Search Results (17)

Marine fungi associated with sponges and brown algae are promising sources of pharmacologically active compounds. This study investigated the cytotoxic potential and metabolomic profiles of fungal strains isolated from the marine environment of Mauritius. Among the twenty extracts screened, the mycelium extracts were more cytotoxic than the broth extracts. Four extracts demonstrated the most potent activity: Aspergillus chevalieri (F2M), Aspergillus ochraceus (F25M) and Biatriospora sp. (F34M, F34B). The algal endophyte Aspergillus chevalieri (F2M) mycelium extract displayed an IC₅₀ of 14.27 ± 1.22 µg/mL after 24 h against HepG2 cells. The sponge-associated fungi Aspergillus ochraceus (F25M) showed promising cytotoxic activities against HepG2 cells (IC₅₀ of 8.775 ± 0.78 µg/mL) after 24 h of treatment, with a selectivity index of 2.27, and had the lowest IC₅₀ (2.49 ± 0.60 µg/mL after 24 h; 7.14 ± 3.14 µg/mL after 48 h) against FLO-1 cells, also reducing tumor spheroid growth and integrity during the first four hours. All four extracts increased the intracellular ROS production, but only the mycelium extract of A. chevalieri (F2M) significantly increased superoxide dismutase (SOD) and catalase (CAT) activity. Metabolomic profiling identified diverse compound classes, including alkaloids, terpenoids, amino acids, anthraquinones and coumarins. The findings revealed that the marine fungi from Mauritius are promising sources of cytotoxic metabolites that require purification and subsequent confirmation and mechanistic studies. Full article

To investigate the influence of single fungi fermentation on dark tea, Aspergillus chevalieri and Aspergillus cristatus were isolated from Fu-brick tea in this study. Both strains were used for solid-state fermentation of Fu-brick tea to analyze volatile compounds, while A. cristatus was used for liquid-state fermentation to analyze metabolite changes. Solid-state fermentation with Aspergillus chevalieri and Aspergillus cristatus yielded 56 and 63 volatile compounds, respectively, with alcohols, aldehydes, and ketones as the predominant classes. Notably, A. cristatus biotransformation resulted in the highest total volatile content, primarily characterized by trans-linalool oxide, cis-linalool oxide, and dihydroactinidiolide. Conversely, Aspergillus chevalieri fermentation produced fewer aroma compounds, mainly trans-linalool oxide and dihydroactinidiolide. Widely targeted metabolomics further revealed that flavonoids, amino acids and derivatives, phenolic acids, lipids, and tannins were significantly reduced in the liquid-state-fermented tea leaves, whereas most differential metabolites accumulated in the tea infusions. Flavonoid biosynthesis and amino acid metabolism were identified as the most significantly enriched pathways. These findings elucidate strain-dependent divergence in aroma composition and non-volatile metabolite transformation, offering a scientific basis for targeted strain selection and process optimization in the development of industrial fermented tea products. Full article

This study investigates the effect of gamma irradiation on the physicochemical, mechanical, and antimicrobial properties of biodegradable composite films based on modified cassava starch/gelatin (GS) and wheat gluten/gelatin (GG), including their active formulations with 2% potassium sorbate (GS2S and GG2S, respectively). Films were produced by casting and irradiated at 2–32 kGy. Irradiation modulated the structure–property relationships of starch–protein matrices in a dose-dependent manner. In GG systems, tensile strength increased while elongation decreased, indicating enhanced intermolecular interactions. At higher doses (16–32 kGy), excessive rigidity was observed, whereas lower doses (2–8 kGy) provided a more favorable balance between strength and flexibility. Water vapor permeability decreased in selected formulations, while solubility results indicated the coexistence of crosslinking and chain scission mechanisms. Among the tested conditions, 2 kGy was identified as the optimal dose. Despite the incorporation of 2% potassium sorbate, antimicrobial performance remained limited, with modest inhibition against Wallemia sebi and negligible effects on Aspergillus chevalieri and Aspergillus montevidensis. HPLC analysis demonstrated a significant reduction in sorbate release after irradiation (up to ~80%), indicating that restricted mass transfer, rather than intrinsic antimicrobial inefficiency, governs the observed behavior. The main novelty of this work lies in demonstrating that irradiation-induced structural modifications improve mechanical and barrier properties but simultaneously hinder active compound release. This decoupling between structural performance and functional activity highlights a critical limitation in irradiated active films. Overall, gamma irradiation at 2 kGy is effective for tuning material properties; however, controlling release kinetics is essential to achieve functional antimicrobial performance in biodegradable active packaging systems. Full article

Sea buckthorn (Hippophae rhamnoides L.) leaves are rich in nutrients and bioactive constituents, with great potential for fermented tea development. It has been demonstrated that Fuzhuan brick tea processing can improve sea buckthorn leaf tea flavor, but the underlying microbial succession remains unexplored. Therefore, we characterized the dynamic succession and interrelationships of bacterial and fungal communities via Illumina NovaSeq 6000 sequencing. β-diversity analysis revealed successive shifts in microbial community structure, with fungal communities changing mainly in the early stage and bacterial communities varying more in the late stage of fermentation. The relative abundance of Pseudomonas, a genus frequently associated with flavor formation and tea quality, increased steadily. Fungal taxonomic analysis revealed that the genus Aspergillus, particularly the species Aspergillus chevalieri, remained dominant throughout the fermentation process. Linear discriminant analysis effect size indicated an enrichment of microbial taxa typical of fermentation, accompanied by a relative reduction in putative opportunistic microbes. Additionally, Aspergillus exhibited significant negative correlations with five key differentially abundant bacterial genera. Interestingly, microbial co-occurrence networks suggested an overall tendency toward coexistence rather than mutual exclusion between the bacterial and fungal communities. This work provides a theoretical foundation for the development of novel fermented sea buckthorn leaf tea products. Full article

This study assessed mycotoxin contamination in roasted peanut snacks and kluiklui (fried pressed peanut cake), and consumer exposure in southern Benin. Roasted peanut snacks and kluiklui were sampled from markets across six municipalities, and their production follow-up was conducted on two sites using different processing methods. Mycotoxins were quantified using UPLC-MS/MS, while fungal species were identified via culture-based methods. Exposure to aflatoxin B1, total aflatoxins and ochratoxin A was estimated. Aflatoxin B1 predominated, reaching 169 µg/kg in roasted peanut snacks and 2144.64 µg/kg in marketed kluiklui. In contrast, just-produced kluiklui contained much lower levels (11.73–37.78 µg/kg). Aspergillus flavus and Aspergillus niger predominated in kluiklui from the first processing site, while Aspergillus chevalieri dominated in kluiklui from the second processing site. The grinding step (using public grinder) was identified as the main contamination point. The significative higher mycotoxin levels in kluiklui sampled on markets compared to just-produced kluiklui are probably due to poor storage conditions. Dietary exposure estimates revealed that margins of exposure for aflatoxins were far below the safety threshold of 10,000, and liver cancer risk estimates were particularly high for kluiklui consumers. Kluiklui consumption poses a significant health risk in Benin. Improved hygiene in public grinders and better storage practices are urgently needed to reduce contamination and protect consumers’ health. Full article

Tannase, a highly adaptive biocatalyst, plays a pivotal role in diverse bioconversion reactions in nature. This enzyme exhibits numerous applications across various industrial sectors, including food, pharmaceuticals, chemicals, and beverages. This study aimed to screen and characterize fungal endophytes isolated from mangrove plants for their enzyme tannase-producing ability. Eighty-five filamentous endophytic fungi were isolated from different mangrove samples and subsequently identified. These fungal strains were initially screened using the tannic acid agar plate method. Out of the screened strains, 13 fungal isolates demonstrated tannase production ability. The quantitative estimation of extracellular tannase was performed using the submerged fermentation technique. Among the studied endophytes, eight isolates, namely LV_084 (21.21 IU/mL), LV_074 (15.41 IU/mL), LV_078 (6.98 IU/mL), LV_038 (6.97 IU/mL), LV_077 (6.32 IU/mL), LV_016 and LV_066 (6.37 IU/mL), and LV_060 (6.18 IU/mL) exhibited excellent tannase activity. Among these isolates, LV_084 Phyllosticta capitalensis and LV_074 Aspergillus chevalieri showed the highest enzyme-producing ability. These isolates were authenticated using ITS rDNA sequencing, followed by BLAST search and phylogenetic analysis. Furthermore, the physical and chemical conditions for the maximum enzyme production were optimized. This is the first report of enzyme tannase production by Phyllosticta capitalensis and Aspergillus chevalieri. Full article

Background: Coronary artery bypass grafting (CABG) is one of the main treatments for coronary heart disease (CHD). Gut microbiota, including bacteria, fungi, archaea, and virus, has been reported to be associated with CHD. However, the changes in the multi-kingdom gut microbiota after CABG are not yet clear. This study aimed to explore the changes in multi-kingdom gut microbiota during the early postoperative period of CABG. Methods: We collected fecal samples from 40 patients before and 1 week after CABG surgery. Metagenomic sequencing was used to detect the microbial spectrum and gene functions in the patients’ fecal samples. Results: Post-CABG patients exhibited significant changes in the composition of multi-kingdom gut microbiota and gene functions. Among bacteria, beneficial species such as Bifidobacterium, Bacteroides, and Blautia were significantly reduced after CABG, while the harmful species Enterococcus was significantly increased. In fungi, Schizosaccharomyces pombe was significantly decreased in the postoperative group, while Saccharomyces cerevisiae and Aspergillus chevalieri were significantly increased postoperatively. Spearman correlation analysis indicated that Schizosaccharomyces pombe had positive interactions with beneficial bacteria such as Lachnospiraceae, Ruminococcus, and Blautia. Among archaea, the preoperatively enriched Methanomethylovorans-SGB40959 was significantly reduced postoperatively, and Spearman correlation analysis showed a significant positive interaction with probiotics Ruminococcus and Dorea. In viruses, the phage Enterococcus virus EFP01, which infects Enterococcus, was significantly increased postoperatively and showed a significant positive interaction with Enterococcus. Additionally, postoperative dysregulation of gene functions such as the Phosphoenolpyruvate-dependent Sugar Phosphotransferase System (PTS), Transposition, DNA-mediated, and Transposase Activity was observed, and Spearman correlation analysis indicated significant correlations between the dysregulated gene functions and the microbial communities. Conclusions: This study comprehensively revealed the changes in multi-kingdom species post-CABG. The reduction of beneficial microorganisms and the increase of harmful microorganisms after surgery are of significant clinical importance for understanding the overall health status of post-CABG patients and for optimizing postoperative treatment plans. Future research needs to further explore how to improve the prognosis of post-CABG patients by modulating the gut microbiota. Full article

In this study, the effects of adding glutamate (Glu), glutamine (Gln), aspartate (Asp), and asparagine (Asn) on the flavor formation of Huangjiu were investigated, and the effect of Gln concentration on the quality, microbial community structure, and flavor development of Huangjiu was further explored. Varied Gln concentrations influenced yeast growth, sugar utilization, microbial communities, and quality attributes. Additional Gln promoted yeast cell counts and sugar depletion. It increased the complexity of bacterial co-occurrence networks and reduced the impact of stochastic processes on assembly. Correlation analysis linked microorganisms to flavor compounds. Isolation experiments verified the role of Saccharomyces cerevisiae, Aspergillus chevalieri, Bacillus altitudinis, and Lactobacillus coryniformis in flavor production under Gln conditions. This research elucidated the microbiological mechanisms by which amino acid supplementation, especially Gln, enhances Huangjiu quality by modulating microbial metabolic functions and community dynamics during fermentation. This research is significant for guiding the production of Huangjiu and enhancing its quality. Full article

A new prenylated indole diketopiperazine alkaloid, rubrumline P (1), was isolated along with six more analogues and characterized from the fermentation culture of a marine sediment-derived fungus, Aspergillus chevalieri, collected at a depth of 15 m near the lighthouse in Dahab, Red Sea, Egypt. In the current study, a bioassay-guided fractionation allowed for the identification of an active fraction displaying significant cytotoxic activity against the human pancreatic adenocarcinoma cell line PANC-1 from the EtOAc extract of the investigated fungus compared to the standard paclitaxel. The structures of the isolated compounds from the active fraction were established using 1D/2D NMR spectroscopy and mass spectrometry, together with comparisons with the literature. The absolute configuration of the obtained indole diketopiperazines was established based on single-crystal X-ray diffraction analyses of rubrumline I (2) and comparisons of optical rotations and NMR data, as well as on biogenetic considerations. Genome sequencing indicated the formation of prenyltransferases, which was subsequently confirmed by the isolation of mono-, di-, tri-, and tetraprenylated compounds. Compounds rubrumline P (1) and neoechinulin D (4) confirmed preferential cytotoxic activity against PANC-1 cancer cells with IC₅₀ values of 25.8 and 23.4 µM, respectively. Although the underlying mechanism-of-action remains elusive in this study, cell cycle analysis indicated a slight increase in the sub-G1 peak after treatment with compounds 1 and 4. Full article

Herbal teas, including Camellia sinensis (black and green teas), are popular beverages with health benefits for consumers worldwide. These products are prepared from natural materials of different plant parts containing antioxidant properties and vitamins. The aim of this study was to investigate fungal contaminants and their ability to produce ochratoxin A (OTA) in herbal tea samples. Seven herbal teas were obtained from local markets in Chiang Rai, northern Thailand. Samples were incubated on potato dextrose agar (PDA), and the growing mycelia were isolated into a pure culture. The cultures were identified via both morphology and molecular analysis to confirm species identification. The identified species were subjected to OTA analysis using high-performance liquid chromatography (HPLC) with a fluorescence detector. Ochratoxin A was produced by Aspergillus chevalieri and A. niger, isolated from seven herbal tea samples (black tea, green tea, bael fruit, goji berry, jasmine, lavender, and rose). This finding raises concerns about the safety of herbal tea and should be investigated further for potential health implications. Full article

The contamination and spoilage of heat-treated fruit juices by heat-resistant mold ascospores present significant challenges to the food industry. Understanding effective strategies to mitigate this contamination is vital for ensuring the shelf-life and microbial safety of heat-treated fruit juices. This study investigated the thermal resistance of ascospores from different heat-resistant mold species, including Aspergillus laciniosus, A. chevalieri, A. denticulatus, A. siamensis, Hamigera pallida, and Talaromyces macrosporus, isolated from pineapple and sugarcane field soils. Ascospores inactivation kinetics in pineapple juice under heat treatment (75–97 °C) were analyzed using log-linear and Weibull models. Among these species, A. laciniosus displayed the highest heat resistance (δ-value: 104.59 min at 85 °C), while A. siamensis exhibited the lowest (δ-value: 3.39 min at 80 °C). Furthermore, A. laciniosus, the most heat-resistant species, showed notable tolerance to sanitizers. The most effective inactivation was achieved using 1.0% (w/v) sodium hypochlorite for 15 min. Chlorine dioxide, however, was generally ineffective and even activated dormant ascospores in some cases. The combination of hot water (65 °C for 5 min) with sanitizer increased ascospore reduction in most species but did not achieve the 3-log reduction required by the European Standard N13697. This study revealed a correlation between ascospore resistance to heat and chlorine dioxide, offering significant findings for practical inactivation strategies. Full article

The main hypothesis of the present research is investigating the efficacy of titanium oxide nanoparticles (TiO₂-NPs) to prevent the growth of fungal strains when applied on leather under an experimental study. Therefore, fifteen fungal strains were isolated from a deteriorated historical manuscript (papers and leathers) and identified by traditional methods and ITS sequence analysis, including Aspergillus chevalieri (one isolate), A. nidulans (two strains), A. flavus (four strains), A. cristatus (one strain), A. niger (one strain), Paecilomyces fulvus (two strains), Penicillium expansum (two strains), and P. citrinum (two strains). The enzymes cellulase, amylase, pectinase, and gelatinase, which play a crucial role in biodegradation, were highly active in these fungal strains. TiO₂-NPs were formed using the cell-free filtrate of the probiotic bacterial strain, Lactobacillus plantarum, and characterized. Data showed that the TiO₂-NPs were successfully formed with a spherical shape and anatase phase with sizes of 2–8 nm. Moreover, the EDX analysis revealed that the Ti and O ions occupied the main component with weight percentages of 41.66 and 31.76%, respectively. The in vitro cytotoxicity of TiO₂-NPs toward two normal cell lines, WI38 and HFB4, showed a low toxicity effect against normal cells (IC₅₀ = 114.1 ± 8.1µg mL⁻¹ for Wi38, and 237.5 ± 3.5µg mL⁻¹ for HFB4). Therefore, concentrations of 100 μg mL⁻¹ were used to load on prepared leather samples before inoculation with fungal strain P. expansum AL1. The experimental study revealed that the loaded TiO₂-NPs have the efficacy to inhibit fungal growth with percentages of 73.2 ± 2.5%, 84.2 ± 1.8%, and 88.8 ± 0.6% after 7, 14, and 21 days, respectively. Also, the analyses including SEM, FTIR-ART, color change, and mechanical properties for leather inoculated with fungal strain AL1 in the absence of NPs showed high damage aspects compared to those inoculated with fungal strains in the presence of TiO₂-NPs. Full article

A large body of fungal secondary metabolites has been discovered to exhibit potent antibacterial activities with distinctive mechanisms and has the potential to be an untapped resource for drug discovery. Here, we describe the isolation and characterization of five new antibacterial indole diketopiperazine alkaloids, namely 24,25-dihydroxyvariecolorin G (1), 25-hydroxyrubrumazine B (2), 22-chloro-25-hydroxyrubrumazine B (3), 25-hydroxyvariecolorin F (4), and 27-epi-aspechinulin D (5), along with the known analogue neoechinulin B (6) from a fungal strain of deep-sea cold seep-derived Aspergillus chevalieri. Among these compounds, 3 and 4 represented a class of infrequently occurring fungal chlorinated natural products. Compounds 1–6 showed inhibitory activities against several pathogenic bacteria with MIC values ranging from 4 to 32 μg/mL. It was revealed that compound 6 could induce structural damage to the Aeromonas hydrophila cells based on the observation by scanning electron microscopy (SEM), which led to the bacteriolysis and death of A. hydrophila, suggesting that neoechinulin B (6) might be a potential alternative to novel antibiotics development. Full article

“Golden flower” fungi in dark tea are beneficial to human health. The rapid identification method of “golden flower” fungi can verify the quality of dark tea products and ensure food safety. In this study, 6 strains were isolated from Liupao tea. They were respectively identified as A. cristatus, A. chevalieri, and A. pseudoglaucus. A. pseudoglaucus was reported as Liupao tea “golden flower” fungus for the first time. It was found that the ITS and BenA sequences of A. cristatus and A. chevalieri were highly conserved. It is difficult to clearly distinguish these closely related species by ITS sequencing. To rapidly identify species, multiplex PCR species-specific primers were designed based on orphan genes screened by comparative genomics analysis. Multiplex PCR results showed that orphan genes were specific and effective for the identification of A. cristatus and A. chevalieri isolated from Liupao tea and Fu brick tea. We confirmed that orphan genes can be used for identification of closely related Aspergillus species. Validation showed that the method is convenient, rapid, robust, sequencing-free, and economical. This promising method will be greatly beneficial to the dark tea processing industry and consumers. Full article

This study aimed to identify surface mould species overgrowing the Croatian protected meat products “Istarski pršut” and “Dalmatinski pršut” and their effect on sensory properties. Dry-cured hams were produced in 2018/2019 and obtained from annual fairs. The predominant surface species found on “Dalmatinski pršut” were Aspergillus chevalieri, Penicillium citrinum and Aspergillus cibarius, whereas those overgrowing “Istarski pršut” were Aspergillus proliferans, P. citrinum and Penicillium salamii. The results show species diversity, higher presence, and greater variety of Aspergillus species in “Dalmatinski pršut” in comparison to “Istarski pršut”, and significant variations in 9 of 20 sensory attributes. Principal component analysis revealed a clear distinction between the two, and a large contribution of P. salamii and Penicillium bialowienzense to one principal component. The texture traits, smoky odour, muscle and subcutaneous fatty tissue colour, and mould species found are valuable for product characterisation. The results also indicate that mould species may be responsible for some sensory traits, such as tenderness, juiciness, and lesser freshness. Full article