Lignin is the largest renewable source of aromatic carbon, yet its heterogeneity and recalcitrance limit its use in higher-value bioconversion processes. In this study, Aspergillus niger was engineered to enable the bioconversion of lignin-derived aromatics and base-catalyzed depolymerized (BCD) lignin streams into malic acid, a value-added C4 dicarboxylic acid with broad industrial relevance. Overexpression of the C4 dicarboxylate transporter C4T318 from Aspergillus oryzae enhanced malic acid secretion, while medium optimization under buffered conditions further improved the production. The engineered strain efficiently assimilated representative lignin-derived aromatics, including 4-hydroxybenzoic acid and p-coumaric acid, producing up to 3.9g/L malic acid. Conversion of BCD lignin liquors from poplar and sorghum demonstrated effective utilization of heterogeneous aromatic mixtures, generating up to 0.82g/L malic acid. This work demonstrates direct fungal conversion of real lignin streams into malic acid and establishes A. niger as a promising platform for sustainable lignin valorization.

Naringinase: A comprehensive review on its characteristics, production, and biotechnological applications.

Fungi and mycotoxins hugely contaminate food and feed commodities and consequently contribute to adverse effects on health and the economy. While various measures have been adopted to control food contamination, the potential application of nanotechnology to control fungi and mycotoxins in food seems promising; nevertheless, it has not been sufficiently explored. This study investigated the antifungal effect of plant-mediated silver nanoparticles (AgNPs) form Garcinia kola, Carica papaya, Achillea millefolium, Ocimum gratissimum, and Perilla frutescens against ten food-borne fungi. Furthermore, the effect of Garcinia kola AgNPs and Achillea millefolium AgNPs against aflatoxin (AFB1 and AFB2) and ochratoxin (OTA and OTB) production by Aspergillus flavus, Aspergillus ochraceus, and Aspergillus clavatus was determined by using an Ultra Performance Liquid Chromatography-Triple Quadrupole Spectrometry (UPLC-MS/MS) instrument to quantify the amount of aflatoxins and ochratoxins produced following AgNPs antifungal treatments. The characterization analysis of AgNPs showed that stable and crystalline AgNPs were bioformulated, with sizes ranging from 10.9 to 67.5nm. The antifungal effect of AgNPs by agar well diffusion method after 7 days of incubation revealed that at a concentration of 100mg/L, AgNPs were able to exhibit an antifungal effect on the tested food-borne pathogens. As found, a maximum inhibitory zone (MIZ) of 20.3mm by Penicillium frutescens AgNPs on Penicillium chrysogenum was obtained, while a 10.7mm MIZ exhibited by Carica papaya AgNPs on Aspergillus Niger was recorded. Mycelial growth inhibition (MGI) activity of AgNPs at varying concentrations of 6.25, 12.5, 25, 50, and 100mg/L was established. The highest MGI of AgNPs of 100% was recorded against Penicillium citrinum, while the lowest MGI of 6.7% for Aspergillus flavus was noted. The significant difference at p≤0.05 was validated by comparing MIZ and MGI induced by the tested AgNPs to the control groups. The ability of AgNPs derived from Garcinia kola and Achillea millefolium showed a reduction in mycotoxin (AFB1, AFB2, OTA, and OTB) production as the concentration of the synthesized AgNPs increased. These findings demonstrate that AgNPs have immense potential as antifungal agents for controlling the growth of fungi and the subsequent biosynthesis of their respective mycotoxins.

Green flocculant of Aspergillus niger fungus cultured from food waste hydrolysate for enhanced sludge dewatering.

Enhancement in the nutritional profile and hepatoprotective activity of pine pollen via Aspergillus niger fermentation.

Shaping Aspergillus niger into a next-generation cell factory for L-malic acid.

Antifungal activity of Lactobacillus sakei PLL12 and Lactococcus lactis PLL15 against Aspergillus niger and their application in bread preservation

Volatile profile and antimicrobial activity of essential oil of Juniperus phoenicea L. and its combination effect with sodium chloride, used in traditional preparation of Djeld of Bouhezza.

Extraction and Identification of Fungal Melanin Pigment of Fungus Aspergillus niger and its Antifungal Effect on Candida albicans

Multi-strategy engineering of Aspergillus niger for high-level production of recombinant human lactoferrin

Anti-aging effects of rare prosaikogenin F from microbial biotransformation of saikosaponin A.

Chemical surface modification of enzymes represents a powerful strategy to improve immobilization and catalytic performance. In this study, glucose oxidase (GOx) from Aspergillus niger was chemically modified via periodate oxidation and reductive amination to incorporate L-aspartate (D-GOx) and L-histidine (H-GOx) residues. These modifications enhanced electrostatic and coordinative interactions with Zn2+ and 2-methylimidazole during biomimetic mineralization, leading to efficient encapsulation in ZIF-8 frameworks. The resulting D-GOx@ZIF-8 and H-GOx@ZIF-8 biocomposites showed significantly improved activity and stability compared to native GOx. H-GOx@ZIF-8 achieved a specific activity of 4551IU/g, representing a sixfold increase over previously reported systems. Both modified biocomposites also demonstrated greater resistance to detergent washing and retained higher activity after exposure to 65°C, indicating stronger incorporation into the ZIF-8 matrix. These results highlight the dual advantage of introducing negatively charged and imidazole-functional groups for promoting biomineralization and improving biocatalyst robustness. This strategy provides a mild, scalable route for preparing enzyme@MOF composites with enhanced operational stability, offering direct potential for industrial bioprocesses, continuous-flow catalysis, and biosensing applications.

In the present study, novel isoxazole-based hybrid compounds 5a–h were synthesized with satisfactory yields. Their structure was confirmed by FT-IR, NMR (1H, 13C, 2D), and HRMS. The antimicrobial properties of this class of compounds were thoroughly investigated in vitro against a variety of Gram-positive and Gram-negative bacteria as well as different fungi, both yeast and molds. Their antioxidant ability was also assessed by molybdate reduction assay. The compounds showed excellent antifungal activity, particularly against Aspergillus niger and Fusarium oxysporum, equivalent to that of fluconazole. Among the series, 5d was the most potent antibacterial agent against Escherichia coli (minimal inhibitory concentration, MIC = 2.582 µmol mL−1), whereas the highest potency against Bacillus subtilis was found for 5h (MIC = 0.083 µmol mL−1) which was comparable to the efficacy of ampicillin. With respect to the antifungal activity, 5h showed the lowest MIC value against Candida albicans (MIC = 0.083 µmol mL−1) and A. niger (MIC = 0.083 µmol mL−1), and 5g was the most effective against Aspergillus flavus (MIC = 0.044 µmol mL−1). All hybrids were more effective as compared to fluconazole against F. oxysporum (MIC range: 0.43–0.94 µmol mL−1). Furthermore, assessment of their antioxidant potential shows that compounds 5e and 5g exhibit excellent reducing potency. Molecular docking and dynamic simulations demonstrated that compounds 5a–h, especially 5d, interact strongly and stably with key bacterial and fungal proteins, forming hydrogen bonds, hydrophobic interactions, and water bridges, with minimal root-mean-square fluctuations (RMSF), confirming the structural integrity of the complexes. Additionally, in silico predictions of Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADME-Tox) analysis predicted 5d to possess an optimal profile, with high gastrointestinal absorption and minimal toxicity, highlighting it as the lead candidate for the development of broad-spectrum antimicrobial drugs.

Aspergillus carbonarius is the main producer of ochratoxin A (OTA) in grape and grape products. Good agricultural practices and preventive measures such as the use of biological control agents are key to decreasing OTA concentration in the final product. This study evaluated non-ochratoxigenic strains from Aspergillus section Nigri isolated from grape environments for their ability to control OTA production. In vitro interactions between an ochratoxigenic strain of A. carbonarius and 22 non-ochratoxigenic strains were evaluated using microtiter plates. Biocontrol potential was determined by measuring OTA reduction, while competitiveness was quantified through a specific qPCR assay. Results showed that both OTA reduction and competitive ability were strain-dependent. Co-inoculation experiments revealed that most non-OTA-producing strains reduced OTA levels, with Aspergillus uvarum showing the strongest inhibition. Aspergillus japonicus and Aspergillus trinidadensis also reduced OTA, whereas biseriate species such as Aspergillus niger, Aspergillus welwitschiae, and Aspergillus brasiliensis had minimal impact. The qPCR competitiveness assays revealed that A. carbonarius typically dominated mixed cultures, except when co-cultured with highly competitive A. uvarum strains. Notably, strain A-6760 reduced A. carbonarius abundance to below 6%. This strong competitiveness aligned with significant OTA suppression, suggesting competitive exclusion as the main biocontrol mechanism. Overall, the developed qPCR assay provides a rapid, precise method for fungal interaction evaluation. A. uvarum strains showed great promise for mitigating OTA contamination in grapes and wine through its combined dominance and toxin reduction capacity. Future research should evaluate their effectiveness under field conditions. KEY POINTS: •Atoxigenic black aspergilli were tested as biocontrol agents vs. A. carbonarius. •Competitiveness and OTA reduction varied by strain; uniseriates performed best. •A. uvarum A-6760 shows promise as a biocontrol agent to reduce OTA in grapes.

Pulmonary aspergillosis represents a significant public health concern resulting from the proliferation of Aspergillus species within the respiratory tract. This infection is frequently underdiagnosed in comparison to tuberculosis during the management of pulmonary infections, especially among individuals living with HIV. The objective of this study was to determine the positivity rate of Aspergillus spp. from sputum and bronchoalveolar lavage (BAL) samples of patients presenting with tuberculosis-like symptoms at Jamot Hospital in Yaoundé, Cameroon, and to evaluate their antifungal resistance profiles. A total of 114 samples (104 sputum and 10 bronchoalveolar lavage) were collected for mycological analysis. Data were verified, coded, and analyzed using StatView v5.0 and GraphPad v8.0.2 for Windows. Pearson's chi-square test of independence and multivariate logistic regression models were used to compare percentages, with p < 0.05 considered statistically significant. Aspergillus spp. were detected in 12.3% of samples, with two species identified. Aspergillus niger was predominant (57%0), followed by Aspergillus flavus (29%). A. niger isolates tested (5) exhibited resistance to polyenes, with 80% resistant to amphotericin B and 40% to nystatin, and 20% resistant to the azole fluconazole. All A. niger isolates were susceptible to econazole and clotrimazole. Among the five A. flavus isolates tested, all demonstrated resistance to amphotericin B and fluconazole, 60% to nystatin, and 20% to clotrimazole. Aspergillus spp. is present in the respiratory tract but often overlooked, and can lead to a misdiagnosis of tuberculosis. Although the very small number of isolates tested, Aspergillus spp. could be also affected to the antimicrobial resistance observed in recent years.

introduction: β-caryophyllene and its derivatives play an important role as antibacterial agents. This study is a continuation of the biotransformation of β-caryophyllene using Aspergillus niger, where metabolite 1 was isolated and identified in our previous study. Here, we investigate its antibacterial activity against both Gram-positive and Gram-negative bacteria, in addition to molecular docking studies. methods: The antibacterial activity of the transformed product was evaluated by using the standard agar cup bioassay method. A deep computational study has been performed to elucidate the antibacterial mechanism of Compound 1, including Glide XP docking and Prime/MMGBSA free-energy calculations against PBP1b, DNA gyrase AⁿBⁿ, and ClpP. results: Metabolite 1 showed significant growth inhibitions of Gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus (9.0 ± 0.2 mm and 10.0 ± 0.2 mm). Also, against Gramnegative bacteria, Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhi (7.0 ± 0.2 mm, 8.0 ± 0.2 mm, and 9.0 ± 0.2 mm). ADMET analysis indicated that Compound 1 has excellent oral absorption (83.3%) and fully complies with Lipinski’s rules, outperforming imipenem. discussion: The present study aimed to evaluate antibacterial activities of metabolite 1 (100 ug/mL) against Gram-positive organisms (B. subtilis and S. aureus) and Gram-negative organisms (P. aeruginosa, E. coli, and S. typhi), in comparison with imipenem, followed by computational studies. conclusion: Metabolite 1 showed significant antibacterial activities against Gram-positive and Gram-negative organisms. Our findings demonstrate that Compound 1 binds strongly to ClpP (Glide Gscore –6.27; ΔG_bind –34.51 kcal/mol), engaging key hydrogen-bond and hydrophobic interactions, thus reinforcing its promise as a multi-target antibacterial candidate

Synthesis and evaluation of novel 4-thiazolidinone-5-nitrofuran hybrids as promising antimicrobial agents.

Chitosan coating functionalized with silver nanoparticles synthesized from avocado leaves and cinnamon oil/β-cyclodextrin: An eco-friendly approach to avocado preservation.

Insulin glargine, a long-acting insulin analog, is essential for diabetes treatment. However, its industrial production remains challenging due to limitations in conventional expression systems. Here, we employed the industrial filamentous fungus Trichoderma reesei as an alternative expression host for insulin glargine production, leveraging its superior protein secretion capacity. Initially, expression constructs containing the constitutive Pcdna1 promoter and CBH1 signal peptide (SP1) showed successful transcription but failed to achieve extracellular secretion, presumably due to induced endoplasmic reticulum (ER) stress. Consequently, we implemented a fusion protein strategy utilising three distinct carrier proteins (CBH1, CBH2, and LA-20) to enhance glargine secretion. Notably, the CBH1 fusion not only enabled detectable glargine secretion but also significantly alleviated the ER stress. Furthermore, replacement of SP1 with the Aspergillus niger β-glucoamylase signal peptide achieved a fourfold enhancement in glargine secretion and further reduced cellular stress responses. Following these systematic optimizations, a final yield of 58.95 mIU/L glargine was achieved in shake-flask cultures. Thus, the combined strategy described here could achieve extracellular production of glargine in T. reesei, suggesting that it is a promising host for secretory production of therapeutic recombinant proteins, particularly complex analogs like glargine.

Jabuticaba (Plinia cauliflora) processing generates substantial epicarp waste rich in phenolic compounds, which have antioxidant and health‐promoting potential. To valorize the jabuticaba epicarps via a green biotechnological approach, we developed and optimized an enzyme extraction of phenolic compounds using a fungal cocktail produced by Aspergillus niger LBM 321. A central composite design was employed to evaluate the effects of temperature, pH, and time of extraction. The optimal conditions were 38.5 °C, pH 5.34, and 10 h yielded 72.94 mg GAE 100 mL⁻¹. Under these conditions, enzymatic extraction outperformed alkaline hydrolysis (1 N NaOH, pH 9.5) and commercial enzyme extraction (Viscozyme L). UHPLC‐MS/MS analysis revealed that ρ-coumaric and ferulic acids were the predominant phenolics in the fungal enzyme extracts, suggesting preferential liberation of ester‐linked hydroxycinnamic acids from the cell wall matrix. FTIR spectroscopy presented enhanced C–O stretching bands after enzymatic treatment, indicating selective polysaccharide hydrolysis and release of phenolic compounds. This study demonstrates that A. niger LBM 321 enzymes offer an eco-friendly and cost-effective strategy for recovering high-value phenolics from jabuticaba epicarps. By converting waste into functional ingredients, this approach supports a circular‐economy model and aligns with consumer demands for natural, sustainable food additives.