Search Results (1,432)

This work presents a green chemistry route to obtain titanium dioxide TiO₂ nanoparticles with an average size of about 13.25 nm using lemongrass (Cymbopogon citratus) extract. For these assessments, TiO₂ nanoparticles were added to the coating at concentrations of 1% and 5% w/w on fiber-cement sheets. Self-cleaning evaluation was analyzed by the photodegradation of methylene blue (MB) dye at concentrations of 5, 10, and 20 mg/L applied to the coated sheet, and then exposed to simulated sunlight. The coating containing 5 wt% TiO₂ nanoparticles showed the highest photodegradation, reaching 93.3% after 4 h under simulated sunlight exposure at the lowest MB concentration (5 mg/L). Additionally, average contact angles of 80.4°, 92.03°, and 104.25° were determined for coatings containing 0%, 1%, and 5 wt% TiO₂, respectively. Moreover, the modified 5 wt% TiO₂ exhibited up to 30.9% greater hydrophobicity than the control. Antifungal efficacy against Aspergillus niger and Penicillium was evaluated using the Poisoned Food method with nanoparticles at concentrations of 1 and 3 mg/mL showing a moderate growth inhibition. In conclusion, the versatility demonstrated suggests potential applications such as a nano-additive for aqueous acrylic coatings, improving hydrophobicity, self-cleaning and antifungal properties, which could be attractive to the construction industry. Full article

The livestock sector is a major source of methane, a potent greenhouse gas, while heat stress impairs ruminant health. This study evaluated the efficacy of Aspergillus niger (AN) and its compound preparation (CP) as feed additives to mitigate methane emissions and heat stress in Holstein bulls. Twenty-four bulls were assigned to a control group (CON), a group supplemented with 6 g/d of AN, and a group with 20 g/d of CP. Methane emissions were measured using the SF₆ tracer technique. Blood and ruminal fermentation parameters were also analyzed. Results showed that both AN and CP significantly reduced total methane emissions, emissions per unit of body weight, and per unit of dry matter intake compared to CON. Supplemented groups had significantly lower rectal temperatures and higher superoxide dismutase activity, with AN also increasing total antioxidant capacity. AN groups showed increased total volatile fatty acids, acetate, and propionate. Microbiota analysis revealed significant beta-diversity shifts with differential taxon enrichment. In conclusion, Aspergillus niger and its compound preparation effectively reduce enteric methane and alleviate heat stress by boosting antioxidant defenses and modulating rumen function, offering a dual-benefit strategy for sustainable ruminant production. Full article

Using the Autoregressive Distributed Lag (ARDL) model cointegration framework, this paper examines the long- and short-run impact of domestic financial investment and natural resource rents on economic growth in Niger within the period 1990–2021. The Bounds test confirms a long-run relationship among variables: F = 4.646 > 3.79 at 5%. Long-run results indicate that increasing domestic investment by 1% raises real Gross Domestic Product (GDP) per capita by approximately 0.30%, whereas 1% increase in natural resource rents leads to a reduction in growth by approximately 0.06%. At the same time, exports have a positive but very small effect, while imports and labor have negative long-run influences. Short-run dynamics further support a significant positive impact of domestic investment, at p = 0.0007, and a lagged effect of natural resources at p = 0.0308. The error-correction term is negative and significant, at −0.75, showing rapid adjustment toward equilibrium. Diagnostic tests confirm an absence of serial correlation and heteroskedasticity, while stability is confirmed by CUSUM and CUSUMSQ tests. The findings reveal a dualism in the growth path of Niger in that domestic financial investments favor sustainable expansion, whereas resource-based revenues undermine the growth process in the long run and call for financial market deepening and improved governance of resource revenues. Full article

Canine systemic aspergillosis is a rare but highly serious condition, often associated with a fatal outcome. This review encompasses all reported cases of canine systemic aspergillosis from 1978 to the present, focusing exclusively on studies in which the diagnosis was confirmed through fungal culture. A total of 155 clinical cases reported in the literature were included. Among these, the German Shepherd was the most frequently affected breed (65.16%), followed by mixed-breed dogs (7.74%). The predominant Aspergillus species isolated was A. terreus (57.69%), although other species were also reported, including A. deflectus, A. fumigatus, A. niger, A. caninus, A. versicolor, A. alabamensis, A. citrinoterreus, and A. floccosus. Recognizing clinical signs and accurately interpreting laboratory findings are crucial for early diagnosis and timely intervention, both of which can potentially improve outcomes. This review provides a detailed discussion of these aspects. Full article

Chitin–glucan complex (CGC) is a naturally occurring heteropolysaccharide in which chitin chains are covalently integrated with β-glucans, forming a rigid structural framework in fungal and yeast cell walls. CGC exhibits a broad spectrum of functional properties, including antimicrobial, antioxidant, adsorption, and tissue-regenerative activities; however, its technological exploitation has been severely constrained by its intrinsic insolubility in water and most common solvents. In this work, CGC was isolated from Aspergillus niger mycelial biomass and, for the first time, completely dissolved in a precooled aqueous NaOH/urea solvent system (12 wt.% NaOH, 8 wt.% urea) within 5 min at ambient temperature, yielding a clear and stable solution. The influence of alkali concentration on dissolution efficiency and solution stability was systematically examined. Structural integrity and covalent linkage between chitin/chitosan and glucan segments were confirmed using FTIR spectroscopy, two-dimensional NMR, and electron microscopy. The degree of deacetylation determined by NMR was approximately 25%. Rheological analysis revealed concentration- and temperature-dependent sol–gel transitions, with well-defined storage and loss moduli during gelation. Crosslinking with epichlorohydrin enabled the fabrication of lightweight, highly porous three-dimensional CGC aerogels. In vitro cytocompatibility studies using NIH 3T3 fibroblasts demonstrated no detectable cytotoxicity over 72 h. These results establish a green, efficient route for CGC dissolution and processing and highlight the promise of CGC aerogels as sustainable biomaterials for biomedical and environmental applications. Full article

Background: Lavandula stoechas and Artemisia absinthium essential oils (EOs) were evaluated as natural antimicrobial and repellent agents. Methods: The chemical composition was determined using gas chromatography-mass spectrometry (GC-MS). The antibacterial activity was evaluated by agar diffusion method, and the minimal inhibitory concentration (MIC) values were determined for antifungal activity, while the repellent effect against mill moth was tested by fumigation. Results: Camphor was the main component in both EOs, accounting for 31.83% of L. stoechas and 41.92% of A. absinthium. In antibacterial assays, both EOs showed very good activity against Gram-positive bacteria, with inhibition zone diameters (IZDs) higher than 15 mm, and average activity against Gram-negative bacteria, with IZDs ranging from 8 to 14 mm. The EOs reduced Aspergillus niger mycelial growth by 61% to 80% for LsEO and 50% to 61% for AaEO at concentrations ranging from 1 to 3 mg/mL. The oils exhibited variation in repellent and insecticidal potential, with L. stoechas showing higher activity, while both had an impact on development and fecundity of Ephestia kuehniella.Conclusions: Thus, the two EOs may be effective as biological and sustainable alternatives to conventional chemical products for food preservation. Full article

This review surveys literature from 2010 to 2025 on Aspergillus-derived enzymes for kinetic resolution (KR), using conventional databases and AI-assisted platforms. Among over 340 species, A. niger, A. oryzae, and A. terreus are widely recognized as safe and industrially relevant. Lipases from these fungi exhibit high stability, broad substrate specificity, and enantioselectivity, enabling efficient resolution of racemic mixtures. Advances in enzyme immobilization, protein engineering, and reaction medium optimization have enhanced catalytic performance under diverse conditions. Complementary enzymes, including esterases and epoxide hydrolases, further expand biocatalytic applications. Despite increasing demand for enantiopure compounds, challenges in yield, scalability, and enzyme discovery call for integrated molecular and process strategies. Aspergillus spp. emerge as a promising system for high-level enzyme expression, offering robust secretion capacity, efficient post-translational processing, and strong adaptability for industrial biocatalysis. Full article

The metabolism of polyunsaturated fatty acids (PUFAs) is a broad research field, and the products identified so far offer potential medical and industrial applications. Epoxy fatty acids (EpFAs) act as lipid mediators that modulate renal function, angiogenesis, vascular dilatation and inflammation; moreover, they regulate monocyte aggregation and are involved in cardiovascular and metabolic diseases. On the other hand, EpFAs are precursors of environmentally friendly products for the plastics industry, in which the grade of epoxidation of the compounds gives the polymeric material different advantageous characteristics. The controlled chemical synthesis of poly epoxidized PUFAs is challenging as the reactions are non-selective. In contrast, the biosynthetic route based on cytochrome P450 monooxygenases and lipoxygenases is highly selective but ineffective due to the instability of the enzymes in cell-free systems. Fungal unspecific peroxygenases (UPOs, EC 1.11.2.1) with P450-like activity offer a suitable alternative for the selective synthesis of EpFAs from PUFAs. Here we demonstrate that a recombinant unspecific peroxygenase from Aspergillus niger (rAniUPO) is able to sequentially epoxidize eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to 14,15-17,18 diepoxyeicosatrienoic acid (14,15-17,18 diEpETrE) and 16,17-19,20-diepoxydocosatetraenoic acid (16,17-19,20 diEpDTE), respectively, while arachidonic acid is transformed into 13-hydroxy-14,15-epoxyeicosatrienoic acid (14,15-hepoxilin B₃). Optimal production for these oxygenated derivatives (up to 15 mg) was achieved using 2 mM hydrogen peroxide as the co-substrate. The obtained molecules were identified using high-resolution mass spectrometry and their structure was verified by NMR. Our results demonstrate the suitability of UPOs for the synthesis of EpFAs that can be used in medical research and industrial applications. Full article

Copper slag, a by-product of copper ore and concentrate smelting, is rich in non-ferrous metals; therefore, it has been considered a valuable raw material in recent years. This study aimed to compare the extraction of zinc, copper, and cobalt from two types of copper slag from a dump located near the village of Eliseyna, Bulgaria, which differ in mineralogical composition and chemical content, using indirect bioleaching with a spent medium of Aspergillus niger and Penicillium ochrochloron. Chemical leaching with sulphuric acid revealed that zinc and cobalt existed mainly as an acidic-soluble phase in both types of copper slag. In contrast, it contained 50–75% of the total copper content. Each fungal species was cultivated for one week, and the biomass and the spent medium were separated a week later. Owing to the production of a higher concentration of citric acid, A. niger facilitated more efficient base metal recovery. However, their effective recovery from the acidic-soluble phase required leaching at a 5% pulp density and supplementing the spent medium with sulphuric acid. The temperature played a secondary role. Conclusions: Non-ferrous metal extraction from copper slag exposed to weathering using a spent medium supplemented with sulphuric acid was achieved under milder leaching conditions and with better selectivity. In contrast, slag unaffected by weathering behaved as a refractory due to the worsened results of base metal extraction under similar experimental conditions. Full article

The aim of this study was to evaluate the effect of surface modification of porous hyaluronic acid (HA)-based materials with a titanium dioxide (TiO₂) layer deposited via atomic layer deposition (ALD) on the selected structural, physicochemical, and antimicrobial properties of materials intended for applications in regenerative medicine. The obtained HA-based materials, enriched with silk and elastin, were analyzed in terms of their rheological behavior, wettability, solubility, and resistance to colonization by clinically relevant bacterial pathogens (Staphylococcus aureus, Klebsiella pneumoniae) and environmental filamentous fungi (Aspergillus niger, Chaetomium globosum). The results demonstrated that even a thin, continuous TiO₂ layer formed after 200 ALD cycles reduced the hydrophilicity of the foams, indicating improved durability in aqueous environments. Microbiological tests confirmed enhanced antimicrobial properties of the foams after TiO₂ modification—showing inhibition of both tested bacterial strains and C. globosum within 24 h. These findings suggest that surface functionalization of hyaluronic acid-based foams with a TiO₂ layer can improve both their environmental stability and, to some extent, reduce microbiological risk, while preserving the layered-porous structure of the foams, which is advantageous for biomedical applications. Full article

Root exudates play a critical role in enabling plants to respond to environmental stresses and mediate information exchange within the rhizosphere. These compounds regulate plant–rhizosphere interactions and significantly influence the structural and functional properties of the rhizosphere micro-ecosystem. Under continuous cropping systems, allelochemicals derived from root exudates progressively accumulate in the root zone, thereby contributing to the development of continuous cropping obstacles. In this study, root exudates were collected from wolfberry (Lycium barbarum L.) and four forages under controlled conditions to test their effects on seed germination and seedling growth in mangold (Betu vulgaris L.) and wolfberry, as well as on the root rot pathogen. Our research shows that forage root exudates could promote wolfberry seedling growth. White clover (Trifolium repens L.) and alfalfa (Medicago sativa L.), especially, could have their growth increased by up to 61% and 90% (p < 0.05). Wolfberry root exudates could promote the seed germination and seedling growth of white clover and mangold, the seed germination of Ryegrass (Lolium perenne L.), and the seedling growth of alfalfa. In addition, mangold root rots were identified as Molds, Aspergillus niger, and Fusarium solani and wolfberry root rots were Mucor cirrus, Rhizopus, Fusarium oxysporum, and Fusarium solani. What is more, wolfberry root exudates could promote Fusarium plaque expansion and mycelial growth. Ryegrass inhibited the growth of Mucor, Fusarium putrum, and oxysporum, and alfalfa and white clover promoted the plaque expansion of Rhizopus, Aspergillus niger, and Fusarium fulcrum, but inhibited the mycelial growth of related pathogens; mangold root exudates could inhibit wolfberry root rot, which affects interspecific relationships. This study provides robust technical support for elucidating interspecific relationships and promoting the development and application of the wolfberry-forage intercropping system. Full article

Bambara groundnut is an underutilized legume with significant potential for enhancing nutrition and food security. However, limited knowledge of its seed systems hinders the development of targeted interventions. This study assessed the Bambara groundnut seed systems and seed quality in Ghana. A semi-structured questionnaire was used to examine seed production, conditioning, and saving practices, while 150 farmer-saved seed samples were evaluated for quality. The findings revealed that the seed system is predominantly informal, with 99% of farmers relying on their own saved seeds, which showed poor germination and emergence. About 54.4% sourced seeds from local markets, and 60.7% recycled seeds for five years or more. Seeds were stored unshelled in polypropylene bags in Tolon and shelled in the Kintampo South and Talensi Districts. Seed selection was primarily based on size (in Tolon) and visible absence of disease symptoms (in Kintampo South and Talensi). An incidence (7.6%) of seed-borne pathogens was recorded, with Aspergillus flavus (38.8%) and A. niger (16.6%) being most prevalent. Other pathogens included Macrophomina phaseolina (11.5%), Rhizopus spp. (6.5%), Curvularia lunata (5.3%), and A. fumigatus (1.9%). This study highlights the need to support community-based seed systems to improve farmers’ access to quality Bambara groundnut seed. Full article

The medicinal plant Malva neglecta Wallr. is known for its high concentration of beneficial bioactive compounds. This study investigated extracts prepared from the plant’s flowers, leaves, and roots. Different green solvents were used: 70% ethanol, and for the first time in relation to this plant species, natural deep eutectic solvents (NADES)—one based on choline chloride and citric acid (NADES1) and another using choline chloride and glycerol (NADES2). Key bioactive compounds were identified and quantified using spectrophotometric assays and HPLC-PDA-MS profiling to determine their role in the plant’s antioxidant activity. The analysis revealed that M. neglecta contains a wide range of flavonoid glycosides and phenolic acids, with the flowers and leaves exhibiting the highest diversity and concentrations of these compounds with a predominance of quercetin and kaempferol glycosides. Among the solvents tested, the ethanolic extracts showed the highest total contents of phenols, flavonoids, and condensed tannins. The flower extracts—regardless of the solvent used—exhibited the strongest antioxidant activity, as demonstrated by the DPPH, FRAP, and ABTS assays. Alkaloids were detected in all organs tested only in low quantities. The antibacterial (against Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) and antifungal activity (against Penicillium chrysogenum, Fusarium oxysporum, Aspergillus parasiticus, A. carbonarius, A. niger, A. flavus, and A. ochraceus) of the extracts was evaluated and compared. As a whole, the NADES1 extracts exhibited higher antibacterial potential than the ethanolic extracts. Such a clear trend regarding the antifungal activity was not observed. The highest antifungal activity was exhibited by NADES1 root extracts. NADES2 extracts showed a complete lack of antimicrobial effects. Full article

Mycotoxigenic molds pose a threat to human health and cause economic losses in bread production. To address this issue, postbiotics have emerged as promising natural bioprotective agents due to their antifungal properties. In this study, postbiotics were obtained from Lactiplantibacillus (Lp.) plantarum Y48, Liquorilactobacillus (Lq.) hordei SK-6, and Lp. plantarum VB-29 strains and subsequently lyophilized. The functional groups of the bioactive components in these postbiotics were identified using FTIR spectroscopy. Samples extracted with different solvents were analyzed for their volatile compound profiles by GC-MS, and the results were compared using principal component analysis (PCA). The antifungal activities of postbiotics were tested. Subsequently, the antifungal activity of Lp. plantarum Y48 postbiotic was evaluated on bread contaminated with Aspergillus niger and Penicillium expansum. The postbiotic was incorporated into the bread formulation both alone and in combination with potassium sorbate, and it was also applied to the bread surface as a spray. Notably, the formulation containing 3% postbiotic + 0.1% potassium sorbate completely inhibited the growth of A. niger and P. expansum. These results indicate that the combined use of Lp. plantarum Y48 postbiotic and potassium sorbate can effectively prevent mold growth in bread and holds potential as a natural bioprotective approach in food preservation applications. Full article

Agro-industrial residues rich in carbohydrates represent low-cost and sustainable feedstock for enzyme production. This study demonstrates that green Arabica coffee press cake, a mannan-rich coproduct of oil extraction, is an efficient carbon source for Aspergillus niger (CFAM 1234) cultivation and for inducing mannanase production. Furthermore, the enzymes obtained were tested for mannose recovery in the enzymatic hydrolysis of healthy and defective coffee beans to investigate their hydrolytic potential. Mannanase production was investigated using various carbon sources—including ground coffee beans; coffee press cake; different particle sizes of coffee press cake; aqueous coffee cake extract (prepared at 30 g·L⁻¹ under constant stirring (300 rpm) at 80 °C for 2 h, followed by filtration.); and a commercial galactomannan, locust bean gum (LBG). CNHSO analysis was performed in the best carbon source (coffee press cake) and LBG. Statistical optimization (Plackett–Burman and Central Composite Rotatable Design) simplified the culture medium composition to coffee press cake (48.78 g·L⁻¹), yeast extract (4 g·L⁻¹), and potassium phosphate (0.25 g·L⁻¹, pH 5.5) and increased mannanases productivity to 22.4 ± 0.6 U·mL⁻¹ within only 3 days (a 42.9% improvement compared to non-optimized conditions, which were 30 g·L⁻¹, carbon source, 4 g·L⁻¹ yeast extract, 1 g·L⁻¹ Al₂O₃, 0.5 g·L⁻¹ potassium phosphate buffer (pH 5.5), 0.5 g·L⁻¹ of MgSO₄·7H₂O, and 0.05 g·L⁻¹ of CaCl₂·2H₂O, which resulted in a maximum of ~20 U·mL⁻¹ in 7 days). The crude extract also exhibited β-mannosidase activity (1.39 ± 0.06 U·mL⁻¹). When applied to the hydrolysis of untreated healthy and defective coffee beans, the enzyme preparation enabled ~25% mannose recovery (considering the value obtained through acid hydrolysis as 100%), highlighting its potential as a mannose resource. The results demonstrate that coproducts from the coffee production chain can be used as an efficient carbon source (coffee cake) for mannanase production, as well as sugar recovery (defective coffee beans), offering an integrated strategy to strengthen the circular bioeconomy and generate carbohydrates with potential industrial and nutritional applications. Full article