Isolates Of Aspergillus Flavus Research Articles

Prevalence of azole-resistant Aspergillus fumigatus and other aspergilli in the environment from Argentina.

Azole resistance has emerged as a new therapeutic challenge in patients with aspergillosis. Various resistance mutations are attributed to the widespread use of triazole-based fungicides in agriculture. This study explored the prevalence of azole-resistant Aspergillus fumigatus (ARAF) and other aspergilli in the Argentine environment. A collection of A. fumigatus and other aspergilli strains isolated from soil of growing crops, compost, corn, different animal feedstuffs, and soybean and chickpea seeds were screened for azole resistance. No ARAF was detected in any of the environmental samples studied. However, five A. flavus, one A. ostianus, one A. niger and one A. tamarii recovered from soybean and chickpea seeds showed reduced susceptibility to medical azole antifungals (MAA). The susceptibility profiles of five A. flavus isolates, showing reduced susceptibility to demethylase inhibitors (DMIs), were compared with those of 10 isolates that exhibited susceptibility to MAA. Aspergillus flavus isolates that showed reduced MAA susceptibility exhibited different susceptibility profiles to DMIs. Prothioconazole and tebuconazole were the only DMIs significantly less active against isolates with reduced susceptibility to MAA. Although no ARAF isolates were found in the samples analysed, other aspergilli with reduced susceptibility profile to MAA being also important human pathogens causing allergic, chronic and invasive aspergillosis, are present in the environment in Argentina. Although a definitive link between triazole-based fungicide use and isolation of azole-resistant human pathogenic aspergilli from agricultural fields in Argentina remains elusive, this study unequivocally highlights the magnitude of the environmental spread of azole resistance among other Aspergillus species.

Impact of storage conditions on the shelf life of aflatoxin biocontrol products containing atoxigenic isolates of Aspergillus flavus as active ingredient applied in various countries in Africa

Aflatoxin contamination significantly threatens food safety and security, particularly in tropical and sub-tropical regions where staple crops such as maize, groundnut, and sorghum become frequently affected. This contamination is primarily caused by the fungus Aspergillus flavus. The contamination causes adverse health effects, reduced income, and trade restrictions. In response to this challenge, various technologies have been developed to mitigate the impacts of aflatoxin. Among these, biocontrol products containing atoxigenic isolates of A. flavus as the active ingredient can effectively reduce aflatoxin levels both at pre- and post-harvest. A notable example of such products is Aflasafe, which contains four atoxigenic isolates native to specific target regions. These products have undergone rigorous testing, have received regulatory approval, and are commercially available in multiple African countries. However, their manufacturing processes have evolved, and comprehensive shelf life studies for current formulations are lacking. Evaluations of the spore production ability of atoxigenic A. flavus isolates in Aflasafe products over 4 years, under various storage conditions, revealed a significant linear decrease in sporulation with storage months (P < 0.001; R2 = 0.203), with no significant differences observed between treatments. However, this marginal decline (P = 0.398) is unlikely to be sufficient to prevent the effectiveness in limiting aflatoxin. In addition, storing the products for 2 weeks at 54 °C did not affect (P > 0.05) the ability of the coated fungi to produce spores compared to when the products were stored at 24 °C. The findings contribute valuable insights for manufacturers and users of atoxigenic-based aflatoxin biocontrol products, informing best practices for product storage and utilization to ensure prolonged effectivenes in aflatoxin mitigation efforts.

Molecular and aflatoxigenicity analyses of Aspergillus flavus isolates indigenous to grain corn in Malaysia; potentials for biological control.

The present work aimed to distinguish the indigenous Aspergillus flavus isolates obtained from the first (pioneer) grain corn farms in Terengganu, Malaysia, into aflatoxigenic and non-aflatoxigenic by molecular and aflatoxigenicity analyses, and determine the antagonistic capability of the non-aflatoxigenic isolates against aflatoxigenic counterparts and their aflatoxin production in vitro. Seven A. flavus isolates previously obtained from the farms were characterized molecularly and chemically. All isolates were examined for the presence of seven aflatoxin biosynthesis genes, and their aflatoxigenicity were confirmed using high performance liquid chromatography with fluorescence detector (HPLC-FLD). Phylogenetic relationships of all isolates were tested using ITS and β-tubulin genes. Of the seven isolates, two were non-aflatoxigenic, while the remaining were aflatoxigenic based on the presence of all aflatoxin biosynthesis genes tested, and the productions of aflatoxins B1 and B2. All isolates were also confirmed as A. flavus following phylogenetic analysis. The indigenous non-aflatoxigenic isolates were further examined for their antagonistic potential against aflatoxigenic isolates on 3% grain corn agar (GCA). Both non-aflatoxigenic isolates significantly reduced AFB1 production of the aflatoxigenic isolates. The indigenous non-aflatoxigenic A. flavus strains identified in the present work were effective in controlling the aflatoxin production by the aflatoxigenic A. flavus isolates in vitro and can be utilized for in situ testing.

Application of Cystoseira myrica phycosynthesized selenium nanoparticles incorporated with nano-chitosan to control aflatoxigenic fungi in fish feed.

The recurrent contaminations of feed materials with mycotoxigenic fungi can endanger both farmed animals and humans. Biosynthesized nanomaterials are assumingly the ideal agents to overcome fungal invasion in feed/foodstuffs, especially when utilizing sustainable sources for synthesis. Herein, the phycosynthesis of selenium nanoparticles (SeNPs) was targeted using Cystoseira myrica algal extract (CE), and the conjugation of CE/SeNPs with chitosan nanoparticles (NCt) to produce potential antifungal nanocomposites for controlling Aspergillus flavus isolates in fish feed. The phycosynthesis of SeNPs with CE was effectually carried out and validated using visible/UV analysis, X-ray diffraction and transmission microscopy; CE/SeNPs had diameters of 8.7 nm and spherical shapes. NCt/CE/SeNPs nanocomposite (173.3 nm mean diameter) was achieved and the component interactions were validated via infrared spectroscopic analysis. The antifungal assessment of screened nanomaterials against three Aspergillus flavus strains indicated that NCt/CE/SeNPs exceeded the fluconazole action using qualitative/quantitative assays. Severe alteration/distortions in A. flavus mycelial structure and morphology were microscopically observed within 48 h of NCt/CE/SeNPs treatment. The treatment of feed ingredients (crushed corn and feed powder) by blending with nanomaterials (NCt, CE/SeNPs and NCt/CE/SeNPs) led to significant reduction in A. flavus count/growth after storage for 7 days; NCt/CE/SeNPs could completely inhibit any fungal growth in feed material. The pioneering phycosynthesis of CE/SeNPs and their nanoconjugation with NCt generated bioactive antifungal agents to control A. flavus strains. The innovatively constructed NCt/CE/SeNPs nanocomposite is advised for application as an effectual, biosafe and natural fungicidal conjugate for the protection of fish feed from mycotoxigenic fungi. © 2024 Society of Chemical Industry.

Molecular Characterization and Tolerance Potential of Culturable Crude Oil-Degrading Microbes in Santa-Barbara River, Bayelsa State, Nigeria

There has been chronic contamination of the surrounding aquatic and terrestrial environments in the Niger Delta region of Nigeria due to the enormous activities of crude oil exploration. This study aimed to characterize and assess the crude oil tolerance potential of indigenous microbes from crude oil spills in Santa Barbara River, Bayelsa State, Nigeria, that could serve as potential consortia for bioremediation of the crude oil spills. Total crude oil hydrocarbon-utilizing bacteria count (THUBC) and total crude oil hydrocarbon-utilizing fungi count (THUFC) in the samples were determined with a culture-dependent spread plate technique. Bacterial and fungal isolates were characterised using standard phenotypic and 16S/Internal Transcribed Spacer region rRNA gene sequencing techniques, respectively. The tolerance of autochthonous bacterial isolates to different concentrations of crude oil was subsequently determined. THUBC and THUFC in crude oil-polluted water samples ranged from 1.88 log10 CFU/ml to 2.74 log10 CFU/ml and from 0.00 log10 CFU/ml to 1.70 log10 CFU/ml, respectively. Representative strains of Proteus mirabilis, Bacillus subtilis, Pseudomonas aeruginosa, Micrococcus luteus and Aspergillus flavus isolates obtained from crude oil-polluted water samples were deposited in the GenBank (NCBI) under accession numbers OQ969924, OQ969951, OQ969987, OQ970009 and OQ975908. Proteus mirabilis, Pseudomonas aeruginosa and Aspergillus flavus demonstrated the most significant tolerance to crude oil pollutants (minimum crude oil inhibitory concentrations (MIC) = 80%) followed by Bacillus subtilis and Micrococcus luteus (MIC= 40%). The findings from this study are pointers to the potential role of the microbial isolates as bioremediation consortia to remediate the polluted Santa Barbara River.

Bacteria-mediated green synthesis of silver nanoparticles and their antifungal potentials against Aspergillus flavus.

The best biocontroller Bacillus subtilis produced silver nanoparticles (AgNPs) with a spherical form and a 62 nm size through green synthesis. Using UV-vis spectroscopy, PSA, and zeta potential analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy, the properties of synthesized silver nanoparticles were determined. Silver nanoparticles were tested for their antifungicidal efficacy against the most virulent isolate of the Aspergillus flavus fungus, JAM-JKB-BHA-GG20, and among the 10 different treatments, the treatment T6 [PDA + 1 ml of NP (19: 1)] + Pathogen was shown to be extremely significant (82.53%). TG-51 and GG-22 were found to be the most sensitive groundnut varieties after 5 and 10 days of LC-MS QTOF infection when 25 different groundnut varieties were screened using the most toxic Aspergillus flavus isolate JAM- JKB-BHA-GG20, respectively. In this research, the most susceptible groundnut cultivar, designated GG-22, was tested. Because less aflatoxin (1651.15 g.kg-1) was observed, treatment T8 (Seed + Pathogen + 2 ml silver nanoparticles) was determined to be much more effective. The treated samples were examined by Inductively Coupled Plasma Mass Spectrometry for the detection of metal ions and the fungicide carbendazim. Ag particles (0.8 g/g-1) and the fungicide carbendazim (0.025 g/g-1) were found during Inductively Coupled Plasma Mass Spectrometry analysis below detectable levels. To protect plants against the invasion of fungal pathogens, environmentally friendly green silver nanoparticle antagonists with antifungal properties were able to prevent the synthesis of mycotoxin by up to 82.53%.

Preliminary study for evaluation of some fungicides against Aspergillus flavus isolated from historical illuminated paper manuscript dated back to the Mamluk period

Various valuable illuminated paper manuscripts in museums and libraries suffer from fungal deterioration. The treatment and protection of illuminated paper manuscripts from fungal damage is an important process. Therefore, the current study aimed to evaluate different fungicides against fungi isolated from historical illuminated paper manuscript dated back to the Mamluk period (1250–1516 AD). Fungi isolated from infected historical illuminated paper manuscripts were identified and their cellulolytic enzyme activity was performed. The identified fungi were A. fumigatus, A. niger, A. flavus, Alternaria alternate, and Trichoderma sp. Isolate (4-1), identified as Aspergillus flavus, possessed the highest cellulase activity. This isolate was tested against the following fungicides: azoxystrobin, boscalid, difenoconazole, dimethomorph, propiconazole, pyraclostrobin, and thiophanate-methyl at concentrations from 1 to 200 ppm, nanoparticles of TiO2 and SiO2 at concentrations of 0.5%, and 1% and mixtures of fungicides [difenoconazole + propiconazole (1:1)] at 100 and 200 ppm and [boscalid + pyraclostrobin (2:1)] at 150 and 300 ppm. The disc diffusion method (DDM) was used to evaluate the efficiency of the prepared individual and mixed fungicides against Aspergillus flavus (4-1) isolate. The results of this study revealed that treatments with individual difenoconazole at 200 ppm exhibited the best antifungal activity, followed by the propiconazole fungicide. Further research is needed to evaluate the in vitro practical application of these fungicides with infected illuminated paper samples with Aspergillus flavus agents in the field.

Morphed aflaxotin concentration produced by Aspergillus flavus strain VKMN22 on maize grains inoculated on agar culture

This study identified and monitored the levels of aflatoxins (B1 and B2) produced by Aspergillus flavus isolate VKMN22 (OP355447) in maize samples sourced from a local shop in Johannesburg, South Africa. Maize samples underwent controlled incubation after initial rinsing, and isolates were identified through morphological and molecular methods. In another experiment, autoclaved maize grains were intentionally re-inoculated with the identified fungal isolate using spore suspension (106 spore/mL), after which 1 g of the contaminated maize sample was inoculated on PDA media and cultured for seven days. The aflatoxin concentrations in the A. flavus contaminated maize inoculated on culture media was monitored over seven weeks and then measured using liquid chromatography–mass spectroscopy (LC-MS). Results confirmed the successful isolation of A. flavus strain VKMN22 with accession number OP355447, which consistently produced higher levels of AFB1 compared to AFB2. AF concentrations increased from week one to five, then declined in week six and seven. AFB1 levels ranged from 594.3 to 9295.33 µg/kg (week 1–5) and then reduced from 5719.67 to 2005 µg/kg in week six and seven), while AFB2 levels ranged from 4.92 to 901.67 µg/kg (weeks 1–5) and then degraded to 184 µg/kg in week six then 55.33 µg/kg (weeks 6–7). Levene's tests confirmed significantly higher mean concentrations of AFB1 compared to AFB2 (p ≤ 0.005). The study emphasizes the importance of consistent biomonitoring for a dynamic understanding of AF contamination, informing accurate prevention and control strategies in agricultural commodities thereby safeguarding food safety.

Evaluation of the efficacy of cinnamon oil on Aspergillus flavus and Fusarium proliferatum growth and mycotoxin production on paddy and polished rice: Towards a mitigation strategy

In the present investigation, the effect of cinnamon oil (CO) (10, 30, 50 and 70 %) on the growth rate (mm/day) and aflatoxin B1 (AFB1) and fumonisin B1 (FB1) production of Aspergillus flavus (AF01) and Fusarium proliferatum (FP01) isolates, respectively was determined at optimum water activities (0.95 and 0.99 aw) and temperatures (25, 30 and 35 °C) on paddy and polished rice grains. The results showed that the growth rate, AFB1 and FB1 production of all the fungal isolates decreased with an increase in CO concentrations on both matrices. AF01 and FP01 failed to grow under all conditions on paddy at 50 % of CO concentration whereas both fungi were completely inhibited (No Growth-NG) at 70 % of CO on polished rice. Regarding mycotoxin production, 30 % of CO concentrations could inhibit AFB1 and FB1 production in both matrices (No Detection-ND). In this study, the production of mycotoxins was significantly influenced by cinnamon oil compared to the growth of both fungi. These results indicated the promising potential of CO in improving the quality of rice preservation in post-harvest; however, further investigations should be evaluated on the effects on the qualitative characteristics of grains. Especially, the prospective application of CO in rice storage in industry scales to mitigate mycotoxin contamination need also to be further researched. Moreover, collaboration between researchers, agricultural experts, and food industry should be set up to achieve effective and sustainable strategies for preserving rice.

Categorization of mycotoxin producing fungi in leguminous crops and its eco-friendly management under in vitro condition

Four legume crops, viz., groundnut (Arachis hypogea L.), soybean (Glycine max (L.) Merr.) of Kharif season, chickpea (Cicer arietinum L.), and lentil (Lens esculentum L.) of Rabi season belonging to family Fabaceae were taken for investigation of seed-borne mycoflora. Since these are severely affected by many plant-pathogenic fungi at various stages of the whole life cycle, they were chosen for the study. Many post-harvest fungal pathogens cause severe loss by contaminating the grains with various mycotoxins and also deteriorate the nutritional quality of grains. The goal of any agricultural system is to increase the yield of crops as per the population demand. Various eco-friendly management practices were performed on highly mycotoxin-producing isolates of Aspergillus flavus and A. niger isolated from these grains. Four Trichoderma isolates (T2, T3, T4 and T5) were used as a biocontrol agent in the dual culture method to check antagonism between various Aspergillus isolates and Trichoderma isolates. It gave a satisfactory result in controlling mycelial growth. Achyranthes aspera leaf and stem phytoextract (10%, 20%, 30%, and 40%) was used as a botanical treatment in the well diffusion method, which successfully restricts the Aspergillus spp. mycelial growth.

Telomere-to-telomere genome assembly of the aflatoxin biocontrol agent Aspergillus flavus isolate La3279 isolated from maize in Nigeria.

Here, we report the complete genome of the non-aflatoxigenic Aspergillus flavus isolate La3279, which is an active ingredient of the aflatoxin biocontrol product Aflasafe. The chromosome-scale assembly clarifies the deletion pattern in the aflatoxin biosynthesis gene cluster and corrects a misidentified assembly previously published for this isolate.

Assessment of Potential of Sugarcane Bagasse as Substrate in the Growth of Selected Fungal Species

The cost of culture media is continuously rising at a very fast rate, thus, there is need to devise means by which low-cost media of comparative performance could be produced. This study was aimed at assessing the potential of sugarcane bagasse (one of the major waste biomasses in Northern Nigeria) to directly support fungal growth, as it contains a considerable amount of nutrients for growth. Isolates of Aspergillus flavus and Trichophyton species obtained from the Department of Microbiology, Ahmadu Bello University, Zaria were used for this study. The sugarcane bagasse was dried, cut into smaller pieces then ground into finer particles (1-2mm diameter) using a milling machine and sterilized in Petridishes by autoclaving. The fungal isolates Aspergillus flavus and Trichophyton species were resuscitated and authenticated using standard procedures, and then inoculated aseptically onto duplicate plates of the sugarcane bagasse and other minerals, and incubated at a temperature of 25oC for 7days. It was observed that the sugarcane bagasse supported a luxuriant and rapid growth of both fungi without any visible form of contamination. It was also observed that A. flavus grew more luxuriantly, consuming about 52.5% of the original amount of the bagasse than Trichophyton species, which consumed 32.5%. Sugarcane bagasse as a growth medium does not essentially meet the needs for growth of every microbe, most especially bacteria, and therefore, it can be used effectively to minimize contamination by microorganisms other than fungi. It can therefore be used as a good alternative and cheaper medium for the detection of fungi in the laboratory. This could also be an easier and cost-effective means by which wastes such as sugarcane bagasse could be removed from the environment, as opposed to using hazardous methods like burning, which could cause air pollution.

Drug-Resistant Aspergillus spp.: A Literature Review of Its Resistance Mechanisms and Its Prevalence in Europe.

Infections due to the Aspergillus species constitute an important challenge for human health. Invasive aspergillosis represents a life-threatening disease, mostly in patients with immune defects. Drugs used for fungal infections comprise amphotericin B, triazoles, and echinocandins. However, in the last decade, an increased emergence of azole-resistant Aspergillus strains has been reported, principally belonging to Aspergillus fumigatus species. Therefore, both the early diagnosis of aspergillosis and its epidemiological surveillance are very important to establish the correct antifungal therapy and to ensure a successful patient outcome. In this paper, a literature review is performed to analyze the prevalence of Aspergillus antifungal resistance in European countries. Amphotericin B resistance is observed in 2.6% and 10.8% of Aspergillus fumigatus isolates in Denmark and Greece, respectively. A prevalence of 84% of amphotericin B-resistant Aspergillus flavus isolates is reported in France, followed by 49.4%, 35.1%, 21.7%, and 20% in Spain, Portugal, Greece, and amphotericin B resistance of Aspergillus niger isolates is observed in Greece and Belgium with a prevalence of 75% and 12.8%, respectively. The prevalence of triazole resistance of Aspergillus fumigatus isolates, the most studied mold obtained from the included studies, is 0.3% in Austria, 1% in Greece, 1.2% in Switzerland, 2.1% in France, 3.9% in Portugal, 4.9% in Italy, 5.3% in Germany, 6.1% in Denmark, 7.4% in Spain, 8.3% in Belgium, 11% in the Netherlands, and 13.2% in the United Kingdom. The mechanism of resistance is mainly driven by the TR34/L98H mutation. In Europe, no in vivo resistance is reported for echinocandins. Future studies are needed to implement the knowledge on the spread of drug-resistant Aspergillus spp. with the aim of defining optimal treatment strategies.

Reconsidering the Co-Occurrence of Aspergillus flavus in Spanish Vineyards and Aflatoxins in Grapes

Aspergillus flavus is a xerophilic fungus whose geographical distribution is expected to change due to the current climate change scenario. Grapes are one of the most important crops worldwide, and it is essential to evaluate the risk posed by their contamination with potential mycotoxigenic species. Recently, a few reports have described A. flavus as an emerging contaminant in vineyards, which has led to a discussion on the need to legislate aflatoxin contents in grapes. Using a specific PCR assay, the occurrence of A. flavus was demonstrated in 43 out of 61 grape samples collected from Spanish vineyards. Considering the high incidence observed, the risk of the grapes becoming contaminated with aflatoxin was subsequently evaluated. Aspergillus flavus isolates from grapes can grow in grape-based media under a variety of environmental conditions, but they were unable to produce either aflatoxin B1 (AFB1) or aflatoxin B2 (AFB2) even though their ability to produce these toxins was confirmed in a permissive medium (CYA). These results confirm that climate change is affecting the distribution of mycotoxigenic fungi, thereby increasing the occurrence of A. flavus in vineyards, although the risk of the grapes becoming contaminated with aflatoxin needs to be reconsidered.

Microscopic fungi of wheat grain in the Polissya zone

The article presents the data on the quantitative and qualitative composition of micromycetes of wheat grain grown in the Polissya region. During the research period, an average of 2.88-104 ± 3.62-103 colony forming units (CFU) per 1 g of grain was found in wheat grain samples collected in the Polissya region. Twenty species of microscopic fungi belonging to 9 genera were isolated from the wheat grain of the Polissya zone. Among them were the genera Alternaria (92.5 %), Mucor (92.5 %), Aspergillus (83.0 %), Penicillium (47.2 %), Fusarium (60.4 %), Phoma (15,.1 %), Mycelia (15.1 %), Trichotecium (1.9 %) and Monascus (1.9 %) of the samples. Aspergillus niger (17.0 %), Aspergillus candidus (9.4 %), and Aspergillus terreus (1.9 %) were detected less frequently among Aspergillus. Fusarium spp. (17.0 %), Fusarium oxysporum, Fusarium moniliforme, Fusarium semitectum in (5.7 %), and Fusarium culmorum (3.8 %) of the samples were identified among Fusarium. A smaller number of microscopic fungi species represents the endophytic mycobiota of wheat grain. Among the isolates of micromycetes isolated from the Polissya zone, pure cultures were obtained from F. sporotrichiella var. tricinctum isolate 1218/4, and F. sporotrichiella isolate 1218/5. These isolates were atoxic against the test culture Candida pseudotropicalis strain 44 PC, but F. sporotrichiella var. tricinctum 1218/4 produced a growth retardation zone with Rf 0.05 and produced an unidentified trichothecene mycotoxin (TTMT). Among the isolated fungi, Aspergillus flavus isolate 1219/3 and Aspergillus flavus isolate 1221/1 were the first to produce kojic and aspergillic acids and the second to synthesize penicillic and aspergillic acids. To reduce the negative effect of the mycotoxin deoxynivalenol on the body of chickens of the meat and egg breed Adler Silver, the birds were fed the sorbent “Mikosorb”. It was found that when added to the diet, the sorbent “Mikosorb” in the amount of 2.0 % of the total feed weight reduces the negative effect of deoxynivalenol on the body of chickens of the experimental group. This was confirmed by a 12.0 % reduction in bird mortality. Feeding “Microsorb” in the amount of 2.0 % by weight of complete feed contributed to an increase in the average daily weight gain of poultry during the experiment by 5.43 % compared to the experimental group that consumed feed with the toxin deoxynivalenol (DON). During the experiment, the birds of the experimental group No. 2 consumed 28.91 kg of feed more than group No. 2. Feeding the sorbent “Mikosorb” in the amount of 2.0 % of the feed weight to chickens of the meat and egg breed Adler silver contributes to an increase in gross weight gain by 9.69 kg during the experiment. The use of “Mikosorb” in the technology of feeding chickens of experimental group No. 2 contributed to an increase in the profitability of poultry production by up to 12.0 % compared to poultry that consumed feed affected by DON toxin. After analyzing the scientific results from the literature and our research results, we concluded that the abovementioned studies on wheat grain should be carried out throughout Ukraine during harvesting and storage in warehouses or storages.

Testing the Efficiency of Silver Nanoparticles Manufactured Locally by the Alga Spirogyra in Inhibiting the Fungus Aspergillus flavus and Reduction of Aflatoxin B1

This experiment was conducted in the mycotoxins lab at the College of Agricultural Engineering Sciences-University of Baghdad with the aim of evaluating the effectiveness of bio- and locally manufactured silver nanoparticles by the alga Spirogyra locally and biologically manufactured silver nanoparticles in inhibiting the fungus Aspergillus flavus and reduction of aflatoxin B1. The results showed the alga Spirogyra highly efficient in the biologically manufactured silver nanoparticles and the size of the synthesized nanoparticles was 8.504 nm when examined by atomic force microscope AFM, which showed a high efficiency in inhibiting the isolate of the fungus Aspergillus flavus at concentrations 1.5, 2 and 3, and the percentage of inhibition was 86.7%, 97.64, 100%, respectively, It also indicated a high efficiency in preventing the fungus from producing aflatoxin B1 on the stored wheat grains. The concentrations of toxins in stored wheat samples were 6.25 ppb, 4.11 ppb and 0.0ppb for concentrations 1.5, 2, and 3 compared with the control treatment in which the concentration of aflatoxin B1 was 88.4ppb, as the percentage of reduction was 92.92%, 95.35% and 100, respectively. The results of biologically manufactured silver nanoparticles also showed an efficiency in reducing aflatoxin B1 from stored wheat grains. The concentration (3) was superior in reducing aflatoxin B1 to 2ppb compared to concentrations of (1.5 and 2), in which the toxin concentration reached 10.25 ppb and 7.15 ppb, respectively, with a reduction percentage of 88.4%, 91.91% and 97.73%.

Comparison of Aflatoxin Yield from Peanut Isolate of Aspergillus flavus with Other Isolates

Background: Mouldy growth in food commodities by aflatoxin producing fungi is a serious health concern to animals as well as human beings due to the harmful effects of aflatoxins like hepatotoxicity, carcinogenicity, impairment of protein synthesis, formation of DNA adducts, etc. even in minute concentrations. A tropical climate with moderate temperature, high humidity and heavy rainfall provides optimal conditions for the growth of aflatoxin producing fungi like Aspergillus flavus in different food items. The current study was to examine if the substrate(s) in a food item has any role to play in aflatoxin production by A. flavus. Methods: The fungus was isolated from ten different edible materials and identified using standard procedure. The isolates were cultured in potato dextrose agar slants keeping the culture conditions identical in triplicates. The toxin extracted using chloroform as solvent and downstream processing to get crude toxin was quantified on the basis of dry weight. Thin layer chromatography was done and the fluorescence of the toxins from different isolates was visualised under high wavelength of ultra-violet light with standard Aflatoxin B1 chromatographed vis-a-vis to confirm presence of the toxin in all the extracted toxins. Result: Results of the extracted toxin dry weight comparison between different isolates as well as the fluorescence intensity in the chromatograms revealed that contaminated peanut isolate of A. flavus yielded the highest amount of crude toxin. Thus, the results indicate that there are some factor(s) in peanut that promote(s) aflatoxin production by A. flavus. This information was further used for formulating potato dextrose agar media for isolation of aflatoxin producing fungi by incorporating peanut extract in the media and comparing the amount of crude toxin yield.

In ovo Vaccination in Ducks against Aflatoxin-Ovalbumin Conjugate

Background: Aflatoxicosis is a major disease affecting ducklings especially due to their high susceptibility during the post-natal stage. There is no vaccination schedule for this disease as aflatoxins are haptens and incapable of generating immune response by itself. Methods: In this study to combat this malady, in ovo vaccination with an aflatoxin-chicken ovalbumin conjugate was done on 25th day of incubation to generate adequate immune response during the post-natal period of ducklings. An isolate of Aspergillus flavus was used for harvesting of the aflatoxin. The purified crude toxin was checked by TLC to observe the presence of all 4 isomers. Chicken ovalbumin was used as carrier protein due to its similarity with duck ovalbumin as well as to avoid autoimmunity. The conjugate was then encapsulated with chitosan to prevent clearance of the antigen as well as to provide a balanced Th1/Th2 response. A booster dose of the conjugate was given on 14th day post hatch along with sheep red blood cells. The antibody titre was checked by passive haemagglutination test. Result: The results seen i.e., Log2 antibody titre of 1.33±0.21 proved that an immune response was generated. This could provide protection to the ducklings against aflatoxins. Also, this is the first time in ovo vaccination in ducks with aflatoxin-chicken ovalbumin conjugate has been carried out.

The Effect of Nano-bentonite Supplementation on Reducing the Toxicity of Aflatoxin B1 in Kampung Unggul Balitbangtan Chickens Diet

Aspergillus flavus and Aspergillus parasiticus are fungi that produce toxic secondary metabolites known as aflatoxins. These toxins can contaminate various food and feed products, including grains and nuts, before or after they are harvested. This contamination is most commonly found in tropical countries. Many studies have demonstrated that clay additions can reduce animal aflatoxin toxicity. The objective of this research was to study how the usage of Pacitan's local bentonite, located in East Java, Indonesia, could potentially decrease the harmful effects of aflatoxin B1 in native chicken species. The Masking Gel Calcification method was used to create bentonite nanoparticles at the Center for Ceramics in Bandung, West Java, Indonesia. The in vivo study was conducted at a native chicken farm in Bantul, Yogyakarta, Indonesia, with 1200 unsexed Kampung Unggul Balitbangtan (KUB) chickens. Kampung Unggul Balitbangtan chickens were divided into 4 treatments and 6 replications, each containing 50 chickens. The diets in the treatments were named as T0 (the control group in which chickens were fed basal diet, without aflatoxin B1), T1 ( T0 + 200 µg/kg aflatoxin B1), T2 (T0 + 200 µg/kg aflatoxin B1 + 1 g/kg Factory Feed with standard factory absorbent), and T3 (T0 + 200 µg/kg aflatoxin B1 + 1 g/kg nano bentonite). Aspergillus flavus isolates from PAU Universitas Gadjah Mada were created using crude aflatoxin (FNC 2262). This study found a significant difference in KUB chicken performance, specifically in feed conversion ratio (FCR). Compared to T0, the findings indicated that T1 had the highest FCR value, followed by T2 and T3. It can be concluded that nanoparticle bentonite has a looser structure because of decreased packing density with the lowest FCR. Based on hematology analysis, it can suppress aflatoxin B1 toxicity in KUB chickens.

WITHDRAWN: Detection and isolation of aflatoxin producing Aspergillus sp. in chewing and smokeless tobacco by microbial and molecular methods

Tobacco contains many harmful chemicals, toxins, and carcinogens that cause serious health hazards. Mycotoxins and aflatoxins are present in all forms of tobacco, including chewing tobacco and smokeless tobacco. Using microbial and molecular techniques, we identified and isolated the aflatoxins-producing fungus Aspergillus species. 50 samples were collected randomly and grown on SDA media by spread plate method. Aspergillus flavus isolates were tested for aflatoxin production using ammonia vapour test. Additionally, their DNA was extracted and utilized for molecular identification. Different fungal genera were observed, including the most commonly found Aspergillus as well as Penicillium, Rhizopus, Candida and Trichophyton. The isolated Aspergillus flavus was characterized by its soft, velvety white surface. The colony diameter ranged from 50 to 70 mm. When exposed to UV light at 365 nm on coconut agar medium, blue-green fluorescence was observed on the reverse side of the colonies. Further, the DNA extracted from all aflatoxin-producing strains was quantified. The study revealed high levels of aflatoxin in 10 different samples, while the remaining samples showed a lower range. The research employed both quantitative and qualitative techniques for the detection of aflatoxin-producing fungi. Notably, aflR and aflS were identified as potential candidates for the detection of aflatoxigenic fungi.