Gene hunting and semi-rational design of β-xylosidase from Aspergillus aculeatus for highly efficient hydrolysis of astragaloside.

Structurally diverse polyketides with herbicidal activity from the fungus Aspergillus aculeatus.

Cashew is a key economic crop in coastal Kenya, yet its production faces significant challenges due to post-harvest fungal contamination, particularly by Aspergillus flavus and Aspergillus aculeatus. These fungi are known producers of mycotoxins, including aflatoxins, potent carcinogenic and mutagenic compounds that pose serious food safety and public health risks. Despite growing concerns, the genomic architecture, metabolic potential, and ecological adaptations of these fungi in cashew-growing regions remain poorly understood. This study investigated the genetic diversity, aflatoxin biosynthetic gene clusters (BGCs), secondary metabolite profiles, and carbohydrate-active enzyme (CAZyme) repertoires of aflatoxigenic A. flavus and compared them with non-aflatoxigenic A. aculeatus isolates obtained from cashew nuts collected in Kilifi, Kwale, and Lamu counties. A total of 18 fungal isolates (16 A. flavus, 2 A. aculeatus) were cultured and subjected to whole-genome sequencing using the Illumina platform. Genome mining and comparative analyses were performed using OrthoFinder, antiSMASH, and dbCAN. Phylogenomic analysis revealed five distinct clades among A. flavus isolates, suggesting substantial intraspecific diversity and potential regional adaptation, while A. aculeatus formed a single monophyletic clade. Comparative analysis of aflatoxin BGCs in A. flavus revealed notable structural variation, including gene deletions (aflT, omtA), insertions, and rearrangements, with conservation observed for core genes such as ordB, moxY, avfA, and adhA; however, the regulatory gene aflR was not conserved across all isolates. All the 2 A. aculeatus isolates lacked aflatoxin biosynthetic genes, indicating they are not aflatoxigenic. Both species harbored diverse SMBGCs, including PKS, NRPS, and strain-specific clusters such as YWA1, fusarin, and aspergillic acid, suggesting potential for co-production of multiple bioactive compounds. CAZyme profiling revealed abundant glycoside hydrolases and auxiliary activity enzymes, underscoring adaptation to pectin-rich cashew substrates. Despite similar genome sizes and GC content, species-specific differences in carbohydrate metabolism and secondary metabolite pathways indicate ecological plasticity. Our findings demonstrate that A. flavus and A. aculeatus populations in coastal Kenya are genetically diverse, metabolically versatile, and shaped by local environmental and anthropogenic pressures. The study provides essential genomic insights for region-specific aflatoxin risk assessment and highlights the need for careful screening of atoxigenic strains in biocontrol applications, as well as further exploration of cryptic BGCs and CAZyme functions in post-harvest fungal ecology.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-26433-y.

Harnessing Aspergillus aculeatus for Lead (Pb) bioremediation from a contaminated dump site in Guwahati, Assam, North-Eastern India

The Asian citrus psyllid (ACP) is the primary vector of huanglongbing (HLB), a severe citrus disease. This study identified three insecticidal paraherquamide alkaloids (paraherquamide E, SB200437, and paraherquamide B) that were effective against the ACP from the strain Aspergillus aculeatus GC-147-5 using a bioactivity-guided isolation method. The median lethal doses (LD50) of paraherquamide E were 19.93 μg/mL (24 h) and 29.08 μg/mL (12 h), comparable to those of imidacloprid. Investigations into the insecticidal mechanism revealed that paraherquamide E disrupts fatty acid synthesis, inhibits vitellogenin production, and alters metabolic homeostasis, ultimately leading to ACP mortality. Microscopic analysis confirmed ovarian abnormalities in treated females. Additionally, paraherquamide E exhibited negligible toxicity to the nontarget species, the ladybug, indicating its high selectivity and favorable environmental safety profile. The findings of this study could lead to the development of new, environmentally friendly, and effective insecticidal agents for managing ACP.

Ultraviolet B (UVB) radiation severely damages human skin by causing DNA damage, oxidative stress, and collagen degradation. This study explored the photoprotective properties of Asparagus cochinchinensis extracts fermented with endophytic fungus Aspergillus aculeatus TD103. Compared to the unfermented control, TD103-fermented A. cochinchinensis demonstrated stronger radical scavenging and ferric ion reduction abilities in vivo, significantly reduced intracellular reactive oxygen species (ROS) and increased the antioxidant enzymes including heme oxygenase-1 (HO-1), superoxide dismutase (SOD), and catalase (CAT) in UVB-induced HaCaT cells. It also downregulated the expression of the AP-1 and MMP genes, reduced the content of matrix metalloproteinase (MMP-1) and increased type I procollagen amino-terminal propeptide (PINP) levels in UVB-induced HaCaT cells. Non-targeted metabolomics and HPLC quantification revealed that elevated sarsasapogenin content may critically contribute to enhanced photoprotective capacity in Asparagus cochinchinensis. The safety assessment of fungus TD103 revealed that this strain was not drug resistant and did not produce mycotoxins, thereby indicating its safety for application. Eye irritation tests demonstrated the safety profile of the fermented extract, indicating negligible irritant potential. The TD103-mediated fermentation markedly potentiated the photoprotective capacity of A. cochinchinensis, ​providing a viable biotechnological platform for sustainable cosmeceutical development targeting UV-induced skin damage.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12896-025-01034-9.

Identification, pathogenic mechanism and control of Aspergillus aculeatus causing postharvest fruit rot in Longan

This study aimed to produce spray-dried tomato powder with improved product yield and powder quality. The experiment for this investigation entailed the use of two carrier agents which were maltodextrin (MD) dextrose equivalent (DE) 20 and gum Arabic (GA) from acacia tree G9752, each at 10% concentration. The carrier agents were combined and mixed with three different enzymes, alpha-amylase from porcine pancreas (AAPP) A6255, pectinase from Aspergillus aculeatus (PAA) P2611, and pectinase from Aspergillus niger (PAN) P4716, each at 1% v/w concentration. This study was conducted by altering the spray drying inlet temperatures to 140oC, 160oC, and 180oC separately. The physicochemical analysis of the tomato powder samples was conducted on the moisture content, powder yield, hygroscopicity, colour features, and 2,2-diphenil-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA). The powder analysis conducted presented the moisture content of 1.30%-7.00%, colour analysis indices of * at 1.31–5.72, * at 7.5–9.8, * at 89.6–95.39, the production yield of 27.73%–42.65%, hygroscopicity value at 1.05%-6.79%, and antioxidant activity value of 9.51 mg/mL–28.81 mg/mL. Results indicated that sample TP9 was the best powder produced with output analysis of moisture content percentage of 1.3%, colour analysis * value of 3.14, production yield 42.65%, hygroscopicity 1.05%, and antioxidant activity value of 11.94 mg/mL. The study revealed that at higher inlet temperatures and in combination with enzyme PAN it is possible to produce powder characteristics with low moisture content, high * colour index, high production yield, low hygroscopicity value, and high antioxidant activity.

Studies have shown that limited availability, supply shortages and pricing of conventional antibiotics including carcinogenic and mutagenic nature are serious global problems that restrict access to effective treatment for common bacterial infections, and this may not only worsen clinical outcomes but potentially accelerate the development of antibiotic resistance. Hence this study focused on the structural elucidation of antibacterial substances from Mycelia of Negric section of Aspergillus species using natural sources. The fungal isolates were isolated from garden soil samples using standard microbiological techniques. The fungi were grown in a submerged medium prepared from Phoenix dactylifera (PD) fruits (20g), Chrysophyllum albidum (C.A) fruits (10g), Glycine max (GM) peel (10g) and Musa paradisiaca (MP) peel (10g). The antibacterial substances were precipitated, eluted, purified and structurally elucidated using column chromatographic, thin layer chromatographic and C-S-MS techniques respectively. The Aspergillus species isolated were Aspergillus niger strain HUS1 (ANH1), Aspergillus aculeatus strain AN5 (AAA5) and Aspergillus awamori strain DN-SN2 (AAD2). The optical growth and production of antibacterial substances occurred when the pH, Temperature, Carbon Source and nitrogen source were 7.0, 25, and sugar extracted from PD and NOdz respectively. The purified fractions; oleic acid (N1) > 1-docosene (N2) > I-octadecene (N3) > 2,3 furanone-4-hydroxyl (N4) from ANH1 showed significant (P<0.05) inhibitory activities against sorbitol positive and sorbitol negative Escherichia coli; Escherichia coli O157: H7 strain MB4-1 (SECM41) and Escherichia coli HH35 (SECH35). Similarly trans (2-doscenyl) succinic acid (A2) > E-15-hepadecenal (A1) > silane ethyl-trimethoxy (A3) from AAA5 and oleic acid (D1) > hexacosanoic acid (D2) > n-hexadecenoic acid (D3) > 9-octadecenoic acid (Z) methyl ester (D4) from AAD2 also showed significant (P<0.5) pronounced activities against the Sor+ and Sor- Escherichia coli. From this study, the purified fractions from ANH1, AAA5 and AAD2 showed pronounced activities against uropathogenic Escherichia coli and formed the basis of newer antibiotics from natural sources.

As research into lovastatin derivatives continues to advance, exploring their structural diversity and potential therapeutic applications has become increasingly significant in pharmaceutical chemistry. This paper focuses on the total synthesis of aculeatiols A-C, derived from Aspergillus aculeatus, and provides a comprehensive account of the key strategies and steps employed throughout the synthesis process. Initially, a linearization analysis was conducted, identifying 35 potential structures, from which the most suitable linearized structure was selected for synthesis. The core reactions utilized in this study included Robinson annulation, olefin metathesis, and asymmetric synthesis, which were crucial for constructing the complex molecular framework and ensuring the accurate stereochemical features of the target compounds. Furthermore, applying the "chiral pool" concept facilitated the optimization of the synthetic pathway, enhancing the efficiency of the synthesis. This research not only offers effective methodologies for the synthesis of novel lovastatin derivatives but also contributes valuable insights into their structure-activity relationships. The findings underscore the importance of continued exploration in this area, as they promise to develop more effective cholesterol-lowering therapies and personalized medicine approaches, ultimately benefiting patient care and treatment outcomes.

The eradication of keratin waste substrate in environment is of great concern, hence the need to look for an ecofriendly way of getting rid of them. Hence, the objective of this paper was to isolate, screen and identify keratin degrading microorganisms from soil samples collected from different chicken feather dumpsites in Ilorin metropolis, Kwara State, Nigeria using appropriate standard methods. A total of thirteen (13) microorganisms were purified and screened for proteolytic activity, seven (B1, B2, B3, B4, B5, F1 and F3) showed appreciable zone of clearance and were further used in keratinase activity determination over 21days, after which percentage chicken feather weight loss was determined. B1 showed highest keratinase activity of 42.48 U/ml at day 7, B2 40.88 U/ml at day 9, B3 24.32 U/ml at day 11, B4 49.36 U/ml at day 9, B5 19.36 U/ml at day 7, F1 45.52 U/ml at day 11 and F3 45.04 U/ml at day 13. All isolate except B5 had the least activity at day 1. Percentage chicken feather weight loss after 21 days revealed that B1, B2, B3, B4, B5, F1 and F3 had 49, 38, 6, 64, 9, 39 and 57 respectively. Molecular identification of best keratinase producers (B1, B2 B4 F1 and F3) revealed the isolates to be Pseudomonas aeruginosa, Bacillus cereus, Alcaligenes faecalis, Aspergillus niger and Aspergillus aculeatus respectively. These organisms have shown they are good keratinase producers and should consider in the large-scale degradation of chicken feather pollutant.

Background: The carrot (Daucus carota L.) is a popular root vegetable grown throughout the world. In the present study, an attempt was made to use the carrot outgrades, which are purely rejected for aesthetic reasons, not meeting the standards based on size and shape. Further enzymes (Pectinase and Cellulase) are used to extract the carrot coagulum from carrot outgrades. Carrier agents were mixed into carrot coagulum and spray dried at three different inlet air temperatures (160, 170, and 180 °C) to encapsulate enzyme-extracted carrot coagulum. Aim: Carrots are nutritious and mainly rich in carotenoids. Often, very high losses are incurred during post-harvesting operations. A significant proportion of carrots are rejected due to bad aesthetics. Therefore, the objective of the study was to utilise such non-commercial carrot out-grades to recover carotenoids and produce encapsulated powder using spray drying. Methodology: The process of spray drying of enzymatically extracted carrot coagulum was standardised by varying carrier agents (maltodextrin and gum arabica) concentration and at different inlet temperatures. Pectinase (Pectinex Ultra SPL from Aspergillus aculeatus aqueous solution, ≥3,800 units/mL) and cellulose (Celluclast 1.5L from Trichoderma reesei aqueous solution, ≥700 units/g) were obtained from Novozymes, Bangalore. Trans-β-carotene was obtained from Sigma Chemical Company. All other chemicals used were of analytical grade. Results: All physicochemical properties were significantly affected by the carrier agents and temperature. Carotenoid content was highest (9.80%) at an inlet temperature of 170 °C with MD100. Overall moisture content was reduced, while other physical properties were enhanced when the temperature increased. Increasing the gum Arabica content showed a significant increase in moisture content and wettability time, as well as poorer physical properties. Results showed that the physicochemical and microstructural properties of encapsulated carrot coagulum powder (ECCP) were affected by inlet temperatures and carrier agents. Conclusion: Among all the spray-dried powders, the powder dried at 170 °C using maltodextrin at 15% alone had comparatively lower moisture content, good flowability, higher solubility, and less wetting time compared to other combination treatments and inlet temperatures, and thus fulfills the requirement of good quality spray-dried powders. Certainly, carrot out grades have a significant content of total carotenoids, which makes the utilisation of such material worthwhile for processing.

Medicinal plants are rich sources of specialised metabolites, crucial for various fields like agriculture, forestry, food processing, biofuels and environmental remediation. Microbes, particularly endophytic and rhizospheric fungi, play a significant role in optimising the production and regulation of these compounds. Several research showed these fungi in various plants, but they have not been thoroughly studied in Phyllanthus niruri, especially to promote growth and elicit lignan compounds like phyllanthin in P. niruri. A total of 131 fungi, consist of 57 rhizospheric fungi and 74 endophytic fungi, were successfully isolated from P. niruri in six different lowland areas in West Java. The potency assay results indicated that 106 fungi could produce indole-3-acetic acid (IAA). Six fungi could synthesise cellulase, and one fungus had the capability to solubilise phosphate. Our results showed that Fusarium sp., Colletotrichum gloeosporioides, Colletotrichum tenuissimum, Colletotrichum fructicola, Pseudallescheria boydii, Aspergillus aculeatus, Myrothecium inundatum, Colletotrichum truncatum can synthesise IAA. Fusarium sp. and Myrothecium inundatum could synthesise cellulase and only Aspergillus aculeatus have activity as phosphate solubilisation. Cocultivation of P. niruri and eight endophytic and rhizospheric fungi showed that Fusarium sp., C. gloeosporioides, P. boydii, A. aculeatus and M. inundatum had the potential traits to increase biomass, phyllanthin levels and phyllanthin yield. In general, these fungi have the potency to be elicitors to enhance phyllanthin in P. niruri.

Aculeanoids A-D, the second 17-nor fusicoccane diterpenoids with immunosuppressive activity from Aspergillus aculeatus.

Abstract. Khalimi K, Pranatayana IBG, Yuliadhi KA, Gargita IWD, Yudha IKW. 2025. Identification of rhizobacteria isolate from Bali Barat National Park, Indonesia and the potential as biological agents against soybean seed-borne pathogen. Biodiversitas 26: 1799-1806. The use of biological agents is a method of suppressing plant pathogenic fungi. Therefore, this study aimed to determine biochemical characteristics, identity, antifungal activity, and types of compounds produced by rhizobacteria isolates from Taman National Bali Barat (West Bali National Park/TNBB), Bali, Indonesia. Rhizobacteria was characterized using Microbact Biochemical Kits and molecular identification of rhizobacteria based on the 16S rRNA gene sequence analysis. Antifungal compounds were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). The results showed that rhizobacteria used gelatin and arabinose as carbon sources, producing indole, acetoin, urease, and tryptophan deaminase compounds. The identity of rhizobacteria isolate TNBB is Bacillus thuringiensis. Furthermore, rhizobacteria filtrate of TNBB isolate inhibited the growth of Alternaria alternata, Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Aspergillus niger, Aspergillus tubingensis, Aspergillus aculeatus, and Rhizopus oryzae fungi. The diameter of the inhibition zone formed was categorized as having very strong power. The filtrate of TNBB isolate rhizobacteria contained 16 antifungal compounds, namely 1,3,5-triazine-2,4,6-triamine, 2(1H)-pyridinone 6-hydroxy-, tridecanoic acid, N-acetyl-d-glucosamine, hexadecanoic acid, butanoic acid, pentyl ester, pentanoic acid butyl ester, pentanoic acid pentyl ester, linoleic acid, 1-naphthalene-sulfonic acid, 2-naphthalene-sulfonic acid, stearic acid, cyclotrisiloxane hexamethyl-, cyclotrisiloxane hexamethyl, 1,2-benzenedicarboxylic acid, diisooctyl ester, and benzo[h]quinoline, 2,4-dimethyl-. The results of this study provided information that TNBB isolate rhizobacteria are suitable for use as biological agents.

The simplest cyclo-peptides, also known as diketopiperazines (DKPs), are widespread in nature. The growing interest in these simplest cyclo-peptides is driven by their significant potential for therapeutic applications. In this study, we identified a biosynthetic gene cluster from Aspergillus aculeatus CRI323-04 through genome mining and heterologous expression in Aspergillus nidulans. The two core genes, aacA and aacB, within the gene cluster were characterized for their role in the biossoynthesis of aspkyncin, a novel DKP compound that incorporates a l-kynurenine (l-Kyn) unit. Furthermore, we successfully reconstituted the activities of the minimal bimodular non-ribosomal peptide synthetase (NRPS) AacA and the methyltransferase AacB both in vivo and in vitro. Our findings demonstrate that AacA catalyzes the condensation and cyclization of two non-proteinogenic amino acids, l-Kyn and N-methyl-l-alanine, to produce aspkyncin without the involvement of any release domain. Notably, the N-methyl-l-alanine is generated by a specialized l-alanine N-methyltransferase AacB prior to NRP assembly. This study reveals an unconventional pathway for the biosynthesis of fungal DKPs.

We investigated mycoremediation potential of endophytic and rhizospheric fungi from Tezpur litchi in lead (Pb) and cadmium (Cd) contaminated soil. Fungal strains Aspergillus aculeatus, Penicillium citrinum, Fusarium solani, and two Mycelia sterilia documented high Pb (> 95%) and Cd (> 85%) absorption capacities. The consortium developed by using these fungal strains was applied to Pb (75, 100 and 150mgkg⁻1) and Cd (0.5, 1.0 and 1.5mgkg⁻1) contaminated soil under tomato cultivation till the flowering stage of the plants. Applied consortium increased fungal colony-forming units (CFUs) by 2-3 folds. It also significantly (p ≤ 0.05) enhanced shoot biomass (upto 132.8% under Pb and 80.1% under Cd) of tomato plants. Consortia reduced the accumulation of Pb in tomato plants upto 64.16%, while Cd uptake decreased (upto 10.31%). Significant (p ≤ 0.05) improvement in photosynthesis rates of tomato plants was noted under Pb exposure (upto 58.8%) than Cd (upto 9.2%) due to application of consortium. The results highlight the potential of the tested endophytic and rhizospheric fungal strains from Tezpur litchi for remediating Pb in contaminated soils. Additionally, the study suggests the possible application of the fungal consortium for Cd phytoextraction using hyperaccumulator plants, thereby paving the way for sustainable heavy metal remediation strategies.

Malaysia ranks among the world's top 20 pineapple producers, driven by the success of the MD2 variety in meeting domestic and international demand. However, postharvest losses due to pathological diseases remain a challenge. Black rot, a major postharvest disease, causes significant economic losses in pineapples. Despite its presence in various cultivars, its aetiology, specifically in MD2 pineapples remains unclear. This study was conducted to identify the principal causative pathogen of black rot disease in pineapple from three different regions. In addition, critical factors influencing black rot disease were investigated, such as the minimum inoculum concentration, appropriate storage temperature, and maturity index required to initiate infection. Thielaviopsis paradoxa was identified as the primary pathogen causing black rot, with 50 and 45% occurrence at two specific cultivation sites. Other associated pathogens included Lasiodiplodea theobromae, Trichoderma asperellum, Curvularia eragrostidis, Neoscytalidium dimidiatum, Aspergillus assiutensis, and Aspergillus aculeatus. Fruits stored at ambient temperature with a maturity index of 2 showed higher disease progression than those in cold storage. A minimum inoculum concentration of 1 × 104 CFU/mL was sufficient for infection at both storage conditions. The Pearson correlation analysis revealed a weak positive link (r > 0.39, p < 0.0001) between harvesting index and fruit pH, while pH and storage temperature had a strong positive correlation (r = 0.83, p < 0.0001). The increments in pH correlated with lesion length and infected area (r = 0.83 and r = 0.82, respectively). The harvesting index showed a strong positive correlation with the proportion of infected area (r = 0.86, p < 0.0001). The telomorph state of T. paradoxa, identified as Ceratocystis paradoxa, persists in soil and decaying plant material, acting as a quiescent pathogen, increasing cross-contamination risks. Urgent measures are required to reduce postharvest losses and maintain the quality of pineapples for international markets.

Endophytic fungi are microorganisms that infect living plant tissues internally without producing obvious symptoms of infection, existing in a symbiotic relationship with plants for a portion of their life cycle. Currently, endophytic fungi serve as alternate sources for the production of new bioactive chemicals with great efficacy. This study aimed to examine the antimigration and anti-invasion capabilities of the endophytic fungus Aspergillus aculeatus extract, isolated from Capsicum annuum L., utilizing in vitro and in silico methods. This study isolated the endophytic fungus A. aculeatus from the leaves of C. annuum L. LC–MS analysis revealed fifty-five active components within the extract. Ten compounds exhibited favorable results in the in silico assessment. Computational predictions indicate that tajixanthone methanoate (−8.80 kcal/mol) and aspernigerin (−12.95 kcal/mol) exhibited high binding affinity against MMP-2. The A. aculeatus extract demonstrated antiproliferative activity with an IC50 value of 286.36 ± 122.57 μg/mL. The extract, at noncytotoxic concentrations, reduced the migration and invasion of A549 cells in a dose-dependent manner. Furthermore, A. aculeatus extract demonstrated a marked reduction in MMP-2 activity. According to these results, the compounds may serve as antimigration and anti-invasion agents by inhibiting the MMP-2 protein. The results demonstrated that A. aculeatus extract derived from C. annuum L. inhibited A549 cell migration and invasion via reducing MMP-2 activity. The findings indicated that A. aculeatus extract derived from C. annuum L. may be utilized for the treatment of lung cancer.

The production of cellulolytic enzymes in Aspergillus aculeatus is regulated at transcriptional levels in response to inducers and various physiological signals. In this study, we identified that a component of the septation initiation network complex, SepL, a putative protein kinase, was involved in the expression of carbohydrate-active enzyme (CAZyme) encoding genes. The deletion of sepL (ΔsepL) in A. aculeatus resulted in a deficiency in both septation and conidiation and sensitivity to Congo red. These phenotypes of ΔsepL are conserved in Aspergillus. In addition to the conserved function of SepL in Aspergillus, we found that SepL in A. aculeatus was necessary for the inducible expression of the CAZyme genes in response to cellobiose, whereas the inducible expression of these genes in response to 1,4-β-mannobiose was significantly reduced but not abolished. Combining the results of the present functional analysis of SepL with previous evidence that the expression of the CAZyme genes, which is responsive to both cellobiose and 1,4-β-mannobiose, is regulated by a transcription factor ManR in A. aculeatus, indicates that SepL in A. aculeatus is involved in the selective expression of the cellobiose-responsive CAZyme genes under the control of ManR.