Jul 2026· Jurnal MIPA dan Pembelajarannya· Vol 6, pp. 3· 0 citations· 24 references
Abstract
Background: Aspergillus flavus is an important aflatoxigenic fungus associated with contamination of maize, wheat, peanuts and other stored crops. Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic secondary metabolite, and its biosynthesis is controlled by clustered structural and regulatory genes, including aflR, aflS, aflD, aflM, aflP and aflQ. Objective: This study evaluated the inhibitory effects of cinnamon, clove and thyme essential oils on A. flavus growth, AFB1 production and relative expression of selected aflatoxin biosynthetic genes under controlled in vitro conditions. Methods: An aflatoxigenic A. flavus isolate was exposed to essential oils at 0.25, 0.50 and 1.00 µL/mL. Radial growth inhibition was determined on potato dextrose agar, while mycelial dry weight and AFB1 production were evaluated in yeast extract sucrose broth. AFB1 was quantified by HPLC with fluorescence detection. Relative expression of aflR, aflS, aflD, aflM, aflP and aflQ was determined by RT-qPCR using β-tubulin as the reference gene and the 2^-ΔΔCt method. Results: The results showed a concentration-dependent decrease in fungal growth, biomass and AFB1 production. Cinnamon oil produced the strongest inhibition, reducing radial growth by 54.3% and AFB1 production by 81.7% at 1.00 µL/mL. Clove oil reduced AFB1 by 73.4%, whereas thyme oil reduced it by 65.2% at the same concentration. RT-qPCR analysis showed downregulation of all tested biosynthetic genes, with aflR and aflD showing the most consistent suppression. Cinnamon oil reduced aflR expression to 0.24-fold and aflD expression to 0.19-fold compared with the untreated control. Conclusion: The findings demonstrate that essential oils, particularly cinnamon and clove oils, reduced AFB1 production through both growth inhibition and transcriptional suppression of key aflatoxin biosynthetic genes. These results support the use of plant-derived essential oils as natural anti-aflatoxigenic agents in strategies aimed at reducing crop contamination.
Aflatoxins (AFL) are mycotoxins produced by
Aspergillus flavus
that pose major risks to food safety. This study evaluated fungal growth and AFL production in planta across the following five pulse species: chickpeas (
Cicer arietinum
L
.), lentils (
Lens culinaris
Medik
.), peas (
Pisum sativum
L
.), soybeans (
Glycine max
L
.), and with corn (
Zea mays
L
.) as a susceptible reference host. Plants were grown in a greenhouse and arranged in a 5 × 2 factorial completely randomized design (CRD) with crop species and inoculation treatment as factors. Each crop had 10 mock‐inoculated plants and 10 plants inoculated with
A. flavus
strain AF‐70 expressing green fluorescent protein (GFP). Fungal colonization was monitored using GFP imaging, and toxin levels (AFB
1
, AFB
2
, cyclopiazonic acid [CPA], α‐aflatrem, aflavarin, and ditryptophenaline [DTP]) were quantified at 7 days after inoculation and at physiological maturity. Corn accumulated the highest AFL (20,639 ng/g AFB
1;
6146/g AFB
2
), representing a ~7‐fold and ~6‐fold higher concentration than chickpeas (2548 ng/g AFB
1
; 900 ng/g AFB
2
) (
p
< 0.0001). Soybeans showed intermediate contamination (1807 ng/g AFB
1
; 584 ng/g AFB
2
), while lentils and peas accumulated minimal AFL (< 63 ng/g AFB
1
and AFB
2
). GFP imaging of lentils and chickpeas showed early fungal colonization, yet corn exhibited the strongest fluorescence at maturity. Secondary metabolite profiles showed high α‐aflatrem, CPA, and DTP in corn, elevated aflavarin in chickpeas, and limited production in lentils and peas. These findings demonstrate fungal colonization and mycotoxin contamination are not consistently coupled across hosts and highlight key food safety implications, as well as validating earlier studies.
E. Branstad‐Spates, K. Rajasekaran, E. Wyman et al.· Legume Science· 0 citations
Aflatoxin contamination in corn presents significant risks to feed safety and animal performance, emphasizing the importance of effective control methods such as fermentation with Aspergillus niger and Rhizopus oligosporus to lower toxin levels. The study aimed to evaluate the effects of initial aflatoxin levels, microbial fermentation type, and their interaction on the concentration of aflatoxin in ground corn following fermentation. An experimental approach was employed using a two-factor completely randomized design. The first factor consisted of aflatoxin levels (38.53 and 88.06 μg/kg), while the second factor comprised microbial treatments: non-fermented control, Aspergillus niger (0.25%), and Rhizopus oligosporus (0.25%). Fermentation was conducted for 60 hours, and Aflatoxin concentration was analyzed using LC-MS/MS. Statistical analysis revealed that both aflatoxin level and fungal treatment significantly affected (P<0.01) AFB1, AFB2, and total aflatoxin content in ground corn. Higher initial contamination (88.06 μg/kg) resulted in greater residual aflatoxin compared to the lower level (38.53 μg/kg). Fermentation with Aspergillus niger and Rhizopus oligosporus markedly (P<0.05) reduced AFB1, AFB2, and total aflatoxin to very low levels (<1–1.33 μg/kg), while the control treatments retained high toxin concentrations. A significant interaction (P<0.05) between aflatoxin level and fungal type indicated that detoxification efficiency depended on both initial contamination and the fermenting microorganism. Overall, fermentation with A. niger and R. oligosporus proved to be an effective biological approach for reducing aflatoxin levels in ground corn. Therefore, fermentation can be considered a promising biological approach for mitigating aflatoxin contamination in corn.
Wilfridus V. Lende, C. L. Nalle, Stormy Vertygo· IOP Conference Series: Earth...· 0 citations
Aflatoxin contamination of cereal grains represents a serious food safety concern due to the toxic and carcinogenic properties of aflatoxins produced mainly by Aspergillus species. The present study aimed to evaluate the antifungal and antiaflatoxigenic potential of lactic acid bacteria (LAB) cell-free supernatants as a natural approach for controlling aflatoxin-producing fungi in wheat grains. A total of fifty fungal isolates recovered from agricultural samples were screened for their aflatoxigenic potential using phenotypic and molecular approaches. The toxigenic isolates were identified as Aspergillus flavus (AF) and Aspergillus parasiticus (AP), and their aflatoxigenic potential was confirmed by PCR amplification of aflatoxin biosynthesis-related genes (nor-1 and aflR). The antifungal activity of selected LAB strains was evaluated against the identified Aspergillus isolates using the agar diffusion method. The obtained results demonstrated that LAB cell-free supernatants exhibited significant antifungal activity, with variations among strains. Among the tested LAB strains, Lactobacillus plantarum P3 and Lactobacillus acidophilus ATCC 20552 showed the highest inhibitory activity against both fungal species. Furthermore, LAB treatments significantly reduced fungal-induced wheat grain damage and decreased aflatoxin accumulation during storage. Application of 100% LAB supernatants resulted in a remarkable reduction in total aflatoxins, reaching more than 99% reduction compared with untreated controls. The inhibitory effect decreased with increasing dilution of the supernatants, indicating a concentration-dependent antifungal and antiaflatoxigenic activity. The findings demonstrate that LAB-derived metabolites can effectively suppress the growth of aflatoxin-producing Aspergillus species and limit aflatoxin biosynthesis. Therefore, LAB cell-free supernatants represent a promising biological control strategy for improving cereal safety and reducing mycotoxin contamination in food systems.
Mohammed Aladhadh, F. Abou-Elazm, R. Ahmed et al.· Microorganisms· 0 citations
Contamination of maize grains with aflatoxigenic genus Aspergillus negatively impacts public health, food security, and postharvest storage. Biological control (BC) of molds is becoming more popular. Regardless, invitro validation of BC agents’ efficiency is crucial to successful postharvest deployment. This study investigated antifungal action of an endophytic Bacillus cereus against four Aspergillus strains, and its metabolic profiling. Decontaminated apple seeds and maize grains were blended, and plated on mannitol egg yolk polymyxin B agar, and potato dextrose agar for Bacillus and Aspergillus strains isolation respectively. Molecular identification of isolates was done. A 72 h Bacillus cell-free extract dilutions (undiluted, 1:10, and 1:1000), were used in agar well antifungal susceptibility test against three Aspergillus species, and aflatoxigenic A. flavus ATCC 22546. Nystatin was positive control, and incubation done at 28 °C. AST was repeated at pH 6, 8 and 9, and zones of inhibition were measured (mm). Minimum inhiibitiory concentration and minimum fungicidal concentration was done. Enzyme assay and GCMS scan of CFE, and ZOI agar blocks were done for A. flavus ATCC 22546 and an A. flavus. B. cereus strain JCM 2152, and A. flavus isolate K1, A. flavus isolate W5 and A. fumigatus strain 3162953 were confirmed. The 1:10 dilution produced widest ZOI, and A. flavus isolate W5 susceptibility was significant at 30.00 ± 2.50 mm. Also, pH and ZOI correlated. MIC ranged 1:8 – 1:256, and was fungistatic. Hexadecanoic acid, 4-methyl-3-pent-2-one, and extracellular enzymes were detected. A. flavus isolate W5 was significantly susceptible to enzymes. Possible synergistic inhibition was the mechanism of inhibition, and preliminary features required of a BC for postharvest trial were affirmed for B. cereus strain JCM 2152.
O. Sotayo, R. Uzeh, O. Ayejuyo· Journal of Microbiology, Bio...· 0 citations
Aflatoxin B1 is a potent Group I carcinogen that contaminates food and feed, necessitating efficient detoxification strategies. This study isolated a novel bacterial strain, Enterobacter sp. HNGD-822 from soil, which efficiently degrades AFB1. Genome analysis identified two novel multicopper oxidase (laccase) genes, EbMCO1 and EbMCO2. The recombinant enzymes were heterologously expressed, exhibiting optimal activity at 50 °C and pH 7.0, with strict Cu2+ dependence. Within 12 h, EbMCO1 degraded over 99% of AFB1, while EbMCO2 also showed high activity under the same conditions. Both enzymes primarily converted AFB1 into AFQ1 and epi-AFQ1, products that exhibited significantly reduced hepatotoxicity, developmental toxicity, and oxidative stress in transgenic zebrafish. Applied to artificially contaminated peanut meal matrices, EbMCO1 and EbMCO2 achieved degradation efficiencies of 89.35% and 82.66%, respectively, without altering nutritional quality. This work presents novel laccases with promising potential for the biocontrol of AFB1 in the feed and food industries.
Yan Zhang, Yiqian Zhang, Nazish Muzaffar et al.· Journal of Agricultural and...· 0 citations
Nuts are widely consumed worldwide and valued for their high nutritional quality. Tree nuts are, however, prone to colonization by various fungal genera that can cause spoilage and lead to the formation of toxic secondary metabolites, among which mycotoxigenic Aspergillus (A.) species are of particular concern because they produce hepatotoxic aflatoxins (AFs). In this study, untreated, shelled walnuts, hazelnuts, cashews, pistachios, and peanuts were surface-sterilized, inoculated with different A. flavus strains and incubated under controlled conditions. The concentrations of AFs and sterigmatocystin (STC) in the edible kernels were quantified by an ultra-high-performance liquid chromatography method, coupled with tandem mass spectrometry (UHPLC-MS/MS). In walnuts inoculated with five A. flavus strains, toxin production was highly strain dependent: four strains produced AFB1 in a wide range from 0.18 µg/kg to > 11,000 µg/kg, three strains formed AFB2 (3.58-1,411 µg/kg), and three strains synthesized STC (0.26–262 µg/kg), whereas one strain did not generate any AFs or STC, and none of the strains produced AFG1 or AFG2. In pistachios, inoculation with strains AF70 and CBS119.62 did not result in detectable AF formation, in contrast to hazelnuts, cashews, and peanuts, on which these strains yielded measurable toxin levels (AFB1: hazelnuts 0.11–3.56 µg/kg, cashews 0.15–0.16 µg/kg, peanuts 0.06–17.9 µg/kg; AFB2: hazelnuts 0.13–0.18 µg/kg, cashews < LOQ, peanuts 0.26–7.59 µg/kg; STC: hazelnuts 0.08 µg/kg, peanuts 5.28 µg/kg). Overall, markedly higher concentrations of A. flavus toxins were detected in walnuts than in the other nut types, identifying walnuts as a particularly susceptible matrix and indicating that AF and STC contamination of walnuts may pose an increasing food-safety challenge under future climate-change scenarios.
Sarah Schneidemann-Bostelmann, Franka Nöth, S. Asam et al.· Mycotoxin Research· 0 citations
