental frequency signals, providing robust support for the practical deployment and extension of ENF signal applications. Full article

Food security and food safety are major aspects for human and animal health, yet mycotoxins contaminate 60–80% of food crops before and after harvest, elevating the risk of chronic toxicity and cancer development. This study investigates the potential of ferulic acid (FA) as an antioxidant against mycotoxin-induced oxidative stress in Caco-2 cells exposed to aflatoxin B1 (AFB1) and ochratoxin A (OTA) for 24 and 48 h. The effects on the degree of lipid peroxidation and non-enzymatic and enzymatic mechanisms against oxidative stress were evaluated. FA appears to mitigate oxidative stress by modulating lipid and protein oxidation, decreasing the level of 4-hydroxy-2-nonenal (4-HNE), increasing superoxide dismutase (SOD) activity, and preserving thiol groups by scavenging reactive oxygen species (ROS). Additionally, the reduction in polyubiquitinated Nrf2 level, and higher SOD activity, suggest that FA stabilizes Nrf2, delaying its degradation and reinforcing its antioxidant role. These findings indicate that FA partially counteracts mycotoxin-induced oxidative damage, highlighting the need for further investigation into its long-term effects. Full article