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ABSTRACT Tin complexes, Sn(IV)‐TSC 1·MeOH and Sn(IV)‐TSC 2, with thiosemicarbazones possessing an N2S ligation system [TSC 1 = 4‐(4‐nitrophenyl)‐1‐((pyridin‐2‐yl)methylene)thiosemicarbazide and TSC 2 = 4‐(2‐methoxyphenyl)‐1‐((pyridin‐2‐yl)methylene)thiosemicarbazide] were prepared and structurally characterized. These complexes are found in the space groups P1¯$$ \overline{1} $$ and P21/n, respectively, with their tin atoms in octahedral environments established by three chlorine atoms and an anionic thiosemicarbazone ligand. All compounds (20 mg/mL in DMSO) were tested for their antibacterial [against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa] and antifungal [against Aspergillus flavus and Candida albicans] properties. The ligand TSC 2 displayed inhibitions in the S. aureus and E. coli cultures (with zones of 11 and 10 mm, respectively), whereas Sn(IV)‐TSC 1·MeOH and Sn(IV)‐TSC 2 inhibited all bacteria with 11–15 and 14–16 mm, respectively. In the fungal cultures, only Sn(IV)‐TSC 1·MeOH (10 mm) showed an inhibition zone against A. flavus. The ligands' antiproliferative activities were determined against human cancer cells of the lung, breast, liver, and colon, and both ligands afforded the highest activity against the breast MCF‐7 cells. The complexation enhanced the ligands' activities as TSC 1, TSC 2, Sn(IV)‐TSC 1·MeOH, and Sn(IV)‐TSC 2 afforded respective IC50 values of 52.4, 153.7, 18.3, and 63.9 μM. However, against normal baby hamster kidney (BHK) cells, these compounds showed IC50 data of 54.8, 82.7, 16.1, and 15.3 μM, respectively. [ABSTRACT FROM AUTHOR]

Food crops around the world are commonly contaminated with Aspergillus flavus, which can produce the carcinogenic mycotoxin aflatoxin B1 (AFB1). The objective of this study is to test an X-ray irradiation sterilization method for studying AFB1 in contaminated maize samples in the laboratory. Maize that had been naturally contaminated with 300 ppb AFB1 by the growth of aflatoxigenic A. flavus was ground and then irradiated at 0.0, 1.0, 1.5, 2.0, 2.5, and 3.0 kGy. A. flavus was quantified by dilution plating on potato dextrose agar (PDA) and modified Rose Bengal media (MDRB) for viability and qPCR for gene presence. AFB1 was quantified by HPLC and ELISA. A. flavus viability, but not gene copies, significantly decreased with increasing doses of radiation (PDA: p < 0.001; MDRB: p < 0.001; qPCR: p = 0.026). AFB1 concentration did not significantly change with increasing doses of radiation (HPLC: p = 0.153; ELISA: p = 0.567). Our results imply that X-ray irradiation is an effective means of reducing viable A. flavus without affecting AFB1 concentrations. Reducing the hazard of fungal spores and halting AFB1 production at the targeted dose are important steps to safely and reproducibly move forward research on the global mycotoxin challenge. [ABSTRACT FROM AUTHOR]

We evaluated the specificity of the primers OPF-01, P54, and 1253 to identify A. fumigatus, A. flavus, and A. niger, respectively, with the RAPD-PCR method. Eighty-two isolates belonging to the sections Fumigati, Flavi, and Nigri were used. The isolates were identified by phenotypic (macro- and micromorphology) and genotypic (partial sequences of the BenA gene) methods. The RAPD-PCR method was used to obtain polymorphic patterns with the primers OPF-01, P54, and 1253. The specificity of the polymorphic patterns of the isolates of each species was evaluated through the UPGMA clustering method and logistic regression model. All isolates of the genus Aspergillus were identified at the section level by macro- and micromorphology showing the typical morphology of the sections Fumigati, Flavi, and Nigri, and the species were identified by the construction of the phylogeny of the partial sequence of the BenA gene. The patterns' polymorphic strains obtained with the primers OPF-01, P54, and 1253 for the isolates of A. fumigatus, A. flavus, and A niger, respectively, showed the same polymorphic pattern as the reference strains for each species. To verify the specificity of the primers, they were tested with other species from the sections Fumigati, Flavi and Nigri. The results support that the primers OPF-01, P54, and 1253 generate polymorphic patterns by RAPD-PCR species specific to A. fumigatus, A. flavus, and A. niger, respectively. [ABSTRACT FROM AUTHOR]

Melanin is an Aspergillus flavus cell wall component that provides chemical and physical protection to the organism. However, the molecular and biological mechanisms modulating melanin-mediated host–pathogen interaction in A. flavus keratitis are not well understood. This work aimed to compare the morphology, surface proteome profile, and virulence of melanized conidia (MC) and non-melanized conidia (NMC) of A. flavus. Kojic acid treatment inhibited melanin synthesis in A. flavus, and the conidial surface protein profile was significantly different in kojic acid-treated non-melanized conidia. Several cell wall-associated proteins and proteins responsible for oxidative stress, carbohydrate, and chitin metabolic pathways were found only in the formic acid extracts of NMC. Scanning electron microscopy (SEM) analysis showed the conidial surface morphology difference between the NMC and MC, indicating the role of melanin in the structural integrity of the conidial cell wall. The levels of calcofluor white staining efficiency were different, but there was no microscopic morphology difference in lactophenol cotton blue staining between MC and NMC. Evaluation of the virulence of MC and NMC in the Galleria mellonella model showed NMC was less virulent compared to MC. Our findings showed that the integrity of the conidial surface is controlled by the melanin layer. The alteration in the surface protein profile indicated that many surface proteins are masked by the melanin layer, and hence, melanin can modulate the host response by preventing the exposure of fungal proteins to the host immune defense system. The G. mellonella virulence assay also confirmed that the NMC were susceptible to host defense as in other Aspergillus pathogens. Key points: • l-DOPA melanin production was inhibited in A. flavus isolates by kojic acid, and for the first time, scanning electron microscopy (SEM) analysis revealed morphological differences between MC and NMC of A. flavus strains • Proteome profile of non-melanized conidia showed more conidial surface proteins and these proteins were mainly involved in the virulence, oxidative stress, and metabolism pathways • Non-melanized conidia of A. flavus strains were shown to be less virulent than melanised conidia in an in vivo virulence experiment with the G. melonella model [ABSTRACT FROM AUTHOR]

Phenylalanine ammonia-lyase (PAL) is an essential enzyme in the phenylpropanoid pathway, in which numerous aromatic intermediate metabolites play significant roles in plant growth, adaptation, and disease resistance. Cultivated peanuts are highly susceptible to Aspergillus flavus L. infection. Although PAL genes have been characterized in various major crops, no systematic studies have been conducted in cultivated peanuts, especially in response to A. flavus infection. In the present study, a systematic genome-wide analysis was conducted to identify PAL genes in the Arachis hypogaea L. genome. Ten AhPAL genes were distributed unevenly on nine A. hypogaea chromosomes. Based on phylogenetic analysis, the AhPAL proteins were classified into three groups. Structural and conserved motif analysis of PAL genes in A. hypogaea revealed that all peanut PAL genes contained one intron and ten motifs in the conserved domains. Furthermore, synteny analysis indicated that the ten AhPAL genes could be categorized into five pairs and that each AhPAL gene had a homologous gene in the wild-type peanut. Cis-element analysis revealed that the promoter region of the AhPAL gene family was rich in stress- and hormone-related elements. Expression analysis indicated that genes from Group I (AhPAL1 and AhPAL2), which had large number of ABRE, WUN, and ARE elements in the promoter, played a strong role in response to A. flavus stress. [ABSTRACT FROM AUTHOR]

Aflatoxin-producing Aspergillus species are extensively dispersed throughout the environment and have seriously affected human and animal food supplies, posing health dangers and even resulting in death, as a consequence. Our study's goal was to investigate infections of Aspergillus flavus and the amount of aflatoxins (AF) in chicken livers where they are metabolized specially AFB1. Sixty-five chicken liver samples were bought from frozen meat shops, supermarkets, and special slaughterhouses in Qena, Egypt. The samples were evaluated traditionally, molecularly, and HPLC analysis was performed to quantify the amount of AFs. In addition, A. flavus' susceptibility to amphotericin B and voriconazole was also determined. The findings revealed the presence of different fungal species, in particular, Aspergillus species (21.5%). A total percentage of 85.7 of A. flavus isolates were classified as low aflatoxin producers, according to HPLC analyses. Furthermore, aflatoxins contaminated 70% of the liver samples from which AFB1 was detected at 60%. Although this measurement was lower than the European limits, Egyptian standards found it unacceptable. Antifungal susceptibility testing revealed that 71.4 and 42.8% of A. flavus isolates were resistant to amphotericin B and voriconazole, respectively. These results show the extent of the role of chicken livers in the transmission of aflatoxicosis to humans. Hinting that these samples are dangerous to consumers. Consequently, there is a need to adopt aflatoxin residue monitoring and controls in all poultry meat; this cost-effective and efficient technology looks to be beneficial for better food safety. Or at least, liver from poultry that has been exposed to aflatoxins should not be consumed by humans until be cleared before slaughtering. [ABSTRACT FROM AUTHOR]

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.

Peanuts and maize, both known highly susceptible to mycotoxin producing fungi are significant component of local diet. These micro organisms especially Aspergillus flavus can reduce the yield due to contamination of the crop with production of aflatoxin. Bitter plant extract like Azadirachta indica is favoured as biotic control because it has no side effect and its relatively cheap and easily available in our surroundings. The maximum % inhibition at 2.5 ml of Azadirachta indica recorded in maize seeds (95 %) and peanut (92 %) at 2.0 and 2.4 ppm concentration of Aflatoxin Bi after 7 days, respectively. Whereas minimum % inhibition at 0.5 ml of Azadirachta indica were recorded in maize seeds (10 %) and peanut (21 %) at 2.0 and 2.4 ppm concentration of Aflatoxin Bi after 3 days, respectively. Our findings concluded that the Azadirachta indica control the growth of Aspergillus flavus and aflatoxin production i.e., means control the diseases by microorganisms. [ABSTRACT FROM AUTHOR]

The better approach to control the contamination of food by aflatoxin (AF), is identifying the fungal strains responsible for producing that toxin. To estimate the presence of aflatoxigenic fungi growth and AFs in pistachios, thirty two pistachios samples (8 fresh and 24 salt roasted) were collected from Sulaimani markets (Iraq).Rapid screening method for AFs production were utilized initially based on culture methods, the positive samples confirmed by polymerase chain reaction (PCR) that were applied using DNA extracted from the isolates of A. flavus targeting the genes (afR, aflP, aflD, and aflQ). For determination of AF production of those isolates, ELISA technique was applied. The results show, contamination of 20 (62.5%) samples of pistachios with fungi, among them A. flavus was the predominant. Ten (71.4%( of the A. flavus isolates were amplified the target genes by applying PCR, indicating their ability to produce AFs. Application of ELISA technique revealed AFs detection in 21(65.6%) samples of pistachios. The mean levels of AFs determined were 6.06 and 12.08 μg/kg in fresh and salt roasted samples respectively. 19 (59.4%) of pistachio samples were exceed the maximum allowable limit set by the European union of total AFs concentration .Strong correlation obtained between AFs gene expression with AFs production. However, to avoid false negative and false positive results, applying more than one diagnostic molecular technique were suggested. [ABSTRACT FROM AUTHOR]

Microorganisms and the problems they cause are the most important problems in the meat and meat products industry, as in all branches of the food industry. Utilizing natural additives in food is the emerging trend for preventing microbial growth. For this reason, studies on the antimicrobial properties of natural herbal products have increased in recent years. In this study, it was aimed to determine the potential antimicrobial activity of the chemical components of Juniperus sabina berry essential oil (EO) on the most isolated bacteria and molds from meat products. Sabinene (31.13 %), a-pinene (27.14 %), limonene (16.14 %), b-myrcene (9.28 %) were found to be the major components of J. sabina berry EO. The EO showed the highest antifungal activity on R. nigricans with a zone of 22.57 in mm diameter, followed by A. flavus (22.45 mm), P. chrysogenum (20.20 mm) and M. racemosus (17.69 mm), respectively. The minimum inhibitory concentration (MIC) values of J. sabina EO on the mold species used in the study varied between 70.32 and 468.75 mg/L, and the minimum fungicidal concentration values ranged from 78.13 to 312.50 mg/L. The EO showed the highest antibacterial activity on S. aureus with a zone of 20.27 mm in diameter and the lowest antibacterial activity on S. dysenteria (13.98 mm). The MIC values of J. sabina EO on the bacteria species used in the study varied between 54.69 and 281.25 mg/L, and the value of minimum bactericidal concentration values ranged from 39.06 to 187.50 mg/L. [ABSTRACT FROM AUTHOR]

Food crops around the world are commonly contaminated with Aspergillus flavus, which can produce the carcinogenic mycotoxin aflatoxin B1 (AFB1). The objective of this study is to test an X-ray irradiation sterilization method for studying AFB1 in contaminated maize samples in the laboratory. Maize that had been naturally contaminated with 300 ppb AFB1 by the growth of aflatoxigenic A. flavus was ground and then irradiated at 0.0, 1.0, 1.5, 2.0, 2.5, and 3.0 kGy. A. flavus was quantified by dilution plating on potato dextrose agar (PDA) and modified Rose Bengal media (MDRB) for viability and qPCR for gene presence. AFB1 was quantified by HPLC and ELISA. A. flavus viability, but not gene copies, significantly decreased with increasing doses of radiation (PDA: p < 0.001; MDRB: p < 0.001; qPCR: p = 0.026). AFB1 concentration did not significantly change with increasing doses of radiation (HPLC: p = 0.153; ELISA: p = 0.567). Our results imply that X-ray irradiation is an effective means of reducing viable A. flavus without affecting AFB1 concentrations. Reducing the hazard of fungal spores and halting AFB1 production at the targeted dose are important steps to safely and reproducibly move forward research on the global mycotoxin challenge.

We evaluated the specificity of the primers OPF-01, P54, and 1253 to identify A. fumigatus, A. flavus, and A. niger, respectively, with the RAPD-PCR method. Eighty-two isolates belonging to the sections Fumigati, Flavi, and Nigri were used. The isolates were identified by phenotypic (macro- and micromorphology) and genotypic (partial sequences of the BenA gene) methods. The RAPD-PCR method was used to obtain polymorphic patterns with the primers OPF-01, P54, and 1253. The specificity of the polymorphic patterns of the isolates of each species was evaluated through the UPGMA clustering method and logistic regression model. All isolates of the genus Aspergillus were identified at the section level by macro- and micromorphology showing the typical morphology of the sections Fumigati, Flavi, and Nigri, and the species were identified by the construction of the phylogeny of the partial sequence of the BenA gene. The patterns’ polymorphic strains obtained with the primers OPF-01, P54, and 1253 for the isolates of A. fumigatus, A. flavus, and A niger, respectively, showed the same polymorphic pattern as the reference strains for each species. To verify the specificity of the primers, they were tested with other species from the sections Fumigati, Flavi and Nigri. The results support that the primers OPF-01, P54, and 1253 generate polymorphic patterns by RAPD-PCR species specific to A. fumigatus, A. flavus, and A. niger, respectively.

Silver nanoparticles (AgNPs), which have recently gained attention due to their antimicrobial activity, can also be produced by green synthesis. The aims of this study were to (i) characterise green synthesized AgNPs using microwave-assisted aqueous extracts of Galium aparine (G-AgNPs) and Helichrysum arenarium (H-AgNPs) and (ii) investigate the combined antimicrobial effects of the G- and H-AgNPs in different ratios. Nanoparticle formation and reactions were determined with UV-Vis spectroscopy. The G-AgNPs were 52.0±10.9 nm in size, with a 0.285±0.034 polydispersity index (PDI), and a -17.9±0.9 mV zeta potential. For H-AgNPs these characteristics were 23.9±1.0 nm, 0.280±0.032, and -21.3±2.7 mV, respectively. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) confirmed that the particles were monodisperse and spherical. The Fourier transform-infrared spectroscopy (FT-IR) results showed the presence of reducing agents that stabilised the AgNPs. Three different nanoformulations (NF-1, NF-2, and NF-3) were prepared by combining these two synthesised nanoparticles in different ratios and their antimicrobial activity was tested against E. coli, S. aureus, C. albicans, and A. flavus. Our study is the first to show that combining AgNPs from two different biological sources can produce effective nanoformulations with improved antibacterial activity against E. coli and S. aureus. These nanoformulations showed lower minimum inhibitory concentrations (31.25 µg/mL against E. coli with all NFs; 62.5 µg/mL for NF-1 and 125 µg/mL for NF-2/3 against S. aureus) than G-AgNPs (62.5 µg/mL for E. coli) or H-AgNPs (125 µg/mL for S. aureus) alone. Their high combined inhibitory effect against E. coli (NF-1–3) was synergistic and against S. aureus (NF-2 and NF-3) potentially additive. Considering such promising results, we believe our study provides some direction for new research and strategies in antimicrobial therapeutics.

Aspergillus flavus and Aspergillus fumigatus are important human pathogens that can infect the lung and cornea. During infection, Aspergillus dormant conidia are the primary morphotype that comes in contact with the host. As the conidial surface-associated proteins (CSPs) and the extracellular proteins during the early stages of growth play a crucial role in establishing infection, we profiled and compared these proteins between a clinical strain of A. flavus and a clinical strain of A. fumigatus. We identified nearly 100 CSPs in both Aspergillus, and these non-covalently associated surface proteins were able to stimulate the neutrophils to secrete interleukin IL-8. Mass spectrometry analysis identified more than 200 proteins in the extracellular space during the early stages of conidial growth and germination (early exoproteome). The conidial surface proteins and the early exoproteome of A. fumigatus were enriched with immunoreactive proteins and those with pathogenicity-related functions while that of the A. flavus were primarily enzymes involved in cell wall reorganization and binding. Comparative proteome analysis of the CSPs and the early exoproteome between A. flavus and A. fumigatus enabled the identification of a common core proteome and potential species-specific signature proteins. Transcript analysis of selected proteins indicate that the transcript-protein level correlation does not exist for all proteins and might depend on factors such as membrane-anchor signals and protein half-life. The probable signature proteins of A. flavus and A. fumigatus identified in this study can serve as potential candidates for developing species-specific diagnostic tests. Key points: • CSPs and exoproteins could differentiate A. flavus and A. fumigatus. • A. fumigatus conidial surface harbored more antigenic proteins than A. flavus. • Identified species-specific signature proteins of A. flavus and A. fumigatus. [ABSTRACT FROM AUTHOR]

The lignocellulosic biomass is presenting an enormous potential in biofuel production, which requires a hydrolyzing step in the bioconversion process. The biomass is hydrolyzed using costly enzymes like cellulase and xylanase. These enzymes can be produced by using lignocellulosic biomass as feedstock, and on-site produced crude enzyme can saccharify biomass. The integration of both approaches can lower down the cost of biofuel production. Keeping this in view, the present study was conducted to explore various agro-industrial waste as carbon sources and best-suited conditions for enhanced cellulase and xylanase production by Aspergillus flavus under solid-state fermentation. Among all studied biomass, microwave alkali-pretreated rice straw was found most suitable as a carbon source for enzyme production. Maximum enzyme activities FPase 12.5 IU/gds, CMCase 235 IU/gds, β-glucosidase 190 IU/gds, and xylanase 180 IU/gds were obtained under optimum conditions of initial pH 5.5, temperature 30 °C, substrate to liquid ratio 1:3.5 (w/v), particle size 500–1000 μm, and NaNO3 on the 5th day of the incubation period. Enzyme activities FPase, CMCase, β-glucosidase, and xylanase were enhanced by approximately 1.27-, 1.18-, 1.06-, and 1.09-fold during tray fermentation. The adopted approach utilized low-cost lignocellulosic biomass for enzyme production as an additional avenue to biomass valorization along with solid waste management and its reduction which would otherwise cause environmental pollution problems. [ABSTRACT FROM AUTHOR]

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Objectives: This study was designed to isolate, identify, and determine the prevalence of Aspergilli in commercial chicken in selected areas of Bangladesh. Materials and Methods: A total of 50 lung samples from suspected dead chickens, comprising broilers (n = 32) and layers (n = 18), aged between 5 days and 45 weeks, were collected from poultry farms located in the Gazipur district in Bangladesh. Fungi were primarily identified based on the colony morphology using potato dextrose agar (PDA). DNA was extracted from the suspected colonies. Aspegillus spp. was detected by genus-specific ASAP-1 and ASAP-2. Aspergillus spp. were then screened by polymerase chain reaction targeting Aspergillus flavus (FLA-1 and FLA-2), Aspergillus fumigatus (ASPU and Af3r), and Aspergillus niger (ASPU and Nilr). Results: The overall prevalence of Aspergillus spp. was 44% (n = 22/50; p < 0.05). Among the Aspergilli, A. flavus was detected in 10% (n = 5/50) of the samples. Similarly, A. fumigatus and A. niger were detected at 26% (n = 13/50) and 8% (n = 4/50) respectively. Three samples were associated with more than one fungus; two fungi (A. flavus and A. niger) were in two samples, and three fungi (A. flavus, A. fumigatus, and A. niger) were in one sample. Conclusion: Isolation and prevalence of Aspergillus spp. in commercial chicken were studied for the first time in Bangladesh. [J Adv Vet Anim Res 2022; 9(2.000): 184-190]

During storage, a significant quantity of wheat is lost due to insect and fungal pest complexes, where insects possibly disseminate the mycotoxic fungal pests. We have studied the role Sitotroga cerealella, Tribolium castaneum and Rhyzopertha dominica in propagating mycotoxic fungi in stored wheat grains. We found that 85% of wheat collected from steel and brick-walled grain silos were contaminated with Alternaria alternata, Alternaria infectoria, Aspergillus flavus and Aspergillus tenuissima, and these species were also isolated from the bodies of S. cerealella adults. Our results clearly demonstrated that the prevalence of A. flavus was higher when S. cerealella was co-infesting the grain along with fungal species. We have noticed that 75% of adult moths (both male and female) were attracted toward the fungal contaminated seeds as compared to sterilized seeds even after two weeks of incubation. This proportion increased to more than 87% in just four weeks after fungal infestation. This study suggests further investigation to understand the chemical basis of identified mutualistic association between A. flavus and S. cerealella, for efficient management of grain losses due to insect–fungal pest complexes. [ABSTRACT FROM AUTHOR]

Essential oils possess significant antimicrobial and antioxidant properties and are increasingly used as natural substitutes for food preservation. Therefore, this study investigated the potential application of rosemary essential oil (REO) and REO nano-emulsion in the dairy plant. The antimicrobial effects of REO and REO nano-emulsion were determined by an agar well diffusion assay after chemical profiling by Gas Chromatography-Mass Spectrometry (GC–MS). The REO nano-emulsion was characterized by a Transmission Electron Microscope (TEM). The REO chemical profile revealed the presence of 42 chemical compounds, including 1, 8-cineole (9.72 %), and α-pinene (5.46 %) as major active components. REO nano-emulsion demonstrated significant antimicrobial activity compared to REO (P < 0.05) with a MIC value of 0.0001 mg/ml against Listeria monocytogenes and Aspergillus flavus and 0.001 mg/ml against Pseudomonas aeruginosa and Bacillus cereus. REO nano-emulsion enhanced the oxidative stability of pasteurized fresh cream, revealing a non-significant difference compared with that inoculated with butylated hydroxy anisol (BHA; synthetic antioxidant) (P ˃ 0.05). Fortified cream and Karish cheese with REO nano-emulsion were evaluated organoleptically, and the results showed higher grades of overall acceptability when compared to control samples with a statistically significant difference (P < 0.05). Viability studies were estimated using the previously mentioned microorganisms in fortified fresh cream and Karish cheese with REO nano-emulsion. Results of the fortified cream showed a complete reduction of L. monocytogenes , A. flavus , and B. cereus on days 5, 7, and 10, respectively, and a 96.93 % reduction of P. aeruginosa by the end of the storage period. Regarding Karish cheese viability studies, C. albicans , A. flavus , and P. aeruginosa exhibited complete reduction on days 10, 10, and 15 of storage, respectively. In conclusion, REO nano-emulsion was recommended as a natural, safe, and effective antimicrobial and antioxidant additive in the dairy industry. • GC-MS analysis of Rosemary Essential Oil (REO) reveled 1, 8-Cineole (9.72%) and α-pinene (5.46%) as predominant constituents • REO nano-emulsion showed significant antimicrobial activity against L. monocytogenes, A. flavus, P. aeruginosa, and B. cereus • REO nano-emulsion improved the oxidative stability of fortified cream, with no significant difference from BHA • REO nano-emulsion significantly improved the overall acceptability of fortified cream and Karish cheese • Complete reduction of the inoculated microorganisms on Karish cheese and cream fortified with REO nano-emulsion [ABSTRACT FROM AUTHOR]

Although non-thermal plasma (NTP) has recently been widely studied for decontaminating fungi and mycotoxins, its application in grains is still rarely reported. This study investigated the influence of NTP on A. flavus growth as well as AFB 1 production and degradation in maize. The inactivation efficacy of NTP on A. flavus spores in maize was improved with increasing voltage, decreasing frequency, and reducing sample weight. Moreover, the Weibull model was suitable for describing the inactivation of A. flavus spores in maize. Furthermore, the contamination and AFB 1 production by A. flavus in maize were reduced by 79% and 96% at 12-min treatment stored for 8 days. Besides, there was an 80% degradation rate in AFB 1 of maize. NTP treatment had no significant effect on the physiological properties except for malondialdehyde, induced the accumulation of total soluble sugars, and decreased the digestibility in maize. • NTP inactivates A. flavus spores in maize with the Weibull model. • NTP significantly inhibited contamination and aflatoxin production by A. flavus in maize during storage. • NTP can effectively degrade aflatoxin B 1 in maize. • NTP has minimal effect on the physiological properties and nutritional properties of maize samples. [ABSTRACT FROM AUTHOR]

Due to the widespread of A. flavus spores and the high risk of its mycotoxins in our environment, we investigated the pathological effects of A. flavus on genitourinary system in experimental rats using a whole sonicated antigen (WSA), and modified mycotoxin (mycotoxoid) in the immunization process. Fifty albino male rats were involved, subdivided into five group, each group of 10 male rats. Group one as a negative control received phosphate buffer saline, group two as a positive control received a challenge dose of 1×106 /0.5ml viable conidia/rat, while group three was immunized by a mixture of WSA and mycotoxoid, G4 was immunized by WSA alone, and G5 was immunized by mycotoxoid alone. The immunization was performed in two doses with 2 weeks interval. The results showed a high immune response (in group three G3) stimulated by the mixture (WSA and mycotoxoid), which revealed a significant increase in both IL-17 and IFN-γ. After experimental infection, the sero-analysis showed a significant increase in IL-17 and IFN-γ serum levels compared with the mixture-immunized group which showed no significant increases. In addition, the histopathologic sections illustrated severe chronic inflammation with a typical fungal granulomatous reaction in the prostate glands and kidneys compared with the WSA-immunized groups which showed mild histological reactions. Finally, we conclude that A. flavus is a serious opportunistic pathogen that can disseminate into genitourinary organs inducing severe pathologic lesions and even death. Moreover, we found that immunization by WSA and mycotoxoid can significantly reduce both immune and histopathological effects of A. flavus and its mycotoxins.

Aspergillus flavus (A. flavus) is a postharvest fungus, causing pitaya fruit decay and limiting pitaya value and shelf life. However, safer and more efficient methods for preventing A. flavus contamination for pitaya fruit remain to be investigated. In this study, we successfully proved exogenous Fe2+ could inhibit A. flavus colonization in pitaya fruit and extend pitaya’s shelf life after harvest. Moreover, gel electrophoresis, CD analysis and Raman spectrum tests revealed Fe2+ could more effectively and thoroughly promote conidial death by directly binding to A. flavus DNA. Increased expression of DNA damage repair-related genes after Fe2+ treatment was observed by transcription analysis, which might eventually lead to SOS response in A. flavus. These results indicated Fe2+ could prevent A. flavus infestation on pitaya in a novel, quickly responsive mechanism. Our results shed light on the potential application of Fe2+ in the food industry and provided a more universal antifungal agent against food pathogens.

The main goal of this study is to choose the best citric acid producing fungi and single cell protein taken from various plants sources. The best fungi samples were chosen then study of some factors such as incubation period, carbon, hydrogen and hydrogen number affecting their growth and production. Results showed that the best production and growing dynasties were (Aspergillus niger, A. flavus). The best acid production reached (18.42,20.81)gm/l respectively on 8th incubation day. Best production of protein content reached (4.02, 6.18)gm/l respectively. During the same incubation period for the same species followed by Pencillium sp. Species unlike other species that failed to give tangible amount. Thus A. flavus was selected as the best growth and production fungi. Also the results showed that sucrose and Ammonium uniphosphate were the best hydrogen resources respectively at the hydrogen number at (6.0). [ABSTRACT FROM AUTHOR]

As a member of the Rho family, Rac plays important roles in many species, including proliferation, differentiation, apoptosis, DNA damage responses, metabolism, angiogenesis, and immunosuppression. In this study, by constructing Rac-deleted mutants in Aspergillus flavus, it was found that the deletion of Rac gene led to the decline of growth and development, conidia production, AFB1 toxin synthesis, and seed infection ability of A. flavus. The deletion of Rac gene also caused the disappearance of A. flavus sclerotium, indicating that Rac is required for sclerotium formation in A. flavus. The sensitivity of Rac-deficient strains responding to cell wall stress and osmotic pressure stress increased when compared to A.flavus WT. The Western blot result showed that mitogen-activated serine/threonine-protein kinase Slt2 and mitogen-activated protein kinase Hog1 proteins were no longer phosphorylated in Rac-deficient strains of A. flavus, showing that Rac may be used as a molecular switch to control the Slt2-MAPK cascade pathway and regulate the osmotic Hog-MAPK cascade pathway in A. flavus in response to external stress. Altogether, these results indicated that Rac was involved in regulating the growth and development, conidia formation and AFB1 synthesis, and response to cell wall stress and osmotic pressure stress in A. flavus. [ABSTRACT FROM AUTHOR]

There is an important reason for the accelerated use of non-aflatoxigenic Aspergillus flavus to mitigate pre-harvest aflatoxin contamination... it effectively addresses the imperative need for safer food and feed. Now that we have decades of proof of the effectiveness of A. flavus as biocontrol, it is time to improve several aspects of this strategy. If we are to continue relying heavily on this form of aflatoxin mitigation, there are considerations we must acknowledge, and actions we must take, to ensure that we are best wielding this strategy to our advantage. These include its: (1) potential to produce other mycotoxins, (2) persistence in the field in light of several ecological factors, (3) its reproductive and genetic stability, (4) the mechanism(s) employed that allow it to elicit control over aflatoxigenic strains and species of agricultural importance and (5) supplemental alternatives that increase its effectiveness. There is a need to be consistent, practical and thoughtful when it comes to implementing this method of mycotoxin mitigation since these fungi are living organisms that have been adapting, evolving and surviving on this planet for tens-of-millions of years. This document will serve as a critical review of the literature regarding pre-harvest A. flavus biocontrol and will discuss opportunities for improvements. [ABSTRACT FROM AUTHOR]

The peanut seed coat acts as a physical and biochemical barrier against Aspergillus flavus infection; however, the nature of the inhibitory chemicals in the peanut seed coat in general is not known. This study identified and characterized peanut seed coat metabolites that inhibit A. flavus growth and aflatoxin contamination. Selected peanut accessions grown under well-watered and water-deficit conditions were assayed for A. flavus resistance, and seed coats were metabolically profiled using liquid chromatography mass spectrometry. Kyoto Encyclopedia of Genes and Genome phenylpropanoid pathway reference analysis resulted in the identification of several seed coat metabolic compounds, and ten selected metabolites were tested for inhibition of A. flavus growth and aflatoxin contamination. Radial growth bioassay demonstrated that 2,5-dihydroxybenzaldehyde inhibited A. flavus growth (98.7%) and reduced the aflatoxin contamination estimate from 994 to 1 μg/kg. Scanning electron micrographs showed distorted hyphae and conidiophores in cultures of 2,5-dihydroxybenzaldehyde-treated A. flavus , indicating its potential use for field application as well as seed coat metabolic engineering.

Artemisia afra is a medicinal plant with antimicrobial activities, known to treat tuberculosis, measles, cough, and influenza. In consequence, its applications have increasingly become pivotal to control various microbes which cause different diseases. This study therefore, evaluated the chemical composition and the antifungal activity of A. afra essential oil. The extraction of essential oil was done using steam distillation. The essential oil chemical composition was analysed by GC-MS. The analysis revealed 19 compounds from A. afra. The main compounds were borneol (71.529%), terpinen-4-ol (8.582%), ß-thujone (3.283%), ß-terpineol (2.590%), a-terpineol (1.791%), chrysanthenone (1.507%), myrtenal (1.393%), eucalyptol (1,8-cineole) (1.263%), cis-sabinene hydrate (1.172%) and trans-carane, 4,5-epoxy (1.088%). The growth and aflatoxin production inhibitions against A. flavus were determined via antifungal and antiaflatoxigenic bioassays of the A. afra essential oil at the concentration range of 10-50 µL/mL using a poisoned-food method. The quantification of the aflatoxins production was carried out using high-performance liquid chromatography. The antifungal activity of A. afra essential oil was effective against A. flavus with growth inhibition of 99.97-99.99% and controlled aflatoxins production by 99.25-99.63%. The results indicated that A. afra essential oil can become an alternative natural fungicide for the control of A. flavus growth and aflatoxins production. [ABSTRACT FROM AUTHOR]

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Objectives: This study was designed to isolate, identify, and determine the prevalence of Aspergilli in commercial chicken in selected areas of Bangladesh. Materials and Methods: A total of 50 lung samples from suspected dead chickens, comprising broilers (n = 32) and layers (n = 18), aged between 5 days and 45 weeks, were collected from poultry farms located in the Gazipur district in Bangladesh. Fungi were primarily identified based on the colony morphology using potato dextrose agar (PDA). DNA was extracted from the suspected colonies. Aspegillus spp. was detected by genus-specific ASAP-1 and ASAP-2. Aspergillus spp. were then screened by polymerase chain reaction targeting Aspergillus flavus (FLA-1 and FLA-2), Aspergillus fumigatus (ASPU and Af3r), and Aspergillus niger (ASPU and Nilr). Results: The overall prevalence of Aspergillus spp. was 44% (n = 22/50; p < 0.05). Among the Aspergilli, A. flavus was detected in 10% (n = 5/50) of the samples. Similarly, A. fumigatus and A. niger were detected at 26% (n = 13/50) and 8% (n = 4/50) respectively. Three samples were associated with more than one fungus; two fungi (A. flavus and A. niger) were in two samples, and three fungi (A. flavus, A. fumigatus, and A. niger) were in one sample. Conclusion: Isolation and prevalence of Aspergillus spp. in commercial chicken were studied for the first time in Bangladesh. [ABSTRACT FROM AUTHOR]

Abstract Background Meat-products are considered an enriched media for mycotoxins. This study aimed to investigate the prevalence of toxigenic Aspergillus species in processed meat samples, HPLC-quantitative measurement of aflatoxin B1 and ochratoxin A residues, and molecular sequencing of aflR1 and pks genes. One hundred and twenty processed beef meat specimens (basterma, sausage, and minced meat; n = 40 for each) were collected from Ismailia Province, Egypt. Samples were prepared for total mold count, isolation, and identification of Aspergillus species. All samples were analyzed for the production of both Aflatoxin B1 and Ochratoxin A mycotoxins by HPLC. Molecular identification of Aspergillus flavus and Aspergillus ochraceus was performed using PCR amplification of the internal transcribed spacer (ITS) region; furthermore, the aflR1 and pks genes were sequenced. Results The total mold count obtained from sausage samples was the highest one, followed by minced meat samples. The prevalence of A. flavus was (15%), (7.5%), and (10%), while the prevalence of A. ochraceus was (2.5%), (10%), and (0%) in the examined basterma, sausage, and minced meat samples, respectively. Using PCR, the ITS region was successfully amplified in all the tested A. flavus and A. ochraceus strains. Aflatoxin B1 was detected in six basterma samples (15%). Moreover, the ochratoxin A was detected only in four sausage samples (10%). The aflR1 and pks genes were amplified and sequenced successfully and deposited in the GenBank with accession numbers MF694264 and MF694264, respectively. Conclusions To the best of our knowledge, this is the first report concerning the HPLC-Molecular-based approaches for the detection of aflatoxin B1 and ochratoxin A in processed beef meat in Egypt. The production of aflatoxin B1 and ochratoxin A in processed meat constitutes a public health threat. Aflatoxin B1 is commonly associated with basterma samples. Moreover, ochratoxin A was detected frequently in sausage samples. The routine inspection of mycotoxins in processed meat products is essential to protect human consumers.

Aflatoxins from the fungus Aspergillus flavus (A. flavus) that contaminate stored peanuts is a major hazard to human health worldwide. Reducing A. flavus in soil can decrease the risk of aflatoxins in stored peanuts. In this experiment, we determined whether peanuts grown on soil fumigated with dazomet (DZ), metham sodium (MS), allyl isothiocyanate (AITC), chloropicrin (PIC) or dimethyl disulfide (DMDS) would reduce of the quantity of A. flavus and its toxin's presence. The results of bioassays and field tests showed that PIC was the most effective fumigant for preventing and controlling A. flavus , followed by MS. PIC and MS applied to the soil for 14 d resulted in LD 50 values against A. flavus of 3.558 and 4.893 mg kg−1, respectively, leading to almost 100% and 98.82% effectiveness of A. flavus , respectively. Peanuts harvested from fumigated soil and then stored for 60 d resulted in undetectable levels of aflatoxin B1 (AFB1) compared to unfumigated soil that contained 0.64 ug kg−1 of AFB1, which suggested that soil fumigation can reduce the probability of aflatoxin contamination during peanut storage and showed the potential to increase the safety of peanuts consumed by humans. Further research is planned to determine the practical value of our research in commercial practice. [Display omitted] • This study initially applied soil disinfection to control peanut aflatoxin pollution. • Fumigants can control As pergillus flavus and other harmful organisms in the soil. • Soil fumigation can well reduce aflatoxin levels and extend the peanuts shelf life. • The application of soil disinfection is vital for ensuring peanut food safety. [ABSTRACT FROM AUTHOR]

In this study, superparamagnetic iron oxide nanoparticles (MNPs) were synthesized via exposure of fungal cell filtrate from Aspergillus flavus to aqueous iron ions. The extracellular synthesis of MNPs was monitored by UV–Vis spectrophotometry and showed an absorption peak at 310 nm. The morphology of MNPs was found to be flake-like, as confirmed by Field Emission Scanning Electron Microscopy (FESEM), while the average crystallite size was ∼16 nm, as determined by X-ray diffraction (XRD). Energy dispersive X-ray (EDX) analysis was performed to confirm the presence of elemental Fe in the sample. Pectinase and xylanase were covalently immobilized on MNPs with efficiencies of ∼84% and 77%, respectively. Compared to the free enzymes, the immobilized enzymes were found to exhibit enhanced tolerance to variation of pH and temperature and demonstrated improved storage stability. Furthermore, the residual activity of the immobilized enzymes was about 56% for pectinase and 52% for xylanase, after four and three consecutive use cycles, respectively.

The harmful effects of chemical fertilizers on soil, plants, and eco-systems have stimulated the growth of the global biofertilizer market. However, biofertilizer use remains limited in developing countries due to inadequate research and poor technology. The use of readily available materials for biofertilizer production can be a good starting point. This study aimed to investigate phosphate-solubilizing potentials of soil fungi and the shelf-life of their biofertilizer formulations using sawdust and charcoal as carriers. Soil samples from the rhizosphere were cultured on Pikovskaya (PVK) agar, and the best phosphate solubilizers (Aspergillus niger, Aspergillus fumigatus and A. flavus) were screened for their phosphatesolubilization potentials on solid medium. Results obtained showed that A. niger had the highest solubilization index of 1.72, followed by A. fumigatus, and A. flavus with a solubilization index of 1.01 and 0.95, respectively. Optimization studies showed that after 5 days of incubation, A. niger, A. flavus and A. fumigatus solubilized 149, 112 and 126 mg L-1 of phosphate, respectively. These values increased to 549 mg L-1 on day 11 for A. niger, 379 mg L-1 on day 9 for A. flavus and 430 mg L-1 on day 9 for A. fumigatus. Furthermore, A. fumigatus and A. flavus proved to be better inoculants than A. niger as they maintained higher CFU g-1 counts throughout the experiment. Also, sawdust supported higher counts of the three inoculants than charcoal and was thus the best carrier. The findings demonstrated that these aspergilli can be harnessed for improving soil fertility and plant development. [ABSTRACT FROM AUTHOR]

Background: Meat-products are considered an enriched media for mycotoxins. This study aimed to investigate the prevalence of toxigenic Aspergillus species in processed meat samples, HPLC-quantitative measurement of aflatoxin B1 and ochratoxin A residues, and molecular sequencing of aflR1 and pks genes. One hundred and twenty processed beef meat specimens (basterma, sausage, and minced meat; n = 40 for each) were collected from Ismailia Province, Egypt. Samples were prepared for total mold count, isolation, and identification of Aspergillus species. All samples were analyzed for the production of both Aflatoxin B1 and Ochratoxin A mycotoxins by HPLC. Molecular identification of Aspergillus flavus and Aspergillus ochraceus was performed using PCR amplification of the internal transcribed spacer (ITS) region; furthermore, the aflR1 and pks genes were sequenced. Results: The total mold count obtained from sausage samples was the highest one, followed by minced meat samples. The prevalence of A. flavus was (15%), (7.5%), and (10%), while the prevalence of A. ochraceus was (2.5%), (10%), and (0%) in the examined basterma, sausage, and minced meat samples, respectively. Using PCR, the ITS region was successfully amplified in all the tested A. flavus and A. ochraceus strains. Aflatoxin B1 was detected in six basterma samples (15%). Moreover, the ochratoxin A was detected only in four sausage samples (10%). The aflR1 and pks genes were amplified and sequenced successfully and deposited in the GenBank with accession numbers MF694264 and MF694264, respectively. Conclusions: To the best of our knowledge, this is the first report concerning the HPLC-Molecular-based approaches for the detection of aflatoxin B1 and ochratoxin A in processed beef meat in Egypt. The production of aflatoxin B1 and ochratoxin A in processed meat constitutes a public health threat. Aflatoxin B1 is commonly associated with basterma samples. Moreover, ochratoxin A was detected frequently in sausage samples. The routine inspection of mycotoxins in processed meat products is essential to protect human consumers. [ABSTRACT FROM AUTHOR]

La contaminación de productos agrícolas y pecuarios con aflatoxinas (AF) está distribuida mundialmente. Las AF son tóxicas, inmunodepresoras y carcinogénicas, pero en México es escasa la información sobre Aspergillus flavus, principal hongo que las produce. El objetivo fue caracterizar morfológica, molecular y aflatoxigénicamente aislados de A. flavus y cuantificar AF en pienso y en leche de vacas Holstein en Aguascalientes (México). Se seleccionó por conveniencia una unidad de producción lechera (2,749 vacas) y se recolectaron muestras mensuales (24 meses) de ingredientes alimenticios y ración total mezclada (n= 267), leche cruda (n= 288) y suelo agrícola (n= 40), las cuales se cultivaron (PDA) mediante vaciado en placa con diluciones seriadas. Los hongos se caracterizaron mediante MEB, TLC y vapores de amonio en agar coco; se secuenciaron los genes de calmodulina y regulador de la ruta biosintética de AF, así como la región de los espaciadores internos de la transcripción. Se cuantificaron AF en pienso con HPLC y en leche con ELISA. Se caracterizaron molecularmente 283 aislados fúngicos; 88 resultaron ser Aspergillus spp, de los que 5 fueron A. flavus con capacidad aflatoxigénica y uno no aflatoxigénico. El 99.3 % de las muestras de alimento y 39.9 % de las muestras de leche presentaron niveles detectables de AF (14.8 y 0.021 µg/kg). Las vacas ingirieron diariamente 621 µg de AF y eliminaron el 0.09 % como aflatoxina M1 en leche. Lo anterior sugiere que la ocurrencia A. flavus aflatoxigénico en el alimento de vacas lecheras conduce a una amplia contaminación por AF de las dietas y de la cadena alimenticia.

Over the years, researchers, food specialists, and all authorities concerned with food safety around the world could develop many ways to preserve and improve the shelf life of food. Recently, volatile oils have been gaining attention for their antifungal and anti-mycotoxin properties. The objectives of the present study were first to investigate mold contamination of four chilled meat products (luncheon, beef burger, sausage, and minced meat) retailed in Zagazig city, Sharkia Governorate, Egypt. Second, identification of the prevalent mould genera was followed. Third, the inhibitory effects of some essential oils against Aspergillus flavus were tested. The results of the present study showed that the mean values of the total mould count were 2.47 ± 0.04, 2.85 ± 0.11, 3.08 ± 0.12 and 2.24 ± 0.02 (log10 CFU/g) in luncheon, beef burger, sausage, and minced meat, respectively. The most contaminated samples were that belonging to sausage, followed by beef burger, luncheon, and minced meat. Five mould genera were isolated and identified in the current study, namely, Aspergillus, Penicillum, Cladosporium, Alternaria, and Mucor Furthermore, Aspergillus species was further identified into A. flavus, A. niger, A. fumigatus, A. ochraceus, and A. terreus. Essential oils of cinnamon, lemongrass, and thyme at 1% and 2% had a clear inhibitory effect against A. flavus-artificially contaminated beef burger. The effects of thyme oil 1%, cinnamon oil 1%, and lemongrass oil 1% at the 9th day on the overall acceptability score were 7.33 ± 0.28, 7.13 ± 0.27, and 7.09 ± 0.18, respectively. A. flavus counts were 3.79 ± 0.05, 3.18 ± 0.07, and 3.61 ± 0.05, respectively after these treatments. While, at the same day, thyme oil 2% effect > lemongrass oil 2% > cinnamon oil 2% for both overall acceptability score and total A. flavus count. These findings suggest that thyme, cinnamon, and lemongrass EOs have significant antifungal activity, which is a promising solution for mould decontamination and consequently extends the shelf life of meat products.

Over the years, researchers, food specialists, and all authorities concerned with food safety around the world could develop many ways to preserve and improve the shelf life of food. Recently, volatile oils have been gaining attention for their antifungal and anti-mycotoxin properties. The objectives of the present study were first to investigate mold contamination of four chilled meat products (luncheon, beef burger, sausage, and minced meat) retailed in Zagazig city, Sharkia Governorate, Egypt. Second, identification of the prevalent mould genera was followed. Third, the inhibitory effects of some essential oils against Aspergillus flavus were tested. The results of the present study showed that the mean values of the total mould count were 2.47 ± 0.04, 2.85 ± 0.11, 3.08 ± 0.12 and 2.24 ± 0.02 (log10CFU/g) in luncheon, beef burger, sausage, and minced meat, respectively. The most contaminated samples were that belonging to sausage, followed by beef burger, luncheon, and minced meat. Five mould genera were isolated and identified in the current study, namely, Aspergillus, Penicillum, Cladosporium, Alternaria, and Mucor Furthermore, Aspergillus species was further identified into A. flavus, A. niger, A. fumigatus, A. ochraceus, and A. terreus. Essential oils of cinnamon, lemongrass, and thyme at 1% and 2% had a clear inhibitory effect against A. flavus-artificially contaminated beef burger. The effects of thyme oil 1%, cinnamon oil 1%, and lemongrass oil 1% at the 9th day on the overall acceptability score were 7.33 ± 0.28, 7.13 ± 0.27, and 7.09 ± 0.18, respectively. A. flavus counts were 3.79 ± 0.05, 3.18 ± 0.07, and 3.61 ± 0.05, respectively after these treatments. While, at the same day, thyme oil 2% effect > lemongrass oil 2% > cinnamon oil 2% for both overall acceptability score and total A. flavus count. These findings suggest that thyme, cinnamon, and lemongrass EOs have significant antifungal activity, which is a promising solution for mould decontamination and consequently extends the shelf life of meat products. [ABSTRACT FROM AUTHOR]

Aspergillus flavus (A. flavus) is a ubiquitous and opportunistic fungal pathogen that causes invasive and non-invasive aspergillosis in humans and animals. This fungus is also capable of infecting a large number of agriculture crops (e.g., peanuts, maze, cotton seeds, rice, etc.), causing economic losses and posing serious food-safety concerns when these crops are contaminated with aflatoxins, the most potent naturally occurring carcinogens. In particular, A. flavus and aflatoxins are intensely studied, and they continue to receive considerable attention due to their detrimental effects on humans, animals, and crops. Although several studies have been published focusing on the biosynthesis of the aforementioned secondary metabolites, some of the molecular mechanisms (e.g., posttranslational modifications, transcription factors, transcriptome, proteomics, metabolomics and transcriptome, etc.) involved in the fungal development and aflatoxin biosynthesis in A. flavus are still not fully understood. In this study, a review of the recently published studies on the function of the genes and the molecular mechanisms involved in development of A. flavus and the production of its secondary metabolites is presented. It is hoped that the information provided in this review will help readers to develop effective strategies to reduce A. flavus infection and aflatoxin production. [ABSTRACT FROM AUTHOR]

As a member of the Rho family, Rac plays important roles in many species, including proliferation, differentiation, apoptosis, DNA damage responses, metabolism, angiogenesis, and immunosuppression. In this study, by constructing Rac-deleted mutants in Aspergillus flavus, it was found that the deletion of Rac gene led to the decline of growth and development, conidia production, AFB1 toxin synthesis, and seed infection ability of A. flavus. The deletion of Rac gene also caused the disappearance of A. flavus sclerotium, indicating that Rac is required for sclerotium formation in A. flavus. The sensitivity of Rac-deficient strains responding to cell wall stress and osmotic pressure stress increased when compared to A.flavus WT. The Western blot result showed that mitogen-activated serine/threonine-protein kinase Slt2 and mitogen-activated protein kinase Hog1 proteins were no longer phosphorylated in Rac-deficient strains of A. flavus, showing that Rac may be used as a molecular switch to control the Slt2-MAPK cascade pathway and regulate the osmotic Hog-MAPK cascade pathway in A. flavus in response to external stress. Altogether, these results indicated that Rac was involved in regulating the growth and development, conidia formation and AFB1 synthesis, and response to cell wall stress and osmotic pressure stress in A. flavus.

The aim of this study was to evaluate the performance of volatile organic compounds (VOCs) for evolution monitoring and early detection of Aspergillus flavus (A. flavus) contamination in walnuts. We successfully applied headspace–gas chromatography–ion mobility spectrometry (HS‐GC‐IMS) to evaluate walnut VOC changes caused by A. flavus contamination. A total of 48 VOCs were identified in walnuts contaminated with A. flavus. After identification of VOCs, a heat map and principal component analysis (PCA) highlighted ethyl acetate‐D, 3‐methyl‐2‐butanol, and cyclohexanone as potential biomarkers specific to A. flavus contamination in walnuts. These results provided valid targets for the development of sensors to evaluate the early mold contamination in stored walnuts. [ABSTRACT FROM AUTHOR]