WorldWideScience

Sample records for aspergillus flavus aflatoxins

  1. Inhibiting Aspergillus flavus growth and degrading aflatoxin B1 by ...

    African Journals Online (AJOL)

    Aflatoxin B1 (AFB1) is a type of toxin produced by Aspergillus flavus, which has a negative effect on animal production and economic profits. In order to inhibit A. flavus growth and degrade aflatoxin, the optimal proportion of beneficial microbes such as Lactobacillus casei, Bacillus subtilis and Pichia anomala were selected.

  2. Aflatoxin B 1 producing potential of Aspergillus flavus strains ...

    African Journals Online (AJOL)

    Aflatoxin B 1 (AFB1) producing potential of different strains of Aspergillus flavus, isolated from 1,200 stored rice grains collected from 43 locations in 20 rice growing states in India was investigated. Eighty-five strains of A. flavus were isolated from the discolored rice grains and tested for their AFB1 producing potential on ...

  3. How peroxisomes affect aflatoxin biosynthesis in Aspergillus flavus.

    Directory of Open Access Journals (Sweden)

    Massimo Reverberi

    Full Text Available In filamentous fungi, peroxisomes are crucial for the primary metabolism and play a pivotal role in the formation of some secondary metabolites. Further, peroxisomes are important site for fatty acids β-oxidation, the formation of reactive oxygen species and for their scavenging through a complex of antioxidant activities. Oxidative stress is involved in different metabolic events in all organisms and it occurs during oxidative processes within the cell, including peroxisomal β-oxidation of fatty acids. In Aspergillus flavus, an unbalance towards an hyper-oxidant status into the cell is a prerequisite for the onset of aflatoxin biosynthesis. In our preliminary results, the use of bezafibrate, inducer of both peroxisomal β-oxidation and peroxisome proliferation in mammals, significantly enhanced the expression of pex11 and foxA and stimulated aflatoxin synthesis in A. flavus. This suggests the existence of a correlation among peroxisome proliferation, fatty acids β-oxidation and aflatoxin biosynthesis. To investigate this correlation, A. flavus was transformed with a vector containing P33, a gene from Cymbidium ringspot virus able to induce peroxisome proliferation, under the control of the promoter of the Cu,Zn-sod gene of A. flavus. This transcriptional control closely relates the onset of the antioxidant response to ROS increase, with the proliferation of peroxisomes in A. flavus. The AfP33 transformant strain show an up-regulation of lipid metabolism and an higher content of both intracellular ROS and some oxylipins. The combined presence of a higher amount of substrates (fatty acids-derived, an hyper-oxidant cell environment and of hormone-like signals (oxylipins enhances the synthesis of aflatoxins in the AfP33 strain. The results obtained demonstrated a close link between peroxisome metabolism and aflatoxin synthesis.

  4. Atoxigenic Aspergillus flavus endemic to Italy for biocontrol of aflatoxins in maize

    Science.gov (United States)

    Effective biological control of aflatoxin­producing Aspergillus flavus with atoxigenic members of that species requires suitable A. flavus well adapted to and resident in target agroecosystems. Eighteen atoxigenic isolates of A. flavus endemic in Italy were compared for ability to reduce aflatoxin c...

  5. RNA interference reduces aflatoxin accumulation by Aspergillus flavus in peanut seeds

    Science.gov (United States)

    Aflatoxins are among the most powerful carcinogens in nature. They are produced by the fungal pathogen Aspergillus flavus Link and other Aspergillus species. Aflatoxins accumulate in many crops, including rice, wheat, oats, pecans, pistachios, soybean, cassava, almonds, peanuts, beans, corn and cot...

  6. NsdC and NsdD affect Aspergillus flavus morphogenesis and aflatoxin production

    Science.gov (United States)

    The transcription factors NsdC and NsdD have been shown to be necessary for sexual development in Aspergillus nidulans. Herein we examine the role of these proteins in development and aflatoxin production of the agriculturally important, aflatoxin-producing fungus, Aspergillus flavus. We found tha...

  7. Evaluation of intraspecific competition (Aspergillus flavus Link) and aflatoxin formation in suspended disc culture and preharvest maize

    Science.gov (United States)

    The abilities of non-aflatoxin producing strains of Aspergillus flavus NRRL 32354; 18543; 21882; 21368 as well as domesticated koji strains Aspergillus oryzae (syn. A. flavus var. oryzae) NRRL 451; 1911; 5592; 6271; 30038 to interfere with aflatoxin formation by A. flavus NRRL 3357; 32355 were exami...

  8. Genome-Wide Association Mapping of and Aspergillus flavus Aflatoxin Accumulation Resistance in Maize

    Science.gov (United States)

    Marilyn L. Warburton; Juliet D. Tang; Gary L. Windham; Leigh K. Hawkins; Seth C. Murray; Wenwei Xu; Debbie Boykin; Andy Perkins; W. Paul Williams

    2015-01-01

    Contamination of maize (Zea mays L.) with aflatoxin, produced by the fungus Aspergillus flavus Link, has severe health and economic consequences. Efforts to reduce aflatoxin accumulation in maize have focused on identifying and selecting germplasm with natural host resistance factors, and several maize lines with significantly...

  9. Aspergillus flavus infection and aflatoxin contamination of peanut ...

    African Journals Online (AJOL)

    Under certain conditions Aspergillus plants and produce aflatoxin, one of the most highly carcinogenic natural substances known. An ongoing project seeks to reduce aflatoxin contamination of peanut (Arachis hypogae L.). This paper describes new research tools, which have been developed to reach this goal.

  10. Inhibiting Aspergillus flavus growth and degrading aflatoxin B1 by ...

    African Journals Online (AJOL)

    ajl2

    2012-08-14

    Aug 14, 2012 ... of this study was to select the most effective method and products for inhibiting A. flavus growth and ... The supernatants were filtered to remove microbes with 0.20 μm Minisart High-flow filter (Sartorius Stedim .... pseudoplanturum 371 could inhibit mold growth and aflatoxin production, and the inhibitory ...

  11. Aflatoxin B1 producing potential of Aspergillus flavus strains isolated ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... rice cultivars tested. Key words: Rice, Aspergillus flavus, AFB1. INTRODUCTION. Rice (Oryza sativa L.) is the most important staple food crop in India and the bulk of rice is grown in ... storehouse was a mixture of 10 sub-samples (200 g each). Such ..... estimated in 11 cultivars of rice and 6 cultivars of wheat.

  12. Effect of intraspecific competition by Aspergillus flavus on aflatoxin formation in suspended disc culture.

    Science.gov (United States)

    Wicklow, Donald T; Bobell, John R; Palmquist, Debra E

    2003-05-01

    The ability of two non-aflatoxin producing strains of Aspergillus flavus to interfere with aflatoxin production by a toxigenic A. flavus strain was examined using a replacement series with suspended disc culture method. Individual glass fiber discs, affixed to a pin suspended from the caps of scintillation vials, were inoculated with medium containing A. flavus conidial mixtures in different proportions (aflatoxin producer:non-producer = 100:0, 80:20, 60:40, 20:80 and 0:100 by vol) at a constant total density (1 x 10(5) spores ml(-1)). Reductions in the total conidial density of these strains when grown alone, had little effect on fungal growth (mycelium dry weight) or aflatoxin production. Significant (P < 0.0001) reductions in aflatoxin B1 were recorded when non-toxigenic strains represented any proportion of the inoculum mixture. Aflatoxin yield values were less than (P < 0.0001) expected from the input ratios for toxigenic vs. non-toxigenic conidial inoculum within the replacement series. Aflatoxin yields were also reduced (P < 0.001), with a corresponding increase in fungal growth (P < 0.001), when conidia from aflatoxin producing strains were mixed in equal proportions. This suggests that the substantial inhibition of aflatoxin yield for inoculum mixtures results from the failure of spore germlings to establish a cooperative mycelial network.

  13. Enhanced aflatoxin production by aspergillus parasiticus and aspergillus flavus after low dose gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hitoshi (Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment)

    1992-09-01

    Spores of Aspergillus parasiticus IFO 30179 and A. flavus var. columnaris S46 were irradiated at 0.05, 0.2 and 0.4 kGy in the synthetic low salts (SL) broth, and the effect on aflatoxin production was examined after 10 days incubation at 30 or 25degC. In these two strains, irradiation of spores at 0.05 kGy resulted in higher B1 or G1 production than the non-irradiated controles. However, spores of the both strains irradiated at 0.2 or 0.4 kGy produced less aflatoxins than non-irradiated controles. In the SL broth, apparent stimulation by low dose irradiation was slight, and these enhanced effects were not observed after reinfection to fresh SL broth. In the case of food samples, the levels of aflatoxin B[sub 1] and G[sub 1] with A. parasiticus were increased from 15 to 90% by incubation of irradiated spores at 1 kGy in autoclaved polished rice, black pepper, white pepper and red pepper. These enhancement would be induced by change of composition in each substrates. Mutations of fungi induced by irradiation is not effective for enhancement of aflatoxin production. (author).

  14. Evaluation of resistance to aflatoxin contamination in kernels of maize genotypes using a GFP-expressing Aspergillus flavus strain

    Science.gov (United States)

    Evaluation of resistance or susceptibility of corn inbreds to infection by Aspergillus flavus was evaluated by a kernel screening assay. A GFP-expressing strain of A. flavus was used to accomplish this study to measure fungal spread and aflatoxin levels in real time. Among the four inbreds tested, ...

  15. The plant growth regulator methyl jasmonate inhibits aflatoxin production by Aspergillus flavus.

    Science.gov (United States)

    Goodrich-Tanrikulu, M; Mahoney, N E; Rodriguez, S B

    1995-11-01

    Aflatoxins are highly toxic and carcinogenic compounds produced by certain Aspergillus species on agricultural commodities. The presence of fatty acid hydroperoxides, which can form in plant material either preharvest under stress or postharvest under improper storage conditions, correlates with high levels of aflatoxin production. Effects on fungal growth and aflatoxin production are known for only a few of the numerous plant metabolites of fatty acid hydroperoxides. Jasmonic acid (JA), a plant growth regulator, is a metabolite of 13-hydroperoxylinolenic acid, derived from alpha-linolenic acid. The volatile methyl ester of JA, methyl jasmonate (MeJA), is also a plant growth regulator. In this study we report the effect of MeJA on aflatoxin production and growth of Aspergillus flavus. MeJA at concentrations of 10(-3)-10(-8) M in the growth medium inhibited aflatoxin production, by as much as 96%. Exposure of cultures to MeJA vapour similarly inhibited aflatoxin production. The amount of aflatoxin produced depended on the timing of the exposure. MeJA treatment also delayed spore germination and inhibited the production of a mycelial pigment. These fungal responses resemble plant jasmonate responses.

  16. Aflatoxin B1 producing potential of Aspergillus flavus strains isolated ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... Extraction of AFB1 from A. flavus strains grown on agar media. Eighty five strains of A. flavus isolated from rice grain samples were grown on sterilized different agar media (AFPA, Czapeks agar, PDA and YES agar) for 5 days at 25 ± 2°C. Three replications were maintained for each isolate for each media.

  17. Antifungal properties and inhibitory effects upon aflatoxin production of Thymus vulgaris L. by Aspergillus flavus Link.

    Science.gov (United States)

    Kohiyama, Cássia Yumie; Yamamoto Ribeiro, Milene Mayumi; Mossini, Simone Aparecida Galerani; Bando, Erika; Bomfim, Natália da Silva; Nerilo, Samuel Botião; Rocha, Gustavo Henrique Oliveira; Grespan, Renata; Mikcha, Jane Martha Graton; Machinski, Miguel

    2015-04-15

    The antifungal and antiaflatoxigenic properties of Thymus vulgaris essential oil (TEO) were evaluated upon Aspergillus flavus "in vitro". Suspension containing 10(6) of A. flavus were cultivated with TEO in concentrations ranging from 50 to 500 μg/mL. TEO reached minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) at 250 μg/mL. Inhibition of ergosterol biosynthesis was detected at a concentration of 100 μg/mL of TEO. Morphological evaluation performed by both light microscopy and scanning electron microscopy showed that antifungal activity of TEO could be detected starting at a concentration of 50 μg/mL and the fungicide effect at a concentration of 250 μg/mL. TEO completely inhibited production of both B1 and B2 aflatoxins (AFB1 and AFB2) at a concentration of 150 μg/mL. This way, fungal biomass development and aflatoxin production were dependent on TEO concentration. Therefore, TEO was capable of controlling the growth of A. flavus and its production of aflatoxins. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Morphological Characterization and Determination of Aflatoxin-Production Potentials of Aspergillus flavus Isolated from Maize and Soil in Kenya

    Directory of Open Access Journals (Sweden)

    Matome Gabriel Thathana

    2017-09-01

    Full Text Available This study aimed at morphologically identifying Aspergillus flavus in soil and maize and at determining their aflatoxin-producing potentials. Five hundred and fourteen isolates obtained from maize and soil in Kenya were cultivated on Czapeck Dox Agar, Malt Extract Agar, Sabouraud Dextrose Agar, Potato Dextrose Agar, and Rose-Bengal Chloramphenicol Agar. Isolates were identified using macro-morphological characteristics. Micromorphological characteristics were determined using slide cultures. Aflatoxin production was determined by direct visual determination of the UV fluorescence of colonies on Coconut Agar Medium, Yeast Extract Sucrose agar, and Yeast Extract Cyclodextrin Sodium Deoxycholate agar and by Thin Layer Chromatography. Forty-three presumptive A. flavus isolates were identified; aflatoxin was detected in 23% of the isolates by UV fluorescence screening and in 30% by Thin-Layer Chromatography (TLC. The aflatoxins produced were: aflatoxin B1 (AFB1, aflatoxin B2 (AFB2, and aflatoxin G1 (AFG1; some isolates produced only AFB1, whereas others produced either AFB1 and AFB2 or AFB1 and AFG1. The highest incidence of A. flavus (63% and aflatoxin production (28% was recorded in samples from Makueni District. Isolates from Uasin Gishu (21% and Nyeri (5% were non-aflatoxigenic. Bungoma District recorded 11% positive isolates of which 2% were aflatoxin producers. The occurrence of aflatoxin-producing A. flavus emphasises the need for measures to eliminate their presence in food crops.

  19. Molecular Detection of Aflatoxin Producing Strains of Aspergillus Flavus from Peanut (Arachis Hypogaea

    Directory of Open Access Journals (Sweden)

    Adeela Hussain

    2015-02-01

    Full Text Available Aflatoxins are the potential carcinogens produced as secondary metabolites by Aspergillus flavus. They have the ability to contaminate large number of food which ultimately affect the human population. Malt extract agar was selected for the growth of control stains of fungus. The aim of the study was to develop a reliable and quick method for the detection of aflatoxin producing strains in peanuts by using molecular approaches. Total 80 samples of infected peanuts were collected from four different cities of Punjab and checked for their aflatoxin contamination. For aflatoxin detection, three target genes nor1, ver1 and aflR were selected which was involved in the aflatoxin biosynthesis. In all examined cases, 24 out of 80 (30% samples successfully amplified all three genes indicating aflatoxigenic activity. Discrimination between aflatoxigenic and non-aflatoxigenic strains were also determined on the basis of amplification of these three target DNA fragments. In this study, it was also demonstrated that only specific strains were able to produce the aflatoxin contamination in peanuts.

  20. Effect of climate change on Aspergillus flavus and aflatoxin B1 production

    Directory of Open Access Journals (Sweden)

    Angel eMedina

    2014-07-01

    Full Text Available This review considers the available information on the potential impact of key environmental factors and their interactions on the molecular ecology, growth and aflatoxin production by Aspergillus flavus in vitro and in maize grain. The recent studies which have been carried out to examine the impact of water activity x temperature on aflatoxin biosynthesis and phenotypic aflatoxin production are examined. These have shown that there is a direct relationship between the relative expression of key regulatory and structural genes under different environmental conditions which correlate directly with aflatoxin B1 production. A model has been developed to integrate the relative expression of 10 biosynthetic genes in the pathway, growth and aflatoxin B1 (AFB1 production which was validated under elevated temperature and water stress conditions. The effect of interacting conditions of aw x temperature x elevated CO2 (2x and 3x existing levels are detailed for the first time. This suggests that while such interacting environmental conditions have little effect on growth they do have a significant impact on aflatoxin biosynthetic gene expression (structural aflD and regulatory aflR genes and can significantly stimulate the production of AFB1. While the individual factors alone have an impact, it is the combined effect of these three abiotic factors which have an impact on mycotoxin production. This approach provides data which is necessary to help predict the real impacts of climate change on mycotoxigenic fungi.

  1. POTENTIAL OF ESSENTIAL OILS FOR PROTECTION OF GRAINS CONTAMINATED BY AFLATOXIN PRODUCED BY Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Renata Hadad Esper

    2014-06-01

    Full Text Available Aflatoxin B1 (AFB1 is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oils of Ageratum conyzoides (mentrasto and Origanum vulgare (oregano on the mycelial growth and aflatoxin B1 production by Aspergillus flavus have been studied previously in culture medium. The aim of this study was to evaluate aflatoxin B1 production by Aspergillus flavus in real food systems (corn and soybean treated with Ageratum conyzoides (mentrasto and Origanum vulgare (oregano essential oils. Samples with 60 g of the grains were treated with different volumes of essential oils, 200, 100, 50, and 10 μL for oregano and 50, 30, 15, and 10μL for mentrasto. Fungal growth was evaluated by disk diffusion method. Aflatoxin B1 production was evaluated inoculating suspensions of A. flavus containing 1.3×105 spores/ mL in 60 g of grains (corn and soybeans after adjusting the water activity at 0.94. Aflatoxin was quantified by photodensitometry. Fungal growth and aflatoxin production were inhibited by essential oils, but the mentrasto oil was more effective in soybeans than that of oregano. On the other hand, in corn samples, the oregano essential oil was more effective than that of mentrasto. Chemical compositions of the essential oils were also investigated. The GC/MS oils analysis showed that the main component of mentrasto essential oil is precocene I and of the main component of oregano essential oil is 4-terpineol. The results indicate that both essential oils can become an alternative for the control of aflatoxins in corn and soybeans.

  2. Effects of Nutrients in Substrates of Different Grains on Aflatoxin B1 Production by Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2016-01-01

    Full Text Available The current study was to better understand the potential factors affecting aflatoxin B1 (AFB1 accumulation varies between different grains. The nutrient composition and contents of defatted substrates were determined; additionally, according to the nutrient content of the substrates, the effects of starch, soluble sugars, amino acids, and trace elements on AFB1 production and mycelial growth in Czapek-Dox medium were examined. These results verified that removal of lipids from ground substrates significantly reduced the substrate’s potential for AFB1 production by Aspergillus flavus. Maltose, glucose, sucrose, arginine, glutamic acid, aspartic acid, and zinc significantly induced AFB1 production up to 1.7- to 26.6-fold. And stachyose more significantly promoted A. flavus growth than the other nutrients. Thus, this study demonstrated that, combined with the nutrients content of grains, in addition to lipids, sucrose, stachyose, glutamic acid, and zinc might play key roles in various grains that are differentially infected by A. flavus. Particularly, two new nutrients (arginine and stachyose of the grains we found significantly stimulate AFB1 production and A. flavus growth, respectively. The results provide new concepts for antifungal methods to protect food and animal feed from AFB1 contamination.

  3. Effects of Nutrients in Substrates of Different Grains on Aflatoxin B1 Production by Aspergillus flavus

    Science.gov (United States)

    Liu, Jie; Sun, Lvhui; Zhang, Niya; Zhang, Jiacai; Guo, Jiao; Li, Chong; Rajput, Shahid Ali; Qi, Desheng

    2016-01-01

    The current study was to better understand the potential factors affecting aflatoxin B1 (AFB1) accumulation varies between different grains. The nutrient composition and contents of defatted substrates were determined; additionally, according to the nutrient content of the substrates, the effects of starch, soluble sugars, amino acids, and trace elements on AFB1 production and mycelial growth in Czapek-Dox medium were examined. These results verified that removal of lipids from ground substrates significantly reduced the substrate's potential for AFB1 production by Aspergillus flavus. Maltose, glucose, sucrose, arginine, glutamic acid, aspartic acid, and zinc significantly induced AFB1 production up to 1.7- to 26.6-fold. And stachyose more significantly promoted A. flavus growth than the other nutrients. Thus, this study demonstrated that, combined with the nutrients content of grains, in addition to lipids, sucrose, stachyose, glutamic acid, and zinc might play key roles in various grains that are differentially infected by A. flavus. Particularly, two new nutrients (arginine and stachyose) of the grains we found significantly stimulate AFB1 production and A. flavus growth, respectively. The results provide new concepts for antifungal methods to protect food and animal feed from AFB1 contamination. PMID:27294129

  4. The pathogenesis-related maize seed (PRms) gene plays a role in resistance to Aspergillus flavus infection and aflatoxin contamination

    Science.gov (United States)

    Aspergillus flavus is an opportunistic plant pathogen that colonizes and produces the toxic and carcinogenic secondary metabolites, aflatoxins, in oil-rich crops such as maize (Zea mays ssp. mays L.). Pathogenesis-related proteins serve as a first line of defense against invading pathogens by confer...

  5. Leaf application of a sprayable bioplastic-based formulation of biocontrol Aspergillus flavus strains for reduction of aflatoxins in corn.

    Science.gov (United States)

    Accinelli, Cesare; Abbas, Hamed K; Vicari, Alberto; Shier, W Thomas

    2016-08-01

    Applying non-aflatoxin-producing Aspergillus flavus isolates to the soil has been shown to be effective in reducing aflatoxin levels in harvested crops, including peanuts, cotton and corn. The aim of this study was to evaluate the possibility of controlling aflatoxin contamination using a novel sprayable formulation consisting of a partially gelatinized starch-based bioplastic dispersion embedded with spores of biocontrol A. flavus strains, which is applied to the leaf surfaces of corn plants. The formulation was shown to be adherent, resulting in colonization of leaf surfaces with the biocontrol strain of A. flavus, and to reduce aflatoxin contamination of harvested kernels by up to 80% in Northern Italy and by up to 89% in the Mississippi Delta. The percentage of aflatoxin-producing isolates in the soil reservoir under leaf-treated corn was not significantly changed, even when the soil was amended with additional A. flavus as a model of changes to the soil reservoir that occur in no-till agriculture. This study indicated that it is not necessary to treat the soil reservoir in order to achieve effective biocontrol of aflatoxin contamination in kernel corn. Spraying this novel bioplastic-based formulation to leaves can be an effective alternative in the biocontrol of A. flavus in corn. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  6. Toward elucidation of genetic and functional genetic mechanisms in corn host resistance to Aspergillus flavus infection and aflatoxin contamination

    Directory of Open Access Journals (Sweden)

    Xueyan eShan

    2014-07-01

    Full Text Available Aflatoxins are carcinogenic mycotoxins produced by some species in the Aspergillus genus, such as A. flavus and A. parasiticus. Contamination of aflatoxins in corn profusely happens at pre-harvest stage when heat and drought field conditions favor A. flavus colonization. Commercial corn hybrids are generally susceptible to A. flavus infection. An ideal strategy for preventing aflatoxin contamination is through the enhancement of corn host resistance to Aspergillus infection and aflatoxin production. Constant efforts have been made by corn breeders to develop resistant corn genotypes. Significantly low levels of aflatoxin accumulation have been determined in certain resistant corn inbred lines. A number of reports of quantitative trait loci (QTLs have provided compelling evidence supporting the quantitative trait genetic basis of corn host resistance to aflatoxin accumulation. Important findings have also been obtained from the investigation on candidate resistance genes through transcriptomics approach. Elucidation of molecular mechanisms will provide in-depth understanding of the host-pathogen interactions and hence facilitate the breeding of corn with resistance to A. falvus infection and aflatoxin accumulation.

  7. Comparison of Aflatoxin B1 production by Aspergillus flavus and Aspergillus parasiticus under various conditions of temperature, light and pH

    Directory of Open Access Journals (Sweden)

    O Fani makk

    2013-07-01

    Full Text Available Abstract Background & aim: Aflatoxins are a large group of mycotoxins. The aim of the present study was the comparison of Aflatoxin B1 (AFB1 production by Aspergillus flavus (IR 111 and Aspergillus parasiticus (NRRL 2999 under various conditions of temperature, light, and pH. Methods: In this experimental study, twenty-four flasks were assigned for incubation of each of the fungi A. Flavus and parasiticus at 18, 24, 32 °C. Both flasks were maintained under conditions of light and darkness. The rate of (AFB1 produced by each groups, was measured by thin layer chromatography. Data were analyzed using descriptive statistical analysis (SPSS, version 16. Results: The lowest yield of (AFB1 produced by A. Flavus and parasiticus belonged to 32 °C and pH 6.5, respectively. On the other hand, the highest yield of toxin was observed at 24 °C and pH 6. The lighting effects were considerable. According to the studies on the adverse effects of light and the fermentation process, aflatoxin production increased in dark conditions. Conclusion: The results of study showed that A. Parasiticus (NRRL 2999 produced more aflatoxin than A. Flavus (IR 111. Key words: Aflatoxin B1, Aspergillus flavus, Aspergillus parasiticus

  8. Pre-harvest aflatoxins and Aspergillus flavus contamination in variable germplasms of red chillies from Kunri, Pakistan.

    Science.gov (United States)

    Akhund, Shaista; Akram, Abida; Hanif, Nafeesa Qudsia; Qureshi, Rahmatullah; Naz, Farah; Nayyar, Brian Gagosh

    2017-05-01

    Various cultivars of red chilli were collected from a small town named Kunri, located in the province Sindh, Pakistan. This town is a hub of red chilli production in Asia. A total of 69 samples belonging to 6 cultivars were obtained and analysed for the occurrence of aflatoxins and Aspergillus flavus, to explore the potential of resistant and susceptible germplasm. Aflatoxins were detected by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC), while A. flavus was isolated and identified using agar plate, blotter paper, deep freezing and dilution techniques. Molecular characterization using internal transcribed spacer (ITS) 1/4 and A. flavus specific FL1-F/R primers confirmed the identity of A. flavus. The data revealed that 67 and 75% samples contaminated with aflatoxin B1 (AFB1) and with A. flavus, respectively. A highly susceptible chilli cultivar was 'Nagina', showing 78.8% frequency of total aflatoxins (1.2-600 μg/kg) and a mean of 87.7 μg/kg for AFB1 and 121.9 μg/kg for total aflatoxins. A. flavus was detected with 93% frequency and 2.14 × 10(4) colony forming units. In contrast, cultivars 'Kunri' and 'Drooping Type' were found to be resistant, with low levels of aflatoxins and fungal counts. The study was conducted for the first time to explore two potential cultivars that were less susceptible towards A. flavus and aflatoxin contamination. These cultivars could be preferably cultivated and thereby boost Pakistan's chilli production.

  9. Drought stress and aflatoxin contamination: Transcriptional responses of Aspergillus flavus to oxidative stress are related to stress tolerance and aflatoxin production capability

    Science.gov (United States)

    Oilseed crops such as maize and peanut are staple food crops which are vital for global food security. The contamination of these crops with carcinogenic aflatoxins during infection by Aspergillus flavus under drought stress conditions is a serious threat to the safety of these commodities. In order...

  10. Milk kefir: ultrastructure, antimicrobial activity and efficacy on aflatoxin B1 production by Aspergillus flavus.

    Science.gov (United States)

    Ismaiel, Ahmed A; Ghaly, Mohamed F; El-Naggar, Ayman K

    2011-05-01

    The association of kefir microbiota was observed by electron microscopic examination. Scanning electron microscopic (SEM) observations revealed that kefir grain surface is very rough and the inner portions had scattered irregular holes on its surface. The interior of the grain comprised fibrillar materials which were interpreted as protein, lipid and a soluble polysaccharide, the kefiran complex that surrounds yeast and bacteria in the grain. Yeast was observed more clearly than bacteria on the outer portion of the grain. Transmission electron microscopic (TEM) observations of kefir revealed that the grain comprised a mixed culture of yeast and bacteria growing in close association with each other. Microbiota is dominated by budded and long-flattened yeast cells growing together with lactobacilli and lactococci bacteria. Bacterial cells with rounded ends were also observed in this mixed culture. Kefir grains, kefir suspensions, and kefiran were tested for antimicrobial activities against several bacterial and fungal species. The highest activity was obtained against Streptococcus faecalis KR6 and Fusarium graminearum CZ1. Growth of Aspergillus flavus AH3 producing for aflatoxin B1 for 10 days in broth medium supplemented with varying concentrations of kefir filtrate (%, v/v) showed that sporulation was completely inhibited at the higher concentrations of kefir filtrate (7-10%, v/v). The average values of both mycelial dry weights and aflatoxin B1 were completely inhibited at 10% (v/v). This is the first in vitro study about the antifungal characteristics of kefir against filamentous fungi which was manifested by applying its inhibitory effect on the productivity of aflatoxin B1 by A. flavus AH3.

  11. Characterization of the Maize Chitinase Genes and Their Effect on Aspergillus flavus and Aflatoxin Accumulation Resistance

    Science.gov (United States)

    Hawkins, Leigh K.; Mylroie, J. Erik; Oliveira, Dafne A.; Smith, J. Spencer; Ozkan, Seval; Windham, Gary L.; Williams, W. Paul; Warburton, Marilyn L.

    2015-01-01

    Maize (Zea mays L.) is a crop of global importance, but prone to contamination by aflatoxins produced by fungi in the genus Aspergillus. The development of resistant germplasm and the identification of genes contributing to resistance would aid in the reduction of the problem with a minimal need for intervention by farmers. Chitinolytic enzymes respond to attack by potential pathogens and have been demonstrated to increase insect and fungal resistance in plants. Here, all chitinase genes in the maize genome were characterized via sequence diversity and expression patterns. Recent evolution within this gene family was noted. Markers from within each gene were developed and used to map the phenotypic effect on resistance of each gene in up to four QTL mapping populations and one association panel. Seven chitinase genes were identified that had alleles associated with increased resistance to aflatoxin accumulation and A. flavus infection in field grown maize. The chitinase in bin 1.05 identified a new and highly significant QTL, while chitinase genes in bins 2.04 and 5.03 fell directly beneath the peaks of previously published QTL. The expression patterns of these genes corroborate possible grain resistance mechanisms. Markers from within the gene sequences or very closely linked to them are presented to aid in the use of marker assisted selection to improve this trait. PMID:26090679

  12. In vitro interaction of actinomycetes isolates with Aspergillus flavus: impact on aflatoxins B1 and B2 production.

    Science.gov (United States)

    Verheecke, C; Liboz, T; Darriet, M; Sabaou, N; Mathieu, F

    2014-06-01

    This work aimed to study the interaction between Actinomycetal isolates and Aspergillus flavus to promote mutual antagonism in contact. Thirty-seven soilborn Streptomyces spp. isolates were chosen as potential candidates. After a 10-day in vitro co-incubation period, 27 isolates respond to the criteria, that is, mutual antagonism in contact. Further aflatoxins B1 and B2 analysis revealed that those 27 isolates reduced aflatoxin B1 residual concentration from 38·6 to 4·4%, depending on the isolate. We selected 12 isolates and tested their capacity to reduce AFB1 in pure culture to start identifying the mechanisms involved in its reduction. AFB1 was reduced by eight isolates. The remaining AFB1 concentration varied between 82·2 and 15·6%. These findings led us to suggest that these eight isolates could be used as biocontrol agents against AFB1 and B2 with low risk of impacting the natural microbial equilibrium. Interaction between Aspergillus flavus and Actinomycetes isolates was conducted in vitro. Actinomycetes isolates having a mutual antagonism in contact with A. flavus were chosen for further aflatoxins production study. This is a new approach based to develop biocontrol against aflatoxins accumulation in maize while respecting natural microbial equilibrium. © 2014 The Society for Applied Microbiology.

  13. Effect of Plectranthus glandulosus and Ocimum gratissimum Essential Oils on Growth of Aspergillus flavus and Aflatoxin B1 Production

    Directory of Open Access Journals (Sweden)

    Mbofung, CMF.

    2008-01-01

    Full Text Available Essential oils of Ocimum gratissimum and Plectranthus glandulosus leaves were extracted by steam distillation and analysed by GC-MS, and their effects on growth and aflatoxin B1 production by Aspergillus flavus were tested at five levels (i.e 200, 400, 600, 800 and 1000 mg/l using SMKY agar medium. The main components of O. gratissimum were thymol (47.7% and -terpinene (14.3% whereas those of P. glandulosus were represented by -terpinene (30.8% and terpinolene (25.2%. After 8 days of incubation on essential oil-supplemented medium, growth of A. flavus was totally inhibited by 800 mg/l of O. gratissimum essential oil and by 1000 mg/l of P. glandulosus essential oil. The effect of essential oils on aflatoxin B1 synthesis was evaluated in SMKY broth. The medium supplemented with different essential oil concentrations, was inoculated with A. flavus mycelium and incubated at 25 °C. At 2, 4, 6 and 8 days, aflatoxin B1 concentrations in the supernatant were estimated using Enzyme Linked Immuno-Sorbent Assay (ELISA. Results showed that aflatoxin B1 synthesis was inhibited by 1000 mg/l of both essential oils of O. gratissimum and P. glandulosus after 8 days of incubation. Results obtained in the present study indicate the possibility of exploiting O. gratissimum and P. glandulosus essential oils in the fight against strains of A. flavus responsible for biodeterioration of stored food products.

  14. The Pathogenesis-Related Maize Seed (PRms) Gene Plays a Role in Resistance to Aspergillus flavus Infection and Aflatoxin Contamination

    Science.gov (United States)

    Majumdar, Rajtilak; Rajasekaran, Kanniah; Sickler, Christine; Lebar, Matthew; Musungu, Bryan M.; Fakhoury, Ahmad M.; Payne, Gary A.; Geisler, Matt; Carter-Wientjes, Carol; Wei, Qijian; Bhatnagar, Deepak; Cary, Jeffrey W.

    2017-01-01

    Aspergillus flavus is an opportunistic plant pathogen that colonizes and produces the toxic and carcinogenic secondary metabolites, aflatoxins, in oil-rich crops such as maize (Zea mays ssp. mays L.). Pathogenesis-related (PR) proteins serve as an important defense mechanism against invading pathogens by conferring systemic acquired resistance in plants. Among these, production of the PR maize seed protein, ZmPRms (AC205274.3_FG001), has been speculated to be involved in resistance to infection by A. flavus and other pathogens. To better understand the relative contribution of ZmPRms to A. flavus resistance and aflatoxin production, a seed-specific RNA interference (RNAi)-based gene silencing approach was used to develop transgenic maize lines expressing hairpin RNAs to target ZmPRms. Downregulation of ZmPRms in transgenic kernels resulted in a ∼250–350% increase in A. flavus infection accompanied by a ∼4.5–7.5-fold higher accumulation of aflatoxins than control plants. Gene co-expression network analysis of RNA-seq data during the A. flavus-maize interaction identified ZmPRms as a network hub possibly responsible for regulating several downstream candidate genes associated with disease resistance and other biochemical functions. Expression analysis of these candidate genes in the ZmPRms–RNAi lines demonstrated downregulation (vs. control) of a majority of these ZmPRms-regulated genes during A. flavus infection. These results are consistent with a key role of ZmPRms in resistance to A. flavus infection and aflatoxin accumulation in maize kernels. PMID:29089952

  15. The Pathogenesis-Related Maize Seed (PRms Gene Plays a Role in Resistance to Aspergillus flavus Infection and Aflatoxin Contamination

    Directory of Open Access Journals (Sweden)

    Rajtilak Majumdar

    2017-10-01

    Full Text Available Aspergillus flavus is an opportunistic plant pathogen that colonizes and produces the toxic and carcinogenic secondary metabolites, aflatoxins, in oil-rich crops such as maize (Zea mays ssp. mays L.. Pathogenesis-related (PR proteins serve as an important defense mechanism against invading pathogens by conferring systemic acquired resistance in plants. Among these, production of the PR maize seed protein, ZmPRms (AC205274.3_FG001, has been speculated to be involved in resistance to infection by A. flavus and other pathogens. To better understand the relative contribution of ZmPRms to A. flavus resistance and aflatoxin production, a seed-specific RNA interference (RNAi-based gene silencing approach was used to develop transgenic maize lines expressing hairpin RNAs to target ZmPRms. Downregulation of ZmPRms in transgenic kernels resulted in a ∼250–350% increase in A. flavus infection accompanied by a ∼4.5–7.5-fold higher accumulation of aflatoxins than control plants. Gene co-expression network analysis of RNA-seq data during the A. flavus-maize interaction identified ZmPRms as a network hub possibly responsible for regulating several downstream candidate genes associated with disease resistance and other biochemical functions. Expression analysis of these candidate genes in the ZmPRms–RNAi lines demonstrated downregulation (vs. control of a majority of these ZmPRms-regulated genes during A. flavus infection. These results are consistent with a key role of ZmPRms in resistance to A. flavus infection and aflatoxin accumulation in maize kernels.

  16. CEMARAN ASPERGILLUS FLAVUS DAN AFLATOKSIN PADA RANTAI DISTRIBUSI PRODUK PANGAN BERBASIS JAGUNG DAN FAKTOR YANG MEMPENGARUHINYA [Contamination of Aspergillus flavus and Aflatoxin at Distribution Chain of Maize Based Food Product and its Influencing Factors

    Directory of Open Access Journals (Sweden)

    Harsi D. Kusumaningrum*

    2010-12-01

    Full Text Available Aflatoxin is a human carcinogen, produced by fungus Aspergillus flavus that frequently contaminates maize. Analysis of A. flavus by plate counting and aflatoxin by Thin Layer Chromatography were performed on 104 samples and 25 samples, respectively, of maize grain and maize based food products from different places in Bogor-West Java, Boyolali-Central Java and Bojonegoro-East Java. These regions support significant number of maize production in Java. Forty percent of the samples were contaminated by A. flavus, whereas aflatoxin level of higher than 20 ppb was found in 4 of 25 samples. The highest contamination level of A. flavus was found at the collector trader that often stored the maize grain in average of 15 days, at room temperature. There was a significant correlation between the length of storage as well as relative humidity with the contamination levels of A. flavus. Significant correlation was also found between the contamination levels of A. flavus with the level of aflatoxin in maize grain. However, no significant correlation was found between the aflatoxin level and the contamination levels of A. flavus in the processed maize based food products.

  17. Loss of msnA, a Putative Stress Regulatory Gene, in Aspergillus parasiticus and Aspergillus flavus Increased Production of Conidia, Aflatoxins and Kojic Acid

    Science.gov (United States)

    Chang, Perng-Kuang; Scharfenstein, Leslie L.; Luo, Meng; Mahoney, Noreen; Molyneux, Russell J.; Yu, Jiujiang; Brown, Robert L.; Campbell, Bruce C.

    2011-01-01

    Production of the harmful carcinogenic aflatoxins by Aspergillus parasiticus and Aspergillus flavus has been postulated to be a mechanism to relieve oxidative stress. The msnA gene of A. parasiticus and A. flavus is the ortholog of Saccharomyces cerevisiae MSN2 that is associated with multi-stress response. Compared to wild type strains, the msnA deletion (∆msnA) strains of A. parasiticus and A. flavus exhibited retarded colony growth with increased conidiation. The ∆msnA strains also produced slightly higher amounts of aflatoxins and elevated amounts of kojic acid on mixed cereal medium. Microarray assays showed that expression of genes encoding oxidative stress defense enzymes, i.e., superoxide dismutase, catalase, and cytochrome c peroxidase in A. parasiticus ∆msnA, and the catalase A gene in A. flavus ∆msnA, was up-regulated. Both A. parasiticus and A. flavus ∆msnA strains produced higher levels of reactive oxygen species (ROS), and ROS production of A. flavus msnA addback strains was decreased to levels comparable to that of the wild type A. flavus. The msnA gene appears to be required for the maintenance of the normal oxidative state. The impairment of msnA resulted in the aforementioned changes, which might be used to combat the increased oxidative stress in the cells. PMID:22069691

  18. The two genome sequence release and blast server construction for aflatoxin-producing L and S strains Aspergillus parasiticus and A. flavus

    Science.gov (United States)

    Aflatoxins are toxic and carcinogenic secondary metabolites. These compounds, produced by Aspergillus flavus and A. parasiticus, contaminate pre-harvest agricultural crops in the field and post-harvest grains during storage. In order to reduce and eliminate aflatoxin contamination of food and feed...

  19. Nanocapsular Dispersion of Cinnamaldehyde for Enhanced Inhibitory Activity against Aflatoxin Production by Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Hongbo Li

    2015-04-01

    Full Text Available Cinnamaldehyde (CA is marginally soluble in water, making it challenging to evenly disperse it in foods, and resulting in lowered anti-A. flavus efficacy. In the present study, nano-dispersed CA (nano-CA was prepared to increase its aqueous solubility. Free and nano-dispersed CA were compared in terms of their inhibitory activity against fungal growth and aflatoxin production of A. flavus both in Sabouraud Dextrose (SD culture and in peanut butter. Our results indicated that free CA inhibited the mycelia growth and aflatoxin production of A. flavus with a minimal inhibitory concentration (MIC value of 1.0 mM, but promoted the aflatoxin production at some concentrations lower than the MIC. Nano-CA had a lower MIC value of 0.8 mM against A. flavus, and also showed improved activity against aflatoxin production without the promotion at lower dose. The solidity of peanut butter had an adverse impact on the antifungal activity of free CA, whereas nano-dispersed CA showed more than 2-fold improved activity against the growth of A. flavus. Free CA still promoted AFB1 production at the concentration of 0.25 mM, whereas nano-CA showed more efficient inhibition of AFB1 production in the butter.

  20. Identification of maize genes associated with host plant resistance or susceptibility to Aspergillus flavus infection and aflatoxin accumulation.

    Directory of Open Access Journals (Sweden)

    Rowena Y Kelley

    Full Text Available BACKGROUND: Aspergillus flavus infection and aflatoxin contamination of maize pose negative impacts in agriculture and health. Commercial maize hybrids are generally susceptible to this fungus. Significant levels of host plant resistance have been observed in certain maize inbred lines. This study was conducted to identify maize genes associated with host plant resistance or susceptibility to A. flavus infection and aflatoxin accumulation. RESULTS: Genome wide gene expression levels with or without A. flavus inoculation were compared in two resistant maize inbred lines (Mp313E and Mp04:86 in contrast to two susceptible maize inbred lines (Va35 and B73 by microarray analysis. Principal component analysis (PCA was used to find genes contributing to the larger variances associated with the resistant or susceptible maize inbred lines. The significance levels of gene expression were determined by using SAS and LIMMA programs. Fifty candidate genes were selected and further investigated by quantitative RT-PCR (qRT-PCR in a time-course study on Mp313E and Va35. Sixteen of the candidate genes were found to be highly expressed in Mp313E and fifteen in Va35. Out of the 31 highly expressed genes, eight were mapped to seven previously identified quantitative trait locus (QTL regions. A gene encoding glycine-rich RNA binding protein 2 was found to be associated with the host hypersensitivity and susceptibility in Va35. A nuclear pore complex protein YUP85-like gene was found to be involved in the host resistance in Mp313E. CONCLUSION: Maize genes associated with host plant resistance or susceptibility were identified by a combination of microarray analysis, qRT-PCR analysis, and QTL mapping methods. Our findings suggest that multiple mechanisms are involved in maize host plant defense systems in response to Aspergillus flavus infection and aflatoxin accumulation. These findings will be important in identification of DNA markers for breeding maize lines

  1. Utilization of waste fruit-peels to inhibit aflatoxins synthesis by Aspergillus flavus: a biotreatment of rice for safer storage.

    Science.gov (United States)

    Naseer, R; Sultana, Bushra; Khan, M Z; Naseer, D; Nigam, Poonam

    2014-11-01

    Antifungal activity in lemon and pomegranate peels was considerable against Aspergillus flavus, higher in pomegranate (DIZ 37mm; MIC 135μg/mL). Powdered peels (5, 10, 20% w/w) were mixed in inoculated rice. The inhibitory effect on fungal-growth and production of aflatoxins by A. flavus was investigated at storage conditions - temperature (25, 30°C) and moisture (18%, 21%) for 9months. The maximum total aflatoxins accumulated at 30°C, 21% moisture and at 25°C, 18% moisture were 265.09 and 163.45ng/g, respectively in control. Addition of pomegranate-peels inhibited aflatoxins production to 100% during four month-storage of rice at 25°C and 18% moisture, while lemon-peels showed similar inhibitory effect for 3months at same conditions. However a linear correlation was observed in aflatoxins level with temperature and moisture. Studies showed that both fruit-wastes are potent preventer of aflatoxin production in rice, useful for a safer and longer storage of rice. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Inhibitory Effect of Cinnamaldehyde, Citral, and Eugenol on Aflatoxin Biosynthetic Gene Expression and Aflatoxin B1 Biosynthesis in Aspergillus flavus.

    Science.gov (United States)

    Liang, Dandan; Xing, Fuguo; Selvaraj, Jonathan Nimal; Liu, Xiao; Wang, Limin; Hua, Huijuan; Zhou, Lu; Zhao, Yueju; Wang, Yan; Liu, Yang

    2015-12-01

    In order to reveal the inhibitory effects of cinnamaldehyde, citral, and eugenol on aflatoxin biosynthesis, the expression levels of 5 key aflatoxin biosynthetic genes were evaluated by real-time PCR. Aspergillus flavus growth and AFB1 production were completely inhibited by 0.80 mmol/L of cinnamaldehyde and 2.80 mmol/L of citral. However, at lower concentration, cinnamaldehyde (0.40 mmol/L), eugenol (0.80 mmol/L), and citral (0.56 mmol/L) significantly reduced AFB1 production with inhibition rate of 68.9%, 95.4%, and 41.8%, respectively, while no effect on fungal growth. Real-time PCR showed that the expressions of aflR, aflT, aflD, aflM, and aflP were down-regulated by cinnamaldehyde (0.40 mmol/L), eugenol (0.80 mmol/L), and citral (0.56 mmol/L). In the presence of cinnamaldehyde, AflM was highly down-regulated (average of 5963 folds), followed by aflP, aflR, aflD, and aflT with the average folds of 55, 18, 6.5, and 5.8, respectively. With 0.80 mmol/L of eugenol, aflP was highly down-regulated (average of 2061-folds), followed by aflM, aflR, aflD, and aflT with average of 138-, 15-, 5.2-, and 4.8-folds reduction, respectively. With 0.56 mmol/L of citral, aflT was completely inhibited, followed by aflM, aflP, aflR, and aflD with average of 257-, 29-, 3.5-, and 2.5-folds reduction, respectively. These results suggest that the reduction in AFB1 production by cinnamaldehyde, eugenol, and citral at low concentration may be due to the down-regulations of the transcription level of aflatoxin biosynthetic genes. Cinnamaldehyde and eugenol may be employed successfully as a good candidate in controlling of toxigenic fungi and subsequently contamination with aflatoxins in practice. © 2015 Institute of Food Technologists®

  3. Co-occurrence of aflatoxin B(1) and cyclopiazonic acid in sour lime (Citrus aurantifolia Swingle) during post-harvest pathogenesis by Aspergillus flavus.

    Science.gov (United States)

    Bamba, Rozy; Sumbali, Geeta

    2005-04-01

    During hot and humid seasons, extensive rot of sour lime was observed to be caused by Aspergillus flavus. In view of this, investigations were undertaken to obtain data on the production of various toxins by A. flavus during post harvest pathogenesis of sour lime. Sixty percent of the pathogenic A. flavus isolates were detected to be aflatoxin B(1) producers in sour lime tissue. It was also noted that thirty three percent of aflatoxigenic A. flavus isolates had the potential to coproduce cyclopiazonic acid (CPA). Such aflatoxigenic isolates produced quantitatively more CPA (ranging from 250.0 to 2501.3 microg/kg) than aflatoxin B(1) (ranging from 141.3 to 811.7 microg/kg) in the affected sour lime. This study demonstrates for the first time that sour lime are a favourable substrate for aflatoxin B(1) and cyclopiazonic acid production by A. flavus isolates. This is of great concern to the health of consumers.

  4. Non-aflatoxigenic Aspergillus flavus as potential biocontrol agents to reduce aflatoxin contamination in peanuts harvested in Northern Argentina.

    Science.gov (United States)

    Alaniz Zanon, María Silvina; Barros, Germán Gustavo; Chulze, Sofía Noemí

    2016-08-16

    Biological control is one of the most promising strategies for preventing aflatoxin contamination in peanuts at field stage. A population of 46 native Aspergillus flavus nonaflatoxin producers were analysed based on phenotypic, physiological and genetic characteristics. Thirty-three isolates were characterized as L strain morphotype, 3 isolates as S strain morphotype, and 10 isolates did not produce sclerotia. Only 11 of 46 non-aflatoxigenic isolates did not produce cyclopiazonic acid. The vegetative compatibility group (VCG) diversity index for the population was 0.37. For field trials we selected the non-aflatoxigenic A. flavus AR27, AR100G and AFCHG2 strains. The efficacy of single and mixed inocula as potential biocontrol agents in Northern Argentina was evaluated through a 2-year study (2014-2015). During the 2014 peanut growing season, most of the treatments reduced the incidence of aflatoxigenic strains in both soil and peanut kernel samples, and no aflatoxin was detected in kernels. During the 2015 growing season, there was a reduction of aflatoxigenic strains in kernel samples from the plots treated with the potential biocontrol agents. Reductions of aflatoxin contamination between 78.36% and 89.55% were observed in treated plots in comparison with the un-inoculated control plots. This study provides the first data on aflatoxin biocontrol based on competitive exclusion in the peanut growing region of Northern Argentina, and proposes bioproducts with potential use as biocontrol agents. Copyright © 2016. Published by Elsevier B.V.

  5. Effect of Citrus reticulata and Cymbopogon citratus essential oils on Aspergillus flavus growth and aflatoxin production on Asparagus racemosus.

    Science.gov (United States)

    Singh, Priyanka; Shukla, Ravindra; Kumar, Ashok; Prakash, Bhanu; Singh, Shubhra; Dubey, Nawal Kishore

    2010-09-01

    Essential oils extracted from Citrus reticulata and Cymbopogon citratus were tested in vitro against the toxigenic strain of Aspergillus flavus, isolated from the tuberous roots of Asparagus racemosus, used in preparation of herbal drugs. The essential oils completely inhibited the growth of A. flavus at 750 ppm and also exhibited a broad fungitoxic spectrum against nine additional fungi isolated from the roots. Citrus reticulata and Cymbopogon citratus essential oils completely inhibited aflatoxin B(1) production at 750 and 500 ppm, respectively. During in vivo investigation, the incidence of fungi and aflatoxin B(1) production decreased considerably in essential oil-treated root samples. The findings thus indicate possible exploitation of the essential oils as effective inhibitor of aflatoxin B(1) production and as post-harvest fungitoxicant of traditionally used plant origin for the control of storage fungi. These essential oils may be recommended as plant-based antifungals as well as aflatoxin B(1) suppressors in post-harvest processing of herbal samples.

  6. Aflatoxin B1 Degradation by Metabolites of Phoma glomerata PG41 Isolated From Natural Substrate Colonized by Aflatoxigenic Aspergillus flavus.

    Science.gov (United States)

    Shcherbakova, Larisa; Statsyuk, Natalia; Mikityuk, Oleg; Nazarova, Tatyana; Dzhavakhiya, Vitaly

    2015-01-01

    Aflatoxin B1 (AFB1), produced by Aspergillus flavus, is one of the most life threatening food contaminants causing significant economic losses worldwide. Biological AFB1 degradation by microorganisms, or preferably microbial enzymes, is considered as one of the most promising approaches. The current work aimed to study the AFB1-degrading metabolites, produced by Phoma glomerata PG41, sharing a natural substrate with aflatoxigenic A. flavus, and the preliminary determination of the nature of these metabolites. The AFB1-degrading potential of PG41 metabolites was determined by a quantitative high performance liquid chromatography (HPLC) of residual AFB1 after 72 hours incubation at 27ºC. The effects of pH, heat, and protease treatment on the AFB1-destroying activity of extracellular metabolites were examined. The AFB1-degrading activity of protein-enriched fractions, isolated from culture liquid filtrate and cell-free extract, is associated with high-molecular-weight components, is time- and pH-dependent, thermolabile, and is significantly reduced by proteinase K treatment. The AFB1 degradation efficiency of these fractions reaches 78% and 66%, respectively. Phoma glomerata PG41 strain sharing natural substrate with toxigenic A. flavus secretes metabolites possessing a significant aflatoxin-degrading activity. The activity is associated mainly with a protein-enriched high-molecular-weight fraction of extracellular metabolites and appears to be of enzymatic origin.

  7. Chemoprevention by essential oil of turmeric leaves (Curcuma longa L.) on the growth of Aspergillus flavus and aflatoxin production.

    Science.gov (United States)

    Sindhu, S; Chempakam, B; Leela, N K; Suseela Bhai, R

    2011-05-01

    Turmeric is well known for a wide range of medicinal properties. Essential oil of turmeric leaves (Curcuma longa L.) were evaluated at varying concentrations of 0.01, 0.05, 0.1, 0.5, 0.75, 1.0 and 1.5% (v/v) in Yeast Extract Sucrose (YES) broth inoculated with spore suspension of Aspergillus flavus of 10(6)conidia/ml. These were evaluated for their potential in the control of aflatoxigenic fungus A. flavus and aflatoxin production. Turmeric leaf oil exhibited 95.3% and 100% inhibition of toxin production respectively at 1.0% and 1.5%. The extent of inhibition of fungal growth and aflatoxin production was dependent on the concentration of essential oil used. The oil exhibited significant inhibition of fungal growth as well as aflatoxins B(1) and G(1) production. The LD(50) and LD(90) were also determined. GC-MS analysis of the oil showed α-phellandrene, p-cymene and terpinolene as the major components in turmeric leaf oil. The possibility of using these phytochemical components as bio-preservatives for storage of spices is discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Transient transmembrane secretion of H2O2: a mechanism for the citral-caused inhibition of aflatoxin production from Aspergillus flavus.

    Science.gov (United States)

    Li, Jinhan; Li, Jialin; Lu, Zhisong; Liu, Yang; Li, Chang Ming

    2015-12-21

    A polydopamine-Fe3O4 nanocomposite-based H2O2 electrochemical sensor is fabricated to real-time monitor the transmembrane release of reactive oxygen species from citral-treated Aspergillus flavus, revealing a mechanism involving transient transmembrane secretion of H2O2 for the citral-caused inhibition of aflatoxin production from a fungus for the first time.

  9. Nuclear heterogeneity in conidial populations of Aspergillus flavus

    Science.gov (United States)

    Aspergillus flavus is a major producer of aflatoxin and an opportunistic pathogen for a wide range of hosts. Understanding genotypic and phenotypic variations within strains of A. flavus is important for controlling disease and reducing aflatoxin contamination. A. flavus is multinucleate and predomi...

  10. Aflatoxin B1 degradation during co-cultivation of Aspergillus flavus and Pleurotus ostreatus strains on rice straw.

    Science.gov (United States)

    Das, Arijit; Bhattacharya, Sourav; Palaniswamy, Muthusamy; Angayarkanni, Jayaraman

    2015-06-01

    Aflatoxin B1 (AFB1) produced by Aspergillus flavus is known to have carcinogenic and teratogenic effects on animal health. Accidental feeding of AFB1-contaminated rice straw may be detrimental to dairy cattle. White-rot basidiomycetous fungus Pleurotus ostreatus can grow on different agronomic wastes by synthesizing different ligninolytic enzymes. These extracellular enzymes are capable of degrading many environmentally hazardous compounds including AFB1. The present study examines the ability of different strains of P. ostreatus to degrade AFB1 in contaminated rice straw. Different strains of A. flavus were inoculated on rice straw for AFB1 production. The moldy straw was then subjected to co-cultivation by different strains of P. ostreatus. The extent of AFB1 degradation was determined by high performance liquid chromatography. Results indicated the presence of AFB1 in the moldy straw samples at levels of 27.95 ± 0.23 and 21.26 ± 0.55 µg/g of dry substrate for A. flavus MTCC 2798 and A. flavus GHBF09, respectively. Co-cultivation of P. ostreatus strains on AFB1-contaminated rice straw revealed their ability to rapidly colonize the substrate by profuse hyphal ramification. Highest degradation of AFB1 (89.41 %) was recorded in the straw containing co-cultures of A. flavus MTCC 2798 and P. ostreatus GHBBF10. Natural isolate P. ostreatus GHBBF10 demonstrated higher AFB1-degradation potential than P.ostreatus MTCC 142. This basidiomycete strain can be further exploited to effectively degrade moderate concentrations of AFB1 in contaminated moldy rice straw.

  11. New ion-exchanged zeolite derivatives: antifungal and antimycotoxin properties against Aspergillus flavus and aflatoxin B1

    Science.gov (United States)

    Savi, Geovana D.; Cardoso, Willian A.; Furtado, Bianca G.; Bortolotto, Tiago; Da Agostin, Luciana O. V.; Nones, Janaína; Torres Zanoni, Elton; Montedo, Oscar R. K.; Angioletto, Elidio

    2017-08-01

    Zeolites are microporous crystalline hydrated aluminosilicates with absorbent and catalytic properties. This material can be used in many applications in stored-pest management such as: pesticide and fertilizer carriers, animal feed additives, mycotoxin binders and food packaging materials. Herein, four 4A zeolite forms were prepared by ion-exchange and their antifungal effect against Aspergillus flavus was highlighted. Additionally, the antimycotoxin activity and the aflatoxin B1 (AFB1) adsorption capacity of these zeolites as well as their toxic effects on Artemia sp. were investigated. The ion-exchanged zeolites with Li+ and Cu2+ showed the best antifungal activity against A. flavus, including effects on conidia germination and hyphae morphological alterations. Regarding to antimycotoxin activity, all zeolite samples efficiently inhibited the AFB1 production by A. flavus. However, the ion-exchanged zeolites exhibited better results than the 4A zeolite. On the other hand, the AFB1 adsorption capacity was only observed by the 4A zeolite and zeolite-Li+. Lastly, our data showed that all zeolites samples used at effective concentrations for antifungal and antimycotoxin assays (2 mg ml-1) showed no toxic effects towards Artemia sp. Results suggest that some these ion-exchanged zeolites have great potential as an effective fungicide and antimycotoxin agent for agricultural and food safety applications.

  12. Effects of Cymbopogon citratus L. essential oil on the growth, morphogenesis and aflatoxin production of Aspergillus flavus ML2-strain.

    Science.gov (United States)

    Helal, G A; Sarhan, M M; Abu Shahla, A N K; Abou El-Khair, E K

    2007-02-01

    The mycelial growth of Aspergillus flavus Link was completely inhibited using 1.5 (microl/ml or 2.0 (microl/ml of Cymbopogon citratus essential oil applied by fumigation or contact method in Czapek's liquid medium, respectively. This oil was found also to be fungicidal at the same concentrations. The sublethal doses 1.0 and 1.5 (microl/ml inhibited about 65% of fungal growth after five days of incubation and delayed conidiation as compared with the control. Microscopic observations using Light Microscope (LM), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) were carried out to determine the ultra structural modifications of A. flavus hyphae after treatment with C. citratus essential oil. The hyphal diameter decreased and hyphal wall appeared as precipitates and disappeared in some regions. This oil also caused plasma membrane disruption and mitochondrial structure disorganization. Moreover, Ca(+2), K(+) and Mg(+2) leakages increased from the fumigated mycelium and its total lipid content decreased, while the saturated and unsaturated fatty acids increased. One of the most important results obtained during this study was the ability of C. citratus essential oil at its sublethal dose to completely inhibit aflatoxin B(1) production from A. flavus. These findings increase the possibility of exploiting C. citratus essential oil as an effective inhibitor of biodegradation and storage contaminating fungi and also in fruit juice preservation.

  13. Biocontrol Activity of Volatile-Producing Bacillus megaterium and Pseudomonas protegens against Aspergillus flavus and Aflatoxin Production on Stored Rice Grains

    Science.gov (United States)

    Mannaa, Mohamed; Oh, Ji Yeon

    2017-01-01

    In our previous study, three bacterial strains, Bacillus megaterium KU143, Microbacterium testaceum KU313, and Pseudomonas protegens AS15, were selected as effective biocontrol agents against Aspergillus flavus on stored rice grains. In this study, we evaluated the inhibitory effects of the volatiles produced by the strains on A. flavus growth and aflatoxin production on stored rice grains. The three strains significantly reduced mycelial growth of A. flavus in dual-culture assays compared with the negative control strain, Sphingomonas aquatilis KU408, and an untreated control. Of these tested strains, volatiles produced by B. megaterium KU143 and P. protegens AS15 markedly inhibited mycelial growth, sporulation, and conidial germination of A. flavus on agar medium and suppressed the fungal populations in rice grains. Moreover, volatiles produced by these two strains significantly reduced aflatoxin production in the rice grains by A. flavus. To our knowledge, this is the first report of the suppression of A. flavus aflatoxin production in rice grains using B. megaterium and P. protegens volatiles. PMID:29138628

  14. Evaluation of antifungal activity of aqueous extracts of some medicinal plants against Aspergillus flavus, pistachio aflatoxin producing fungus in vitro

    Directory of Open Access Journals (Sweden)

    Sahar Omidpanah

    2015-01-01

    Full Text Available Background: Contamination with aflatoxin, by Aspergillus flavus, is one the major challenges in agriculture and food industry. Preparation of organic products using natural components is widely considered these days. Aims: In this study, effects of aqueous extracts of five medicinal herbs, including thyme, senna, mentha, basil, and safflower on the growth of the A. flavus were investigated. Mterials and Methods: The extracts with different concentrations (200-800 µg/mL and polyethylene glycol with the equal osmotic potential of plant extracts were added to the potato dextrose agar medium to evaluate fungus growth after 7 days using agar dilution method. Benomyl, a fungicide, was used as a positive standard. The tests were performed in triplicate, and the mean diameters of fungus growth were calculated as well. Results and Conclusion: All concentrations of the plants extracts significantly inhibited the fungus growth in comparison with each other and control treatments, while the extracts of thyme and safflower manifested the most effective prohibition compared to benomyl with minimum inhibitory concentration of 200 and 400 µg/mL, respectively.

  15. INHIBITION OF AFLATOXIN PRODUTION BY ASPERGILLUS FLAVUS USING LOW LEVEL Y - IRRADIATION

    Directory of Open Access Journals (Sweden)

    F

    1981-05-01

    Full Text Available Effects o f s e l ected l ow l evel doses of y - Rad iation (100-400 K rad on t he abi l ity o f toxin strain o f Asperg i l l us flavus t o survive and pr oduce a f latox in in c ul t ure med ium and p is tachio nuts hav e been s tudied . A reduction of 60 per c e nt in growth and spore production by Asperg i l l us flavus in c u l ture me di um was observed after treatment wi th 100 K rad of y - Radiation ."nIn spore inoculated pistachio nuts , 100 K rad o f y Radi a tion reduced the a f la toxin B l and G l nroduction by 75% aft er e i ght week s s t orage per iod . The afla toxin prod~ ction ability by Aspergillus f lavus on pistachio nuts was affectively eliminated by t he treatment o f spore inoculated pist achio nuts wi th 200 K rad of y-Radiation , although very l itt le growth coul d be detected after eight weeks ' storage of 40 0 K rad y-irradiated pistachio nuts.  

  16. Production of aflatoxins by Aspergillus flavus and of fumonisins by Fusarium species isolated from Brazilian sorghum Avaliação da toxigenidade das cepas de Aspergillus flavus e Fusarium spp. isoladas de amostras de sorgo

    Directory of Open Access Journals (Sweden)

    Josefa B. da Silva

    2004-09-01

    Full Text Available Fifty-nine Aspergillus flavus and 35 Fusarium verticillioides strains, isolated from freshly harvested (10 and stored (130 Brazilian sorghum samples, were tested regarding their ability to produce aflatoxins (coconut milk agar and fumonisins (rice culture, respectively. Aflatoxins B1 and B2 were detected by TLC, and fumonisins B1 and B2 were analyzed by HPLC. Thirty-eight (64.4% A. flavus strains produced detectable levels of aflatoxins at concentrations ranging from 12.00 to 3282.50 µg/kg (AFB1 + AFB2, while thirty two (91% F. verticillioides strains produced FB1 at concentrations ranging from 0.12 to 5.38 µg/g. Two F. proliferatum strains produced low fumonisin levels. The toxigenic potential of A. flavus (64.4% and F. verticillioides (91.5% strains observed in sorghum samples indicates that rigorous control should be directed at the storage conditions of these products to minimize contamination with toxigenic deteriorating fungi, preventing further hazard to human and animal health.A produção de aflatoxinas por 59 cepas de Aspergillus flavus e fumonisinas por 35 cepas de Fusarium verticillioides isoladas de amostras de grãos de sorgo recém colhido (10 amostras e armazenado (130 amostras, foram avaliadas. A detecção de aflatoxinas (AFB1 e AFB2 foi efetuada por Cromatografia em Camada Delgada (CCD e fumonisinas (FB1 e FB2 foram analisadas por Cromatografia Líquida de Alta Eficiência (CLAE. Os resultados demonstram a produção de AFB1 e AFB2 em 38 cepas (64,4% de A. flavus cujos níveis variaram de 12,00 a 3282,50 µg/kg. Referente às cepas de F. verticillioides, 32 (91% produziram FB1, nas concentrações de 0,12 a 5,38 µg/g. Baixos níveis de fumonisinas foram detectados em 2 cepas de F. proliferatum. A constatação da potencialidade toxígena das cepas de A. flavus (64,4% e de F. verticillioides (91,5% nesta investigação, revelam a importância da pesquisa de aflatoxinas e fumonisinas nas amostras de sorgo. Diante disto

  17. Variabilidade de produção de aflatoxinas por linhagens de Aspergillus flavus em diferentes tempos de manutenção Aflatoxin production variability by Aspergillus flavus strains after different storage times

    Directory of Open Access Journals (Sweden)

    M.H. Taniwaki

    1993-05-01

    Full Text Available O presente trabalho fui realizado com a finalidade de se estudar a produção de aflatoxinas por linhagens de A. flavus, recém isoladas, em diferentes tempos de manutenção, a fim de contribuir para um melhor entendimento do mecanismo de variação na produção de aflatoxinas. Para isso, foram utilizadas três linhagens de A. flavus produtoras de aflatoxinas, classificadas como: a grande produtora; b média produtora e c baixa produtora. Neste experimento, que se estendeu por 280 dias, os fungos foram estudados em dois métodos de preservação: mantido em óleo mineral, no meio Czapeck, e repicado periodicamente em meio Czapeck modificado. A análise da produção de aflatoxinas foi efetuada de 30 em 30 dias. A quantificação da toxina foi feita por cromatografía em camada delgada, pela técnica de avaliação visual, de diluição até extinção. Foi constatada uma variação na produção de toxina em todas as linhagens, contudo elas não perderam suas características originais.Aflatoxin production by strains recently isolated of Aspergillus flavus was studied, after different storage times understand the mechanisms of possible variations in aflatoxin production. Three A. flavus aflatoxin producing strains were utilized, classified as: a high producer; b medium producer and c low producer. The experiment lasted 280 days and the moulds were studied by two preservation methods: oil covered slants on Czapeck's medium and periodic transfer on Czapeck's modified medium. Quantification of the aflatoxin produced was made at 30 day intervals, on thin-layer chromatography and visual determination by the dilution-to-extinction technique. The production of aflatoxin by all strains varied but they did not lose their initial characteristics. Microscopic examinations revealed thickened zones and hifal enlargements over some globous structures that may be related to aflatoxin production sites.

  18. Effects of Medicinal Plant Extracts and Photosensitization on Aflatoxin Producing Aspergillus flavus (Raper and Fennell

    Directory of Open Access Journals (Sweden)

    Loise M. Njoki

    2017-01-01

    Full Text Available This study was undertaken with an aim of exploring the effectiveness of medicinal plant extracts in the control of aflatoxin production. Antifungal properties, photosensitization, and phytochemical composition of aqueous and organic extracts of fruits from Solanum aculeastrum, bark from Syzygium cordatum, and leaves from Prunus africana, Ocimum lamiifolium, Lippia kituiensis, and Spinacia oleracea were tested. Spores from four-day-old cultures of previously identified toxigenic fungi, UONV017 and UONV003, were used. Disc diffusion and broth dilution methods were used to test the antifungal activity. The spores were suspended in 2 ml of each extract separately and treated with visible light (420 nm for varying periods. Organic extracts displayed species and concentration dependent antifungal activity. Solanum aculeastrum had the highest zones of inhibition diameters in both strains: UONV017 (mean = 18.50±0.71 mm and UONV003 (mean = 11.92±0.94 mm at 600 mg/ml. Aqueous extracts had no antifungal activity because all diameters were below 8 mm. Solanum aculeastrum had the lowest minimum inhibitory concentration at 25 mg/ml against A. flavus UONV017. All the plant extracts in combination with light reduced the viability of fungal conidia compared with the controls without light, without extracts, and without both extracts and light. Six bioactive compounds were analyzed in the plant extracts. Medicinal plant extracts in this study can control conidia viability and hence with further development can control toxigenic fungal spread.

  19. The proportion of non-aflatoxigenic strains of the Aspergillus flavus/oryzae complex from meju by analyses of the aflatoxin biosynthetic genes.

    Science.gov (United States)

    Hong, Seung-Beom; Lee, Mina; Kim, Dae-Ho; Chung, Soo-Hyun; Shin, Hyeon-Dong; Samson, Robert A

    2013-12-01

    Strains of the Aspergillus flavus/oryzae complex are frequently isolated from meju, a fermented soybean product, that is used as the starting material for ganjang (soy sauce) and doenjang (soybean paste) production. In this study, we examined the aflatoxin producing capacity of A. flavus/oryzae strains isolated from meju. 192 strains of A. flavus/oryzae were isolated from more than 100 meju samples collected from diverse regions of Korea from 2008 to 2011, and the norB-cypA, omtA, and aflR genes in the aflatoxin biosynthesis gene cluster were analyzed. We found that 178 strains (92.7%) belonged to non-aflatoxigenic group (Type I of norB-cypA, IB-L-B-, IC-AO, or IA-L-B- of omtA, and AO type of aflR), and 14 strains (7.3%) belonged to aflatoxin-producible group (Type II of norB-cypA, IC-L-B+/B- or IC-L-B+ of omtA, and AF type of aflR). Only 7 strains (3.6%) in the aflatoxin-producible group produced aflatoxins on Czapek yeast-extract medium. The aflatoxin-producing capability of A. flavus/oryzae strains from other sources in Korea were also investigated, and 92.9% (52/56) strains from air, 93.9% (31/33) strains from rice straw, 91.7% (11/12) strains from soybean, 81.3% (13/16) strains from corn, 82% (41/50) strains from peanut, and 73.2% (41/56) strains from arable soil were included in the non-aflatoxigenic group. The proportion of non-aflatoxigenicity of meju strains was similar to that of strains from soybean, air and rice straw, all of which have an effect on the fermentation of meju. The data suggest that meju does not have a preference for non-aflatoxigenic or aflatoxin-producible strains of A. flavus/oryzae from the environment of meju. The non-aflatoxigenic meju strains are proposed to be named A. oryzae, while the meju strains that can produce aflatoxins should be referred to A. flavus in this study.

  20. Effect of Capsicum carotenoids on growth and aflatoxins production by Aspergillus flavus isolated from paprika and chilli.

    Science.gov (United States)

    Santos, L; Kasper, R; Sardiñas, N; Marín, S; Sanchis, V; Ramos, A J

    2010-12-01

    The aim of this study was to determine the effect of a carotenoid mixture (Capsantal FS-30-NT), containing capsanthin and capsorubin, on growth and aflatoxins (AF) production of AF-producing Aspergillus flavus isolates. Each isolate, previously isolated from paprika and chilli, was inoculated on Czapek Yeast extract Agar (CYA) medium supplemented with different amounts of capsantal (0-1%) and incubated at 10, 15 and 25 °C during 21 days. Growth rates and lag phases were obtained, and AF production was determined at 7, 14 and 21 days. None of the isolates grew at 10 °C and one isolate (UdLTA 3.193) hardly grew at 15 °C. Capsantal addition had no effect over lag phases and growth rates at 15 °C. At 25 °C capsantal reduced growth rates and increased lag phases. However, the effect of capsantal on AF production was inconclusive, because it depended on temperature or time, and most of the times it was not significant. Low temperature has been a crucial factor in AF production, regardless of the capsantal concentration tested. Industrial storage temperature for paprika and chilli use to be approximately 10 °C, so if this temperature is maintained mould growth and AF production should be prevented. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Evaluation of viability of Aspergillus flavus and aflatoxins degradation in irradiated samples of maize Avaliação da viabilidade de Aspergillus flavus e degradação de aflatoxinas em amostras de milho irradiadas

    Directory of Open Access Journals (Sweden)

    Simone Aquino

    2005-12-01

    Full Text Available One of the currently most important fungi in stored grains is Aspergillus flavus, which produce aflatoxins. This fungus can grow on diverse substrates and represents a serious public health and animal nutritional problem. Therefore, the study of techniques that can be applied to the control of aflatoxins is of great importance. The objective of the present study was to determine the effects of gamma radiation on the growth of Aspergillus flavus Link and on degradation of aflatoxin B1 and B2 (AFB1 and AFB2 at a relative humidity of 97 99% and a water activity (Aw of 0.88-0.94. Samples of corn grains were irradiated using a cobalt 60 source emitting gamma rays at doses of 2, 5 and 10 kGy. Irradiation was found to be effective in reducing the number colony-forming units of A. flavus, per gram, in the corn samples analyzed. In addition, the fluorescent viability test (fluorescein diacetate and ethidium bromide revealed a decrease in the number of viable cells with increasing irradiation doses and three different fluorescence patterns. Furthermore, irradiation induced a partial reduction in AFB1 and AFB2 levels at the doses of 2 and 5 kGy, whereas complete degradation of aflatoxins was observed in the assay employing 10 kGy.Um dos fungos mais importantes atualmente em grãos armazenados é o Aspergillus flavus, o qual produz aflatoxinas. Este fungo pode crescer em diversos substratos e representa uma séria preocupação em saúde pública e nutrição animal. Portanto, o estudo de técnicas que possam ser aplicadas no controle das aflatoxinas é de grande importância. Assim sendo, o objetivo do presente trabalho foi estudar os efeitos da radiação gama no crescimento de Aspergillus flavus Link e na degradação das aflatoxinas B1 e B2, (AFB1 e AFB2 em umidade relativa (UR de 97-99% e atividade de água (Aa de 0,88-0,94. Amostras de grãos de milho foram irradiadas, utilizando-se uma fonte de Cobalto 60, emissora de raios gama, com as doses de 2; 5

  2. A Public Platform for the Verification of the Phenotypic Effect of Candidate Genes for Resistance to Aflatoxin Accumulation and Aspergillus flavus Infection in Maize

    Directory of Open Access Journals (Sweden)

    Xueyan Shan

    2011-06-01

    Full Text Available A public candidate gene testing pipeline for resistance to aflatoxin accumulation or Aspergillus flavus infection in maize is presented here. The pipeline consists of steps for identifying, testing, and verifying the association of selected maize gene sequences with resistance under field conditions. Resources include a database of genetic and protein sequences associated with the reduction in aflatoxin contamination from previous studies; eight diverse inbred maize lines for polymorphism identification within any maize gene sequence; four Quantitative Trait Loci (QTL mapping populations and one association mapping panel, all phenotyped for aflatoxin accumulation resistance and associated phenotypes; and capacity for Insertion/Deletion (InDel and SNP genotyping in the population(s for mapping. To date, ten genes have been identified as possible candidate genes and put through the candidate gene testing pipeline, and results are presented here to demonstrate the utility of the pipeline.

  3. Aflatoxins

    Science.gov (United States)

    Aflatoxins are toxic and carcinogenic secondary metabolites produced primarily by the filamentous fungi, Aspergillus flavus and Aspergillus parasiticus. Aflatoxin biosynthesis is a quite complex process involving many intermediates and enzymes, regulated at multi-levels. Scientists from biochemist...

  4. Inhibition of the Aspergillus flavus Growth and Aflatoxin B1 Contamination on Pistachio Nut by Fengycin and Surfactin-Producing Bacillus subtilis UTBSP1

    Directory of Open Access Journals (Sweden)

    Mohsen Farzaneh

    2016-06-01

    Full Text Available In this study, the treatment of pistachio nuts by Bacillus subtilis UTBSP1, a promising isolate to degrade aflatoxin B1 (AFB1, caused to reduce the growth of Aspergillus flavus R5 and AFB1 content on pistachio nuts. Fluorescence probes revealed that the cell free supernatant fluid from UTBSP1 affects spore viability considerably. Using high-performance liquid chromatographic (HPLC method, 10 fractions were separated and collected from methanol extract of cell free supernatant fluid. Two fractions showed inhibition zones against A. flavus. Mass spectrometric analysis of the both antifungal fractions revealed a high similarity between these anti-A. flavus compounds and cyclic-lipopeptides of surfactin, and fengycin families. Coproduction of surfactin and fengycin acted in a synergistic manner and consequently caused a strong antifungal activity against A. flavus R5. There was a positive significant correlation between the reduction of A. flavus growth and the reduction of AFB1 contamination on pistachio nut by UTBSP1. The results indicated that fengycin and surfactin-producing B. subtilis UTBSP1 can potentially reduce A. flavus growth and AFB1 content in pistachio nut.

  5. Biological Control of Aflatoxin Contamination in U.S. Crops and the Use of Bioplastic Formulations of Aspergillus flavus Biocontrol Strains To Optimize Application Strategies.

    Science.gov (United States)

    Abbas, Hamed K; Accinelli, Cesare; Shier, W Thomas

    2017-08-23

    Aflatoxin contamination has a major economic impact on crop production in the southern United States. Reduction of aflatoxin contamination in harvested crops has been achieved by applying nonaflatoxigenic biocontrol Aspergillus flavus strains that can out-compete wild aflatoxigenic A. flavus, reducing their numbers at the site of application. Currently, the standard method for applying biocontrol A. flavus strains to soil is using a nutrient-supplying carrier (e.g., pearled barley for Afla-Guard). Granules of Bioplastic (partially acetylated corn starch) have been investigated as an alternative nutritive carrier for biocontrol agents. Bioplastic granules have also been used to prepare a sprayable biocontrol formulation that gives effective reduction of aflatoxin contamination in harvested corn kernels with application of much smaller amounts to leaves later in the growing season. The ultimate goal of biocontrol research is to produce biocontrol systems that can be applied to crops only when long-range weather forecasting indicates they will be needed.

  6. Effects of temperature, water activity and incubation time on fungal growth and aflatoxin B1 production by toxinogenic Aspergillus flavus isolates on sorghum seeds.

    Science.gov (United States)

    Lahouar, Amani; Marin, Sonia; Crespo-Sempere, Ana; Saïd, Salem; Sanchis, Vicente

    2016-01-01

    Sorghum, which is consumed in Tunisia as human food, suffers from severe colonization by several toxigenic fungi and contamination by mycotoxins. The Tunisian climate is characterized by high temperature and humidity that stimulates mold proliferation and mycotoxin accumulation in foodstuffs. This study investigated the effects of temperature (15, 25 and 37°C), water activity (aw, between 0.85 and 0.99) and incubation time (7, 14, 21 and 28 d) on fungal growth and aflatoxin B1 (AFB1) production by three Aspergillus flavus isolates (8, 10 and 14) inoculated on sorghum grains. The Baranyi model was applied to identify the limits of growth and mycotoxin production. Maximum diameter growth rates were observed at 0.99 a(w) at 37°C for two of the isolates. The minimum aw needed for mycelial growth was 0.91 at 25 and 37°C. At 15°C, only isolate 8 grew at 0.99 a(w). Aflatoxin B1 accumulation could be avoided by storing sorghum at low water activity levels (≤0.91 a(w)). Aflatoxin production was not observed at 15°C. This is the first work on the effects of water activity and temperature on A. flavus growth and AFB1 production by A. flavus isolates on sorghum grains. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Cyclopiazonic Acid Biosynthesis of Aspergillus flavus and Aspergillus oryzae

    Science.gov (United States)

    Cyclopiazonic acid (CPA) is an indole-tetramic acid neurotoxin produced by some of the same strains of A. flavus that produce aflatoxins and by some Aspergillus oryzae strains. Despite its discovery 40 years ago, few reviews of its toxicity and biosynthesis have been reported. This review examines w...

  8. Blocking aflatoxins in corn by using non-toxigenic strains of Aspergillus flavus

    Science.gov (United States)

    There are over 500 previously reported mycotoxins. However, only a few have been identified as important for food safety, including aflatoxins, fumonisins, cyclopiazonic acid (CPA), trichothecenes, zearalenone, ochratoxins, and patulin. Mycotoxins contaminate plant materials, causing acute and ch...

  9. Modeling growth rate and assessing aflatoxins production by Aspergillus flavus as a function of water activity and temperature on polished and brown rice.

    Science.gov (United States)

    Mousa, Wael; Ghazali, Farinazleen Mohd; Jinap, Selamat; Ghazali, Hasanah Mohd; Radu, Son

    2013-01-01

    The aim of this study was to model the radial growth rate and to assess aflatoxin production by Aspergillus flavus as a function of water activity (a(w) 0.82 to 0.92) and temperature (12 to 42 °C) on polished and brown rice. The growth of the fungi, expressed as colony diameter (mm) was measured daily, and the aflatoxins were analyzed using HPLC with a fluorescence detector. The growth rates were estimated using the primary model of Baranyi, which describes the change in colony radius as a function of time. Total of 2 secondary models were used to describe the combined effects of a(w) and temperature on the growth rates. The models were validated using independent experimental data. Linear Arrhenius-Davey model proved to be the best predictor of A. flavus growth rates on polished and brown rice followed by polynomial model. The estimated optimal growth temperature was around 30 °C. A. flavus growth and aflatoxins were not detected at 0.82 a(w) on polished rice while growth and aflatoxins were detected at this a(w) between 25 and 35 °C on brown rice. The highest amounts of toxins were formed at the highest a(w) values (0.90 to 0.92) at a temperature of 20 °C after 21 d of incubation on both types of rice. Nevertheless, the consistencies of toxin production within a wider range of a(w) values occurred between 25 to 30 °C. Brown rice seems to support A. flavus growth and aflatoxin production more than the polished rice. The developed models can be used to estimate to what extent the change in grain ecosystem conditions affect the storage stability and safety of grains without the need for running long-standing storage study. By monitoring the intergranular relative humidity and temperature at different locations in the storage facility and inputting these data into the models, it is directly possible to assess either the conditions are conductive for the growth of A. flavus or aflatoxin production. © 2012 Institute of Food Technologists®

  10. Potential involvement of Aspergillus flavus laccases in peanut invasion at low water potential

    Science.gov (United States)

    Aspergillus flavus (Link) accumulates aflatoxins in peanuts, mainly affecting immature kernels during drought. Peanut invasion by A. flavus induces synthesis of phytoalexins, mostly stilbenoids, as a plant defense mechanism. Fungal laccases are often related to pathogenicity, and among other subst...

  11. What Does Genetic Diversity of Aspergillus flavus Tell Us About Aspergillus oryzae?

    Science.gov (United States)

    Aspergillus flavus and Aspergillus oryzae belong to Aspergillus section Flavi. They are closely related and are of significant economic importance. The former species has the ability to produce harmful aflatoxins while the latter is widely used in food fermentation and industrial enzyme production. ...

  12. Assessment of azole fungicides as a tool to control growth of Aspergillus flavus and aflatoxin B1and B2production in maize.

    Science.gov (United States)

    Mateo, Eva M; Gómez, José Vicente; Gimeno-Adelantado, José Vicente; Romera, David; Mateo-Castro, Rufino; Jiménez, Misericordia

    2017-06-01

    Aspergillus flavus is a highly aflatoxin (AF)-producing species infecting maize and other crops. It is dominant in tropical regions, but it is also considered an emerging problem associated with climate change in Europe. The aim of this study was to assess the efficacy of azole fungicides (prochloraz, tebuconazole and a 2:1 (w/w) mixture of prochloraz plus tebuconazole) to control the growth of A. flavus and AF production in yeast-extract-sucrose (YES) agar and in maize kernels under different water activities (a w ) and temperatures. Aflatoxins B 1 and B 2 were determined by LC with fluorescence detection and post-column derivatisation of AFB 1 . In YES medium and maize grains inoculated with conidia of A. flavus, the growth rate (GR) of the fungus and AFB 1 and AFB 2 production were significantly influenced by temperature and treatment. In YES medium and maize kernels, optimal temperatures for GR and AF production were 37 and 25°C, respectively. In maize kernels, spore germination was not detected at the combination 37ºC/0.95 a w ; however, under these conditions germination was found in YES medium. All fungicides were more effective at 0.99 than 0.95 a w , and at 37 than 25ºC. Fungicides effectiveness was prochloraz > prochloraz plus tebuconazole (2:1) > tebuconazole. AFs were not detected in cultures containing the highest fungicide doses, and only very low AF levels were found in cultures containing 0.1 mg l - 1 prochloraz or 5.0 mg l - 1 tebuconazole. Azoles proved to be highly efficient in reducing A. flavus growth and AF production, although stimulation of AF production was found under particular conditions and low-dosage treatments. Maize kernels were a more favourable substrate for AF biosynthesis than YES medium. This paper is the first comparative study on the effects of different azole formulations against A. flavus and AF production in a semi-synthetic medium and in maize grain under different environmental conditions.

  13. Occurrence of toxigenic Aspergillus flavus in commercial Bulgur wheat

    Directory of Open Access Journals (Sweden)

    Carla Bertechini FARIA

    Full Text Available Abstract Aflatoxins are mutagenic, carcinogenic, and teratogenic mycotoxins. The objective of this work was to study the presence of aflatoxigenic Aspergillus in commercial Bulgur wheat in the city of Maringá, Paraná, Brazil. Thirty samples of commercial Bulgur wheat, acquired in the period of August 2011 to January 2012, were evaluated. The enumeration analysis showed that samples had up to 273.3 CFU of molds and 133.3 CFU of aflatoxigenic Aspergillus per gram of wheat. Forty-two monosporic isolates were obtained and identified as Aspergillus flavus. The isolates were analyzed regarding their aflatoxigenic potential by culture in coconut milk agar; hydroxide vapor exposure; chromatography; and polymerase chain reaction (PCR targeting genes that code enzymes of the aflatoxins synthesis pathway. Some of the isolates were confirmed to be aflatoxin producers and several of them presented a genetic profile of aflatoxin synthesis. The obtained results demonstrated that Bulgur wheat A. flavus contamination is concerning.

  14. Influence of sub-lethal antioxidant doses, water potential and temperature on growth, sclerotia, aflatoxins and aflD (=nor-1) expression by Aspergillus flavus RCP08108.

    Science.gov (United States)

    Passone, María Alejandra; Rosso, Laura Cristina; Etcheverry, Miriam

    2012-09-06

    Effects of interacting conditions of sub-lethal levels of antioxidants, water potential (Ψ) and temperature were evaluated on growth, sclerotial characteristics, aflatoxin B(1) (AFB(1)) production and aflD (=nor-1) gene expression by Aspergillus flavus strain RCP08108. These studies were carried out on peanut meal extract agar osmotically modified to -2.8,-7.1, -9.9 and -16.0 MPa and incubated at 28 and 20°C. The food grade antioxidants added were butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) at (1+1 mM-M1) and (5+5 mM-M2). To relate the aflD expression after toxigenic A. flavus grew under interacting stress conditions, real-time PCR was used. Antioxidant mixtures caused a higher and significant (pM2 treatment. These results showed that it is necessary to apply food-grade antioxidants into the peanut storage system at levels higher than 5 mM. This is an important tool to avoid sub-lethal antioxidant doses that can lead to fungal growth, increase resistance structures, and stimulate aflD gene expression and AFB(1) accumulation in this substrate. Copyright © 2011. Published by Elsevier GmbH.

  15. Activity of the aqueous extract from Polymnia sonchifolia leaves on growth and production of aflatoxin B1 by Aspergillus flavus Atividade do extrato aquoso de folhas de Polymnia sonchifolia no crescimento e produção de aflatoxina B1 por Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Marina M. Pinto

    2001-06-01

    Full Text Available The aqueous extract from Polymnia sonchifolia leaves (AE was tested for inhibitory activity on aflatoxin B1(AFB1 production and growth of Aspergillus flavus. The cytotoxicity of AE on Vero cells was also performed. Suspensions of A. flavus spores were inoculated into 50 mL of YES medium together with different concentrations of the AE. The aflatoxin B1 was extracted, analyzed by thin layer chromatography and quantified by photodensitometry. All the concentrations of AE induced inhibition of AFB1 production. The aqueous extract showed in vitro cytotoxicity to Vero cells only at concentrations above 500 µg/mL.Neste trabalho verificou-se a atividade do extrato aquoso de folhas de Polymnia sonchifolia no crescimento e na produção de aflatoxinas B1 por Aspergillus flavus. Suspensões de esporos de A. flavus foram inoculadas em 50 mL de meio de YES com diferentes concentrações do extrato aquoso. A aflatoxina B1 foi extraída e analisada por cromatografia de camada delgada e quantificada por fotodensitometria. Todas as concentrações testadas inibiram a produção de aflatoxina B1. O extrato aquoso apresentou citotoxicidade em células Vero somente em concentrações acima de 500 µg/mL.

  16. Biological control of Aspergillus flavus growth and subsequent ...

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... constraint of grain quality and sorghum production. Various ... respectively. Key words: Sorghum, Aspergillus flavus, AFB1, biological control. ..... J. Appl. Microbiol. 2: 297-306. Mishra HN, Chitrangada D (2003). A review on biological control and metabolism of aflatoxin. Crit. Rev. Food Sci. Nutr. 43(3): ...

  17. Induction, characterization and genetic analysis of Aspergillus flavus ...

    African Journals Online (AJOL)

    The Aspergillus flavus infection of peanut (Arachis hypogaea) results in the accumulation of aflatoxins in seeds, which are very harmful to humans and animals. Mutation breeding programs are an effective way of inducing resistant mutants. In this study, we induced a genetic variation by using ethyl methanesulfonate (EMS) ...

  18. RNA interference-mediated control of Aspergillus flavus in maize

    Science.gov (United States)

    Introduction: Aflatoxigenic Aspergillus flavus is a frequent contaminant of agricultural commodities such as corn, peanut, tree nuts and cottonseed. Ingestion of foods, especially corn, contaminated with aflatoxins has been implicated in acute toxicoses while chronic, low-level exposure can lead to...

  19. Biological control of Aspergillus flavus growth and subsequent ...

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... This study, therefore explored the potential use of certain biocontrol agents for the reduction of growth of toxigenic Aspergillus flavus and subsequent aflatoxin B1 (AFB1) production in sorghum. Among all the biocontrol agents tested, culture filtrate of Rhodococcus erythropolis completely inhibited the A.

  20. Population genetics as a tool for understanding toxigenesis in Aspergillus flavus

    Science.gov (United States)

    Species in Aspergillus section Flavi commonly infect agricultural staples such as corn, peanuts, cottonseed, and tree nuts and produce an array of mycotoxins, the most potent of which is aflatoxin. Aspergillus flavus is the dominant aflatoxin-producing species in the majority of crops. Populations...

  1. Comparative histological and transcriptional analysis of maize kernels infected with Aspergillus flavus and Fusarium verticillioides

    Science.gov (United States)

    Aspergillus flavus and Fusarium verticillioides infect maize kernels and contaminate them with the mycotoxins aflatoxin and fumonisin, respectively. Combined histological examination of fungal colonization and transcriptional changes in maize kernels at 4, 12, 24, 48, and 72 hours post inoculation (...

  2. A novel glass fiber disc culture system for testing of small amounts of compounds on growth and aflatoxin production by Aspergillus flavus.

    Science.gov (United States)

    Norton, R A

    1995-01-01

    A new method for growing Aspergillus flavus for experimental studies is presented. The system consists of a humidified vial with a thick septum pierced by a pin on which a glass fiber disc is affixed. The disc contains the test solution and inoculum plus medium. The method has been used to assess the effect of variations in culture conditions on production of aflatoxin B1 (AFB1). The AFB1 level was affected by the amount of medium placed on the disc and type of disc material. The results for different types of glass fiber and quartz discs were compared with AFB1 produced by fungus grown in liquid medium or on paper discs. When compared to a liquid medium culture there was a 15 to 20-fold increase in AFB1 for one type of disc. Incubations with less than 14 microliters of medium gave satisfactory results. A crude phosphatidylcholine preparation at a concentration of 0.7% of the medium resulted in a 4-fold increase in AFB1.

  3. Biological control products for aflatoxin prevention in Italy: Commercial field evaluation of atoxigenic A.flavus active ingredients

    Science.gov (United States)

    Since 2003, non-compliant aflatoxin concentrations have been detected in maize produced in Italy. The most successful worldwide experiments in aflatoxin prevention resulted from distribution of atoxigenic strains of Aspergillus flavus to displace aflatoxin-producers during crop development. The disp...

  4. Inhibitory effect of the essential oil of Curcuma longa L. and curcumin on aflatoxin production by Aspergillus flavus Link.

    Science.gov (United States)

    Ferreira, Flavio Dias; Kemmelmeier, Carlos; Arrotéia, Carla Cristina; da Costa, Christiane Luciana; Mallmann, Carlos Augusto; Janeiro, Vanderly; Ferreira, Francine Maery Dias; Mossini, Simone Aparecida Galerani; Silva, Expedito Leite; Machinski, Miguel

    2013-01-15

    Aflatoxins are highly toxic, mutagenic, teratogenic and carcinogenic mycotoxins. Consumption of aflatoxin-contaminated food and commodities poses serious hazards to the health of humans and animals. Turmeric, Curcuma longa L., is a native plant of Southeast Asia and has antimicrobial, antioxidant and antifungal properties. This paper reports the antiaflatoxigenic activities of the essential oil of C. longa and curcumin. The medium tests were prepared with the oil of C. longa, and the curcumin standard at concentrations varied from 0.01% to 5.0%. All doses of the essential oil of the plant and the curcumin standard interfered with mycotoxin production. Both the essential oil and curcumin significantly inhibited the production of aflatoxins; the 0.5% level had a greater than 96% inhibitory effect. The levels of aflatoxin B(1) (AFB(1)) production were 1.0 and 42.7 μg/mL, respectively, for the samples treated with the essential oil of C. longa L. and curcumin at a concentration of 0.5%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Transcriptomic responses of the biocontrol yeast Pichia anomala to aflatoxigenic Aspergillus flavus

    Science.gov (United States)

    Pichia anomala (Wickerhamomyces anomalus) WRL-076 is a biocontrol yeast which has been shown to inhibit growth and aflatoxin production of Aspergillus flavus. The molecular mechanism of biological control was further characterized by the temporal transcriptome response of P. anomala to A. flavus in...

  6. Aspergillus flavus whole genome and EST sequence releases and construction of homologous gene search blast server

    Science.gov (United States)

    Aflatoxins are toxic and carcinogenic secondary metabolites. These compounds, produced by Aspergillus flavus and A. parasiticus, contaminate pre-harvest agricultural crops in the field and post-harvest grains during storage. In order to reduce and eliminate aflatoxin contamination of food and feed...

  7. Evaluation of antifungal activity of Pittosporum undulatum L. essential oil against Aspergillus flavus and aflatoxin production Avaliação da atividade antifúngica do óleo essencial de Pittosporum undulatum L. em Aspergillus flavus e produção de aflatoxina

    Directory of Open Access Journals (Sweden)

    Rosane Tamara da Silva Medeiros

    2011-02-01

    Full Text Available The presence of mycotoxins as a result of fungal attack can occur before, after and during the harvest and storage operations on agricultural crops and food commodities. Considering the inhibitory property of essential plant oils on the mycelial development of fungi and the importance of Aspergillus flavus, the main producer of aflatoxins, this research was designed to evaluate the toxicity of essential oil from Pittosporum undulatum against A. flavus. The essential oils were obtained from P. undulatum leaves, collected in different months and analyzed by GC/MS. The oils were rich in hydrocarbon, monoterpenes and sesquiterpenes and it was observed a significant variation on the chemical composition of the essential oil of leaves at different months. Besides, the essential oils were tested against fungal growth and the results showed different spectrum of inhibition on A. flavus. However, the essential oils inhibited the aflatoxin B1 production.A presença de micotoxinas como resultado do ataque fúngico pode ocorrer antes, após e durante a colheita e também no armazenamento de grãos e alimentos. Considerando as propriedades inibitórias dos óleos essenciais de plantas no desenvolvimento do micélio dos fungos e a importâncias do Aspergillus flavus, principal produtor de aflatoxinas, relatou-se neste trabalho, a atividade tóxica do óleo essencial do Pittosporum undulatum em cultura de A. flavus. Os óleos essenciais de P. undulatum foram obtidos a partir de folhas coletadas em diferentes meses e analisado por CG/EM. Os óleos se mostraram ricos em hidrocarbonetos, monoterpenos e sesquiterpenos e foi observada uma significante variação na composição química destes óleos nos diferentes meses de coleta. Os óleos essenciais mostraram diferentes espectros de inibição do crescimento de A. flavus, porém todos foram capazes de inibir a produção de aflatoxina B1.

  8. Effect of gamma radiation on the growth of Aspergillus Flavus aflatoxins producer and on the use of polymerase chain reaction technique (PCR) in samples of maize grains artificially inoculated; Efeitos da radiacao gama no crescimento de Aspergillus flavus produtor de aflatoxinas e no emprego da tecnica da Reacao em Cadeia da Polimerase (RCP) em amostras de graos de milho inoculadas artificialmente

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Simone

    2003-07-01

    The aim of this present study was to verify the effects of gamma radiation on the growth of Aspergillus flavus Link aflatoxins producer; to demonstrate the application of Polymerase Chain Reaction (PCR) technique in the diagnostic of A. Flavus, as well to verify the effect of radiation in the profile of DNA bands. Twenty samples of grains maize with 200 g each were individually irradiated with 20 kGy, to eliminate the microbial contamination. In following, the samples were inoculated with an toxigenic A. flavus (1x10{sup 6} spores/ml), incubated for 15 days at 25 deg C with a relative humidity of around 97,5% and irradiated with 0, 2; 5 and 10 kGy. The samples, 5 to each dose of irradiation, were individually analyzed for the number of fungal cells, water activity, viability test (fluorescein diacetate and ethidium bromide), PCR and aflatoxins (AFB) detection. The results showed that the doses used were effective in reducing the number of Colony Forming Units (CFU/g) mainly the doses of 5 and 10 kGy. In addition, the viability test showed a decrease of viable cells with increase of irradiation doses. The reduction of AFB{sub 1} and AFB-2, was more efficient with the use of 2 kGy in comparison with the dose of 5 kGy, while the dose of 10 kGy, degraded the aflatoxins. Thereby, it was observed that AFB2 showed to be more radiosensitive. The use of PCR technique showed the presence of DNA bands, in all samples. (author)

  9. Effect of gamma radiation on Aspergillus flavus and Aspergillus ochraceus ultrastructure and mycotoxin production

    Science.gov (United States)

    Ribeiro, J.; Cavaglieri, L.; Vital, H.; Cristofolini, A.; Merkis, C.; Astoreca, A.; Orlando, J.; Carú, M.; Dalcero, A.; Rosa, C. A. R.

    2011-05-01

    The aim of this work was to study the effect of gamma radiation (2 kGy) on Aspergillus flavus and Aspergillus ochraceus ultrastructure. Moreover, the influence on aflatoxin B 1 and ochratoxin A production was also observed. Irradiated A. flavus strain showed a dull orangish colony while control strain showed the typical green color. Minor differences were observed on stipes, metulae and conidia size between control and irradiated A. flavus and A. ochraceus strains. Irradiated fungi showed ultrastructural changes on cell wall, plasmalema and cytoplasm levels. The levels of mycotoxins produced by irradiated strains were two times greater than those produced by control strains. Successive transferences of irradiated strains on malt extract agar allowed the fungus to recuperate morphological characteristics. Although minor changes in the fungal morphology were observed, ultrastructural changes at cell wall level and the increase of mycotoxin production ability were observed. Inappropriate storage of irradiated food and feed would allow the development of potentially more toxicogenic fungal propagules.

  10. Genotypic and Phenotypic Versatility of Aspergillus flavus during Maize Exploitation

    Science.gov (United States)

    Reverberi, Massimo; Punelli, Marta; Scala, Valeria; Scarpari, Marzia; Uva, Paolo; Mentzen, Wieslawa I.; Dolezal, Andrea L.; Woloshuk, Charles; Pinzari, Flavia; Fabbri, Anna A.; Fanelli, Corrado; Payne, Gary A.

    2013-01-01

    Aspergillus flavus is a cosmopolitan fungus able to respond to external stimuli and to shift both its trophic behaviour and the production of secondary metabolites, including that of the carcinogen aflatoxin (AF). To better understand the adaptability of this fungus, we examined genetic and phenotypic responses within the fungus when grown under four conditions that mimic different ecological niches ranging from saprophytic growth to parasitism. Global transcription changes were observed in both primary and secondary metabolism in response to these conditions, particularly in secondary metabolism where transcription of nearly half of the predicted secondary metabolite clusters changed in response to the trophic states of the fungus. The greatest transcriptional change was found between saprophytic and parasitic growth, which resulted in expression changes in over 800 genes in A. flavus. The fungus also responded to growth conditions, putatively by adaptive changes in conidia, resulting in differences in their ability to utilize carbon sources. We also examined tolerance of A. flavus to oxidative stress and found that growth and secondary metabolism were altered in a superoxide dismutase (sod) mutant and an alkyl-hydroperoxide reductase (ahp) mutant of A. flavus. Data presented in this study show a multifaceted response of A. flavus to its environment and suggest that oxidative stress and secondary metabolism are important in the ecology of this fungus, notably in its interaction with host plant and in relation to changes in its lifestyle (i.e. saprobic to pathogenic). PMID:23894339

  11. Managing and Monitoring of Aspergillus flavus in Corn Using Bioplastic-based Formulation

    Science.gov (United States)

    In this study, we evaluated the feasibility of bioplastic-based formulations for delivering a non-aflatoxigenic strain of Aspergillus flavus and for monitoring Aspergilli with the final objective of controlling aflatoxin contamination in corn. Field application of inoculated bioplastic granules show...

  12. Isolation and structural elucidation of acidic terpenoid phytoalexins in maize and their interactions with Aspergillus flavus

    Science.gov (United States)

    Plants use a variety of physical and chemical defenses in response to herbivory and pathogen attack. Infection of maize by the fungal pathogen Aspergillus flavus results in the accumulation of aflatoxins, which are among the most detrimental biogenic substances known to man. The majority of maize de...

  13. Resistance to Aspergillus flavus in maize and peanut: Molecular biology, breeding, environmental stress and future perspectives

    Science.gov (United States)

    The colonization of maize (Zea mays L.) and peanut (Arachis hypogaea L.) by the fungal pathogen Aspergillus flavus and A. parasiticus results in the contamination with carcinogenic mycotoxins known as aflatoxins leading to economic losses as well as a potential health threat to human. The interactio...

  14. Two novel aflatoxin-producing Aspergillus species from Argentinean peanuts

    DEFF Research Database (Denmark)

    Pildain, M.B.; Frisvad, Jens Christian; Vaamonde, G.

    2008-01-01

    Two novel species from Aspergillus section Flavi from different species of Arachis (peanuts) in Argentina are described as Aspergillus arachidicola sp. nov. and Aspergillus minisclerotigenes sp. nov. Their novel taxonomic status was determined using a polyphasic taxonomic approach with phenotypic...... (morphology and extrolite profiles) and molecular (beta-tubulin and calmodulin gene sequences) characters. A. minisclerotigenes resembles Aspergillus flavus and Aspergillus parvisclerotigenus in producing aflatoxins B-1 and B-2, cyclopiazonic acid, kojic acid and aspergillic acid, but in addition it produces...... and parasiticolide, and some strains produce aspergillic acid. The type strain of A. arachidicola is CBS 117610(T) =IBT 25020(T) and that of A. minisclerotigenes is CBS 117635(T) =IBT 27196(T). The Mycobank accession numbers for Aspergillus minisclerotigenes sp. nov. and Aspergillus arachidicola sp. nov...

  15. 76 FR 16297 - Aspergillus flavus

    Science.gov (United States)

    2011-03-23

    ... are not limited to: Crop production (NAICS code 111). Animal production (NAICS code 112). Food... AF36, in cotton fields, demonstrated replacement of toxigenic (aflatoxin-producing) fungi with atoxic...

  16. Antifungal activity of silver ion on ultrastructure and production of aflatoxin B1 and patulin by two mycotoxigenic strains, Aspergillus flavus OC1 and Penicillium vulpinum CM1.

    Science.gov (United States)

    Ismaiel, A A; Tharwat, N A

    2014-09-01

    The antifungal activity of silver ion from silver nitrate solution was tested against two pathogenic and toxigenic fungal strains. The first was Aspergillus flavus OC1, a clinical aflatoxigenic strain that causes fungal keratitis and the second was Penicillium vulpinum CM1, a maize-pathogenic strain that is positive for patulin (PAT) producing ability. Agar well diffusion assays on yeast sucrose (YES) agar were applied for determination of the antifungal activity of silver ions either filter- or autoclaved-sterilized. Transmission electron microscopy was used to analyze the cellular effects of silver ion. The mycotoxins AFB1 and PAT were analyzed in the fungal strains cultures treated with silver ion. Filter-sterilized ions have a greater potential for growth inhibition of both fungal strains than autoclaved-sterilized ions. The minimal inhibitory concentration of the filter-sterilized ions against A. flavus OC1 was 70 μg mL(-1) and against P. vulpinum CM1 was 60 μg mL(-1) and that the minimum fungicidal concentration was 120 μg mL(-1) against the first strain and 80 μg mL(-1) against the second strain. Hyphal cells treated with silver ion showed considerable changes in the nature of cell membranes and cytoplasmic organelles. Silver applied to YES broth inhibited mycelial growth and AFB1 and PAT formation of both strains. Growth and mycotoxin production appeared to be correlated processes. These findings indicate the future possibility to use silver ion as substitute for synthetic fungicides to control the growth of pathogenic fungi and their mycotoxin production. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  17. Resistance to Aspergillus flavus in maize and peanut: Molecular biology, breeding, environmental stress, and future perspectives

    Directory of Open Access Journals (Sweden)

    Jake C. Fountain

    2015-06-01

    Full Text Available The colonization of maize (Zea mays L. and peanut (Arachis hypogaea L. by the fungal pathogen Aspergillus flavus results in the contamination of kernels with carcinogenic mycotoxins known as aflatoxins leading to economic losses and potential health threats to humans. The regulation of aflatoxin biosynthesis in various Aspergillus spp. has been extensively studied, and has been shown to be related to oxidative stress responses. Given that environmental stresses such as drought and heat stress result in the accumulation of reactive oxygen species (ROS within host plant tissues, host-derived ROS may play an important role in cross-kingdom communication between host plants and A. flavus. Recent technological advances in plant breeding have provided the tools necessary to study and apply knowledge derived from metabolomic, proteomic, and transcriptomic studies in the context of productive breeding populations. Here, we review the current understanding of the potential roles of environmental stress, ROS, and aflatoxin in the interaction between A. flavus and its host plants, and the current status in molecular breeding and marker discovery for resistance to A. flavus colonization and aflatoxin contamination in maize and peanut. We will also propose future directions and a working model for continuing research efforts linking environmental stress tolerance and aflatoxin contamination resistance in maize and peanut.

  18. A Review on Aflatoxins Reduction in Food

    National Research Council Canada - National Science Library

    Maryam Jalili

    2016-01-01

    Aflatoxins (AFs) are cancerous secondary metabolites produced primarily by Aspergillus flavus and Aspergillus parasiticus in agricultural foodstuff such as peanuts, maize grains, cereals, and animal feeds...

  19. Aqueous extracts of Tulbaghia violacea inhibit germination of Aspergillus flavus and Aspergillus parasiticus conidia.

    Science.gov (United States)

    Somai, Benesh Munilal; Belewa, Vuyokazi

    2011-06-01

    Aspergillus flavus and Aspergillus parasiticus are important plant pathogens and causal agents of pre- and postharvest rots of corn, peanuts, and tree nuts. These fungal pathogens cause significant crop losses and produce aflatoxins, which contaminate many food products and contribute to liver cancer worldwide. Aqueous preparations of Tulbaghia violacea (wild garlic) were antifungal and at 10 mg/ml resulted in sustained growth inhibition of greater than 50% for both A. flavus and A. parasiticus. Light microscopy revealed that the plant extract inhibited conidial germination in a dose-dependent manner. When exposed to T. violacea extract concentrations of 10 mg/ml and above, A. parasiticus conidia began germinating earlier and germination was completed before that of A. flavus, indicating that A. parasiticus conidia were more resistant to the antifungal effects of T. violacea than were A. flavus conidia. At a subinhibitory extract dose of 15 mg/ml, hyphae of both fungal species exhibited increased granulation and vesicle formation, possibly due to increased reactivity between hyphal cellular components and T. violacea extract. These hyphal changes were not seen when hyphae were formed in the absence of the extract. Transmission electron microscopy revealed thickening of conidial cell walls in both fungal species when grown in the presence of the plant extract. Cell walls of A. flavus also became considerably thicker than those of A. parasiticus, indicating differential response to the extract. Aqueous preparations of T. violacea can be used as antifungal treatments for the control of A. flavus and A. parasiticus. Because the extract exhibited a more pronounced effect on A. flavus than on A. parasiticus, higher doses may be needed for control of A. parasiticus infections.

  20. Population structure and aflatoxin production by Aspergillus Sect. Flavi from maize in Nigeria and Ghana.

    Science.gov (United States)

    Perrone, Giancarlo; Haidukowski, Miriam; Stea, Gaetano; Epifani, Filomena; Bandyopadhyay, Ranajit; Leslie, John F; Logrieco, Antonio

    2014-08-01

    Aflatoxins are highly toxic carcinogens that contaminate crops worldwide. Previous studies conducted in Nigeria and Ghana found high concentrations of aflatoxins in pre- and post-harvest maize. However, little information is available on the population structure of Aspergillus Sect. Flavi in West Africa. We determined the incidence of Aspergillus Sect. Flavi and the level of aflatoxin contamination in 91 maize samples from farms and markets in Nigeria and Ghana. Aspergillus spp. were recovered from 61/91 maize samples and aflatoxins B1 and/or B2 occurred in 36/91 samples. Three samples from the farms also contained aflatoxin G1 and/or G2. Farm samples were more highly contaminated than were samples from the market, in terms of both the percentage of the samples contaminated and the level of mycotoxin contamination. One-hundred-and-thirty-five strains representative of the 1163 strains collected were identified by using a multilocus sequence analysis of portions of the genes encoding calmodulin, β-tubulin and actin, and evaluated for aflatoxin production. Of the 135 strains, there were 110 - Aspergillus flavus, 20 - Aspergillus tamarii, 2 - Aspergillus wentii, 2 - Aspergillus flavofurcatus, and 1 - Aspergillus parvisclerotigenus. Twenty-five of the A. flavus strains and the A. parvisclerotigenus strain were the only strains that produced aflatoxins. The higher contamination of the farm than the market samples suggests that the aflatoxin exposure of rural farmers is even higher than previously estimated based on reported contamination of market samples. The relative infrequency of the A. flavus SBG strains, producing small sclerotia and high levels of both aflatoxins (B and G), suggests that long-term chronic exposure to this mycotoxin are a much higher health risk in West Africa than is the acute toxicity due to very highly contaminated maize in east Africa. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Destruction of Aflatoxins in Contaminated Maize Samples using ...

    African Journals Online (AJOL)

    alice

    Ammoniation procedures may be considered suitable for large scale destruction of aflatoxins that contaminate foodstuffs stored in warm moist places. Key words: Aflatoxins, contaminated foodstuffs, ammoniation procedures. INTRODUCTION. Aflatoxins are mold metabolites of Aspergillus flavus and Aspergillus parasiticus.

  2. Characterization of the Far Transcription Factor Family in Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Xingyu Luo

    2016-10-01

    Full Text Available Metabolism of fatty acids is a critical requirement for the pathogenesis of oil seed pathogens including the fungus Aspergillus flavus. Previous studies have correlated decreased ability to grow on fatty acids with reduced virulence of this fungus on host seed. Two fatty acid metabolism regulatory transcription factors, FarA and FarB, have been described in other filamentous fungi. Unexpectedly, we find A. flavus possesses three Far homologs, FarA, FarB, and FarC, with FarA and FarC showing a greater protein similarity to each other than FarB. farA and farB are located in regions of colinearity in all Aspergillus spp. sequenced to date, whereas farC is limited to a subset of species where it is inserted in an otherwise colinear region in Aspergillus genomes. Deletion and overexpression (OE of farA and farB, but not farC, yielded mutants with aberrant growth patterns on specific fatty acids as well as altered expression of genes involved in fatty acid metabolism. Marked differences included significant growth defects of both ∆farA and ∆farB on medium-chain fatty acids and decreased growth of OE::farA on unsaturated fatty acids. Loss of farA diminished expression of mitochondrial β-oxidation genes whereas OE::farA inhibited expression of genes involved in unsaturated fatty acid catabolism. FarA also positively regulated the desaturase genes required to generate polyunsaturated fatty acids. Aflatoxin production on toxin-inducing media was significantly decreased in the ∆farB mutant and increased in the OE::farB mutant, with gene expression data supporting a role for FarB in tying β-oxidation processes with aflatoxin accumulation.

  3. Characterization of the Far Transcription Factor Family in Aspergillus flavus.

    Science.gov (United States)

    Luo, Xingyu; Affeldt, Katharyn J; Keller, Nancy P

    2016-10-13

    Metabolism of fatty acids is a critical requirement for the pathogenesis of oil seed pathogens including the fungus Aspergillus flavus Previous studies have correlated decreased ability to grow on fatty acids with reduced virulence of this fungus on host seed. Two fatty acid metabolism regulatory transcription factors, FarA and FarB, have been described in other filamentous fungi. Unexpectedly, we find A. flavus possesses three Far homologs, FarA, FarB, and FarC, with FarA and FarC showing a greater protein similarity to each other than FarB. farA and farB are located in regions of colinearity in all Aspergillus spp. sequenced to date, whereas farC is limited to a subset of species where it is inserted in an otherwise colinear region in Aspergillus genomes. Deletion and overexpression (OE) of farA and farB, but not farC, yielded mutants with aberrant growth patterns on specific fatty acids as well as altered expression of genes involved in fatty acid metabolism. Marked differences included significant growth defects of both ∆farA and ∆farB on medium-chain fatty acids and decreased growth of OE::farA on unsaturated fatty acids. Loss of farA diminished expression of mitochondrial β-oxidation genes whereas OE::farA inhibited expression of genes involved in unsaturated fatty acid catabolism. FarA also positively regulated the desaturase genes required to generate polyunsaturated fatty acids. Aflatoxin production on toxin-inducing media was significantly decreased in the ∆farB mutant and increased in the OE::farB mutant, with gene expression data supporting a role for FarB in tying β-oxidation processes with aflatoxin accumulation. Copyright © 2016 Luo et al.

  4. Lipids in Aspergillus flavus-maize interaction

    Directory of Open Access Journals (Sweden)

    Massimo eReverberi

    2014-02-01

    Full Text Available In sSome filamentous fungi, the pathways related to the oxidative stress and oxylipins production are involved both in the process of host-recognition of the host that and in the pathogenic phase. In fact, recent studies have shown that the production of oxylipins in filamentous fungi, yeasts and chromists is also related to the development of the organism itself and to mechanisms of communication with the host at the cellular level. The oxylipins, also involved produced in by the host during defense reactions, are able to induce sporulation and to modulate regulate the biosynthesis of mycotoxins in numerous several pathogenic fungi, apparently replacing the endogenous ones. In A. flavus, the oxylipins play a crucial role as signals for the regulation regulatingof the biosynthesis of aflatoxins, the conidiogenesis and the formation of sclerotia.To investigate the involvement of the an oxylipins based cross-talk into Z. mays and A. flavus interaction, we analyzed the oxylipins profile of the wild type strain and of three mutants of A. flavus that are deleted at the Aflox1 gene level also during maize kernel invasion; Aflox1 encodes for a manganese lipoxygenase.A lipidomic approach has been addressed through the use of LC-ToF-MS, followed by a statistical analysis of the principal components (PCA. The results showed the existence of a difference between the oxylipins profile generated by the WT and the mutants onto challenged maize. In relation to this, aflatoxin synthesis which is largely hampered in vitro, is intriguingly restored. These results highlight the important role of maize oxylipin in driving secondary metabolism in A. flavus.

  5. Bisulfite sequencing reveals that Aspergillus flavus holds a hollow in DNA methylation.

    Directory of Open Access Journals (Sweden)

    Si-Yang Liu

    Full Text Available Aspergillus flavus first gained scientific attention for its production of aflatoxin. The underlying regulation of aflatoxin biosynthesis has been serving as a theoretical model for biosynthesis of other microbial secondary metabolites. Nevertheless, for several decades, the DNA methylation status, one of the important epigenomic modifications involved in gene regulation, in A. flavus remains to be controversial. Here, we applied bisulfite sequencing in conjunction with a biological replicate strategy to investigate the DNA methylation profiling of A. flavus genome. Both the bisulfite sequencing data and the methylome comparisons with other fungi confirm that the DNA methylation level of this fungus is negligible. Further investigation into the DNA methyltransferase of Aspergillus uncovers its close relationship with RID-like enzymes as well as its divergence with the methyltransferase of species with validated DNA methylation. The lack of repeat contents of the A. flavus' genome and the high RIP-index of the small amount of remanent repeat potentially support our speculation that DNA methylation may be absent in A. flavus or that it may possess de novo DNA methylation which occurs very transiently during the obscure sexual stage of this fungal species. This work contributes to our understanding on the DNA methylation status of A. flavus, as well as reinforces our views on the DNA methylation in fungal species. In addition, our strategy of applying bisulfite sequencing to DNA methylation detection in species with low DNA methylation may serve as a reference for later scientific investigations in other hypomethylated species.

  6. Atoxigenic strains of Aspergillus flavus isolated from peanuts collected from northern Philippines as potential biocon agents against pre-harvest aflatoxin contamination of peanut and corn

    Science.gov (United States)

    Aflatoxin contamination of food products causes liver cancer and weakened immunity in humans, and stunted growth and reduced productivity in animals (CAST, 2003). Effective control of pre-harvest aflatoxin contamination of peanut and corn due to AflaGuard and Aflasafe in the United States and Africa...

  7. Screening a strain of Aspergillus niger and optimization of fermentation conditions for degradation of aflatoxin B₁.

    Science.gov (United States)

    Zhang, Wei; Xue, Beibei; Li, Mengmeng; Mu, Yang; Chen, Zhihui; Li, Jianping; Shan, Anshan

    2014-11-13

    Aflatoxin B₁, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1) was able to degrade aflatoxin B₁ after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B₁ after 48 h of fermentation in nutrient broth (NB). Optimization of fermentation conditions for aflatoxin B₁ degradation by selected Aspergillus niger was also performed. These results showed that 58.2% of aflatoxin B₁ was degraded after 24 h of culture under the optimal fermentation conditions. The aflatoxin B₁ degradation activity of Aspergillus niger supernatant was significantly stronger than cells and cell extracts. Furthermore, effects of temperature, heat treatment, pH, and metal ions on aflatoxin B₁ degradation by the supernatant were examined. Results indicated that aflatoxin B₁ degradation of Aspergillus niger is enzymatic and this process occurs in the extracellular environment.

  8. Analysis of an nsdC mutant in Aspergillus flavus reveals an extensive role in the regulation of several secondary metabolic gene clusters

    Science.gov (United States)

    Aspergillus flavus is a saprophytic fungus that can invade and contaminate agronomically important crops. The fungus produces a number of toxic secondary metabolites, such as aflatoxin, which are synthesized from genes located in close proximity with each other on the chromosome. A. flavus has appro...

  9. Effect of gamma radiation on Aspergillus flavus and Aspergillus ochraceus ultrastructure and mycotoxin production

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, J. [Departamento de Microbiologia e Inmunologia Veterinaria, Universidad Federal Rural de Rio de Janeiro (UFRRJ) (Brazil); Cavaglieri, L., E-mail: lcavaglieri@arnet.com.a [Departamento de Microbiologia e Inmunologia, Universidad Nacional de Rio Cuarto (UNRC), Rio Cuarto, Cordoba (Argentina); Member of Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CIC-CONICET) (Argentina); Vital, H. [Centro Tecnologico do Exercito (CTEx), Secao de Defesa Nuclear, Rio de Janeiro (Brazil); Cristofolini, A.; Merkis, C. [Departamento de Microscopia Electronica, Universidad Nacional de Rio Cuarto. Ruta 36 km 601 (5800) Rio Cuarto (Argentina); Astoreca, A. [Departamento de Microbiologia e Inmunologia, Universidad Nacional de Rio Cuarto (UNRC), Rio Cuarto, Cordoba (Argentina); Member of Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CIC-CONICET) (Argentina); Orlando, J.; Caru, M. [Departamento de Ciencias Ecologicas, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Dalcero, A. [Departamento de Microbiologia e Inmunologia, Universidad Nacional de Rio Cuarto (UNRC), Rio Cuarto, Cordoba (Argentina); Member of Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CIC-CONICET) (Argentina); Rosa, C.A.R. [Departamento de Microbiologia e Inmunologia Veterinaria, Universidad Federal Rural de Rio de Janeiro (UFRRJ) (Brazil); Member of Consejo Nacional de Pesquisas (CNPq) (Brazil)

    2011-05-15

    The aim of this work was to study the effect of gamma radiation (2 kGy) on Aspergillus flavus and Aspergillus ochraceus ultrastructure. Moreover, the influence on aflatoxin B{sub 1} and ochratoxin A production was also observed. Irradiated A. flavus strain showed a dull orangish colony while control strain showed the typical green color. Minor differences were observed on stipes, metulae and conidia size between control and irradiated A. flavus and A. ochraceus strains. Irradiated fungi showed ultrastructural changes on cell wall, plasmalema and cytoplasm levels. The levels of mycotoxins produced by irradiated strains were two times greater than those produced by control strains. Successive transferences of irradiated strains on malt extract agar allowed the fungus to recuperate morphological characteristics. Although minor changes in the fungal morphology were observed, ultrastructural changes at cell wall level and the increase of mycotoxin production ability were observed. Inappropriate storage of irradiated food and feed would allow the development of potentially more toxicogenic fungal propagules.

  10. In vitro impact on growth, fumonisins and aflatoxins production by Fusarium verticillioides and Aspergillus flavus using anti-fungal compounds and a biological control agent

    Directory of Open Access Journals (Sweden)

    Silvia FORMENTI

    2012-05-01

    Full Text Available The temporal efficacy of three different chemical fungicides (Folicur®, Proline®, Sportak 45EW® and a biocontrol bacterium (Serenade, B. subtilis in reducing growth and toxin production by isolates of F. verticillioides and A. flavus was studied in vitro under different water activity regimes (0.99, 0.98 and 0.95. All the fungicides significantly inhibited mycelial growth compared with the control; the most effective treatment, both against F. verticillioides and A. flavus, was Sportak 45EW® (approx. 99%. The inhibitory effect of all fungicides generally improved with increasing concentration. Serenade always decreased fungal growth, with optimal results at concentrations of 104 and 106 (70‒75% reduction. All the fungicide treatments resulted in a significant reduction in both FB1+FB2 and AFB1 production when compared to the control, at the end of the incubation period and with the 2 concentrations used (approx. 99%. A threshold concentration inoculum of at least 104 CFUs of B. subtilis per g was required to achieve a significant control of mycotoxin production. Sportak 45EW® and Serenade gave the best control of mycotoxin production with a reduction of 95% compared to the controls. Use of Serenade in the field should include due consideration to its sensitivity to low water activities, when compared to the target pathogens.

  11. Population dynamics of Aspergillus flavus following biocontrol treatment of corn

    Science.gov (United States)

    Aspergillus flavus is a fungal pathogen of many agronomically important crops worldwide. We sampled A. flavus strains from a cornfield in Rocky Mount, North Carolina, over a period of two years. The field was planted in 2010 and plots were inoculated at tasselling with either AF36 or NRRL 21882 (=Af...

  12. The maize rachis affects Aspergillus flavus movement during ear development

    Science.gov (United States)

    Aspergillus flavus expressing green fluorescent protein (GFP) was used to follow infection in ears of maize hybrids resistant and susceptible to the fungus. Developing ears were needle-inoculated with GFP-transformed A. flavus 20 days after silk emergence, and GFP fluorescence in the pith was evalu...

  13. An evaluation of aflatoxin and cyclopiazonic acid production in Aspergillus oryzae.

    Science.gov (United States)

    Kim, Nam Yeun; Lee, Jin Hee; Lee, Inhyung; Ji, Geun Eog

    2014-06-01

    To date, edible fungi such as Aspergillus flavus var. oryzae (A. oryzae) has been considered as safe. However, some strains can produce mycotoxins. Thus, the biosynthetic ability to produce mycotoxins should be reevaluated to determine the safety of edible fungi. We analyzed the production of aflatoxins and cyclopiazonic acid (CPA) from edible fungi such as A. oryzae isolated from various Korean foods using multiplex PCR, enzyme-linked immunosorbent assay, and high-performance liquid chromatography (HPLC). In the multiplex PCR analysis of aflatoxin biosynthetic genes omtB, aflR, ver-1, and omtA, 5 of 19 Aspergillus strains produced all PCR products. Among them, aflatoxin B1 and aflatoxin B2 were detected from only A. flavus KACC 41403 by HPLC. Aflatoxins were not detected from the other four strains that produced all positive PCR bands. Aflatoxin also was not detected from 12 strains that had PCR patterns without aflR or ver-1 and from 2 strains that did not produce any of the expected PCR products. Only the seven A. oryzae strains that produced all of the positive PCR bands including the CPA biosynthetic genes maoA, dmaT, and pks-nrps produced CPA. CPA and aflatoxin production must be evaluated before A. oryzae strains are used for the development of fermented foods.

  14. Optimal pcr primers for rapid and accurate detection of Aspergillus flavus isolates.

    Science.gov (United States)

    Al-Shuhaib, Mohammed Baqur S; Albakri, Ali H; Alwan, Sabah H; Almandil, Noor B; AbdulAzeez, Sayed; Borgio, J Francis

    2018-02-07

    Aspergillus flavus is among the most devastating opportunistic pathogens of several food crops including rice, due to its high production of carcinogenic aflatoxins. The presence of these organisms in economically important rice strip farming is a serious food safety concern. Several polymerase chain reaction (PCR) primers have been designed to detect this species; however, a comparative assessment of their accuracy has not been conducted. This study aims to identify the optimal diagnostic PCR primers for the identification of A. flavus, among widely available primers. We isolated 122 A. flavus native isolates from randomly collected rice strips (N = 300). We identified 109 isolates to the genus level using universal fungal PCR primer pairs. Nine pairs of primers were examined for their PCR diagnostic specificity on the 109 isolates. FLA PCR was found to be the optimal PCR primer pair for specific identification of the native isolates, over aflP(1), aflM, aflA, aflD, aflP(3), aflP(2), and aflR. The PEP primer pair was found to be the most unsuitable for A. flavus identification. In conclusion, the present study indicates the powerful specificity of the FLA PCR primer over other commonly available diagnostic primers for accurate, rapid, and large-scale identification of A. flavus native isolates. This study provides the first simple, practical comparative guide to PCR-based screening of A. flavus infection in rice strips. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. What can Aspergillus flavus genome offer for mycotoxin research?

    Science.gov (United States)

    The genomic study of filamentous fungi has made significant advances in recent years, and the genomes of several species in the genus Aspergillus have been sequenced, including Aspergillus flavus. This ubiquitous mold is present as a saprobe in a wide range of agricultural and natural habits, and c...

  16. Rhizospheric Aspergillus flavus as a Possible Contaminant of Maize ...

    African Journals Online (AJOL)

    Chemist

    2012-04-26

    Apr 26, 2012 ... Horn BW, Dorner JW, Greene RL, Blankenship PD, Cole RJ (1994). Effect of Aspergillus parasiticus soil inoculum on invasion of peanut seeds. Mycopathology, 125: 179-191. Jeffrey D, Palumbo, Teresa L, O'Keeffe, Ali K, Hamed KA, Bobbie JJ. (2010). Inhibition of Aspergillus flavus in Soil by Antagonistic.

  17. Antifungal and antiaflatoxigenic activities of coumarinyl thiosemicarbazides against Aspergillus flavus NRRL 3251.

    Science.gov (United States)

    Kovač, Tihomir; Kovač, Marija; Strelec, Ivica; Nevistić, Ante; Molnar, Maja

    2017-03-01

    The antifungal and antiaflatoxigenic effects of two series of coumarinyl thiosemicarbazides on Aspergillus flavus NRRL 3251 were studied. Fungi were grown in YES medium for 72 h at 29 °C in the presence of 0, 0.1, 1, and 10 μg mL-1 of coumarinyl thiosemicarbazides: one series with substitution in position 7 and another with substitution in position 4 of the coumarin core. Dry mycelia weight determination was used for antifungal activity estimation, while the aflatoxin B1 content in YES media, determined by the dilute and shoot LC-MS/MS technique, was used for the antiaflatoxigenic effect estimation. Standard biochemical assays were used for oxidative status marker (TBARS, SOD, CAT, and GPX) determination in A. flavus NRRL 3251 mycelia. Results show that 7-substituted-coumarinyl thiosemicarbazides possess a better antifungal and antiaflatoxigenic activity than 4-substituted ones. The most prominent substituted compound was the compound 3, N-(4-chlorophenyl)-2-(2-((4-methyl-2-oxo-2H-chromen-7-yl)oxy)acetyl)hydrazine-1-carbothioamide, which completely inhibited aflatoxin production at the concentration of 10 μg mL-1. Oxidative stress response of A. flavus exposed to the selected compounds points to the modulation of oxidative stress as a possible reason of aflatoxin production inhibition.

  18. Host-Induced Gene Silencing (HIGS) of aflatoxin synthesis genes in peanut and maize: use of RNA interference and genetic diversity of Aspergillus

    Science.gov (United States)

    Approximately 4.5 billion people are chronically exposed to aflatoxins, these are powerful carcinogens produced by Aspergillus flavus and A. parasiticus. High levels of aflatoxins in crops result in approximately 100 million metric tons of cereals, ¬nuts, root crops and other agricultural products ...

  19. Comparison of expression of secondary metabolite biosynthesis cluster genes in Aspergillus flavus, A. parasiticus, and A. oryzae.

    Science.gov (United States)

    Ehrlich, Kenneth C; Mack, Brian M

    2014-06-23

    Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help to refine the identification of probable functional gene clusters within these species. Our results suggest that A. flavus, a prevalent contaminant of maize, cottonseed, peanuts and tree nuts, is capable of producing metabolites which, besides aflatoxin, could be an underappreciated contributor to its toxicity.

  20. 7 CFR 983.4 - Aflatoxin.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Aflatoxin. 983.4 Section 983.4 Agriculture Regulations... NEW MEXICO Definitions § 983.4 Aflatoxin. Aflatoxin is one of a group of mycotoxins produced by the molds Aspergillus flavus and Aspergillus parasiticus. Aflatoxins are naturally occurring compounds...

  1. Investigations on the Antifungal Effect of Nerol against Aspergillus flavus Causing Food Spoilage

    Directory of Open Access Journals (Sweden)

    Jun Tian

    2013-01-01

    Full Text Available The antifungal efficacy of nerol (NEL has been proved against Aspergillus flavus by using in vitro and in vivo tests. The mycelial growth of A. flavus was completely inhibited at concentrations of 0.8 μL/mL and 0.1 μL/mL NEL in the air at contact and vapor conditions, respectively. The NEL also had an evident inhibitory effect on spore germination in A. flavus along with NEL concentration as well as time-dependent kinetic inhibition. The NEL presented noticeable inhibition on dry mycelium weight and synthesis of aflatoxin B1 (AFB1 by A. flavus, totally restraining AFB1 production at 0.6 μL/mL. In real food system, the efficacy of the NEL on resistance to decay development in cherry tomatoes was investigated in vivo by exposing inoculated and control fruit groups to NEL vapor at different concentration. NEL vapors at 0.1 μL/mL air concentration significantly reduced artificially contaminated A. flavus and a broad spectrum of fungal microbiota. Results obtained from presented study showed that the NEL had a great antifungal activity and could be considered as a benefit and safe tool to control food spoilage.

  2. Menadione-Induced Oxidative Stress Re-Shapes the Oxylipin Profile of Aspergillus flavus and Its Lifestyle

    Directory of Open Access Journals (Sweden)

    Marco Zaccaria

    2015-10-01

    Full Text Available Aspergillus flavus is an efficient producer of mycotoxins, particularly aflatoxin B1, probably the most hepatocarcinogenic naturally-occurring compound. Although the inducing agents of toxin synthesis are not unanimously identified, there is evidence that oxidative stress is one of the main actors in play. In our study, we use menadione, a quinone extensively implemented in studies on ROS response in animal cells, for causing stress to A. flavus. For uncovering the molecular determinants that drive A. flavus in challenging oxidative stress conditions, we have evaluated a wide spectrum of several different parameters, ranging from metabolic (ROS and oxylipin profile to transcriptional analysis (RNA-seq. There emerges a scenario in which A. flavus activates several metabolic processes under oxidative stress conditions for limiting the ROS-associated detrimental effects, as well as for triggering adaptive and escape strategies.

  3. The inhibitory effects of Curcuma longa L. essential oil and curcumin on Aspergillus flavus link growth and morphology.

    Science.gov (United States)

    Dias Ferreira, Flávio; Mossini, Simone Aparecida Galerani; Dias Ferreira, Francine Maery; Arrotéia, Carla Cristina; da Costa, Christiane Luciana; Nakamura, Celso Vataru; Machinski, Miguel

    2013-01-01

    The essential oil from Curcuma longa L. was analysed by GC/MS. The major components of the oil were ar-turmerone (33.2%), α -turmerone (23.5%) and β -turmerone (22.7%). The antifungal activities of the oil were studied with regard to Aspergillus flavus growth inhibition and altered morphology, as preliminary studies indicated that the essential oil from C. longa inhibited Aspergillus flavus Link aflatoxin production. The concentration of essential oil in the culture media ranged from 0.01% to 5.0% v/v, and the concentration of curcumin was 0.01-0.5% v/v. The effects on sporulation, spore viability, and fungal morphology were determined. The essential oil exhibited stronger antifungal activity than curcumin on A. flavus. The essential oil reduced the fungal growth in a concentration-dependent manner. A. flavus growth rate was reduced by C. longa essential oil at 0.10%, and this inhibition effect was more efficient in concentrations above 0.50%. Germination and sporulation were 100% inhibited in 0.5% oil. Scanning electron microscopy (SEM) of A. flavus exposed to oil showed damage to hyphae membranes and conidiophores. Because the fungus is a plant pathogen and aflatoxin producer, C. longa essential oil may be used in the management of host plants.

  4. The Inhibitory Effects of Curcuma longa L. Essential Oil and Curcumin on Aspergillus flavus Link Growth and Morphology

    Directory of Open Access Journals (Sweden)

    Flávio Dias Ferreira

    2013-01-01

    Full Text Available The essential oil from Curcuma longa L. was analysed by GC/MS. The major components of the oil were ar-turmerone (33.2%, α-turmerone (23.5% and β-turmerone (22.7%. The antifungal activities of the oil were studied with regard to Aspergillus flavus growth inhibition and altered morphology, as preliminary studies indicated that the essential oil from C. longa inhibited Aspergillus flavus Link aflatoxin production. The concentration of essential oil in the culture media ranged from 0.01% to 5.0% v/v, and the concentration of curcumin was 0.01–0.5% v/v. The effects on sporulation, spore viability, and fungal morphology were determined. The essential oil exhibited stronger antifungal activity than curcumin on A. flavus. The essential oil reduced the fungal growth in a concentration-dependent manner. A. flavus growth rate was reduced by C. longa essential oil at 0.10%, and this inhibition effect was more efficient in concentrations above 0.50%. Germination and sporulation were 100% inhibited in 0.5% oil. Scanning electron microscopy (SEM of A. flavus exposed to oil showed damage to hyphae membranes and conidiophores. Because the fungus is a plant pathogen and aflatoxin producer, C. longa essential oil may be used in the management of host plants.

  5. The Inhibitory Effects of Curcuma longa L. Essential Oil and Curcumin on Aspergillus flavus Link Growth and Morphology

    Science.gov (United States)

    Mossini, Simone Aparecida Galerani; Ferreira, Francine Maery Dias; Arrotéia, Carla Cristina; da Costa, Christiane Luciana; Nakamura, Celso Vataru; Machinski Junior, Miguel

    2013-01-01

    The essential oil from Curcuma longa L. was analysed by GC/MS. The major components of the oil were ar-turmerone (33.2%), α-turmerone (23.5%) and β-turmerone (22.7%). The antifungal activities of the oil were studied with regard to Aspergillus flavus growth inhibition and altered morphology, as preliminary studies indicated that the essential oil from C. longa inhibited Aspergillus flavus Link aflatoxin production. The concentration of essential oil in the culture media ranged from 0.01% to 5.0% v/v, and the concentration of curcumin was 0.01–0.5% v/v. The effects on sporulation, spore viability, and fungal morphology were determined. The essential oil exhibited stronger antifungal activity than curcumin on A. flavus. The essential oil reduced the fungal growth in a concentration-dependent manner. A. flavus growth rate was reduced by C. longa essential oil at 0.10%, and this inhibition effect was more efficient in concentrations above 0.50%. Germination and sporulation were 100% inhibited in 0.5% oil. Scanning electron microscopy (SEM) of A. flavus exposed to oil showed damage to hyphae membranes and conidiophores. Because the fungus is a plant pathogen and aflatoxin producer, C. longa essential oil may be used in the management of host plants. PMID:24367241

  6. Comparative genomics analysis of field isolates of Aspergillus flavus and A. parasiticus to explain phenotypic variation in oxidative stress tolerance and host preference

    Science.gov (United States)

    Aflatoxin contamination of peanut and other crops is a major concern for producers globally, and has been shown to be exacerbated by drought stress. Previous transcriptomic and proteomic examination of the responses of isolates of Aspergillus flavus to drought-related oxidative stress in vitro have ...

  7. Radiosensitivity of toxigenic Aspergillus isolated from spices and destruction of aflatoxins by gamma-irradiation

    Science.gov (United States)

    Kume, Tamikazu; Ito, Hitoshi; Soedarman, Harsono; Ishigaki, Isao

    Radiosensitivities of Aspergillus flavus var columnaris isolated from spices were investigated. The D10 values and induction doses were 267-293 Gy and 75-165 Gy in wet conditions, respectively. In dry conditions, the survival curves were exponential and D10 values were 538-600 Gy. The survival curves of standard strain of A. parasiticus IFO 30179 were similar both in wet and dry conditions. The necessary dose of 8 kGy for the destruction of these toxigenic Aspergillus was calculated from these values. Two of 11 strains of A. flavus var columnaris produced aflatoxins and the content of B 1 was especially high. In the study of irradiation effect on aflatoxins produced on polished rice, aflatoxins G 1 and B 1 were more radiosensitive than G 2 and B 2. However, these aflatoxins were very stable to radiation and the dose required for destruction was found to be more than 500 kGy. It is therfore concluded that the decontamination of molds by irradiation is necessary prior to their production of aflatoxins.

  8. A Cellular Fusion Cascade Regulated by LaeA Is Required for Sclerotial Development in Aspergillus flavus.

    Science.gov (United States)

    Zhao, Xixi; Spraker, Joseph E; Bok, Jin Woo; Velk, Thomas; He, Zhu-Mei; Keller, Nancy P

    2017-01-01

    Aspergillus flavus is a saprophytic soil fungus that poses a serious threat worldwide as it contaminates many food and feed crops with the carcinogenic mycotoxin called aflatoxin. This pathogen persists as sclerotia in the soil which enables fungal survival in harsh environmental conditions. Sclerotia formation by A. flavus depends on successful cell communication and hyphal fusion events. Loss of LaeA, a conserved developmental regulator in fungi, abolishes sclerotia formation in this species whereas overexpression (OE) of laeA results in enhanced sclerotia production. Here we demonstrate that sclerotia loss and inability to form heterokaryons in A. flavusΔlaeA is mediated by homologs of the Neurospora crassa ham (hyphal anastomosis) genes termed hamE-I in A. flavus. LaeA positively regulates ham gene expression and deletion of hamF, G, H, or I phenocopies ΔlaeA as demonstrated by heterokaryon and sclerotia loss and reduced aflatoxin synthesis and virulence of these mutants. Deletion of hamE showed a less severe phenotype. hamE-I homologs are positively regulated by the clock controlled transcription factor ADV-1 in N. crassa. Similarly, the ADV-1 homolog NosA regulates hamE-I expression in A. flavus, is required for sclerotial development and is itself positively regulated by LaeA. We speculate that a putative LaeA>NosA>fusion cascade underlies the previously described circadian clock regulation of sclerotia production in A. flavus.

  9. A Cellular Fusion Cascade Regulated by LaeA Is Required for Sclerotial Development in Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Xixi Zhao

    2017-10-01

    Full Text Available Aspergillus flavus is a saprophytic soil fungus that poses a serious threat worldwide as it contaminates many food and feed crops with the carcinogenic mycotoxin called aflatoxin. This pathogen persists as sclerotia in the soil which enables fungal survival in harsh environmental conditions. Sclerotia formation by A. flavus depends on successful cell communication and hyphal fusion events. Loss of LaeA, a conserved developmental regulator in fungi, abolishes sclerotia formation in this species whereas overexpression (OE of laeA results in enhanced sclerotia production. Here we demonstrate that sclerotia loss and inability to form heterokaryons in A. flavusΔlaeA is mediated by homologs of the Neurospora crassa ham (hyphal anastomosis genes termed hamE-I in A. flavus. LaeA positively regulates ham gene expression and deletion of hamF, G, H, or I phenocopies ΔlaeA as demonstrated by heterokaryon and sclerotia loss and reduced aflatoxin synthesis and virulence of these mutants. Deletion of hamE showed a less severe phenotype. hamE-I homologs are positively regulated by the clock controlled transcription factor ADV-1 in N. crassa. Similarly, the ADV-1 homolog NosA regulates hamE-I expression in A. flavus, is required for sclerotial development and is itself positively regulated by LaeA. We speculate that a putative LaeA>NosA>fusion cascade underlies the previously described circadian clock regulation of sclerotia production in A. flavus.

  10. The role of rhizospheric Aspergillus flavus in standing maize crop ...

    African Journals Online (AJOL)

    Soil and un-husked maize samples were collected from 29 different locations belonging to three distinct ecological zones (Swat, Hazara and Peshawar) of Khyber Pakhtunkhwa, Pakistan. The samples were evaluated for the incidence of aflatoxigenic strains of Aspergillus flavus. The soil samples collected from Peshawar ...

  11. Cellulase Production by Aspergillus flavus Linn Isolate NSPR 101 ...

    African Journals Online (AJOL)

    Bagasse, corncob and sawdust were used as lignocellulosic substrates for the production of cellulase enzyme using Aspergillus flavus after ballmilling and pretreatment with caustic soda. From the fermentation studies, sawdust gave the best result with an enzyme activity value of 0.0743IU/ml while bagasse and corncob ...

  12. Aspergillus flavus infection on preserved Eel (Thysoidea macrurus)

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, R.; Samuel, C.T.

    The fungus Aspergillus flavus was observed growing on a 2.1 m long specimen of eel (Thyrsoidea macrurus). Half of the eel was submerged in 5% formalin in a loosely covered specimen jar. The fungus grew on the eel skin as yellowish-green, heavily...

  13. Rhizospheric Aspergillus flavus as a Possible Contaminant of Maize ...

    African Journals Online (AJOL)

    Chemist

    2012-04-26

    Apr 26, 2012 ... Soil and un-husked maize samples were collected from 29 different locations belonging to three distinct ecological zones (Swat, Hazara and Peshawar) of Khyber Pakhtunkhwa, Pakistan. The samples were evaluated for the incidence of aflatoxigenic strains of Aspergillus flavus. The soil samples collected.

  14. Purification and Characterization of Lipase from Aspergillus flavus ...

    African Journals Online (AJOL)

    USER

    application. Key words: Lipase, purification, Aspergillus flavus PW2961, magnetic nanoparticles.______. Correspondence: sharafkareem@yahoo.co.uk ..... in solid state fermentation. Process Biochem. 38(5): 715-721. Okoli, C., Boutonnet, M., Mariey, L., Jaras, S. And Rajarao, G. (2011). Application of magnetic iron oxide ...

  15. Oxidant and solvent stable alkaline protease from Aspergillus flavus ...

    African Journals Online (AJOL)

    The increase in agricultural practices has necessitated the judicious use of agricultural wastes into value added products. In this study, an extracellular, organic solvent and oxidant stable, serine protease was produced by Aspergillus flavus MTCC 9952 under solid state fermentation. Maximum protease yield was obtained ...

  16. Identification of resistance to Aspergillus flavus infection in cotton germplasm

    Science.gov (United States)

    Natural resistance of in cottonseed to Aspergillus flavus infection has not been explored to date. A green fluorescent protein (GFP) expressing -70 strain was used to assess the resistance of seed from thirty five35 cotton varieties including representatives from Gossypium arboreum, G. barbadense, a...

  17. Corn-Soybean Rotation Systems in the Mississippi Delta: Implications on Mycotoxin Contamination and Soil Populations of Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Hamed K. Abbas

    2012-01-01

    Full Text Available The effect of corn-soybean rotation on mycotoxin contamination in corn (Zea mays L. and soybean (Glycine max L. Merrill. grains has not been fully evaluated. Therefore, this research investigated the effect of corn-soybean rotation on aflatoxin and fumonisin contamination in respective grains. The results showed that aflatoxin levels in soybean averaged 2.3, <0.5, 0.6, and 6.8 ng/g in 2005, 2006, 2007, and 2008, while corn aflatoxin levels were 16.7, 37.1, 2.4, and 54.8 ng/g, respectively. Aspergillus flavus colonization was significantly greater (P≤0.05 in corn (log 1.9, 2.9, and 4.0 cfu/g compared to soybean (<1.3, 2.6, and 2.7 cfu/g in 2005, 2007, and 2008, respectively. Aflatoxigenic A. flavus isolates were more frequent in corn than in soybean in all four years. Higher fumonisin levels were found in corn (0.2 to 3.6 μg/g than in soybean (<0.2 μg/g. Rotating soybean with corn reduces the potential for aflatoxin contamination in corn by reducing A. flavus propagules in soil and grain and reducing aflatoxigenic A. flavus colonization. These results demonstrated that soybean grain is less susceptible to aflatoxin contamination compared to corn due to a lower level of colonization by A. flavus with a greater occurrence of non-aflatoxigenic isolates.

  18. Identification of Aspergillus species in Central Europe able to produce G-type aflatoxins.

    Science.gov (United States)

    Baranyi, Nikolett; Despot, Daniela Jakšić; Palágyi, Andrea; Kiss, Noémi; Kocsubé, Sándor; Szekeres, András; Kecskeméti, Anita; Bencsik, Ottó; Vágvölgyi, Csaba; Klarić, Maja Šegvić; Varga, János

    2015-09-01

    The occurrence of potential aflatoxin producing fungi was examined in various agricultural products and indoor air in Central European countries including Hungary, Serbia and Croatia. For species identification, both morphological and sequence based methods were applied. Aspergillus flavus was detected in several samples including maize, cheese, nuts, spices and indoor air, and several isolates were able to produce aflatoxins. Besides, three other species of Aspergillus section Flavi, A. nomius, A. pseudonomius and A. parasiticus were also isolated from cheese, maize and indoor air, respectively. This is the first report on the occurrence of A. nomius and A. pseudonomius in Central Europe. All A. nomius, A. pseudonomius and A. parasiticus isolates were able to produce aflatoxins B1, B2, G1 and G2. The A. nomius isolate came from cheese produced very high amounts of aflatoxins (above 1 mg ml⁻¹). All A. nomius, A. pseudonomius and A. parasiticus isolates produced much higher amounts of aflatoxin G1 then aflatoxin B1. Further studies are in progress to examine the occurrence of producers of these highly carcinogenic mycotoxins in agricultural products and indoor air in Central Europe.

  19. Toxicidade de óleos essenciais de alho e casca de canela contra fungos do grupo Aspergillus flavus Evaluation of essential oils from Allium sativum and Cinnamomum zeilanicum and their toxicity against fungi of the Aspergillus flavus group

    Directory of Open Access Journals (Sweden)

    Elson de C. Viegas

    2005-12-01

    Full Text Available Diante da propriedade inibitória de óleos essenciais vegetais sobre o desenvolvimento micelial de fungos e da importância das espécies do grupo Aspergillus flavus, que apresentam potencial para síntese de aflatoxina, este trabalho teve como objetivo avaliar in vitro a toxicidade de óleos essenciais vegetais contra fungos do grupo A. flavus, isolados a partir da cultura do amendoim. Inicialmente, foi avaliada a toxicidade de oito óleos essenciais vegetais no desenvolvimento micelial de dois isolados do grupo A. flavus, em comparação ao fungicida sintético benomyl. Em seguida, foi avaliada a toxicidade dos óleos de casca de canela (Cinnamomum zeilanicum Breym. e de bulbilho de alho (Allium sativum L. contra 37 isolados do grupo A. flavus, durante 12 meses. A maior inibição do desenvolvimento micelial de A. flavus foi obtida com o emprego dos óleos essenciais de casca de canela e de bulbilho de alho, e o efeito inibitório variou com o isolado testado.Considering the inhibitory property of essential plant oils on the mycelial development of fungi, and the importance of Aspergillus flavus-like fungi which may produce aflatoxins, this research was designed to evaluate the toxicity of essential oils against fungi belonging to the group A. flavus isolated from peanut crops. The toxicity of eight essential oils against two isolates of A. Flavuslike fungi was evaluated in comparison to the synthetic fungicide benomyl. The toxicity of Cinnamomum zeilanicum Breym. and Allium sativum L. essential oils was also evaluated against 37 fungal isolates for a period of 12 months. The highest inhibition of the mycelial development of A. flavus was obtained with cinnamon and garlic essential oils. The inhibitory effect on growth was variable according to the fungal isolate.

  20. Implications of European corn borer, Ostrinia nubilalis, infestation in an Aspergillus flavus-biocontrolled corn agroecosystem.

    Science.gov (United States)

    Mencarelli, Mariangela; Accinelli, Cesare; Vicari, Alberto

    2013-09-01

    A novel biocontrol strategy consisting of field application of bioplastic-based granules inoculated with a non-toxigenic Aspergillus flavus L. strain has recently been shown to be effective for reducing aflatoxin contamination in corn. This study focused on other factors that may affect the feasibility of this biocontrol technique, and more specifically the role of the European corn borer (ECB), Ostrinia nubilalis H., in the dispersal and infestation of A. flavus in corn and its impact on crop yield. In spite of the high percentage of corn ears showing larval feeding damage, ECB-bored kernels accounted for only 3 and 4% in 2009 and 2010 respectively. Most of the damaged kernels were localised in the ear tip or immediately below. More precisely, the average incidence of ECB-bored kernels in the upper end of the ear was 32%. However, less than 5% of kernels from the central body of the ear, which includes the majority of kernels, were injured by ECB. Although ECB larvae showed a high tolerance to aflatoxin B1 and thus had the potential to serve as vectors of the mould, fungal infection of kernels was poorly associated with insect damage. ECB infestation resulted in grain yield losses not exceeding 2.5%. © 2012 Society of Chemical Industry.

  1. Orbital tuberculosis with coexisting fungal (Aspergillus flavus) infection

    OpenAIRE

    Sunkara Srikanth Reddy; Devi Chendira Penmmaiah; Alugolu Rajesh; Madhusudan Patil

    2014-01-01

    Background: A coexisting invasive fungal and tubercular involvement of the skull base is a rare event. Co-infection has been reported with involvement of paranasal sinuses and middle ear cleft. Case Description: We herein report a case of an elderly male diabetic patient who presented with gradually progressive visual loss, which on imaging showed an orbital lesion. Surgical decompression and microbiological evaluation showed growth of Mycobacterium tuberculosis and Aspergillus flavus. ...

  2. Purification and Characterization of Lipase from Aspergillus flavus ...

    African Journals Online (AJOL)

    Lipase from Aspergillus flavus was purified in a single step purification using MnFeO4 magnetic nano particles to achieve a 20.53- fold purification with specific activity of 11.29 U/mg and a 59% recovery yield. SDS-PAGE of lipase showed a single pure band with corresponding molecular weight of 35 kDa. The optimal ...

  3. Atypical Aspergillus parasiticus isolates from pistachio with aflR gene nucleotide insertion identical to Aspergillus sojae

    Science.gov (United States)

    Aflatoxins are the most toxic and carcinogenic secondary metabolites produced primarily by the filamentous fungi Aspergillus flavus and Aspergillus parasiticus. The toxins cause devastating economic losses because of strict regulations on distribution of contaminated products. Aspergillus sojae are...

  4. Frequent shifts in Aspergillus flavus populations associated with maize production in Sonora, Mexico.

    Science.gov (United States)

    Ortega-Beltran, Alejandro; Cotty, Peter

    2017-10-13

    Aspergillus flavus frequently contaminates maize, a critical staple of billions, with aflatoxins. Diversity among A. flavus L morphotype populations associated with maize in Sonora, Mexico was assessed and a total of 869 isolates from 83 fields were placed into 136 vegetative compatibility groups (VCGs) using nitrate-nonutilizing mutants. VCG diversity indices did not differ in four agroecosystems (AES) but diversity significantly differed among years. Frequencies of certain VCGs changed manyfold over single years in both multiple fields and multiple AES. Certain VCGs were highly frequenct (>1%) in 2006, but frequencies declined repeatedly in each of the two subsequent years. Other VCGs that had low frequencies in 2006 increased in 2007 and subsequently declined. None of the VCGs were consistently associated with any AES. Fourteen VCGs were considered dominant in at least a single year. However, frequencies often varied significantly among years. Only 9% of VCGs were detected all three years while 66% were detected in only one year. Results suggest that the most realistic measurements of both genetic diversity and the frequency of A. flavus VCGs are obtained by sampling multiple locations in multiple years. Single season sampling in many locations should not be substituted for sampling over multiple years.

  5. A Network Approach of Gene Co-expression in the Zea mays/Aspergillus flavus Pathosystem to Map Host/Pathogen Interaction Pathways.

    Science.gov (United States)

    Musungu, Bryan M; Bhatnagar, Deepak; Brown, Robert L; Payne, Gary A; OBrian, Greg; Fakhoury, Ahmad M; Geisler, Matt

    2016-01-01

    A gene co-expression network (GEN) was generated using a dual RNA-seq study with the fungal pathogen Aspergillus flavus and its plant host Zea mays during the initial 3 days of infection. The analysis deciphered novel pathways and mapped genes of interest in both organisms during the infection. This network revealed a high degree of connectivity in many of the previously recognized pathways in Z. mays such as jasmonic acid, ethylene, and reactive oxygen species (ROS). For the pathogen A. flavus, a link between aflatoxin production and vesicular transport was identified within the network. There was significant interspecies correlation of expression between Z. mays and A. flavus for a subset of 104 Z. mays, and 1942 A. flavus genes. This resulted in an interspecies subnetwork enriched in multiple Z. mays genes involved in the production of ROS. In addition to the ROS from Z. mays, there was enrichment in the vesicular transport pathways and the aflatoxin pathway for A. flavus. Included in these genes, a key aflatoxin cluster regulator, AflS, was found to be co-regulated with multiple Z. mays ROS producing genes within the network, suggesting AflS may be monitoring host ROS levels. The entire GEN for both host and pathogen, and the subset of interspecies correlations, is presented as a tool for hypothesis generation and discovery for events in the early stages of fungal infection of Z. mays by A. flavus.

  6. A Network Approach of Gene Co-expression in the Zea mays/Aspergillus flavus Pathosystem to Map Host/Pathogen Interaction Pathways

    Science.gov (United States)

    Musungu, Bryan M.; Bhatnagar, Deepak; Brown, Robert L.; Payne, Gary A.; OBrian, Greg; Fakhoury, Ahmad M.; Geisler, Matt

    2016-01-01

    A gene co-expression network (GEN) was generated using a dual RNA-seq study with the fungal pathogen Aspergillus flavus and its plant host Zea mays during the initial 3 days of infection. The analysis deciphered novel pathways and mapped genes of interest in both organisms during the infection. This network revealed a high degree of connectivity in many of the previously recognized pathways in Z. mays such as jasmonic acid, ethylene, and reactive oxygen species (ROS). For the pathogen A. flavus, a link between aflatoxin production and vesicular transport was identified within the network. There was significant interspecies correlation of expression between Z. mays and A. flavus for a subset of 104 Z. mays, and 1942 A. flavus genes. This resulted in an interspecies subnetwork enriched in multiple Z. mays genes involved in the production of ROS. In addition to the ROS from Z. mays, there was enrichment in the vesicular transport pathways and the aflatoxin pathway for A. flavus. Included in these genes, a key aflatoxin cluster regulator, AflS, was found to be co-regulated with multiple Z. mays ROS producing genes within the network, suggesting AflS may be monitoring host ROS levels. The entire GEN for both host and pathogen, and the subset of interspecies correlations, is presented as a tool for hypothesis generation and discovery for events in the early stages of fungal infection of Z. mays by A. flavus. PMID:27917194

  7. The Potent of Aspergillus parasiticus to Produce Aflatoxin B1 on the Maize Flour During Storage

    Directory of Open Access Journals (Sweden)

    Agus Selamat Duniaji

    2016-03-01

    Full Text Available Aflatoxin B1 contamination caused by Aspergillus parasiticus and Aspergiluus Aspergillus flavus is a great concern in maize production worldwide. A. parasiticus infection and aflatoxin B1 contamination are usually found in maize and their processed during storage, distribution and processing. Aflatoxin B1 contamination in food and feed can cause the cancer diseases in animal and human. This research was aimed to determinate the potency of A. parasiticus to produce aflatoxin B1 in maize during storage 0, 5, 10 and 15 days. The research methods was using Completed Random Design (CRD with three replicated. The research was investigation of a number of colony A. parasiticus in Petato Dextro Agar (PDA and Aflatoxin B1 content by using Enzym Linked Immunosorbant Assay (ELISA. Result of research showed that A.parasiticus were susceptible to grow in maize flour and produce aflatoxin B1 during storage. The population of A. parasiticus in maize flour were  9.5 x 105 d in primary storage (0 days that was the total colony were increasing  .7 x 106 (storage 5 days, 2.5 x 107 (storage 10 days and 1.5 x 108 cfu/g with storage 15 days A. parasiticus was a potent to produce aflatoxin B1 in myzena flour with total of aflatoxin B1 is  66.50 ppb of mayzena flour during storage 5 days , 46.40 ppb with 10 days storage, 57.00 ppb during storage 15 days and was not found in 0 days.

  8. Aspergillus: introduction

    Science.gov (United States)

    Species in the genus Aspergillus possess versatile metabolic activities that impact our daily life both positively and negatively. Aspergillus flavus and Aspergillus oryzae are closely related fungi. While the former is able to produce carcinogenic aflatoxins and is an etiological agent of aspergill...

  9. Comparison of the ability of three Aspergillus strains to form aflatoxins on bakery products and on nutrient agar.

    Science.gov (United States)

    Reiss, J

    1982-02-19

    The growth of Aspergillus parasiticus NRRL 2999, A. parasiticus NRRL 3000 and A. flavus NRRL 3251 on whole wheat bread and on cake ('Rührkuchen') was compared and the formation of the aflatoxin B1, B2, G1, G2 and M2 on these substrates and, for purpose of comparison, on malt extract agar was determined. On cake the moulds grew better than on bread and formed the highest yields of aflatoxins. Malt extract agar was the most unfavourable substrate for toxin production. The ratio M1/B1 on bread and cake was in the order of 0.1-0.4 and was higher than the data reported for grains. The highest yields of aflatoxin B1 (1.0 micrograms/g) were produced by A. flavus NRRL 3251 on cake.

  10. Toxigenic potentiality of Aspergillus flavus and Aspergillus parasiticus strains isolated from black pepper assessed by an LC-MS/MS based multi-mycotoxin method.

    Science.gov (United States)

    Yogendrarajah, Pratheeba; Devlieghere, Frank; Njumbe Ediage, Emmanuel; Jacxsens, Liesbeth; De Meulenaer, Bruno; De Saeger, Sarah

    2015-12-01

    A liquid chromatography triple quadrupole tandem mass spectrometry method was developed and validated to determine mycotoxins, produced by fungal isolates grown on malt extract agar (MEA). All twenty metabolites produced by different fungal species were extracted using acetonitrile/1% formic acid. The developed method was applied to assess the toxigenic potentiality of Aspergillus flavus (n = 11) and Aspergillus parasiticus (n = 6) strains isolated from black peppers (Piper nigrum L.) following their growth at 22, 30 and 37 °C. Highest mean radial colony growth rates were observed at 30 °C for A. flavus (5.21 ± 0.68 mm/day) and A. parasiticus (4.97 ± 0.33 mm/day). All of the A. flavus isolates produced aflatoxin B1 and O-methyl sterigmatocystin (OMST) while 91% produced aflatoxin B2 (AFB2) and 82% of them produced sterigmatocystin (STERIG) at 30 °C. Except one, all the A. parasiticus isolates produced all the four aflatoxins, STERIG and OMST at 30 °C. Remarkably high AFB1 was produced by some A. flavus isolates at 22 °C (max 16-40 mg/kg). Production of mycotoxins followed a different trend than that of growth rate of both species. Notable correlations were found between different secondary metabolites of both species; R(2) 0.87 between AFB1 and AFB2 production. Occurrence of OMST could be used as a predictor for AFB1 production. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Occurrence of Aspergillus section Flavi and aflatoxins in Brazilian rice: From field to market.

    Science.gov (United States)

    Katsurayama, Aline M; Martins, Ligia M; Iamanaka, Beatriz T; Fungaro, Maria Helena P; Silva, Josué J; Frisvad, Jens C; Pitt, John I; Taniwaki, Marta H

    2018-02-02

    The guarantee of the high quality of rice is of utmost importance because any toxic contaminant may affect consumer health, especially in countries such as Brazil where rice is part of the daily diet. A total of 187 rice samples, from field, processing and market from two different production systems, wetland from the state of Rio Grande do Sul, dryland, from the state of Maranhão and market samples from the state of São Paulo, were analyzed for fungi belonging to Aspergillus section Flavi and the presence of aflatoxins. Twenty-three soil samples from wetland and dryland were also analyzed. A total of 383 Aspergillus section Flavi strains were isolated from rice and soil samples. Using a polyphasic approach, with phenotypic (morphology and extrolite profiles) and molecular data (beta-tubulin gene sequences), five species were identified: A. flavus, A. caelatus, A. novoparasiticus, A. arachidicola and A. pseudocaelatus. This is the first report of these last three species from rice and rice plantation soil. Only seven (17%) of the A. flavus isolates produced type B aflatoxins, but 95% produced kojic acid and 69% cyclopiazonic acid. Less than 14% of the rice samples were contaminated with aflatoxins, but two of the market samples were well above the maximum tolerable limit (5μg/kg), established by the Brazilian National Health Surveillance Agency. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Recurrent Fungal Keratitis and Blepharitis Caused by Aspergillus flavus.

    Science.gov (United States)

    Lee, Chia-Yi; Ho, Yi-Ju; Sun, Chi-Chin; Lin, Hsin-Chiung; Hsiao, Ching-Hsi; Ma, David Hui-Kang; Lai, Chi-Chun; Chen, Hung-Chi

    2016-11-02

    Aspergillus species produces a wide spectrum of fungal diseases like endophthalmitis and fungal keratitis ophthalmologically, but there has been no report about blepharitis caused by Aspergilus flavus to date. Herein, we report a 61-year-old ethnic Han Taiwanese male who had suffered from pain with burning and foreign body sensation after an insect bite on his left eye. Specimens from bilateral eyelids suggested infection of A. flavus, whereas corneal scraping showed the presence of Gram-negative bacteria. He was admitted for treatment of infectious keratitis with topical antibiotic and antifungal eye drops. Two weeks after discharge, recurrent blepharitis and keratitis of A. flavus was diagnosed microbiologically. Another treatment course of antifungal agent was resumed in the following 6 months, without further significant symptoms in the following 2 years. Collectively, it is possible for A. flavus to induce concurrent keratitis and blepharitis, and combined treatment of keratitis as well as blepharitis is advocated for as long as 6 months to ensure no recurrence. © The American Society of Tropical Medicine and Hygiene.

  13. Phytochemicals reduce aflatoxin-induced toxicity in chicken embryos

    Science.gov (United States)

    Aflatoxins (AF) are toxic metabolites produced by molds, Aspergillus flavus and Aspergillus parasicitus, which frequently contaminate chicken feed ingredients. Ingestion of AF-contaminated feed by chickens leads to deleterious effects, including decreased chicken performance and reduced egg producti...

  14. Orbital tuberculosis with coexisting fungal (Aspergillus flavus) infection.

    Science.gov (United States)

    Reddy, Sunkara Srikanth; Penmmaiah, Devi Chendira; Rajesh, Alugolu; Patil, Madhusudan

    2014-01-01

    A coexisting invasive fungal and tubercular involvement of the skull base is a rare event. Co-infection has been reported with involvement of paranasal sinuses and middle ear cleft. We herein report a case of an elderly male diabetic patient who presented with gradually progressive visual loss, which on imaging showed an orbital lesion. Surgical decompression and microbiological evaluation showed growth of Mycobacterium tuberculosis and Aspergillus flavus. Rare combinations of such infections do exist and should be treated aggressively to achieve good outcomes in a losing battle with fastidious organisms in the backdrop of compromised immunity.

  15. Effects of Hydrogen Peroxide on Different Toxigenic and Atoxigenic Isolates of Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Jake C. Fountain

    2015-08-01

    Full Text Available Drought stress in the field has been shown to exacerbate aflatoxin contamination of maize and peanut. Drought and heat stress also produce reactive oxygen species (ROS in plant tissues. Given the potential correlation between ROS and exacerbated aflatoxin production under drought and heat stress, the objectives of this study were to examine the effects of hydrogen peroxide (H2O2-induced oxidative stress on the growth of different toxigenic (+ and atoxigenic (− isolates of Aspergillus flavus and to test whether aflatoxin production affects the H2O2 concentrations that the isolates could survive. Ten isolates were tested: NRRL3357 (+, A9 (+, AF13 (+, Tox4 (+, A1 (−, K49 (−, K54A (−, AF36 (−, and Aflaguard (−; and one A. parasiticus isolate, NRRL2999 (+. These isolates were cultured under a H2O2 gradient ranging from 0 to 50 mM in two different media, aflatoxin-conducive yeast extract-sucrose (YES and non-conducive yeast extract-peptone (YEP. Fungal growth was inhibited at a high H2O2 concentration, but specific isolates grew well at different H2O2 concentrations. Generally the toxigenic isolates tolerated higher concentrations than did atoxigenic isolates. Increasing H2O2 concentrations in the media resulted in elevated aflatoxin production in toxigenic isolates. In YEP media, the higher concentration of peptone (15% partially inactivated the H2O2 in the media. In the 1% peptone media, YEP did not affect the H2O2 concentrations that the isolates could survive in comparison with YES media, without aflatoxin production. It is interesting to note that the commercial biocontrol isolates, AF36 (−, and Aflaguard (−, survived at higher levels of stress than other atoxigenic isolates, suggesting that this testing method could potentially be of use in the selection of biocontrol isolates. Further studies will be needed to investigate the mechanisms behind the variability among isolates with regard to their degree of oxidative stress

  16. Occurrence of Aflatoxins and Aflatoxin-Producing Strains of Aspergillus spp. in Soybeans 1

    Science.gov (United States)

    Bean, George A.; Schillinger, John A.; Klarman, William L.

    1972-01-01

    Above average rainfall in Maryland during August, September, and October 1971 resulted in heavy mold growth in soybeans while still in the field. Of 28 samples of soybean seed, aflatoxins were found in 14, 2 of which had been used in poultry feed. Aflatoxins were identified by thin-layer chromatography, spectrophotometry, and chicken embryo bioassay. Aspergillus spp. were isolated from 11 samples, and 5 of these isolates produced aflatoxins when grown in liquid culture. PMID:4673021

  17. Non-aflatoxigenicity of commercial Aspergillus oryzae strains due to genetic defects compared to aflatoxigenic Aspergillus flavus.

    Science.gov (United States)

    Tao, Lin; Chung, Soo Hyun

    2014-08-01

    Aspergillus oryzae is generally recognized as safe, but it is closely related to A. flavus in morphology and genetic characteristics. In this study, we tested the aflatoxigenicity and genetic analysis of nine commercial A. oryzae strains that were used in Korean soybean fermented products. Cultural and HPLC analyses showed that none of the commercial strains produced detectable amount of aflatoxins. According to the molecular analysis of 17 genes in the aflatoxin (AF) biosynthetic pathway, the commercial strains could be classified into three groups. The group I strains contained all the 17 AF biosynthetic genes tested in this study; the group II strains deleted nine AF biosynthetic genes and possessed eight genes, including aflG, aflI, aflK, aflL, aflM, aflO, aflP, and aflQ; the group III strains only had six AF biosynthetic genes, including aflG, aflI, aflK, aflO, aflP, and aflQ. With the reverse transcription polymerase chain reaction, the group I A. oryzae strains showed no expression of aflG, aflQ and/or aflM genes, which resulted in the lack of AF-producing ability. Group II and group III strains could not produce AF owing to the deletion of more than half of the AF biosynthetic genes. In addition, the sequence data of polyketide synthase A (pksA) of group I strains of A. oryzae showed that there were three point mutations (two silent mutations and one missense mutation) compared with aflatoxigenic A. flavus used as the positive control in this study.

  18. Aspergillus section Flavi community structure in Zambia influences aflatoxin contamination of Maize and Groundnut

    Science.gov (United States)

    Aflatoxins are cancer-causing, immuno-suppressive mycotoxins that frequently contaminate important staples in Zambia including maize and groundnut. Several species within Aspergillus section Flavi have been implicated as causal agents of aflatoxin contamination in Africa. However, Aspergillus popula...

  19. The Inhibition of aflatoxin production from Aspergillus parasiticus ...

    African Journals Online (AJOL)

    The inhibition of Aflatoxin production from Aspergillus parasiticus strain NRRL 2999 was investigated using ethanol extracts of Aframommon danielli flower at concentrations of 250ìg/g, 500ìg/g, 750ìg/g and 1000ìg/g with whole wheat bread as a substrate. Aspergillus parasiticus grew abundantly on whole wheat bread; ...

  20. Identification of the Anti-Aflatoxinogenic Activity of Micromeria graeca and Elucidation of Its Molecular Mechanism in Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Rhoda El Khoury

    2017-03-01

    Full Text Available Of all the food-contaminating mycotoxins, aflatoxins, and most notably aflatoxin B1 (AFB1, are found to be the most toxic and economically costly. Green farming is striving to replace fungicides and develop natural preventive strategies to minimize crop contamination by these toxic fungal metabolites. In this study, we demonstrated that an aqueous extract of the medicinal plant Micromeria graeca—known as hyssop—completely inhibits aflatoxin production by Aspergillus flavus without reducing fungal growth. The molecular inhibitory mechanism was explored by analyzing the expression of 61 genes, including 27 aflatoxin biosynthesis cluster genes and 34 secondary metabolism regulatory genes. This analysis revealed a three-fold down-regulation of aflR and aflS encoding the two internal cluster co-activators, resulting in a drastic repression of all aflatoxin biosynthesis genes. Hyssop also targeted fifteen regulatory genes, including veA and mtfA, two major global-regulating transcription factors. The effect of this extract is also linked to a transcriptomic variation of several genes required for the response to oxidative stress such as msnA, srrA, catA, cat2, sod1, mnsod, and stuA. In conclusion, hyssop inhibits AFB1 synthesis at the transcriptomic level. This aqueous extract is a promising natural-based solution to control AFB1 contamination.

  1. Aspergillus flavus infection induces transcriptional and physical changes in developing maize kernels

    Directory of Open Access Journals (Sweden)

    Andrea L Dolezal

    2014-07-01

    Full Text Available Maize kernels are susceptible to infection by the opportunistic pathogen Aspergillus flavus. Infection results in reduction of grain quality and contamination of kernels with the highly carcinogenic mycotoxin, aflatoxin. To understanding host response to infection by the fungus, transcription of approximately 9,000 maize genes were monitored during the host-pathogen interaction with a custom designed Affymetrix GeneChip® DNA array. More than 1,000 maize genes were found differentially expressed at a fold change of 2 or greater. This included the up regulation of defense related genes and signaling pathways. Transcriptional changes also were observed in primary metabolism genes. Starch biosynthetic genes were down regulated during infection, while genes encoding maize hydrolytic enzymes, presumably involved in the degradation of host reserves, were up regulated. These data indicate that infection of the maize kernel by A. flavus induced metabolic changes in the kernel, including the production of a defense response, as well as a disruption in kernel development.

  2. Carbon Dioxide Mediates the Response to Temperature and Water Activity Levels in Aspergillus flavus during Infection of Maize Kernels

    Directory of Open Access Journals (Sweden)

    Matthew K. Gilbert

    2017-12-01

    Full Text Available Aspergillus flavus is a saprophytic fungus that may colonize several important crops, including cotton, maize, peanuts and tree nuts. Concomitant with A. flavus colonization is its potential to secrete mycotoxins, of which the most prominent is aflatoxin. Temperature, water activity (aw and carbon dioxide (CO2 are three environmental factors shown to influence the fungus-plant interaction, which are predicted to undergo significant changes in the next century. In this study, we used RNA sequencing to better understand the transcriptomic response of the fungus to aw, temperature, and elevated CO2 levels. We demonstrate that aflatoxin (AFB1 production on maize grain was altered by water availability, temperature and CO2. RNA-Sequencing data indicated that several genes, and in particular those involved in the biosynthesis of secondary metabolites, exhibit different responses to water availability or temperature stress depending on the atmospheric CO2 content. Other gene categories affected by CO2 levels alone (350 ppm vs. 1000 ppm at 30 °C/0.99 aw, included amino acid metabolism and folate biosynthesis. Finally, we identified two gene networks significantly influenced by changes in CO2 levels that contain several genes related to cellular replication and transcription. These results demonstrate that changes in atmospheric CO2 under climate change scenarios greatly influences the response of A. flavus to water and temperature when colonizing maize grain.

  3. RNAi-mediated Control of Aflatoxins in Peanut: Method to Analyze Mycotoxin Production and Transgene Expression in the Peanut/Aspergillus Pathosystem.

    Science.gov (United States)

    Arias, Renée S; Dang, Phat M; Sobolev, Victor S

    2015-12-21

    The Food and Agriculture Organization of the United Nations estimates that 25% of the food crops in the world are contaminated with aflatoxins. That represents 100 million tons of food being destroyed or diverted to non-human consumption each year. Aflatoxins are powerful carcinogens normally accumulated by the fungi Aspergillus flavus and A. parasiticus in cereals, nuts, root crops and other agricultural products. Silencing of five aflatoxin-synthesis genes by RNA interference (RNAi) in peanut plants was used to control aflatoxin accumulation following inoculation with A. flavus. Previously, no method existed to analyze the effectiveness of RNAi in individual peanut transgenic events, as these usually produce few seeds, and traditional methods of large field experiments under aflatoxin-conducive conditions were not an option. In the field, the probability of finding naturally contaminated seeds is often 1/100 to 1/1,000. In addition, aflatoxin contamination is not uniformly distributed. Our method uses few seeds per transgenic event, with small pieces processed for real-time PCR (RT-PCR) or small RNA sequencing, and for analysis of aflatoxin accumulation by ultra-performance liquid chromatography (UPLC). RNAi-expressing peanut lines 288-72 and 288-74, showed up to 100% reduction (p ≤ 0.01) in aflatoxin B1 and B2 compared to the control that accumulated up to 14,000 ng · g(-1) of aflatoxin B1 when inoculated with aflatoxigenic A. flavus. As reference, the maximum total of aflatoxins allowable for human consumption in the United States is 20 ng · g(-1). This protocol describes the application of RNAi-mediated control of aflatoxins in transgenic peanut seeds and methods for its evaluation. We believe that its application in breeding of peanut and other crops will bring rapid advancement in this important area of science, medicine and human nutrition, and will significantly contribute to the international effort to control aflatoxins, and potentially other

  4. Inhibitory effect of essential oil on aflatoxin activities | Alpsoy ...

    African Journals Online (AJOL)

    Aflatoxins, which are well-known to be mutagenic, carcinogenic, teratogenic, hepatotoxic and immunosuppressive, also inhibit several metabolic systems. Aflatoxins are biologically active secondary metabolites produced by certain strains of Aspergillus parasiticus, Aspergillus nominus and Aspergillus flavus. Many different ...

  5. Interaction of Wild Strains of Aspergilla with Aspergillus parasiticus ATCC15517 and Aflatoxin Production †

    Science.gov (United States)

    Martins, H. Marina; Almeida, Inês; Marques, Marta; Bernardo, Fernando

    2008-01-01

    Aflatoxins are secondary metabolites produced by some competent mould strains of Aspergillus flavus, A. parasiticus and A. nomius. These compounds have been extensively studied with regards to their toxicity for animals and humans; they are able to induce liver cancer and may cause a wide range of adverse effects in living organisms. Aflatoxins are found as natural contaminants of food and feed; the main line of the strategy to control them is based on the prevention of the mould growth in raw vegetable or during its storage and monitoring of each crop batch. Mould growth is conditioned by many ecological factors, including biotic ones. Hazard characterization models for aflatoxins in crops must take into consideration biotic interactions between moulds and their potential effects on growth development. The aim of this work is to study the effect of the biotic interaction of 14 different wild strains of Aspergilla (different species), with a competent strain (Aspergillus parasiticus ATCC 15517) using an in vitro production model. The laboratory model used was a natural matrix (humidified cracked corn), on which each wild strain challenged the aflatoxin production of a producer strain. Cultures were incubated at 28°C for 12 days and sampled at the 8th and 12th. Aflatoxin detection and quantification was performed by HPLC using a procedure with a MRPL = 1 μg/kg. Results of those interactive cultures revealed both synergic and antagonistic effects on aflatoxin biosynthesis. Productivity increases were particularly evident on the 8th day of incubation with wild strains of A. flavipes (+ 70.4 %), A. versicolor (+ 54.9 %) and A. flavus 3 (+ 62.6 %). Antagonistic effects were found with A. niger (− 69.5%), A. fumigatus (− 47.6 %) and A. terreus (− 47.6 %) on the 12th day. The increased effects were more evident on the 8th of incubation and the decreases were more patent on the 12th day. Results show that the development of Aspergilla strains concomitantly with

  6. WetA bridges cellular and chemical development in Aspergillus flavus.

    Directory of Open Access Journals (Sweden)

    Ming-Yueh Wu

    Full Text Available Bridging cellular reproduction and survival is essential for all life forms. Aspergillus fungi primarily reproduce by forming asexual spores called conidia, whose formation and maturation is governed by the central genetic regulatory circuit BrlA→AbaA→WetA. Here, we report that WetA is a multi-functional regulator that couples spore differentiation and survival, and governs proper chemical development in Aspergillus flavus. The deletion of wetA results in the formation of conidia with defective cell walls and no intra-cellular trehalose, leading to reduced stress tolerance, a rapid loss of viability, and disintegration of spores. WetA is also required for normal vegetative growth, hyphal branching, and production of aflatoxins. Targeted and genome-wide expression analyses reveal that WetA exerts feedback control of brlA and that 5,700 genes show altered mRNA levels in the mutant conidia. Functional category analyses of differentially expressed genes in ΔwetA RNA-seq data indicate that WetA contributes to spore integrity and maturity by properly regulating the metabolic pathways of trehalose, chitin, α-(1,3-glucan, β-(1,3-glucan, melanin, hydrophobins, and secondary metabolism more generally. Moreover, 160 genes predicted to encode transcription factors are differentially expressed by the absence of wetA, suggesting that WetA may play a global regulatory role in conidial development. Collectively, we present a comprehensive model for developmental control that bridges spore differentiation and survival in A. flavus.

  7. Occurrence of Aspergillus section Flavi and aflatoxins in Brazilian rice: From field to market

    DEFF Research Database (Denmark)

    Katsurayama, Aline M.; Martins, Ligia Manoel; Iamanaka, Beatriz T.

    2018-01-01

    The guarantee of the high quality of rice is of utmost importance because any toxic contaminant may affect consumer health, especially in countries such as Brazil where rice is part of the daily diet. A total of 187 rice samples, from field, processing and market from two different production...... systems, wetland from the state of Rio Grande do Sul, dryland, from the state of Maranhão and market samples from the state of São Paulo, were analyzed for fungi belonging to Aspergillus section Flavi and the presence of aflatoxins. Twenty-three soil samples from wetland and dryland were also analyzed....... A total of 383 Aspergillus section Flavi strains were isolated from rice and soil samples. Using a polyphasic approach, with phenotypic (morphology and extrolite profiles) and molecular data (beta-tubulin gene sequences), five species were identified: A. flavus, A. caelatus, A. novoparasiticus, A...

  8. Antibiotic Extraction as a Recent Biocontrol Method for Aspergillus Niger andAspergillus Flavus Fungi in Ancient Egyptian mural paintings

    Science.gov (United States)

    Hemdan, R. Elmitwalli; Fatma, Helmi M.; Rizk, Mohammed A.; Hagrassy, Abeer F.

    Biodeterioration of mural paintings by Aspergillus niger and Aspergillus flavus Fungi has been proved in different mural paintings in Egypt nowadays. Several researches have studied the effect of fungi on mural paintings, the mechanism of interaction and methods of control. But none of these researches gives us the solution without causing a side effect. In this paper, for the first time, a recent treatment by antibiotic "6 penthyl α pyrone phenol" was applied as a successful technique for elimination of Aspergillus niger and Aspergillus flavus. On the other hand, it is favorable for cleaning Surfaces of Murals executed by tembera technique from the fungi metabolism which caused a black pigments on surfaces.

  9. The effect of humidity after gamma-irradiation on aflatoxin B-1 production of A.flavus in ground nutmeg and peanut

    Energy Technology Data Exchange (ETDEWEB)

    Hilmy, N.; Chosdu, R. [Center for the Application of Isotopes and Radiation, Jakarta (Indonesia); Matsuyama, A. [Tokyo University of Agriculture (Japan). Nodai Research Inst.

    1995-10-01

    The effect of humidity of 75 up to 97% after irradiation on radiosensitivity and aflatoxin B1 production of Aspergillus flavus isolated from Indonesian nutmeg were examined. Irradiation doses used were 0;0.5;1 and 3 kGy. Mould free ground nutmeg and peanut were used as the growth media, and about 10{sup 8} of spores were used to contaminate each of the media. Aflatoxin productions were measured after having incubated 3 days up to 5 months under humidity of 91 and 97%. Prior to HPLC analysis, aflatoxin was cleaned-up using an immunoaffinity column. The results were: (1) A. flavus indicated no or almost no growth under RH of 85% or less. (2) Under 91-97% RH, growth of mycelium and toxin production were inhibited more or less by irradiation up to 1 kGy, although the effectiveness of irradiation varied with different RH and media during postirradiation incubation. (3) By 3 kGy or more, both mycelium growth and toxin production of the mould were found to be completely inhibited. (4) The production of aflatoxin in nutmeg began after having incubated for 25 and 45 days and in peanut for 3 and 6 days under 97 and 91% RH, respectively. (Author).

  10. Keratitis by Aspergillus flavus infection after cataract surgery

    Directory of Open Access Journals (Sweden)

    João Luiz Pacini Costa

    Full Text Available ABSTRACT We report a case of keratis infection after cataract phacoemulsification with intraocular lens implantation in a 65-year-old female patient. The patient initially underwent cataract surgery on the right eye. Intraocular inflammation appeared on the second post-operative day and was initially treated as Toxic Anterior Segment Syndrome (TASS. The inflammation was reduced and vision improved initially but very aggressive and progressive keratitis destroyed the cornea due to the delay in correct diagnosis. Aspergillus flavus was isolated from a biopsy.The infection was treated with antifungal agents and loss of the eye was avoided by total corneal transplantation associated with Gundersen conjunctiva cover. To restore the lost vision, a second penetrating corneal graft with removal of the conjunctiva cover was performed 17 months later. The final best-corrected vision was 20/40 but prognosis for long-term graft survival is poor.

  11. Biosynthetic relationship among aflatoxins B1, B2, M1, and M2.

    OpenAIRE

    Dutton, M F; Ehrlich, K.; Bennett, J W

    1985-01-01

    Aflatoxins are a family of toxic, acetate-derived decaketides that arise biosynthetically through polyhydroxyanthraquinone intermediates. Most studies have assumed that aflatoxin B1 is the biosynthetic precursor of the other aflatoxins. We used a strain of Aspergillus flavus which accumulates aflatoxin B2 to investigate the later stages of aflatoxin biosynthesis. This strain produced aflatoxins B2 and M2 but no detectable aflatoxin B1 when grown over 12 days in a low-salt, defined growth medi...

  12. Sexual Reproduction in Aspergillus flavus Sclerotia: Acquisition of Novel Alleles from Soil Populations and Uniparental Mitochondrial Inheritance.

    Directory of Open Access Journals (Sweden)

    Bruce W Horn

    Full Text Available Aspergillus flavus colonizes agricultural commodities worldwide and contaminates them with carcinogenic aflatoxins. The high genetic diversity of A. flavus populations is largely due to sexual reproduction characterized by the formation of ascospore-bearing ascocarps embedded within sclerotia. A. flavus is heterothallic and laboratory crosses between strains of the opposite mating type produce progeny showing genetic recombination. Sclerotia formed in crops are dispersed onto the soil surface at harvest and are predominantly produced by single strains of one mating type. Less commonly, sclerotia may be fertilized during co-infection of crops with sexually compatible strains. In this study, laboratory and field experiments were performed to examine sexual reproduction in single-strain and fertilized sclerotia following exposure of sclerotia to natural fungal populations in soil. Female and male roles and mitochondrial inheritance in A. flavus were also examined through reciprocal crosses between sclerotia and conidia. Single-strain sclerotia produced ascospores on soil and progeny showed biparental inheritance that included novel alleles originating from fertilization by native soil strains. Sclerotia fertilized in the laboratory and applied to soil before ascocarp formation also produced ascospores with evidence of recombination in progeny, but only known parental alleles were detected. In reciprocal crosses, sclerotia and conidia from both strains functioned as female and male, respectively, indicating A. flavus is hermaphroditic, although the degree of fertility depended upon the parental sources of sclerotia and conidia. All progeny showed maternal inheritance of mitochondria from the sclerotia. Compared to A. flavus populations in crops, soil populations would provide a higher likelihood of exposure of sclerotia to sexually compatible strains and a more diverse source of genetic material for outcrossing.

  13. Genetic Diversity and In Vitro Antifungal Susceptibility of 200 Clinical and Environmental Aspergillus flavus Isolates

    NARCIS (Netherlands)

    Taghizadeh-Armaki, M.; Hedayati, M.T.; Ansari, S.; Omran, S.M.; Saber, S.; Rafati, H.; Zoll, J.; Lee, H.A.L. van der; Melchers, W.J.G.; Verweij, P.E.; Seyedmousavi, S.

    2017-01-01

    Aspergillus flavus has been frequently reported as the leading cause of invasive aspergillosis in certain tropical and subtropical countries. Two hundred A. flavus strains originating from clinical and environmental sources and collected between 2008 and 2015 were phylogenetically identified at the

  14. Production and Preliminary Characterization of Alkaline Protease from Aspergillus flavus and Aspergillus terreus

    Directory of Open Access Journals (Sweden)

    P. Chellapandi

    2010-01-01

    Full Text Available Proteases are being an industrial candidate, which are widely used in food, bakery, and beverage and detergent industry. In leather industry, alkaline proteases are exhibiting a prominent role in unhairing and bating processes. An extensive use of filamentous fungi, especially Aspergillus species has been studied elaborately. Although, the significant application of alkaline protease produced from these strains in leather industry is being limited. Aspergillus flavus and Aspergillus terreus found as the potential strains for production of tannery protease in submerged fermentation. To improve the productivity of this enzyme in liquid broth, various media ingredients have been optimized. The crude and partially purified proteases preliminarily characterized and used for unhairing processes at lab scale in tannery. The protease obtained from these strains showed the good activity in wide alkaline condition at 50 °C suggesting the possibility of using in leather and detergent industry.

  15. 10522 ASSESSMENT OF AFLATOXINS B1, B2, G1 AND G2 ...

    African Journals Online (AJOL)

    user

    2013-04-13

    Apr 13, 2013 ... Aflatoxins belong to a group of naturally occurring toxins which contaminate foodstuffs under favourable conditions. Aspergillus flavus and Aspergillus parasiticus produce aflatoxins; the four major aflatoxins which contaminate foodstuffs are B1, B2,. G1 and G2. Maize, groundnuts, rice, wheat and other ...

  16. Cyclopiazonic Acid Is a Pathogenicity Factor for Aspergillus flavus and a Promising Target for Screening Germplasm for Ear Rot Resistance.

    Science.gov (United States)

    Chalivendra, Subbaiah C; DeRobertis, Catherine; Chang, Perng-Kuang; Damann, Kenneth E

    2017-05-01

    Aspergillus flavus, an opportunistic pathogen, contaminates maize and other key crops with carcinogenic aflatoxins (AFs). Besides AFs, A. flavus makes many more secondary metabolites (SMs) whose toxicity in insects or vertebrates has been studied. However, the role of SMs in the invasion of plant hosts by A. flavus remains to be investigated. Cyclopiazonic acid (CPA), a neurotoxic SM made by A. flavus, is a nanomolar inhibitor of endoplasmic reticulum calcium ATPases (ECAs) and a potent inducer of cell death in plants. We hypothesized that CPA, by virtue of its cytotoxicity, may serve as a key pathogenicity factor that kills plant cells and supports the saprophytic life style of the fungus while compromising the host defense response. This proposal was tested by two complementary approaches. A comparison of CPA levels among A. flavus isolates indicated that CPA may be a determinant of niche adaptation, i.e., isolates that colonize maize make more CPA than those restricted only to the soil. Further, mutants in the CPA biosynthetic pathway are less virulent in causing ear rot than their wild-type parent in field inoculation assays. Additionally, genes encoding ECAs are expressed in developing maize seeds and are induced by A. flavus infection. Building on these results, we developed a seedling assay in which maize roots were exposed to CPA, and cell death was measured as Evans Blue uptake. Among >40 maize inbreds screened for CPA tolerance, inbreds with proven susceptibility to ear rot were also highly CPA sensitive. The publicly available data on resistance to silk colonization or AF contamination for many of the lines was also broadly correlated with their CPA sensitivity. In summary, our studies show that i) CPA serves as a key pathogenicity factor that enables the saprophytic life style of A. flavus and ii) maize inbreds are diverse in their tolerance to CPA. Taking advantage of this natural variation, we are currently pursuing both genome-wide and candidate gene

  17. Use of a granular bioplastic formulation for carrying conidia of a non-aflatoxigenic strain of Aspergillus flavus.

    Science.gov (United States)

    Accinelli, Cesare; Saccà, M Ludovica; Abbas, Hamed K; Zablotowicz, Robert M; Wilkinson, Jeffery R

    2009-09-01

    Previous research demonstrated that aflatoxin contamination in corn is reduced by field application of wheat grains pre-inoculated with the non-aflatoxigenic Aspergillus flavus strain NRRL 30797. To facilitate field applications of this biocontrol isolate, a series of laboratory studies were conducted on the reliability and efficiency of replacing wheat grains with the novel bioplastic formulation Mater-Bi to serve as a carrier matrix to formulate this fungus. Mater-Bi granules were inoculated with a conidial suspension of NRRL 30797 to achieve a final cell density of approximately log 7 conidia/granule. Incubation of 20-g soil samples receiving a single Mater-Bi granule for 60-days resulted in log 4.2-5.3 propagules of A. flavus/g soil in microbiologically active and sterilized soil, respectively. Increasing the number of granules had no effect on the degree of soil colonization by the biocontrol fungus. In addition to the maintenance of rapid vegetative growth and colonization of soil samples, the bioplastic formulation was highly stable, indicating that Mater-Bi is a suitable substitute for biocontrol applications of A. flavus NRRL 30797.

  18. Screening a strain of Aspergillus niger and optimization of fermentation conditions for degradation of aflatoxin B

    National Research Council Canada - National Science Library

    Zhang, Wei; Xue, Beibei; Li, Mengmeng; Mu, Yang; Chen, Zhihui; Li, Jianping; Shan, Anshan

    2014-01-01

    ...) was able to degrade aflatoxin B₁ after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B₁...

  19. Genotypic Regulation of Aflatoxin Accumulation but Not Aspergillus Fungal Growth upon Post-Harvest Infection of Peanut (Arachis hypogaea L. Seeds

    Directory of Open Access Journals (Sweden)

    Walid Ahmed Korani

    2017-07-01

    Full Text Available Aflatoxin contamination is a major economic and food safety concern for the peanut industry that largely could be mitigated by genetic resistance. To screen peanut for aflatoxin resistance, ten genotypes were infected with a green fluorescent protein (GFP—expressing Aspergillus flavus strain. Percentages of fungal infected area and fungal GFP signal intensity were documented by visual ratings every 8 h for 72 h after inoculation. Significant genotypic differences in fungal growth rates were documented by repeated measures and area under the disease progress curve (AUDPC analyses. SICIA (Seed Infection Coverage and Intensity Analyzer, an image processing software, was developed to digitize fungal GFP signals. Data from SICIA image analysis confirmed visual rating results validating its utility for quantifying fungal growth. Among the tested peanut genotypes, NC 3033 and GT-C20 supported the lowest and highest fungal growth on the surface of peanut seeds, respectively. Although differential fungal growth was observed on the surface of peanut seeds, total fungal growth in the seeds was not significantly different across genotypes based on a fluorometric GFP assay. Significant differences in aflatoxin B levels were detected across peanut genotypes. ICG 1471 had the lowest aflatoxin level whereas Florida-07 had the highest. Two-year aflatoxin tests under simulated late-season drought also showed that ICG 1471 had reduced aflatoxin production under pre-harvest field conditions. These results suggest that all peanut genotypes support A. flavus fungal growth yet differentially influence aflatoxin production.

  20. Single corn kernel aflatoxin B1 extraction and analysis method

    Science.gov (United States)

    Aflatoxins are highly carcinogenic compounds produced by the fungus Aspergillus flavus. Aspergillus flavus is a phytopathogenic fungus that commonly infects crops such as cotton, peanuts, and maize. The goal was to design an effective sample preparation method and analysis for the extraction of afla...

  1. Effects of gamma radiation and electron beam on samples of the Brazil nuts artificially inoculated with Aspergillus flavus; Efeitos da radiacao gama e feixe de eletrons sobre amostras de castanhas-do-Brasil inoculadas artificialmente com Aspergillus flavus

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Ednei Assuncao Antunes

    2012-07-01

    The high level of contamination by aflatoxin produced by fungi in lots of Brazil nuts and the strict control by importing countries in relation to the levels of toxins in food, European Union countries decided in 2003 by the return of these lots products from Brazil. Despite the economic loss represented by contamination by toxigenic fungi in Brazil nuts, a major product of extractive Northern of Brazil, studies are still preliminary as the control of contamination aflatoxigenic fungal using methods such as gamma radiation (G.R) and mainly, electron beam (E.B). These facts motivated this research, which aimed to evaluate the effects of gamma radiation and application of electron beam in samples of Brazil nut artificially inoculated with Aspergillus flavus. This goal, we were studied 50 samples of the Brazil nut previously inoculated with spores of A. flavus and subsequently incubated at 30 °C in relative humidity controlled at 93%. After incubation, period of 15 days, the average water activity of the samples was 0.80, the samples were divided into 5 groups that received the following doses of radiation: control (0 kGy), 5 and 10 kGy 5 E.B and G.R. The mycobiota was performed by serial dilution, plated on surface using potato dextrose agar. The results demonstrated that treatment with E.B using a dose of 5 kGy and 10 kGy resulted in reduced growth of A. flavus in 74% (37/50) and 94% (47/50) of samples. The samples treated with G.R at the dose of 5 kGy and 10 kGy no fungal growth occurred in 92% (46/50) 100% (50/50) of. The study of aflatoxins showed that doses of E.B of 5 kGy and 10 kGy reduced levels of AFB1 at 53.32% and 65.66% respectively. The application of gamma rays at doses of 5 and 10 kGy reduced levels of toxins in 70.61% and 84.15% respectively. This result may be attributed to higher penetrability of gamma radiation. Sensory analysis showed greater acceptance of the judges for the samples irradiated with E.B and G.R at the dose of 10 kGy. We concluded

  2. Mycotoxin producing potential of some isolates of Aspergillus flavus and Eurotium groups from meat products.

    Science.gov (United States)

    el-Kady, I; el-Maraghy, S; Zohri, A N

    1994-09-01

    All strains (92) of A. flavus group proved to be positive for production of aflatoxin (45 to 1200 micrograms/50 ml medium) on potato dextrose liquid medium, while 59 strains only proved to be positive (35-310 micrograms/50 ml) on 15% NaCl potato-dextrose liquid medium. Most of the strains tested of A. flavus, A. flavus var. columnaris and A. oryzae produced aflatoxins B1, B2, G1 & G2. All positive strains of A. tamarii produced aflatoxins G1 & G2 while the tested isolate of A. zonatus produced aflatoxins B1 & G1. Of 95 strains tested of Eurotium, aflatoxins B1 & G1 were produced by one strain of each of E. chevalieri var. intermedium, E. repens and E. rubrum. Gliotoxin was detected in the extract of two strains of E. chevalieri and one strain of each of E. chevalieri var. intermedium and E. pseudoglaucum on the salt-free medium, and two strains of each of E. chevalieri, E. chevalieri var. intermedium and one of E. pseudoglaucum on 15% NaCl medium. Sterigmatocystin was produced by some strains of E. chevalieri, E. chevalieri var. intermedium, E. amstelodami, E. pseudoglaucum and E. rubrum on the two experimental media. One strain only of E. repens produced ochratoxin A while citrinin was detected in the extract of one strain of E. pseudoglaucum.

  3. Challenges facing the biological control strategy for eliminating aflatoxin contamination

    Science.gov (United States)

    Competition with Aspergillus flavus isolates incapable of aflatoxin production is currently the most widely used biocontrol method for reducing aflatoxin contamination of in maize and cottonseed where aflatoxin contamination is a persistent problem for human and animal health. The method involves sp...

  4. Aflatoxin Accumulation in a Maize Diallel Cross

    OpenAIRE

    W. Paul Williams; Gary L. Windham

    2015-01-01

    Aflatoxins, produced by the fungus Aspergillus flavus , occur naturally in maize. Contamination of maize grain with aflatoxin is a major food and feed safety problem and greatly reduces the value of the grain. Plant resistance is generally considered a highly desirable approach to reduction or elimination of aflatoxin in maize grain. In this investigation, a diallel cross was produced by crossing 10 inbred lines with varying degrees of resistance to aflatoxin accumulation in all possible comb...

  5. Co-inoculation of aflatoxigenic and non-aflatoxigenic strains of Aspergillus flavus to study fungal invasion, colonization, and competition in maize kernels

    Directory of Open Access Journals (Sweden)

    Zuzana eHruska

    2014-03-01

    Full Text Available A currently utilized pre-harvest biocontrol method involves field inoculations with non-aflatoxigenic Aspergillus flavus strains, a tactic shown to strategically suppress native aflatoxin-producing strains and effectively decrease aflatoxin contamination in corn. The present in situ study focuses on tracking the invasion and colonization of an aflatoxigenic A. flavus strain (AF70, labeled with green fluorescent protein (GFP, in the presence of a non-aflatoxigenic A. flavus biocontrol strain (AF36 to better understand the competitive interaction between these two strains in seed tissue of corn (Zea mays. Corn kernels that had been co-inoculated with GFP-labeled AF70 and wild-type AF36 were cross-sectioned and observed under UV and blue light to determine the outcome of competition between these strains. After imaging, all kernels were analyzed for aflatoxin levels. There appeared to be a population difference between the co-inoculated AF70-GFP+AF36 and the individual AF70-GFP tests, both visually and with pixel count analysis. The GFP allowed us to observe that AF70-GFP inside the kernels was suppressed up to 82% when co-inoculated with AF36 indicating that AF36 inhibited progression of AF70-GFP. This was in agreement with images taken of whole kernels where AF36 exhibited a more robust external growth compared to AF70-GFP. The suppressed growth of AF70-GFP was reflected in a corresponding (up to 73% suppression in aflatoxin levels. Our results indicate that the decrease in aflatoxin production correlated with population depression of the aflatoxigenic fungus by the biocontrol strain supporting the theory of competitive exclusion through robust propagation and fast colonization by the non-aflatoxigenic fungus.

  6. High sequence variations in the region containing genes encoding a cellular morphogenesis protein and the repressor of sexual development help to reveal origins of Aspergillus oryzae

    Science.gov (United States)

    Aspergillus oryzae and Aspergillus flavus are closely related fungal species. The A. flavus population that produces numerous small sclerotia (S strain) and aflatoxin has a unique 1.5 kb deletion in the norB-cypA region of the aflatoxin gene cluster (the S genotype). Phylogenetic studies have indica...

  7. Sinusite invasiva por Aspergillus flavus : relato de um caso associado a leucemia aguda bifenotípica

    OpenAIRE

    Xavier, Melissa Orzechowski; Oliveira, Flávio de Mattos; Almeida, Valdir de; Prolla, Gabriel; Severo, Luiz Carlos

    2009-01-01

    Here we report a case of invasive pansinusitis with proptosis of the right eye caused by Aspergillus flavus in an immunocompromised patient with acute biphenotypic leukemia without aggressive therapy response.Descreve-se um caso de pansinusite invasiva com proptose do globo ocular direito causado por Aspergillus flavus em um paciente imunossuprimido com leucemia aguda bifenotípica sem resposta a terapia agressiva.

  8. The chemical heritage of Aspergillus flavus in A. oryzae RIB 40

    DEFF Research Database (Denmark)

    Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj

    Aspergillus oryzae is a very important species in biotechnology and has been used for centuries in traditional Asian fermentation. The RIB40 strain is particularly interesting as it was one of the first genome sequenced Aspergilli together with A. flavus, a prominent food and feed contaminant...... with indications to specific genetic changes. Several new metabolites and changes in biosynthetic routes have been found in A. oryzae, indicating subtle changes in the genomic heritage from A. flavus....

  9. [Medium optimization for antagonistic Streptomyces S24 and its inhibition on Aspergillus flavus].

    Science.gov (United States)

    Zhou, Qisheng; Liu, Xunli; Zhang, Nan; Song, Zhen; Qiu, Nianquan; Zhang, Benfeng; Guo, Hui; Lü, Changxu; Yu, Jian

    2011-02-01

    Streptomyces S24 has broad spectrum against Aspergillus spp. in food and feed, such as Aspergillus flavus, Aspergillus niger and Asperegillus alutacells. The objective of this study was to improve the production of antifungal substances produced by S24 and to test their inhibitory effects on Aspergillus flavus. By using one-factor-at-a-time experiment and orthogonal design method, we optimized the fermentation medium. The composition of an optimized medium for the production of antifungal substances contained (g/L): starch soluble, 10; Glucose, 40; yeast extract, 8; soybean powder, 24; KH2PO4 4; and CaCO3 0.8. As a result, the productivity of antifungal substances could reach to 10 235.45 microg/mL, and this value was 2.81 times higher than that of initial medium before optimization. Additionally, inhibitory effects of the products on Aspergillus flavus were analyzed. Antagonistic tests indicated that the antifungal substances greatly inhibited mycelium growth and spores germination of Aspergillus flavus. We observed through microscope that the mycelia grew abnormally, such as contorting, bulging, vacuole increasing and the cytoplasmic contents inside effusing and the spores appeared unusual, such as gathering, deforming, cytoplasmic contents inside effusing and fracturing.

  10. Effect of γ-radiation on the production of aflatoxin B1 by Aspergillus parasiticus in raisins (Vitis vinifera L.)

    Science.gov (United States)

    Kanapitsas, Alexandros; Batrinou, Anthimia; Aravantinos, Athanasios; Markaki, Panagiota

    2015-01-01

    Aflatoxin B1 (AFB1) mostly produced by Aspergillus flavus and Aspergillus parasiticus, is an extremely toxic and carcinogenic metabolite. The effect of gamma irradiation at dose of 10 kGy on the production of aflatoxin B1 (AFB1) inoculated by Aspergillus parasiticus in raisins (Vitis vinifera L.) and on AFB1 in contaminated samples, was investigated. Values of the amount of aflatoxin B1 produced on the 12th day of incubation, after irradiation, showed that gamma radiation exposure at 10 kGy decreased AFB1 production at 65% compared with the non-irradiated sample, on the same day. The application of 10 kGy gamma radiation directly on 100 ng of AFB1 which were spiked in raisins resulted in ~29% reduction of AFB1. According to the risk assessment analysis the Provisional Maximum Tolerable Daily Intake (PMTDI) of 1.0 ng AFB1 kg-1bw, indicates that consumers are less exposed to AFB1 from the irradiated raisins.

  11. ROS Involves the Fungicidal Actions of Thymol against Spores of Aspergillus flavus via the Induction of Nitric Oxide

    OpenAIRE

    Qingshan Shen; Wei Zhou; Hongbo Li; Liangbin Hu; Haizhen Mo

    2016-01-01

    Aspergillus flavus is a well-known pathogenic fungus for both crops and human beings. The acquisition of resistance to azoles by A. flavus is leading to more failures occurring in the prevention of infection by A. flavus. In this study, we found that thymol, one of the major chemical constituents of the essential oil of Monarda punctate, had efficient fungicidal activity against A. flavus and led to sporular lysis. Further studies indicated that thymol treatment induced the generation of both...

  12. Exposure measurement of aflatoxins and aflatoxin metabolites in human body fluids. A short review.

    Science.gov (United States)

    Leong, Yin-Hui; Latiff, Aishah A; Ahmad, Nurul Izzah; Rosma, Ahmad

    2012-05-01

    Aflatoxins are highly toxic secondary fungal metabolites mainly produced by Aspergillus flavus and A. parasiticus. Human exposure to aflatoxins may result directly from ingestion of contaminated foods, or indirectly from consumption of foods from animals previously exposed to aflatoxins in feeds. This paper focuses on exposure measurement of aflatoxins and aflatoxin metabolites in various human body fluids. Research on different metabolites present in blood, urine, breast milk, and other human fluids or tissues including their detection techniques is reviewed. The association between dietary intake of aflatoxins and biomarker measurement is also highlighted. Finally, aspects related to the differences between aflatoxin determination in food versus the biomarker approach are discussed.

  13. Evaluation of antifungal activity of essential oils against potentially mycotoxigenic Aspergillus flavus and Aspergillus parasiticus

    Directory of Open Access Journals (Sweden)

    Fernanda C. da Silva

    2012-10-01

    Full Text Available The antifungal activity of essential oils of fennel (Foeniculum vulgare Mill., Apiaceae, ginger (Zingiber officinale Roscoe, Zingiberaceae, mint (Mentha piperita L., Lamiaceae and thyme (Thymus vulgaris L., Lamiaceae was evaluated against mycotoxin producers Aspergillus flavus and A. parasiticus. High Resolution Gas Chromatography was applied to analyze chemical constituents of essential oils. The effect of different concentrations of essential oils was determined by solid medium diffusion assay. Mycelial growth and sporulation were determined for each essential oil at the concentrations established by solid medium diffusion assay. At the fifth, seventh and ninth days the mycelial diameter (Ø mm and spore production were also determined. FUN-1 staining was performed to assess cell viability after broth macrodilution assay. Trans-anethole, zingiberene, menthol and thymol are the major component of essential oils of fennel, ginger, mint and thyme, respectively. The effective concentrations for fennel, ginger, mint and thyme were 50, 80, 50 and 50% (oil/DMSO; v/v, respectively. The four essential oils analysed in this study showed antifungal effect. Additionally, FUN-1 staining showed to be a suitable method to evaluate cell viability of potential mycotoxigenic fungi A. flavus and A. parasiticus after treatment with essential oils.

  14. Evaluation of antifungal activity of essential oils against potentially mycotoxigenic Aspergillus flavus and Aspergillus parasiticus

    Directory of Open Access Journals (Sweden)

    Fernanda C. da Silva

    2012-04-01

    Full Text Available The antifungal activity of essential oils of fennel (Foeniculum vulgare Mill., Apiaceae, ginger (Zingiber officinale Roscoe, Zingiberaceae, mint (Mentha piperita L., Lamiaceae and thyme (Thymus vulgaris L., Lamiaceae was evaluated against mycotoxin producers Aspergillus flavus and A. parasiticus. High Resolution Gas Chromatography was applied to analyze chemical constituents of essential oils. The effect of different concentrations of essential oils was determined by solid medium diffusion assay. Mycelial growth and sporulation were determined for each essential oil at the concentrations established by solid medium diffusion assay. At the fifth, seventh and ninth days the mycelial diameter (Ø mm and spore production were also determined. FUN-1 staining was performed to assess cell viability after broth macrodilution assay. Trans-anethole, zingiberene, menthol and thymol are the major component of essential oils of fennel, ginger, mint and thyme, respectively. The effective concentrations for fennel, ginger, mint and thyme were 50, 80, 50 and 50% (oil/DMSO; v/v, respectively. The four essential oils analysed in this study showed antifungal effect. Additionally, FUN-1 staining showed to be a suitable method to evaluate cell viability of potential mycotoxigenic fungi A. flavus and A. parasiticus after treatment with essential oils.

  15. Local isolate of Saccharomyces cerevisiae as biocompetitive agent of Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Eni Kusumaningtyas

    2006-12-01

    Full Text Available Aspergillus flavus is a toxigenic fungus that contaminates feed and influences the animal health. Saccharomyces cerevisiae can be used as a biocompetitive agent to control the contamination. The ability of local isolate of S. cerevisiae as a biocompetitive agent for A. flavus was evaluated. A. flavus (30ml was swept on Sabouraud dextrose agar (SDA, while S. cerevisiae was swept on its left and right. Plates were incubated at 28oC for nine days. Lytic activity of S. cerevisiae was detected by pouring its suspension on the centre of the cross streaks of A. flavus. Plates were incubated at 28oC for five days. Growth inhibition of A. flavus by S. cerevisiae was determined by mixing the two fungi on Potato dextrose broth and incubated at 28oC for 24 hours. Total colony of A. flavus were then observed at incubation time of 2, 4, 6 and 24 hours by pour plates method on the SDA plates and incubated on 28oC for two days. Growth of hyphae of A. flavus sweep were inhibited with the swept of S. cerevisiae. The width of A. flavus colony treated with S. cerevisiae is narrower (3,02 cm than that of control ( 4,60 cm. The growth of A. flavus was also inhibited on the centre of cross streak where the S. cerevisiae poured. S. cerevisiae gradually reduced the colony number of A. flavus in the mixed culture of broth fungi ie. 14 x 103 CFU/ml while colony number of control is 80 x 103 CFU/ml. Results showed that S. cerevisiae could be used as biocompetitive agent of A. flavus.

  16. aflatoxigenic Aspergillus flavus in groundnut seeds across India

    African Journals Online (AJOL)

    user

    2013-05-08

    May 8, 2013 ... problems in the tropical hot and humid climate of World. (Keenan and Savage, 1994; Kishore et al., ... cerns in many countries (Bhatnagar et al., 2003). Aflatoxin is a group of mycotoxins produced .... curves using absorbance (A) vs. logarithm of analyte concentration were plotted. Total aflatoxins in the ...

  17. Functional Analysis of the Nitrogen Metabolite Repression Regulator Gene nmrA in Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Xiaoyun Han

    2016-11-01

    Full Text Available In Aspergillus nidulans, the nitrogen metabolite repression regulator NmrA plays a major role in regulating the activity of the GATA transcription factor AreA during nitrogen metabolism. However, the function of nmrA in Aspergillus flavus has notbeen previously studied. Here, we report the identification and functional analysis of nmrA in A. flavus. Our work showed that the amino acid sequences of NmrA are highly conserved among Aspergillus species and that A. flavus NmrA protein contains a canonical Rossmann fold motif. Deletion of nmrA slowed the growth of A. flavus but significantly increased conidiation and sclerotia production. Moreover, seed infection experiments indicated that nmrA is required for the invasive virulence of A. flavus. In addition, the ΔnmrA mutant showed increased sensitivity to rapamycin and methyl methanesulfonate, suggesting that nmrA could be responsive to target of rapamycin signaling and DNA damage. Furthermore, quantitative real-time reverse transcription polymerase chain reaction analysis suggested that nmrA might interact with other nitrogen regulatory and catabolic genes. Our study provides a better understanding of nitrogen metabolite repression and the nitrogen metabolism network in fungi.

  18. THE EFFECTS OF DRYING AND SHELLING ON ASPERGILLUS FLAWS INFECTION AND AFLATOXIN PRODUCTION OF MAIZE

    Directory of Open Access Journals (Sweden)

    O.S. DHARMAPUTRA

    1997-01-01

    Full Text Available The effects of drying and shelling on Aspergillus fla-us infection and aflatoxin production of maize stored under laboratory conditions were investigated together with the intactness of grain and change of moisture content during the storage period. Fully matured maize var. Arjuna and CPI-2 were harvested at 90 and 97 days after planting, respectively, after which they were unhusked and divided into 4 pans. The 1st and the 2nd parts were sun dried up to 20^ moisture content (m.c. and then shelled and re-dried up to 17 and 14% m.c.. respectively. The 3rd part was sun dried up to 17% m.c. and then shelled but not re-dned. The 4th pan was sun dried up to 17% m.c. and then shelled and re-dried up to 14% m.c. The maize was sun dried by spreading either the cobs or the kernels on the paved floor. The nail-down wood and mechanical sheller were used for shelling the maize. After drying and shelling, maize samples were stored in the jars which were covered with muslin cloth for 3 months under laboratory conditions. A. flavus was isolated using dilution method on Aspergillus Flavus and Parasiticus Agar (AFPA. The damaged kernel analysis was carried out at the beginning of storage to obtain the percentage of damaged kernel caused by shelling. The m.c. and aflatoxin were determined using oven and High Performance Liquid Chromatography (HPLC methods, respectively. The m.c. decreased at 1 month of storage and then it was almost constant at 2 and 3 months of storage. The percentage of damaged kernels of maize var. CPI-2 was higher than those of var. Arjuna. The percentage of damaged kernels of maize shelled at 20% m.c. was higher than that shelled at 17% m.c. The percentage of damaged kernels of maize shelled by mechanical sheller was higher than that shelled by nail-down wood.Paper presented at the Symposium on Pest Management for Stored Food and Feed, 5-7 September 1995 Bogor, Indonesia. 29 The Effects of Drying and Shelling on Aspergillus flavus Infection

  19. Mechanisms of antifungal and anti-aflatoxigenic properties of essential oil derived from turmeric (Curcuma longa L.) on Aspergillus flavus.

    Science.gov (United States)

    Hu, Yichen; Zhang, Jinming; Kong, Weijun; Zhao, Gang; Yang, Meihua

    2017-04-01

    The antifungal activity and potential mechanisms in vitro as well as anti-aflatoxigenic efficiency in vivo of natural essential oil (EO) derived from turmeric (Curcuma longa L.) against Aspergillus flavus was intensively investigated. Based on the previous chemical characterization of turmeric EO by gas chromatography-mass spectrometry, the substantially antifungal activities of turmeric EO on the mycelial growth, spore germination and aflatoxin production were observed in a dose-dependent manner. Furthermore, these antifungal effects were related to the disruption of fungal cell endomembrane system including the plasma membrane and mitochondria, specifically i.e. the inhibition of ergosterol synthesis, mitochondrial ATPase, malate dehydrogenase, and succinate dehydrogenase activities. Moreover, the down-regulation profiles of turmeric EO on the relative expression of mycotoxin genes in aflatoxin biosynthetic pathway revealed its anti-aflatoxigenic mechanism. Finally, the suppression effect of fungal contamination in maize indicated that turmeric EO has potential as an eco-friendly antifungal agent. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Occurrence of Aspergillus spp. and aflatoxin B1 in Malaysian foods used for human consumption.

    Science.gov (United States)

    Reddy, Kasa R N; Farhana, Nazira I; Salleh, Baharuddin

    2011-05-01

    Malaysian population widely consumes the cereal-based foods, oilseeds, nuts, and spices in their daily diet. Mycotoxigenic fungi are well known to invade food products under storage conditions and produce mycotoxins that have threat to human and animal health. Therefore, determining toxigenic fungi and aflatoxin B(1) (AFB1) in foods used for human consumption is of prime importance to develop suitable management strategies and to minimize risk. Ninety-five food products marketed in Penang, Malaysia were randomly collected from different supermarkets and were analyzed for presence of Aspergillus spp. by agar plate assay and AFB1 by enzyme-linked immunosorbent assay (ELISA). A. flavus was the dominant fungi in all foods followed by A. niger. Fifty-five A. flavus strains were tested for their ability to produce aflatoxins on rice grain substrate. Thirty-six (65.4%) strains out of 55 produced AFB1 ranging from 1700 to 4400 μg/kg and 17 strains (31%) produced AFB2 ranging from 620 to 1670 μg/kg. Natural occurrence of AFB1 could be detected in 72.6% food products ranging from 0.54 to 15.33 μg/kg with a mean of 1.95 μg/kg. Maximum AFB1 levels were detected in peanut products ranging from 1.47 to 15.33 μg/kg. AFB1 levels detected in all food products were below the Malaysian permissible limits (Malaysia. © 2011 Institute of Food Technologists®

  1. Aspergillus flavus aswA, a gene homolog of Aspergillus nidulans oefC, regulates sclerotial development and biosynthesis of sclerotium-associated secondary metabolites.

    Science.gov (United States)

    Chang, Perng-Kuang; Scharfenstein, Leslie L; Li, Robert W; Arroyo-Manzanares, Natalia; De Saeger, Sarah; Diana Di Mavungu, José

    2017-07-01

    Aspergillus flavus aswA (AFLA_085170) is a gene encoding a Zn(II)2Cys6 DNA-binding domain and a transcriptional activation domain, DUF3468. Disruption of aswA yielded strains that made a truncated gene transcript and generated a fungus that produced a greatly increased number of sclerotia. These sclerotia were odd-shaped and non-pigmented (white) and different from oval and pigmented (dark brown to black) mature sclerotia. Transcriptomic analysis of the ΔaswA strain grown on potato dextrose agar plates and Wickerham agar plates showed that expression of clustering genes involved in the biosynthesis of three sclerotium-associated secondary metabolites was down-regulated. These included gene clusters of asparasone, aflatrem, and aflavarin. In contrast, those of aflatoxin, cyclopiazonic acid and kojic acid were not affected. Metabolite analyses confirmed that the non-pigmented sclerotia contained aflatoxin and cyclopiazonic acid but not other aforementioned metabolites, three asparasone analogs and dihydroxyaflavinine commonly present in mature sclerotia. Impairment in aswA gene function stalls normal sclerotial development, which in turn prevents biosynthesis and accumulation of sclerotium-specific metabolites. Copyright © 2017. Published by Elsevier Inc.

  2. Aspergillus flavus Keratitis: Experience of a Tertiary Eye Clinic in Turkey

    NARCIS (Netherlands)

    Erdem, E.; Yagmur, M.; Boral, H.; Ilkit, M.; Ersoz, R.; Seyedmousavi, S.

    2017-01-01

    We investigated the clinical and mycological characteristics of four cases of mycotic keratitis caused by Aspergillus flavus that occurred from July 2014 to May 2015 at Cukurova University Hospital, Adana, Turkey. In a 10-month period, a total of 64 corneal smear/scrapings were examined from

  3. Seventeen years of subcutaneous infection by Aspergillus flavus; eumycetoma confirmed by immunohistochemistry

    NARCIS (Netherlands)

    Ahmed, Sarah A; Abbas, Manal A; Jouvion, Gregory; Al-Hatmi, Abdullah M S; de Hoog, G Sybren; Kolecka, Anna; Mahgoub, El Sheikh

    2015-01-01

    Chronic subcutaneous infections caused by Aspergillus species are considered to be extremely rare. Because these fungi are among the most common laboratory contaminants, their role as eumycetoma causative agents is difficult to ascertain. Here, we report the first case of A. flavus eumycetoma

  4. Potential roles of WRKY transcription factors in resistance to Aspergillus flavus colonization of immature maize kernels

    Science.gov (United States)

    Resistance to Aspergillus flavus by maize (Zea mays L.) is mediated by several defense proteins; however the mechanism regulating the expression of these defenses is poorly understood. This study examined the potential roles of six maize WRKY transcription factors, ZmWRKY19, ZmWRKY21, ZmWRKY53, ZmW...

  5. Genomic sequences of Aspergillus flavus accessions in Georgia USA

    Data.gov (United States)

    US Agency for International Development — The data was produced as part of the Feed the Future Innovation Lab for Collaborative Research on Peanut Productivity and Aflatoxin Control (the Peanut &...

  6. Preliminary studies of inhibitions in Aspergillus flavus with extracts of ...

    African Journals Online (AJOL)

    Administrator

    1995). The genus is widely distributed, and A. flavus spores are found in the air and in the soil (Alexopoulos, 1962). They thrive on any organic substance with little moisture. Products with moisture levels above 16% are capable of supporting the.

  7. Invasive Aspergillus flavus sinusitis: case report in a patient with biphenotypic acute leukemia Sinusite invasiva por Aspergillus flavus: relato de um caso associado a leucemia aguda bifenotípica

    Directory of Open Access Journals (Sweden)

    Melissa Orzechowski Xavier

    2009-02-01

    Full Text Available Here we report a case of invasive pansinusitis with proptosis of the right eye caused by Aspergillus flavus in an immunocompromised patient with acute biphenotypic leukemia without aggressive therapy response.Descreve-se um caso de pansinusite invasiva com proptose do globo ocular direito causado por Aspergillus flavus em um paciente imunossuprimido com leucemia aguda bifenotípica sem resposta a terapia agressiva.

  8. Comparative chemistry of Aspergillus oryzae (RIB40) and A. flavus (NRRL 3357)

    DEFF Research Database (Denmark)

    Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj

    2012-01-01

    Aspergillus oryzae and A. flavus are important species in industrial biotechnology and food safety and have been some of the first aspergilli to be fully genome sequenced. Bioinformatic analysis has revealed 99.5% gene homology between the two species pointing towards a large coherence...... in the secondary metabolite production. In this study we report on the first comparison of secondary metabolite production between the full genome sequenced strains of A. oryzae (RIB40) and A. flavus (NRRL 3357). Surprisingly, the overall chemical profiles of the two strains were mostly very different across 15...

  9. Nutritional changes in powdered red pepper upon in vitro infection of Aspergillus flavus Alterações nutricionais em pimenta vermelha em pó após infecção in vitro com Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Smita Tripathi

    2009-03-01

    Full Text Available Quantitative losses in various biochemical constituents like capsaicin, carotenes, ascorbic acid, polyphenols, mineral matter, sugars (soluble and insoluble, protein and fat were estimated after the successful growth of Aspergillus flavus for 30 days on powdered red pepper. The fungal biomass was measured by ergosterol content and Aflatoxin B1 by HPLC. Amongst the various nutritional constituents evaluated for nutritional losses and changes the highest nutritional loss was reported in total carotenoids (88.55% followed by total sugars (85.5%. The protein content of the infected sample increased from 18.01% to 23%. The nutritional profile of chilli powder (Capsicum annum var. sannam L. shows highest share of total soluble sugars (32.89% and fiber content (21.05%, followed by protein (18.01% and fat (13.32% making it an ideal solid - substrate for mould growth. At the end of incubation the fungal biomass was 192. 25 mg / 100 gram powder, total plate count 17.5 X 10 4 CFU/g and Aflatoxin B1 content was 30.06 µg / kg.Foram avaliadas as perdas de vários constituintes bioquímicos como capsaicina, carotenos, acido ascórbico, polifenóis, matéria orgânica, açucares (solúveis e insolúveis, proteína e gordura em pimenta vermelha em pó após a multiplicação de Aspergillus flavus por 30 dias. A biomassa fúngica foi mensurada pelo conteúdo de ergosterol e aflatoxina por HPLC. Entre os vários constituintes avaliados, a maior perda foi a de carotenóides totais (88,55%, seguido de açucares totais (85,5%. O conteúdo protéico da amostra infectada aumentou de 18,01% para 23%. O perfil nutricional da pimenta em pó (Capsicum annum var. sannam L. indica alto teor de açucares totais (32,89% e fibras (21,05%, seguido de proteína (18,01% e gordura (13,32%, tornando-a um substrato ideal para crescimento de fungos. Ao final dos 30 dias, a biomassa fúngica foi 192,25 mg/100g, a contagem total em placas foi 17,5 x 10(4 CFU/g e o conteúdo de

  10. Involvement of the nadA gene in formation of G-group aflatoxins in Aspergillus parasiticus.

    Science.gov (United States)

    Cai, Jingjing; Zeng, Hongmei; Shima, Yoko; Hatabayashi, Hidemi; Nakagawa, Hiroyuki; Ito, Yasuhiro; Adachi, Yoshikazu; Nakajima, Hiromitsu; Yabe, Kimiko

    2008-07-01

    The nadA gene is present at the end of the aflatoxin gene cluster in the genome of Aspergillus parasiticus as well as in Aspergillus flavus. RT-PCR analyses showed that the nadA gene was expressed in an aflatoxin-inducible YES medium, but not in an aflatoxin-non-inducible YEP medium. The nadA gene was not expressed in the aflR gene-deletion mutant, irrespective of the culture medium used. To clarify the nadA gene's function, we disrupted the gene in aflatoxigenic A. parasiticus. The four nadA-deletion mutants that were isolated commonly accumulated a novel yellow-fluorescent pigment (named NADA) in mycelia as well as in culture medium. When the mutants and the wild-type strain were cultured for 3 days in YES medium, the mutants each produced about 50% of the amounts of G-group aflatoxins that the wild-type strain produced. In contrast, the amounts of B-group aflatoxins did not significantly differ between the mutants and the wild-type strain. The NADA pigment was so unstable that it could non-enzymatically change to aflatoxin G(1) (AFG(1)). LC-MS measurement showed that the molecular mass of NADA was 360, which is 32 higher than that of AFG(1). We previously reported that at least one cytosol enzyme, together with two other microsome enzymes, is necessary for the formation of AFG(1) from O-methylsterigmatocystin (OMST) in the cell-free system of A. parasiticus. The present study confirmed that the cytosol fraction of the wild-type A.parasiticus strain significantly enhanced the AFG(1) formation from OMST, whereas the cytosol fraction of the nadA-deletion mutant did not show the same activity. Furthermore, the cytosol fraction of the wild-type strain showed the enzyme activity catalyzing the reaction from NADA to AFG(1), which required NADPH or NADH, indicating that NADA is a precursor of AFG(1); in contrast, the cytosol fraction of the nadA-deletion mutant did not show the same enzyme activity. These results demonstrated that the NadA protein is the cytosol enzyme

  11. Aspergillus flavus and Fusariumverticillioides Induce Tissue Specific Gene Expression of PRms and UGT in Maize Seed before Fungal Colonization

    Science.gov (United States)

    Aspergillus flavus and Fusariumverticillioides are fungal pathogens that colonize maize seeds and contaminate them with mycotoxins. To investigate the plant microbe interactions, we conducted histological and molecular studies to characterize the internal colonization of maize seed by the two fungal...

  12. Unravelling the diversity of the cyclopiazonic acid family of mycotoxins in Aspergillus flavus by UHPLC Triple-TOF HRMS

    Science.gov (United States)

    Cyclopiazonic acid (a-cyclopiazonic acid, a-CPA) is an indole-hydrindane-tetramic acid neurotoxin produced by various fungal species, including the notorious food and feed contaminant Aspergillus flavus. Despite its discovery in A. flavus cultures, approximately 40 years ago, its contribution to the...

  13. Antifungal Effects of Thyme, Agastache and Satureja Essential Oils on Aspergillus fumigatus, Aspergillus flavus and Fusarium solani

    Directory of Open Access Journals (Sweden)

    Karim Mardani

    2010-09-01

    Full Text Available Growth inhibition of Aspergillus fumigatus,Aspergillus flavus and Fusarum solani exposed to the essential oils including Thyme, Agastache and Satureja were studied. Disc Diffusion Method was used to evaluate the fungal growth inhibitory effects of the essential oils. Minimal inhibitory concentration (MIC and minimal fungicidal concentration (MFC of the oils were determined and compared with each other. The results showed that all three essential oils examined, had antifungal effects against three fungi species. The MIC data revealed that Thyme oil was the most effective essential oil with the MIC of 62.5 μl ml-1.

  14. Antifungal activity of extracts of Rosmarinus officinalis and Thymus vulgaris against Aspergillus flavus and A. ochraceus.

    Science.gov (United States)

    Centeno, S; Calvo, M A; Adelantado, C; Figueroa, S

    2010-05-01

    The antifungal activity of ethanolic extracts of Rosmarinus officinalis and Thymus vulgaris were tested against strains of Aspergillus flavus and A. ochraceus, since these two species are common contaminants of cereals and grains and are able to produce and accumulate mycotoxins. The methodology used is based on measuring the inhibition halos produced by discs impregnated with the extracts and establishing their Minimum Inhibitory Concentration (MIC) as well as the Minimum Fungicide Concentration (MFC). The results obtained suggest that the assayed extracts affect the proper development of A. flavus and A. ochraceus; leading to a lower MIC (1200 ppm) and MFC (2400 ppm) for T. vulgaris extract against A. ochraceus than against A. flavus. The results show, that the extracts of Rosmarinus officinalis and Thymus vulgaris used at low concentrations could have significant potential for the biological control of fungi in foodstuffs.

  15. Mycotoxin production and predictive modelling kinetics on the growth of Aspergillus flavus and Aspergillus parasiticus isolates in whole black peppercorns (Piper nigrum L).

    Science.gov (United States)

    Yogendrarajah, Pratheeba; Vermeulen, An; Jacxsens, Liesbeth; Mavromichali, Evangelia; De Saeger, Sarah; De Meulenaer, Bruno; Devlieghere, Frank

    2016-07-02

    The growth and mycotoxin production of three Aspergillus flavus isolates and an Aspergillus parasiticus isolate were studied in whole black peppercorns (Piper nigrum L.) using a full factorial design with seven water activity (aw) (0.826-0.984) levels and three temperatures (22, 30 and 37°C). Growth rates and lag phases were estimated using linear regression. Diverse secondary models were assessed for their ability to describe the radial growth rate as a function of individual and combined effect of aw and temperature. Optimum radial growth rate ranged from 0.75±0.04 to 2.65±0.02mm/day for A. flavus and 1.77±0.10 to 2.50±0.10mm/day for A. parasiticus based on the Rosso cardinal estimations. Despite the growth failure of some isolates at marginal conditions, all the studied models showed good performance to predict the growth rates. Validation of the models was performed on independently derived data. The bias factors (0.73-1.03), accuracy factors (0.97-1.36) and root mean square error (0.050-0.278) show that the examined models are conservative predictors of the colony growth rate of both fungal species in black peppers. The Rosso cardinal model can be recommended to describe the individual aw effect while the extended Gibson model was the best model for describing the combined effect of aw and temperature on the growth rate of both fungal species in peppercorns. Temperature optimum ranged from 30 to 33°C, while aw optimum was 0.87-0.92 as estimated by multi-factorial cardinal model for both species. The estimated minimum temperature and aw for A. flavus and A. parasiticus for growth were 11-16°C and 0.73-0.76, respectively, hence, achieving these conditions should be considered during storage to prevent the growth of these mycotoxigenic fungal species in black peppercorns. Following the growth study, production of mycotoxins (aflatoxins B1, B2, G1, G2, sterigmatocystin and O-methyl sterigmatocystin (OMST)) was quantified using LC-MS/MS. Very small

  16. Two new aflatoxin producing species, and an overview of Aspergillus section Flavi

    DEFF Research Database (Denmark)

    Varga, J.; Frisvad, Jens Christian; Samson, R. A.

    2011-01-01

    Aspergillus subgenus Circumdati section Flavi includes species with usually biseriate conidial heads, in shades of yellow-green to brown, and dark sclerotia. Several species assigned to this section are either important mycotoxin producers including aflatoxins, cyclopiazonic acid, ochratoxins and...

  17. The Mechanism of Antifungal Action of Essential Oil from Dill (Anethum graveolens L.) on Aspergillus flavus

    Science.gov (United States)

    Tian, Jun; Ban, Xiaoquan; Zeng, Hong; He, Jingsheng; Chen, Yuxin; Wang, Youwei

    2012-01-01

    The essential oil extracted from the seeds of dill (Anethum graveolens L.) was demonstrated in this study as a potential source of an eco-friendly antifungal agent. To elucidate the mechanism of the antifungal action further, the effect of the essential oil on the plasma membrane and mitochondria of Aspergillus flavus was investigated. The lesion in the plasma membrane was detected through flow cytometry and further verified through the inhibition of ergosterol synthesis. The essential oil caused morphological changes in the cells of A. flavus and a reduction in the ergosterol quantity. Moreover, mitochondrial membrane potential (MMP), acidification of external medium, and mitochondrial ATPase and dehydrogenase activities were detected. The reactive oxygen species (ROS) accumulation was also examined through fluorometric assay. Exposure to dill oil resulted in an elevation of MMP, and in the suppression of the glucose-induced decrease in external pH at 4 µl/ml. Decreased ATPase and dehydrogenase activities in A. flavus cells were also observed in a dose-dependent manner. The above dysfunctions of the mitochondria caused ROS accumulation in A. flavus. A reduction in cell viability was prevented through the addition of L-cysteine, which indicates that ROS is an important mediator of the antifungal action of dill oil. In summary, the antifungal activity of dill oil results from its ability to disrupt the permeability barrier of the plasma membrane and from the mitochondrial dysfunction-induced ROS accumulation in A. flavus. PMID:22272289

  18. Zizyphus spina-Christi Extract Protects Against Aflatoxin B1 ...

    African Journals Online (AJOL)

    Aflatoxins (AF), a group of closely related, extremely toxic mycotoxins, produced by Aspergillus flavus and A. parasiticus can occur as natural contaminants of foods and feeds. Aflatoxins have been shown to be hepatotoxic, carcinogenic, mutagenic, and teratogenic to different animal species. Zizyphus spina-Christi L. extract ...

  19. A review of agricultural aflatoxin management strategies and ...

    African Journals Online (AJOL)

    Aflatoxins are highly carcinogenic secondary metabolites produced by Aspergillus flavus, A. parasiticus and A. nomius. Aflatoxin contamination of food and animal feeds is, therefore, a major food security, food safety, trade, human and domestic animal health concern. Researchers worldwide have suggested various ...

  20. Aspergillus korhogoensis, a Novel Aflatoxin Producing Species from the Côte d’Ivoire

    Directory of Open Access Journals (Sweden)

    Amaranta Carvajal-Campos

    2017-10-01

    Full Text Available Several strains of a new aflatoxigenic species of Aspergillus, A. korhogoensis, were isolated in the course of a screening study involving species from section Flavi found contaminating peanuts (Arachis hypogaea and peanut paste in the Côte d’Ivoire. Based on examination of four isolates, this new species is described using a polyphasic approach. A concatenated alignment comprised of nine genes (ITS, benA, cmdA, mcm7, amdS, rpb1, preB, ppgA, and preA was subjected to phylogenetic analysis, and resulted in all four strains being inferred as a distinct clade. Characterization of mating type for each strain revealed A. korhogoensis as a heterothallic species, since three isolates exhibited a singular MAT1-1 locus and one isolate exhibited a singular MAT1-2 locus. Morphological and physiological characterizations were also performed based on their growth on various types of media. Their respective extrolite profiles were characterized using LC/HRMS, and showed that this new species is capable of producing B- and G-aflatoxins, aspergillic acid, cyclopiazonic acid, aflavarins, and asparasones, as well as other metabolites. Altogether, our results confirm the monophyly of A. korhogoensis, and strengthen its position in the A. flavus clade, as the sister taxon of A. parvisclerotigenus.

  1. Aflatoxins and ochratoxin A and their Aspergillus causal species in Tunisian cereals.

    Science.gov (United States)

    Jedidi, Ines; Cruz, Alejandra; González-Jaén, Maria Teresa; Said, Salem

    2017-03-01

    Occurrence of aflatoxins (AFs) AFB1, AFB2, AFG1, AFG2 and ochra toxin A (OTA) was studied in 65 samples of stored and freshly harvested wheat, barley and maize collected in Tunisia. The mycotoxins were simultaneously extracted and quantified by high performance liquid chromatography. Determination of AF-producing (section Flavi) and OTA-producing Aspergillus species (sections Nigri and Circumdati) was conducted in these samples by species-specific polymerase chain reaction (PCR). Results showed that most of maize samples were contaminated with AFs, data after storage showing lower values than those collected at harvest. All contaminated maize samples contained AFG1 and AFG2, among which 27.78% also had AFB1 and AFB2. This AFs pattern was consistent with the A. parasiticus toxin profile. A. flavus however showed the highest frequency in maize but was also found in barley and wheat where no AFs were detected. In contrast, OTA was neither found in maize nor in barley and only one wheat sample contained OTA. A. niger was the only OTA-producing species detected.

  2. Molecular identification and antifungal susceptibility profile of Aspergillus flavus isolates recovered from clinical specimens in Kuwait

    Science.gov (United States)

    2013-01-01

    Background Within the genus Aspergillus, A. flavus is the second most important species of clinical significance. It is predominantly associated with infections involving sinuses, eye and skin, mostly in geographic regions with hot and arid climate, including the Middle East. Recent reports on emergence of resistance to triazoles among Aspergillus spp. is a cause of concern for treatment of patients with invasive aspergillosis. In this study we present data on genetic characterization and antifungal susceptibility profile of clinical and environmental isolates of A. flavus. Methods Ninety-nine Aspergillus section Flavi isolates, originating from clinical (n=92) and environmental (n=7) sources, initially identified by morphological characteristics, were analyzed by partial sequencing of β-tubulin and calmodulin gene fragments and their susceptibilities to six antifungal agents was determined by Etest on RPMI1640 and Muller-Hinton agar media. Etest minimum inhibitory concentrations (MICs) of amphotericin B and voriconazole were also compared with zone of inhibition diameters obtained by disc diffusion test on RPMI agar medium. Results The identity of all clinical and environmental isolates was confirmed as A. flavus species by combined analysis of β-tubulin and calmodulin genes. The mean MIC90 (μg/ml) values on RPMI medium for amphotericin B, voriconazole, posaconazole, anidulafungin, micafungin and caspofungin were 3, 0.25, 0.25, 0.002, 0.002 and 0.032, respectively. No environmental isolate exhibited MIC value of >2 μg/ml for amphotericin B. For clinical isolates, the zone of inhibition diameters for amphotericin B and voriconazole ranged from 7–16 mm and 24–34 mm, respectively. Linear regression analysis between Etest MIC values and disk diffusion diameters revealed a significant inverse correlation with amphotericin B (p Triazoles and echinocandins showed very good in vitro activity against the A. flavus, however, 10% clinical isolates showed MICs of >2

  3. Characterization of the chitinase gene family and the effect on A. flavus and aflatoxin resistance in maize.

    Science.gov (United States)

    Maize (Zea mays L.) is a crop of global importance, but is prone to contamination by aflatoxins produced by fungi in the genus Aspergillus. The development of resistant germplasm and the identification of genes contributing to resistance would aid in the reduction of the problem with a minimal need ...

  4. Occurrence of aflatoxins and aflatoxin-producing Aspergillus spp. associated with groundnut production in subsistence farming systems in South Africa

    NARCIS (Netherlands)

    Ncube, E.; Flett, B.C.; Waalwijk, C.; Viljoen, A.

    2010-01-01

    Abstract: Author: Ncube, E. Flett, B.C. Waalwijk, C. Viljoen, A. Vol 27 Issue 2 Publication: 2010 Page: 195-198 : Aflatoxins are carcinogenic mycotoxins produced by Aspergillus spp. in groundnut kernels. Forty-six groundnut samples were collected from subsistence farmers in three provinces of South

  5. Comparative Chemistry of Aspergillus oryzae (RIB40) and A. flavus (NRRL 3357)

    Science.gov (United States)

    Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj; Kildgaard, Sara; Frisvad, Jens Christian; Gotfredsen, Charlotte Held; Larsen, Thomas Ostenfeld

    2012-01-01

    Aspergillus oryzae and A. flavus are important species in industrial biotechnology and food safety and have been some of the first aspergilli to be fully genome sequenced. Bioinformatic analysis has revealed 99.5% gene homology between the two species pointing towards a large coherence in the secondary metabolite production. In this study we report on the first comparison of secondary metabolite production between the full genome sequenced strains of A. oryzae (RIB40) and A. flavus (NRRL 3357). Surprisingly, the overall chemical profiles of the two strains were mostly very different across 15 growth conditions. Contrary to previous studies we found the aflatrem precursor 13-desoxypaxilline to be a major metabolite from A. oryzae under certain growth conditions. For the first time, we additionally report A. oryzae to produce parasiticolide A and two new analogues hereof, along with four new alkaloids related to the A. flavus metabolites ditryptophenalines and miyakamides. Generally the secondary metabolite capability of A. oryzae presents several novel end products likely to result from the domestication process from A. flavus. PMID:24957367

  6. Aspergillus flavus Keratitis: Experience of a Tertiary Eye Clinic in Turkey.

    Science.gov (United States)

    Erdem, Elif; Yagmur, Meltem; Boral, Hazal; Ilkit, Macit; Ersoz, Reha; Seyedmousavi, Seyedmojtaba

    2017-04-01

    We investigated the clinical and mycological characteristics of four cases of mycotic keratitis caused by Aspergillus flavus that occurred from July 2014 to May 2015 at Çukurova University Hospital, Adana, Turkey. In a 10-month period, a total of 64 corneal smear/scrapings were examined from patients with suspected mycotic keratitis. Fungal cultures were positive in six of these patients, indicating a 9.4% incidence of mycotic keratitis in this region, including four cases of A. flavus and two cases of Fusarium spp. The predisposing factors, clinical presentation, and success of the therapeutic approaches were further evaluated. For all cases, topical voriconazole was the first choice of treatment. Surgical procedures were required to control infection in 3 of the 4 cases, including intrastromal voriconazole injection for two cases and keratoplasty for one case. Predisposing factors included trauma (two cases, 50%), contact lens use (one case, 25%), and previous ocular surgery (one case, 25%). The clinical presentations also differed, including a well-limited ulcer (one case), an ulcer with an irregular feathery margin (one case), and ulcers with satellite lesions (two cases). The mean duration between the time of presentation and definitive diagnosis by culture was 14 days (8-25 days). We observed that A. flavus keratitis can present with different underlying factors and clinical conditions. A combination of antifungal therapy and supportive surgical intervention may resolve infections caused by A. flavus in the cornea.

  7. Inactivation of Aspergillus flavus in drinking water after treatment with UV irradiation followed by chlorination.

    Science.gov (United States)

    Al-Gabr, Hamid Mohammad; Zheng, Tianling; Yu, Xin

    2013-10-01

    The disinfection process for inactivating microorganisms at drinking water treatment plants is aimed for safety of drinking water for humans from a microorganism, such as bacteria, viruses, algae, fungi by using chlorination, ozonation, UV irradiation, etc. In the present study, a combination of two disinfectants, UV irradiation followed by chlorination, was evaluated for inactivating Aspergillus flavus under low contact time and low dosage of UV irradiation. The results indicated an inverse correlation between the inactivation of A. flavus by using UV irradiation only or chlorination alone. By using UV radiation, the 2 log10 control of A. flavus was achieved after 30 s of irradiation, while chlorination was observed to be more effective than UV, where the 2 log was achieved at chlorine concentration of 0.5, 1, 2 and 3 mg/l, in contact time of 60, 5, 1 and 1 min, respectively. However, combined use (UV irradiation followed by chlorination) was more effective than using either UV or chlorination alone; 5 s UV irradiation followed by chlorination produced 4 log10 reduction of A. flavus at chlorine concentrations of 2 and 3 mg/l under a contact time of 15 min. The results indicated that efficiency of UV irradiation improves when followed by chlorination at low concentrations. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Data set for the mass spectrometry based exoproteome analysis of Aspergillus flavus isolates

    Directory of Open Access Journals (Sweden)

    Ramu Muthu Selvam

    2015-03-01

    Full Text Available Aspergillus flavus is one of the predominant causative organisms of mycotic keratitis in tropical parts of the world. Extracellular proteins are the earliest proteins that come in contact with the host and have a role in the infection process. Exoproteins of A. flavus isolated from infected cornea, sputum and a saprophyte were pooled and identified using high resolution mass spectrometry in order to get the total exoproteome from cultures isolated from different sources. A total of 637 proteins was identified from the pooled A. flavus exoproteome. Analysis based on GO annotations of the 637 identified proteins revealed that hydrolases form the predominant class of proteins in the exoproteome. Interestingly, a greater proportion of the exoproteins seem to be secreted through the non-classical pathways. This data represent the first in-depth analysis of the representative A. flavus exoproteome of a large set of isolates from distinct sources. This data have been deposited to the ProteomeXchange with identifier PXD001296.

  9. Characterization and anti-Aspergillus flavus impact of nanoparticles synthesized by Penicillium citrinum

    Directory of Open Access Journals (Sweden)

    Mohamed A. Yassin

    2017-09-01

    Full Text Available This work was conducted to evaluate the ability of grape molding fungus; Penicillium citrinum to synthesize silver nanoparticles (Ag NPs. The potency of biosynthesized Ag NPs was checked against the aflatoxigenic Aspergillus flavus var. columnaris, isolated from sorghum grains. Biosynthesized Ag NPs were characterized and confirmed in different ways. X ray diffraction (XRD, Energy Dispersive Spectroscopy (EDS, Transmission Electron Microscopy (TEM and optical absorption measurements confirmed the bio-synthesis of Ag NPs. The in vitro antifungal investigation showed that biosynthesized Ag NPs were capable of inhibiting the growth of aflatoxigenic A. flavus var. columnaris. Utilization of plant pathogenic fungi in the Ag NPs biosynthesis as well as the use of bio-Ag NPs to control fungal plant diseases instead of chemicals is promising. Further work is needed to confirm the efficacy of the bio-Ag NPs against different mycotoxigenic fungi and to determine the potent applicable doses.

  10. Contamination by Aspergillus flavus and A. fumigatus in sunflower seeds used in psittacine bird food

    Directory of Open Access Journals (Sweden)

    Alexsandro Machado Conceição

    2010-06-01

    Full Text Available Widely distributed in food for psittacine birds due its low price, high palatability, and cultural reasons, the Helianthus annuus, called sunflower, is proving important in clinical influenza as a result of excess calories and high incidence of contamination by some fungi, particularly Aspergillus, specifically A. flavus and A. fumigatus. The aim of this study was to evaluate the contamination by Aspergillus spp sunflower seeds for feeding psittacine birds, sold in Aracaju, Sergipe state. The tests were performed in the Laboratory of Microbiology of the Dr. Vicente Borreli Veterinary Hospital in Pio Décimo College. We evaluated four samples of sunflower seeds, soldin a municipal market and in three different supermarkets in bulk and under three bottled trademarks, processed according to Forsythe (2002. Our survey revealed a high development of A. flavus and A. fumigatus sunflower seeds. This contamination may be related to several factors such as inadequate harvest stages of drying, processing and storage of grain. Furthermore, it is important to highlight the need of a better grain storage, with controlled temperature and humidity, to reduce the possibility of contamination by Aspergillus spp. that causes injury in the feeding of psittacine birds and other animal species.

  11. 75 FR 9596 - Notice of Filing of a Pesticide Petition for Residues of a Aspergillus flavus AF36 on Corn Food...

    Science.gov (United States)

    2010-03-03

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY Notice of Filing of a Pesticide Petition for Residues of a Aspergillus flavus AF36 on Corn Food... residues of the antifungal ] agent, Aspergillus flavus AF36, in or on corn food and feed commodities. The...

  12. Control of Aspergillus flavus Growth in Tomato Paste by Cinnamomum zeylanicum and Origanum vulgare L. Essential Oils

    OpenAIRE

    F. Kalantari; M. Barzegar; Z. Hamidi-Esfahani

    2012-01-01

    This study was conducted to evaluate the antifungal activities of Cinnamomum zeylanicum and Origanum vulgare L. essential oil against Aspergillus flavus in culture media and tomato paste. 200 ppm of cinnamon and 500 ppm of oregano completely inhibited A. flavus growth in culture media, while in tomato paste 300 ppm of cinnamon and 200 ppm of oregano had the same effect. Test panel evaluations revealed that samples with 100 and 200 ppm cinnamon were acceptable. The results...

  13. Biotransformation of sucrose into 5-hydroxy-2-hydroxymethyl-γ-pirone by Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Nelson R. Ferreira

    2010-09-01

    Full Text Available The sucrose hydrolysis and the preference of consumption of glucose instead of fructose were investigated for the production of 5-hydroxy-2-hydroxymethyl-γ-pyrone (HHMP in the presence of Aspergillus flavus IOC 3974 cultivated in liquid Czapeck medium. Standardized 0.5g of pellets were transferred as inoculum into twelve conical flasks of 250 ml containing 100 ml of medium with different sucrose concentration, which was kept at 120 rpm and 28"C for 16 days without pH adjustment. Aliquots of 500μl of the broth culture were withdrawn at 24 h intervals and analyzed. The major yield of HHMP was 26g l-1 in 120g l-1 of sucrose. At these conditions, A. flavus produced an invertase capable of hydrolyzing 65% of total sucrose concentration in 24h, and an isomerase capable of converting fructose into glucose. In this work, it focused the preference for glucose and, then, of fructose by A. flavus and the strategy used to produce HHMP.Foram investigadas a hidrólise da sacarose e a preferência pela glicose frente à frutose no processo de produção do 5-hidroxi-2-hidroximetil-γ-pirona (HHMP na presença de Aspergillus flavus IOC 3974 cultivado em meio líquido Czapeck. Quantidades de 0,5g de pelletes foram utilizadas como inóculo. Doze frascos cônicos de 250 ml contendo 100 ml de meio de culturacom diferentes concentrações de sacarose foram utilizados.Os microrganismos foram cultivados a 120 rpm e 28"C por 16 dias sem ajuste do pH. O maior rendimento do HHMP foi 26g l-1em 120g l-1de sacarose. Nestas condições, A. flavus, foi capaz de produzir uma invertase possibilitando a hidrólise de 65% da concentração total de sacarose em 24 horas, conjuntamente com a produção de uma isomerase que foi capaz de converter a frutose em glicose. Este trabalho está focalizado preferencialmente no consumo da glicose frente à frutose por A. flavus e na estratégia de produção do HHMP.

  14. Genetic Diversity and In Vitro Antifungal Susceptibility of 200 Clinical and Environmental Aspergillus flavus Isolates.

    Science.gov (United States)

    Taghizadeh-Armaki, Mojtaba; Hedayati, Mohammad Taghi; Ansari, Saham; Omran, Saeed Mahdavi; Saber, Sasan; Rafati, Haleh; Zoll, Jan; van der Lee, Henrich A; Melchers, Willem J G; Verweij, Paul E; Seyedmousavi, Seyedmojtaba

    2017-05-01

    Aspergillus flavus has been frequently reported as the leading cause of invasive aspergillosis in certain tropical and subtropical countries. Two hundred A. flavus strains originating from clinical and environmental sources and collected between 2008 and 2015 were phylogenetically identified at the species level by analyzing partial β-tubulin and calmodulin genes. In vitro antifungal susceptibility testing was performed against antifungals using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution method. In addition, genotyping was performed using a short-tandem-repeat (STR) assay of a panel of six microsatellite markers (A. flavus 2A, 2B, 2C, 3A, 3B, and 3C), in order to determine the genetic variation and the potential relationship between clinical and environmental isolates. The geometric means of the minimum inhibitory concentrations/minimum effective concentrations (MICs/MECs) of the antifungals across all isolates were (in increasing order): posaconazole, 0.13 mg/liter; anidulafungin, 0.16 mg/liter; itraconazole, 0.29 mg/liter; caspofungin, 0.42 mg/liter; voriconazole, 0.64 mg/liter; isavuconazole, 1.10 mg/liter; amphotericin B, 3.35 mg/liter; and flucytosine, 62.97 mg/liter. All of the clinical isolates were genetically different. However, an identical microsatellite genotype was found between a clinical isolate and two environmental strains. In conclusion, posaconazole and anidulafungin showed the greatest in vitro activity among systemic azoles and echinocandins, respectively. However, the majority of the A. flavus isolates showed reduced susceptibility to amphotericin B. Antifungal susceptibility of A. flavus was not linked with the clinical or environmental source of isolation. Microsatellite genotyping may suggest an association between clinical and environmental strains, although this requires further investigation. Copyright © 2017 American Society for Microbiology.

  15. Toxicity, analgesic and sedative potential of crude extract of soil-borne phytopathogenic fungi Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Bashir Ahmad

    2016-11-01

    Full Text Available Background: Aspergillus flavus is one of the most abundant mold present around the world. The present study was conducted to investigate the acute toxicity, analgesic and sedative effect of the crude extract obtained from soil borne fungi A. flavus. Methods: The fungi was isolated from soil samples and identified morphologically and microscopically. The growth condition i.e. media, temperature, pH, and incubation period were optimized. In these optimized growth condition, A. flavus was grown in batch culture in shaking incubator. Crude contents were extracted by using ethyl acetate solvent. Crude secondary metabolites were screened for acute toxicity, analgesic and sedative effect. Results: Upon completion of the experiment, blood was collected from the tail vein of albino mice, and different haematological tests were conducted. White blood cells counts displayed a slight increase (10.6× 109/L above their normal range (0.8–6.8 × 109/L, which may be due to the increment in the number of lymphocytes or granulocytes. However, the percentage of lymphocytes was much lower (17.7%, while the percentage of the granulocytes was higher (61.4% than its normal range (8.6–38.9%. A reduction in the mean number of writhing in the different test groups was caused by the application of the crude ethyl acetate extract through the i.p. route at different doses (50, 100, and 150 mg/kg body weight. The results of our investigation showed the EtOAc extract of A. flavus can cause a significant sedative effect in open field. Conclusion: It was concluded from the present study that the A. flavus has the potential to produce bioactive metabolites which have analgesic and sedative effect.

  16. ZnS semiconductor quantum dots production by an endophytic fungus Aspergillus flavus

    Energy Technology Data Exchange (ETDEWEB)

    Uddandarao, Priyanka, E-mail: uddandaraopriyanka@gmail.com; B, Raj Mohan, E-mail: rajmohanbala@gmail.com

    2016-05-15

    Graphical abstract: - Highlights: • Endophytic fungus Aspergillus flavus isolated from a medicinal plant Nothapodytes foetida was used for the synthesis of quantum dots. • Morris-Weber kinetic model and Lagergren's pseudo-first-order rate equation were used to study the biosorption kinetics. • Polycrystalline ZnS quantum dots of 18 nm and 58.9 nm from TEM and DLS, respectively. - Abstract: The development of reliable and eco-friendly processes for the synthesis of metal sulphide quantum dots has been considered as a major challenge in the field of nanotechnology. In the present study, polycrystalline ZnS quantum dots were synthesized from an endophytic fungus Aspergillus flavus. It is noteworthy that apart from being rich sources of bioactive compounds, endophytic fungus also has the ability to mediate the synthesis of nanoparticles. TEM and DLS revealed the formation of spherical particles with an average diameter of about 18 nm and 58.9 nm, respectively. The ZnS quantum dots were further characterized using SEM, EDAX, XRD, UV–visible spectroscopy and FTIR. The obtained results confirmed the synthesis of polycrystalline ZnS quantum dots and these quantum dots are used for studying ROS activity. In addition this paper explains kinetics of metal sorption to study the role of biosorption in synthesis of quantum dots by applying Morris-Weber kinetic model. Since Aspergillus flavus is isolated from a medicinal plant Nothapodytes foetida, quantum dots synthesized from this fungus may have great potential in broad environmental and medical applications.

  17. Biotransformation of chalcones by the endophytic fungus Aspergillus flavus isolated from Paspalum maritimum trin

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Marivaldo J.C.; Nunes, Fatima M.; Bitencourt, Heriberto R.; Borges, Fabio C.; Guilhon, Giselle M.S.P.; Arruda, Mara S.P.; Marinho, Andrey M. R.; Santos, Alberdan S.; Alves, Claudio N.; Santos, Lourivaldo S., E-mail: lss@ufpa.b [Universidade Federal do Para (IQ/FEQ/UFPA), Belem, PA (Brazil). Inst. de Tecnologia. Faculdade de Engenharia Quimica; Brasil, Davi S.B. [Universidade Federal do Para (PPGQ/IQ/UFPA), Belem, PA (Brazil). Inst. de Quimica. Programa de Pos-Graduacao em Quimica

    2011-07-01

    The fungus Aspergillus flavus isolated as endophytic of the plant Paspalum maritimum Trin. was evaluated for its potential application in biotransformation reactions. The compounds chalcone (1), 3,4,5-trimethoxychalcone (2) and 2,3,4,4'-tetramethoxy chalcone (3) were biotransformed, respectively, in dihydrochalcone (4), 3,4,5-trimethoxydihydrochalcone (5) and 2,3,4,4'-tetramethoxydihydrochalcone (6). The structures were elucidated by spectroscopic methods including 1D and 2D NMR techniques, and MS analysis. The dihydrochalcones 5 and 6 are new compounds. (author)

  18. Techniques used detection and quantification of aflatoxin M1 in milk

    OpenAIRE

    Adriana Frizzarin; Keila Maria Roncato Duarte

    2012-01-01

    Aflatoxin is a group of toxic substances produced by fungi, mainly Aspergillus flavus and Aspergillus parasiticus. It can be developed in agriculture products such as grains or processed food, when environment conditions of humidity and air humidity are favorable. Aflatoxins can be presented as several forms. In Milk, are called M1 and M2, resulting from aflatoxins B1 and B2 metabolism. Aflatoxin M1 (AFM1) is classified as a possible carcinogen to humans, so the occurrence of aflatoxin M1 in ...

  19. Aflatoxin contamination of corn under different agro-environmental conditions and biocontrol applications

    Science.gov (United States)

    Biological control of the fungus Aspergillus flavus has been shown to be effective in reducing aflatoxin contamination in corn. This study compared field application of a bioplastic-based formulation for delivering atoxigenic A. flavus isolates in Northern Italy and the Mississippi Delta. RESULTS:...

  20. A Review on Aflatoxins Reduction in Food

    Directory of Open Access Journals (Sweden)

    Maryam Jalili

    2016-01-01

    Full Text Available Aflatoxins (AFs are cancerous secondary metabolites produced primarily by Aspergillus flavus and Aspergillus parasiticus in agricultural foodstuff such as peanuts, maize grains, cereals, and animal feeds. Food and Agricultural organization (FAO estimated that as much as 25% of the world’s agricultural commodities are contaminated with mycotoxins, leading to significant economic losses. Moreover, AFs are highly toxic, mutagenic, teratogenic and carcinogenic. Therefore AFs reduction in food and feedstuffs is a major global concern. This review aims to bring up to date the detoxification methods applied for reduction of aflatoxins by physical (cleaning, heating, irradiation, adsorption, chemical (chemical compound, ozonization and biological (applying bacteria, yeast and nontoxigenic Aspergillus strains methods in different foods from 2000 to 2015. Papers related to aflatoxin reduction by managing aflatoxins risks, using resistant crops varieties, and good agricultural practices and papers related to other aflatoxins (M1, M2 were excluded.

  1. Simple and highly discriminatory VNTR-based multiplex PCR for tracing sources of Aspergillus flavus isolates.

    Directory of Open Access Journals (Sweden)

    Dong Ying Wang

    Full Text Available Aspergillus flavus is second only to A. fumigatus in causing invasive aspergillosis and it is the major agent responsible for fungal sinusitis, keratitis and endophthalmitis in many countries in the Middle East, Africa and Southeast Asia. Despite the growing challenge due to A. flavus, data on the molecular epidemiology of this fungus remain scarce. The objective of the present study was to develop a new typing method based on the detection of VNTR (Variable number tandem repeat markers. Eight VNTR markers located on 6 different chromosomes (1, 2, 3, 5, 7 and 8 of A. flavus were selected, combined by pairs for multiplex amplifications and tested on 30 unrelated isolates and six reference strains. The Simpson index for individual markers ranged from 0.398 to 0.818. A combined loci index calculated with all the markers yielded an index of 0.998. The MLVA (Multiple Locus VNTR Analysis technique proved to be specific and reproducible. In a second time, a total of 55 isolates from Chinese avian farms and from a Tunisian hospital have been evaluated. One major cluster of genotypes could be defined by using the graphing algorithm termed Minimum Spanning Tree. This cluster comprised most of the isolates collected in an avian farm in southern China. The MLVA technique should be considered as an excellent and cost-effective typing method that could be used in many laboratories without the need for sophisticated equipment.

  2. Purification and characterization of pectin lyase secreted by Aspergillus flavus MTCC 10938.

    Science.gov (United States)

    Yadav, S; Dubey, A K; Anand, G; Yadav, D

    2013-01-01

    An indigenously isolated fungal strain Aspergillus flavus MTCC 10938 was subjected to pectin lyase (PNL) production under submerged fermentation conditions. The enzyme was purified to homogeneity from the culture filtrate of the fungus involving concentration by ultrafiltration, anion exchange chromatography on DEAE cellulose and gel filtration chromatography on Sephadex G-100. The purified PNL gave a single protein band in SDS-PAGE analysis with a relative molecular mass corresponding to 50 kDa. Using citrus pectin as the substrate the K(m) and k(cat) values of the enzyme lyase were obtained as 1.7 mg/mL and 66 s(-1), respectively. The optimum pH of the purified PNL from A. flavus MTCC 10938 was 8.0 and up to 90% of its activity retained in the pH range from 3.0 to 11.0 after 24 h incubation. The optimum temperature of the purified enzyme was revealed at 55 degrees C and it was completely stable up to 40 degrees C when exposed for 30 min. The purified A. flavus MTCC 10938 PNL showed efficient retting of Crotalaria juncea fibres.

  3. Aflatoxigenic Fungi and Aflatoxins in Portuguese Almonds

    Science.gov (United States)

    Rodrigues, P.; Venâncio, A.; Lima, N.

    2012-01-01

    Aflatoxin contamination of nuts is an increasing concern to the consumer's health. Portugal is a big producer of almonds, but there is no scientific knowledge on the safety of those nuts, in terms of mycotoxins. The aim of this paper was to study the incidence of aflatoxigenic fungi and aflatoxin contamination of 21 samples of Portuguese almonds, and its evolution throughout the various stages of production. All fungi belonging to Aspergillus section Flavi were identified and tested for their aflatoxigenic ability. Almond samples were tested for aflatoxin contamination by HPLC-fluorescence. In total, 352 fungi belonging to Aspergillus section Flavi were isolated from Portuguese almonds: 127 were identified as A. flavus (of which 28% produced aflatoxins B), 196 as typical or atypical A. parasiticus (all producing aflatoxins B and G), and 29 as A. tamarii (all nonaflatoxigenic). Aflatoxins were detected in only one sample at 4.97 μg/kg. PMID:22666128

  4. Sexuality generates diversity in the aflatoxin gene cluster: evidence on a global scale

    Science.gov (United States)

    The worldwide costs associated with aflatoxin monitoring and crop losses are in the hundreds of millions of dollars. Aflatoxins also account for considerable health risks, even in countries where food contamination is regulated. Aspergillus flavus and A. parasiticus are the most common agents of af...

  5. Characterization of the maize lipoxygenase gene family in relation to aflatoxin accumulation resistance

    Science.gov (United States)

    Oluwaseun F. Ogunola; Leigh K. Hawkins; Erik Mylroie; Michael V. Kolomiets; Eli Borrego; Juliet D. Tang; Paul W. Williams; Marilyn L. Warburton

    2017-01-01

    Maize (Zea mays L.) is a globally important staple food crop prone to contamination by aflatoxin, a carcinogenic secondary metabolite produced by the fungus Aspergillus flavus. An efficient approach to reduce accumulation of aflatoxin is the development of germplasm resistant to colonization and toxin...

  6. Effect of crude honey on stability of aflatoxins and growth of ...

    African Journals Online (AJOL)

    Because aflatoxin contamination is unavoidable, numerous strategies for their detoxification have been proposed. sample of natural honey was studied for their detoxification on aflatoxin (B1, B2) and their antimicrobial activities on Aspergillus flavus compared with H2O2 .Dilutions of honey ranging from 12,14,16,18 and ...

  7. Hexane neem leaf extract more potent than ethanol extract against Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Jenny Hidayat

    2015-12-01

    Full Text Available BACKGROUND Aspergillus flavus is one of the causes of aspergillosis, with a high virulence and resistance to standard antifungals, resulting in a high mortality rate. Medicinal plants are increasingly used as they are relatively safer with minimal side effects. Previously we found that the ethanol extract of neem (Azadirachta indica A Juss leaves inhibits A. flavus growth in vitro. However, most chemical compounds with antifungal effect are nonpolar. The purpose of this research was to compare the antifungal effect of neem leaves extracted in a nonpolar solvent to that of leaves extracted in a polar solvent. METHODS An in vitro experimental research was conducted between October 2013 and January 2014. Neem leaves were extracted in ethanol or hexane at various concentrations. A macrodilution test with 48-hour incubation time was done in triplicate on 8 groups of samples. These comprised the neem leaf ethanol extract (NLEE at 0.5, 1.0, and 2.0 g/dL, neem leaf hexane extract (NLHE at 0.5, 1.0, and 2.0 g/dL, positive control, and negative control groups. Fungal growth was detected on Sabouroud dextrose agar. Statistical analysis used Chi square and Fisher’s exact test. RESULTS NLHE had a higher, but statistically non-significant, inhibitory effect on A. flavus than NLEE (p=0.996. At higher concentrations, the antifungal effect of NLHE is better than that of NLEE. CONCLUSION There is no significant difference in in-vitro inhibitory effectivity on A. flavus of neem leaves between extracts in polar and nonpolar solvents.

  8. Antifungal and antimycotoxigenic potency of Solanum torvum Swartz. leaf extract: isolation and identification of compound active against mycotoxigenic strains of Aspergillus flavus and Fusarium verticillioides.

    Science.gov (United States)

    Abhishek, R U; Thippeswamy, S; Manjunath, K; Mohana, D C

    2015-12-01

    The main objective of this study was to investigate the antifungal effect of Solanum torvum leaves against different field and storage fungi, and to identify its active compound. In addition, to evaluate in vitro and in vivo inhibitory efficacy on toxigenic strains of Aspergillus flavus and Fusarium verticillioides. Leaves of S. torvum were sequentially extracted with petroleum ether, toluene, chloroform, methanol and ethanol. The antifungal compound isolated from chloroform extract was identified as torvoside K based on spectral analysis. The antifungal activity of chloroform extract and torvoside K was determined by broth microdilution and poisoned food techniques. The minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC) and zone of inhibition (ZOI) were recorded. Further, inhibitory effects of chloroform extract and torvoside K on growth of A. flavus and F. verticillioides, and their toxin productions were evaluated using in vitro and in vivo assays. Torvoside K showed the significant activity against tested fungi with ZOIs and MICs ranging from 33·4 to 87·4% and 31·25-250 μg ml(-1) , respectively. Further, torvoside K showed concentration-dependent antimycotoxigenic activity against aflatoxin B1 and fumonisin B1 production by A. flavus and F. verticillioides, respectively. It was observed that the compound torvoside K significantly inhibited the growth of all fungi tested. Growth of A. flavus and F. verticillioides, and aflatoxin B1 and fumonisin B1 productions were completely inhibited in vitro and in vivo by torvoside K with increasing concentration. Control of mycotoxigenic fungi requires compounds that able to inhibit both fungal growth and mycotoxin production. The antimycotoxigenic potential of torvoside K of S. torvum is described in this study for the first time. The results indicate the possible use of S. torvum as source of antifungal agents against postharvest fungal infestation of food commodities and

  9. Occurrence of toxigenic Aspergillus spp. and aflatoxins in selected food commodities of Asian origin sourced in the West of Scotland.

    Science.gov (United States)

    Ruadrew, Sayan; Craft, John; Aidoo, Kofi

    2013-05-01

    The occurrence of Aspergillus moulds and aflatoxins in 12 commercially-available dried foods of Asian origin were examined. All food samples, except green beans and three types of dried fruit, contained multiple genera of moulds of which Aspergillus (55%) was the most frequently detected. Penicillium (15%), Rhizopus (11%), Mucor (3%), Monascus (1%), Eurotium (1%) and unidentified (14%) were also observed. The occurrence of aflatoxigenic moulds, however, did not correspond with the occurrence of aflatoxins in foods. Aflatoxigenic Aspergillus spp. (39 isolates) were recovered from long grain rice, fragrant rice, peanuts, black beans and black pepper. The predominant Aspergillus species was A. parasiticus (61%) while Aspergillus oryzae (3%), Aspergillus utus (5%), Aspergillus niger (5%), Aspergillus ochraceus (3%) and unidentified (23%) were also observed. Long grain rice, fragrant rice, peanuts, black beans and black pepper were positive for Aspergillus but contained undetectable aflatoxins. In contrast, Jasmine brown rice and crushed chilli contained 14.7 and 11.4μg/kg of total aflatoxins, respectively, in the absence of Aspergillus so aflatoxigenic Aspergillus was present at some stage of food production. The results from this study emphasise the need for stricter control measures in reducing occurrence of aflatoxins in foods for export and domestic use. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Distribution and incidence of atoxigenic Aspergillus flavus VCG in tree crop orchards in California: a strategy for identifying potential antagonists

    Science.gov (United States)

    To identify predominant isolates for potential use as biocontrol agents, Aspergillus flavus isolates collected soils of almond, pistachio and fig orchard in the Central Valley of California were tested for their membership to 16 atoxigenic vegetative compatibility groups(VCGs), including YV36, the V...

  11. 77 FR 14287 - Aspergillus flavus AF36; Amendment to an Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2012-03-09

    ... runoff) that are intended for eventual human consumption and directed to wastewater treatment systems or..._treatment.html . 7. U.S. EPA. 2004. Primer for Municipal Wastewater Treatment Systems. EPA 832-R-04-001... exemption from the requirement of a tolerance for residues of the microbial pesticide, Aspergillus flavus...

  12. Evaluation of recycled bioplastic pellets and a sprayable formulation for application of an Aspergillus flavus biocontrol strain

    Science.gov (United States)

    Biocontrol of Aspergillus flavus using inoculated bioplastic granules has been proven to be effective under laboratory and field conditions. In the present study, the use of low-density pellets from recycled bioplastic as a biocontrol strain carrier was evaluated. Applying recycled bioplastic pell...

  13. Natural occurrence of aflatoxin, aflatoxigenic and nonaflatoxigenic ...

    African Journals Online (AJOL)

    A survey across different agro-climatic regions of India was done and 38 groundnut seed samples were collected from various sources. Upon analysis, all samples were found infected with Aspergillus flavus ranging from 2 to 50% incidence with aflatoxin content of 0.0 to 28 ppb. Greenhouse studies revealed no correlation ...

  14. Aflatoxin Accumulation in a Maize Diallel Cross

    Directory of Open Access Journals (Sweden)

    W. Paul Williams

    2015-06-01

    Full Text Available Aflatoxins, produced by the fungus Aspergillus flavus, occur naturally in maize. Contamination of maize grain with aflatoxin is a major food and feed safety problem and greatly reduces the value of the grain. Plant resistance is generally considered a highly desirable approach to reduction or elimination of aflatoxin in maize grain. In this investigation, a diallel cross was produced by crossing 10 inbred lines with varying degrees of resistance to aflatoxin accumulation in all possible combinations. Three lines that previously developed and released as sources of resistance to aflatoxin accumulation were included as parents. The 10 parental inbred lines and the 45 single crosses making up the diallel cross were evaluated for aflatoxin accumulation in field tests conducted in 2013 and 2014. Plants were inoculated with an A. flavus spore suspension seven days after silk emergence. Ears were harvested approximately 60 days later and concentration of aflatoxin in the grain determined. Parental inbred lines Mp717, Mp313E, and Mp719 exhibited low levels (3–12 ng/g of aflatoxin accumulation. In the diallel analysis, both general and specific combining ability were significant sources of variation in the inheritance of resistance to aflatoxin accumulation. General combining ability effects for reduced aflatoxin accumulation were greatest for Mp494, Mp719, and Mp717. These lines should be especially useful in breeding for resistance to aflatoxin accumulation. Breeding strategies, such as reciprocal recurrent selection, would be appropriate.

  15. Occupational exposure to Aspergillus and aflatoxins among food-grain workers in India.

    Science.gov (United States)

    Malik, Abida; Ali, Sana; Shahid, Mohd; Bhargava, Rakesh

    2014-01-01

    Aflatoxins are a metabolite of Aspergillus molds and are widespread in the natural environment. Workers who handle food grains are at increased risk of exposure to aflatoxins and subsequently certain respiratory conditions. In India, more than half of the employed population is engaged in some type of agricultural work, yet little known about the respiratory problems as a result of exposure to aflatoxins among workers who handle food grains in India. The aim of this study was to determine the risk of occupational exposure to aflatoxins in food-grain workers compared to workers who are not occupationally exposed to food grains. Bronchoalveolar lavage (BAL) and serum samples from 46 food-grain workers and 44 non-food-grain workers were analyzed for the presence of aflatoxins. Microscopy and culture of BAL samples were performed to detect Aspergillus species. Aflatoxins were detected in 32·6% of the food-grain workers and 9·1% of non food grain workers (Paflatoxins in food-grain workers was found to be associated with the increased presence of respiratory symptoms.

  16. Brazil nuts are subject to infection with B and G aflatoxin-producing fungus, Aspergillus pseudonomius

    DEFF Research Database (Denmark)

    Massi, Fernanda Pelisson; Cameiro Vieira, Maria Lucia; Sartori, Daniele

    2014-01-01

    The exploitation of the Brazil nut is one of the most important activities of the extractive communities of the Amazon rainforest. However, its commercialization can be affected by the presence of aflatoxins produced by fungi, namely Aspergillus section Flavi. In the present study, we investigate...

  17. In vitro comparative analysis of monocrotophos degrading potential of Aspergillus flavus, Fusarium pallidoroseum and Macrophomina sp.

    Science.gov (United States)

    Jain, Rachna; Garg, Veena; Yadav, Deepak

    2014-06-01

    Fungal degradation is emerging as a new powerful tool for the removal of potent neurotoxin pesticide, monocrotophos. Therefore, the present study is aimed at comparative characterization of monocrotophos degrading ability of three different fungal strains. Fungal strains were isolated from local agricultural soil by enrichment culture method, screened by gradient culture and identified as Aspergillus flavus, Fusarium pallidoroseum and Macrophomina sp. Growth kinetics revealed a direct positive influence of monocrotophos on the viability of fungal isolates. Fungal degradation was studied in phosphorus free liquid culture medium supplemented with 150 mg L(-1) concentration of monocrotophos for a period of 15 days under optimized culture conditions. Degradation of MCP followed first order kinetics with kdeg of 0.007, 0.002 and 0.005 day(-1) and half life (t1/2) of 4.21, 12.64 and 6.32 days for A. flavus, F. pallidoroseum and Macrophomina sp. respectively. To the best of our knowledge, it is the first report signifying the potential of monocrotophos degradation by Fusarium and Macrophomina sp. The results were further confirmed by HPTLC and FTIR which indicates disappearance of monocrotophos by hydrolytic cleavage of vinyl phosphate bond. Degradation of monocrotophos by fungal isolates was accompanied by the release of extracellular alkaline phosphatases, inorganic phosphates and ammonia. The overall comparative analysis followed the order of A. flavus > Macrophomina sp. > F. pallidoroseum. Therefore, it could be concluded from the study that these three different fungal strains could be effectively used as a potential candidate for the removal of monocrotophos from contaminated sites.

  18. Optimization of laccase production from Aspergillus flavus by design of experiment technique: Partial purification and characterization

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2016-06-01

    Full Text Available The present study describes isolation of laccase producing fungal strain and optimization of the process parameters by design of experiment (DOE technique to achieve the maximum production of extracellular laccases by Aspergillus flavus obtained from natural habitat. Bromophenol blue dye and ABTS (2,2′-azinobis 3-ethyl-benzothiazoline-6-sulfonate were used as substrates for the screening of laccase activity. Design expert 8.0.7.1 software was used to optimize culture conditions such as carbon source, nitrogen source, temperature and pH. Subsequently, optimization for inoculums size was also carried out. The optimization studies revealed that the laccase yield was highest when operated at the following conditions: carbon source – cellulose (8%, nitrogen source – peptone (2%, temperature – 35 °C, pH – 7 and inoculum of size 1.5 cm.

  19. PLAN OF ACTIONS TO PREVENT, CONTROL AND DESINFECT CONTAMINATED PRODUCTS OF FUNGI AND AFLATOXINS

    OpenAIRE

    Armijo C., J.; Departamento Académico de Operaciones Unitarias, Facultad de Química e Ing. Química Universidad Nacional Mayor de San Marcos Lima, Perú; Calderón, J.; Departamento Académico de Operaciones Unitarias, FQIQ, Universidad Nacional Mayor de San Marcos, Lima, Perú

    2014-01-01

    Aflatoxins, a group of highly toxic substances produced by certain species of Aspergillus, especially A. flavus, have been found to occur in agricultural products such as corn, peanuts, cotton seed, animal feed, and many varieties of nuts. Experimental studies show that aflatoxins are carcinogenic. This paper proposes a plan of actions to prevent, control and desinfecting products contaminated with aflatoxins. Post harvest treatment of the product involves drying and storage temperature of 5 ...

  20. Aspergillus parasiticus growth and aflatoxin production on black and white pepper and the inhibitory action of their chemical constituents.

    OpenAIRE

    Madhyastha, M S; Bhat, R V

    1984-01-01

    Aspergillus parasiticus Speare NRRL 2999 growth and aflatoxin production in black and white pepper and the penetration of the fungus in black pepper corn over various incubation periods were studied. Also, the effects of piperine and pepper oil on growth and aflatoxin production were studied. Under laboratory conditions, black and white pepper supported aflatoxin production (62.5 and 44 ppb (ng/g), respectively) over 30 days of incubation. Fungal growth measured in terms of chitin was conside...

  1. Biosynthesis of extracellular and intracellular gold nanoparticles by Aspergillus fumigatus and A. flavus.

    Science.gov (United States)

    Gupta, Saurabh; Bector, Shruti

    2013-05-01

    Green chemistry is a boon for the development of safe, stable and ecofriendly nanostructures using biological tools. The present study was carried out to explore the potential of selected fungal strains for biosynthesis of intra- and extracellular gold nanostructures. Out of the seven cultures, two fungal strains (SBS-3 and SBS-7) were selected on the basis of development of dark pink colour in cell free supernatant and fungal beads, respectively indicative of extra- and intracellular gold nanoparticles production. Both biomass associated and cell free gold nanoparticles were characterized using X-ray diffractogram (XRD) analysis and transmission electron microscopy (TEM). XRD analysis confirmed crystalline, face-centered cubic lattice of metallic gold nanoparticles along with average crystallite size. A marginal difference in average crystallite size of extracellular (17.76 nm) and intracellular (26 and 22 nm) Au-nanostructures was observed using Scherrer equation. In TEM, a variety of shapes (triangles, spherical, hexagonal) were observed in both extra- and intracellular nanoparticles. 18S rRNA gene sequence analysis by multiple sequence alignment (BLAST) indicated 99 % homology of SBS-3 to Aspergillus fumigatus with 99 % alignment coverage and 98 % homology of SBS-7 to Aspergillus flavus with 98 % alignment coverage respectively. Native-PAGE and activity staining further confirmed enzyme linked synthesis of gold nanoparticles.

  2. Brazil nuts are subject to infection with B and G aflatoxin-producing fungus, Aspergillus pseudonomius.

    Science.gov (United States)

    Massi, Fernanda Pelisson; Vieira, Maria Lúcia Carneiro; Sartori, Daniele; Penha, Rafael Elias Silva; de Freitas Munhoz, Carla; Ferreira, Josué Maldonado; Iamanaka, Beatriz Thie; Taniwaki, Marta Hiromi; Frisvad, Jens C; Fungaro, Maria Helena Pelegrinelli

    2014-09-01

    The exploitation of the Brazil nut is one of the most important activities of the extractive communities of the Amazon rainforest. However, its commercialization can be affected by the presence of aflatoxins produced by fungi, namely Aspergillus section Flavi. In the present study, we investigated a collection of Aspergillus nomius strains isolated from Brazil nuts using different approaches, including morphological characters, RAPD and AFLP profiles, partial β-tubulin and calmodulin nucleotide sequences, aflatoxin patterns, as well as tolerance to low water activity in cultured media. Results showed that most of the isolates do belong to A. nomius species, but a few were re-identified as Aspergillus pseudonomius, a very recently described species. The results of the analyses of molecular variance, as well as the high pairwise FST values between A. nomius and A. pseudonomius suggested the isolation between these two species and the inexistence of gene flow. Fixed interspecific nucleotide polymorphisms at β-tubulin and calmodulin loci are presented. All A. pseudonomius strains analyzed produced aflatoxins AFB1, AFB2, AFG1 and AFG2. This study contains the first-ever report on the occurrence in Brazil nuts of A. pseudonomius. The G-type aflatoxins and the mycotoxin tenuazonic acid are reported here for the first time in A. pseudonomius. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Assessment of the antifungal activity of Spirulina platensis phenolic extract against Aspergillus flavus Avaliação da atividade antifúngica de extrato fenólico de Spirulina platensis contra Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Michele Moraes de Souza

    2011-12-01

    Full Text Available The production of safe food has stimulated the search for natural substances that possess antifungal activity. The indirect methods of estimating fungal biomass are based on the measurement of glucosamine, ergosterol and protein - typical compounds produced during the development of biomass. The aim of the study was to assess the effect of the phenolic extract from Spirulina platensis on the production of structural compounds in Aspergillus flavus, in order to identify its action on fungal inhibition. The Spirulina platensis methanolic extracts presented 1.15 mg phenolic compound/g Spirulina platensis, which showed an antifungal effect against Aspergillus flavus, inhibiting the glucosamine production up to 56%. Therefore, it may be employed as natural defense when food protection is necessary.A produção de alimentos seguros tem estimulado a busca por substâncias naturais que possuem atividade antifúngica. Os métodos indiretos de estimativa de biomassa fúngica são baseados na medição de glucosamina, ergosterol e proteína - compostos típicos produzidos durante o desenvolvimento da biomassa. Neste estudo, objetivou-se avaliar o efeito do extrato fenólico de Spirulina platensis na produção de componentes estruturais em Aspergillus flavus, a fim de identificar seu mecanismo de ação dos fenóis na inibição fúngica. O extrato metanólico de Spirulina platensis apresentou 1,15 mg de compostos fenólicos/g Spirulina platensis, apresentando um efeito antifúngico contra Aspergillus flavus, inibindo a produção de glucosamina em até 56%. Portanto, pode ser empregado como antifúngico natural quando for necessária a proteção de alimentos.

  4. Identification of Aspergillus (A. flavus and A. niger) Allergens and Heterogeneity of Allergic Patients' IgE Response.

    Science.gov (United States)

    Vermani, Maansi; Vijayan, Vannan Kandi; Agarwal, Mahendra Kumar

    2015-08-01

    Aspergillus species (A. flavus and A. niger) are important sources of inhalant allergens. Current diagnostic modalities employ crude Aspergillus extracts which only indicate the source to which the patient has been sensitized, without identifying the number and type of allergens in crude extracts. We report a study on the identification of major and minor allergens of the two common airborne Aspergillus species and heterogeneity of patients' IgE response to them. Skin prick tests were performed on 300 patients of bronchial asthma and/or allergic rhinitis and 20 healthy volunteers. Allergen specific IgE in patients' sera was estimated by enzyme allergosorbent test (EAST). Immunoblots were performed to identify major/minor allergens of Aspergillus extracts and to study heterogeneity of patients'IgE response to them. Positive cutaneous responses were observed in 17% and 14.7% of patients with A. flavus and A. niger extracts, respectively. Corresponding EAST positivity was 69.2% and 68.7%. In immunoblots, 5 allergenic proteins were identified in A. niger extract, major allergens being 49, 55.4 and 81.5 kDa. Twelve proteins bound patients' IgE in A. flavus extract, three being major allergens (13.3, 34 and 37 kDa). The position and slopes of EAST binding and inhibition curves obtained with individual sera varied from patient to patient. The number and molecular weight of IgE-binding proteins in both the Aspergillus extracts varied among patients. These results gave evidence of heterogeneity of patients' IgE response to major/minor Aspergillus allergens. This approach will be helpful to identify disease eliciting molecules in the individual patients (component resolved diagnosis) and may improve allergen-specific immunotherapy.

  5. RNA sequencing of contaminated seeds reveals the state of the seed permissive for pre-harvest aflatoxin contamination and points to a potential susceptibility factor

    Science.gov (United States)

    Pre-harvest aflatoxin contamination (PAC) is a major problem facing peanut production worldwide. Produced by the ubiquitous soil fungus, Aspergillus flavus, aflatoxin is the most potent naturally occurring known carcinogen. The interaction between fungus and host resulting in PAC is complex, and b...

  6. Mitigation of aflatoxin contamination in maize kernels is related to the metabolic alternation of reactive oxygen and nitrogen species by relative humidity

    Science.gov (United States)

    Environmental factors have been shown to be linked to exacerbated infection of maize kernels by Aspergillus flavus and subsequent aflatoxin contamination. Kernel resistance to aflatoxin contamination is associated with kernel water content and relative humidity during in vitro assays examining aflat...

  7. Cloning and characterization of F3PYC gene encoding pyruvate carboxylase in Aspergillus flavus strain (F3).

    Science.gov (United States)

    Qayyum, Sadia; Khan, Ibrar; Bhatti, Zulfiqar Ahmad; Peng, Changsheng

    2017-08-01

    Pyruvate carboxylase is a major enzyme for biosynthesis of organic acids like; citric acid, fumeric acid, and L-malic acid. These organic acids play very important role for biological remediation of heavy metals. In this study, gene walking method was used to clone and characterize pyruvate carboxylase gene (F3PYC) from heavy metal resistant indigenous fungal isolate Aspergillus flavus (F3). 3579 bp of an open reading frame which encodes 1193 amino acid protein (isoelectric point: 6.10) with a calculated molecular weight of 131.2008 kDa was characterized. Deduced protein showed 90-95% similarity to those deduced from PYC gene from different fungal strains including; Aspergillus parasiticus, Neosartorya fischeri, Aspergillus fumigatus, Aspergillus clavatus, and Aspergillus niger. Protein generated from the PYC gene was a homotetramer (α4) and having four potential N-linked glycosylation sites and had no signal peptide. Amongst most possible N-glycosylation sites were -N-S-S-I- at 36 amino acid, -N-G-T-V- at 237 amino acid, N-G-S-S- at 517 amino acid, and N-T-S-R- at 1111 amino acid, with several functions have been proposed for the carbohydrate moiety such as thermal stability, pH, and temperature optima for activity and stabilization of the three-dimensional structure. Hence, cloning of F3PYC gene from A. flavus has important biotechnological applications.

  8. ROS Involves the Fungicidal Actions of Thymol against Spores of Aspergillus flavus via the Induction of Nitric Oxide.

    Science.gov (United States)

    Shen, Qingshan; Zhou, Wei; Li, Hongbo; Hu, Liangbin; Mo, Haizhen

    2016-01-01

    Aspergillus flavus is a well-known pathogenic fungus for both crops and human beings. The acquisition of resistance to azoles by A. flavus is leading to more failures occurring in the prevention of infection by A. flavus. In this study, we found that thymol, one of the major chemical constituents of the essential oil of Monarda punctate, had efficient fungicidal activity against A. flavus and led to sporular lysis. Further studies indicated that thymol treatment induced the generation of both ROS and NO in spores, whereas NO accumulation was far later than ROS accumulation in response to thymol. By blocking ROS production with the inhibitors of NADPH oxidase, NO generation was also significantly inhibited in the presence of thymol, which indicated that ROS induced NO generation in A. flavus in response to thymol treatment. Moreover, the removal of either ROS or NO attenuated lysis and death of spores exposed to thymol. The addition of SNP (exogenous NO donor) eliminated the protective effects of the inhibitors of NADPH oxidase on thymol-induced lysis and death of spores. Taken together, it could be concluded that ROS is involved in spore death induced by thymol via the induction of NO.

  9. [Influence of aflatoxin on Vibrio fischeri luminescence].

    Science.gov (United States)

    Li, Xiang; Pan, Li; Wang, Bin

    2011-12-01

    In the present study, we aim to evaluate the inhibitory effect of aflatoxin on Vibrio fischeri luminescence. V. fischeri culture is treated with aflatoxin or the culture broth of aflatoxin-producing strains, and the luminescence intensity of V. fischeri is detected to analyze the influence of aflatoxin on V. fischeri. The logarithmic value of aflatoxin concentration and the decrease ratio of V. fischeri luminescence is in a linear relationship. Based on the regression equation between aflatoxin concentration and luminescence decrease of V. fischeri, the toxin-producing status of different microbes can be detected quickly and exactly: all of six tested Aspergillus flavus strains show toxigenicity to V. fischeri, and their toxin yield reached 14.94 mg/L - 46.45 mg/L (represented by aflatoxin concentration), while the tested Aspergillus oryzae shows no toxigenicity. The above data showed that the luminescence change of V. fischeri could exactly reflect the capability of various microbes to produce toxin (especially aflatoxin), which provided a new clue for rapid detection of aflatoxin in industrial and agricultural production and could be developed as a potential method for aflatoxin assay.

  10. Aflatoxin and sterigmatocystin contamination of pistachio nuts in orchards.

    Science.gov (United States)

    Sommer, N F; Buchanan, J R; Fortlage, R J

    1976-07-01

    Aspergillus flavus and A. versicolor were both shown to be weak pathogens of developing pistachio fruits, producing aflatoxin and sterigmatocystin, respectively. Aflatoxin concentrations approached those reported in cereal and legume seeds. Fungus lesions on the first hulls were followed by invasion of seeds despite the sclerified shell. Infections and mycotoxins present before harvest would presumably lead to further build-up after harvest if drying was slow or storage was under high humidity.

  11. Using biotechnology to enhance host resistance to aflatoxin ...

    African Journals Online (AJOL)

    Host resistance is the most widely explored strategy for eliminating aflatoxin contamination by Aspergillus flavus. Breeding strategies for developing resistant corn germplasm have been enhanced by the development of new screening tools for field inoculation and for laboratory screening. RFLP analysis of corn populations ...

  12. ASPERGILLUS FLA VUS INFECTION AND AFLATOXIN CONTAMINATION IN PEANUTS AT VARIOUS STAGES OF THE DELIVERY CHAINS IN CIANJUR REGENCY, WEST JAVA, INDONESIA

    Directory of Open Access Journals (Sweden)

    OKKY SETYAWATI DHARMAPUTRA

    2005-01-01

    Full Text Available A survey to obtain information on pre- and postharvest handling of peanuts at farmer, collector, wholesaler and retailer levels, including Aspergillus flavus infection and aflatoxin BI contamination of peanuts collected in Cianjur regency, West Java, was conducted during the harvest period of the wet season of February 2004. The moisture contents and physical qualities of the peanuts were also determined. Thirteen and 40 dry pod samples were collected randomly from 12 farmers and 23 co llectors, respectively. Seven dry kernel samples were also collected from collectors. Five and 45 dry kernel samples were collected randomly from 2 wholesalers and 45 retailers in traditional markets, resp ectively. Thus, a total of 110 dry peanut pod and kernel samples were collected. The results of interviews with farmers, collectors, wholes alers and retailers, and also the moisture contents and physical qualities of the peanuts arc described in this article. The percentages of samples infected by A. flavus were highest at the wholesaler as well as at retailer levels (100%, respectively, followed by those sampled at the collectors (85.0 and 85.7%, respectively, and farmers (84.6%. The mean percentage of infected kernels in infect ed samples of peanuts collected from retailers was the highest (87.6%, followed by those collected from wholesalers (72.4%, collectors in the form of kernels (23.3% and pods (17.7%, and farmers (15.2%. The range of aflatoxin BI contents in peanut samples collected from farmers (dry pods, collectors (dry pods, wholesalers (dry pods and kernels and retailers (dry kernels were < 3.6 -114.2, < 3.6 -2999.5 and < 3,6 - 34.1, < 3.6 - 6065.9, and < 3.6 - 6073.0 ppb, respectively. The highest aflatoxin B, contents at the wholesaler and retailer levels were 6065.9 ppb (in one sample and 6073.0 ppb (in one sample, respectively. The percentage of samples contaminated with more than 15 ppb of aflatoxin BI was the highest in peanuts collected from

  13. Black gill disease of Pacific white leg shrimp (Litopenaeus vannamei by Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Naresh Kumar Dewangan

    2015-10-01

    Full Text Available Objective: To study the epidemiology of black gill disease in white leg shrimp which is a major problem being faced by the commercial shrimp farmers who are culturing Litopenaeus vannamei (L. vannamei in India. Methods: The normal and infected shrimps were collected from shrimp pond and the gill was preserved in appropriate preservative for histopathological examination and scanning electron microscope analysis. Pathogenic fungus was isolated from black gill of L. vannamei in potato dextrose agar medium. Morphological study and fungal strain identification were done by using light microscopy and scanning electron microscope. Fungal DNA was amplified by ITS4 and ITS5 primers and gene sequencing was done by Macrogen Inc., Korea. Phylogenetic tree was prepared by using MEGA 6 software. Results: Fungal spores and hyphae were observed both in internal and external gill surface of infected shrimps. Fungal spores were round in shape and mature sporangium was observed. The histopathology study showed clearly that infected gill was damaged by the fungi. Scanning electron microscopic study showed adherence of fungi in infected gill. Internal transcribed spacer gene sequencing revealed that it was caused by Aspergillus flavus. Conclusions: The outcome of the present study would help to know the cause of black gill disease and to understand the effect of pathogenic fungi in shrimp culture. This study will initiate researchers for work in field of treatment or prevention of black gill disease in commercial L. vannamei culture.

  14. Herbicidal activity of pure compound isolated from rhizosphere inhabiting Aspergillus flavus.

    Science.gov (United States)

    Khattak, Saeed Ullah; Lutfullah, Ghosia; Iqbal, Zafar; Rehman, Irshad Ur; Ahmad, Jamshaid; Khan, Abid Ali

    2017-05-11

    In the quest for bioactive natural products of fungal origin, Aspergillus flavus was isolated from rhizosphere of Mentha piperita using Potato Dextrose Agar (PDA) and Czapec Yeast Broth (CYB) nutrient media for metabolites production. In total, three different metabolites were purified using HPLC/LCMS and the structures were established using 500 Varian NMR experiments. Further the isolated metabolites in different concentrations (10, 100, 1000 μg/mL) were tested for herbicidal activity using Completely Randomized design (CRD) against the seeds of Silybum marianum and Avena fatua which are major threats to wheat crop in Pakistan. Among the isolated metabolites, one compound was found active against the test weed species whose activity is reported in the present work. The chemical name of the compound is 2-(1, 4-dihydroxybutan-2-yl)-1, 3-dihydroxy-6, 8-dimethoxyanthracene-9, 10(4aH, 9aH)-dione with mass of 388. Results showed that all seeds germinated in control treatment; however, with the metabolite treated, the growth was retarded to different levels in all parts of the weeds. At a dose of 1000 μg/mL of the pure compound, 100% seeds of S. marianum and 60% seeds of A. fatua were inhibited. Interestingly, the pure compound exhibited less inhibition of 10% towards the seeds of common wheat (Triticum aestivum).

  15. Purification of a vesicle-vacuole fraction functionally linked to aflatoxin synthesis in Aspergillus parasiticus.

    Science.gov (United States)

    Chanda, Anindya; Roze, Ludmila V; Pastor, Alicia; Frame, Melinda K; Linz, John E

    2009-07-01

    Current studies in our laboratory demonstrate a functional link between vesicles, vacuoles and aflatoxin biosynthesis in the filamentous fungus, Aspergillus parasiticus. Under aflatoxin inducing conditions in liquid yeast-extract sucrose medium, A. parasiticus undergoes a shift from vacuole biogenesis to accumulation of an enhanced number of vesicles which exhibit significant heterogeneity in size and density. As a first step in conducting a detailed analysis of the role of these organelles in aflatoxin synthesis, we developed a novel method to purify the vesicle and vacuole fraction using protoplasts prepared from cells harvested during aflatoxin synthesis. The method includes the following steps: 1] preparation of protoplasts from mycelia grown for 36 h under aflatoxin inducing conditions; 2] release of vesicles and vacuoles from purified protoplasts in the presence of Triton X-100; and 3] fractionation of the vesicles and vacuoles using a "one-step high density cushion". The vesicle-vacuole fraction showed a 35 fold enrichment in alpha-mannosidase activity (vacuole marker) and non-detectable succinate dehydrogenase and lactate dehydrogenase activities (mitochondrial and cytoplasmic markers, respectively). Confocal laser scanning microscopy with the vacuole dyes MDY-64 and CMAC demonstrated that the fraction contained pure vesicles and vacuoles and was devoid of membranous debris. Transmission electron microscopy (TEM) confirmed that no mitochondria or unbroken protoplasts contaminated the purified fraction. The purified organelles exhibited significant size heterogeneity with a range of sizes similar to that observed in whole cells and protoplasts.

  16. Improved production of kojic acid by mutagenesis of Aspergillus flavus HAk1 and Aspergillus oryzae HAk2 and their potential antioxidant activity.

    Science.gov (United States)

    Ammar, Hala A M; Ezzat, Saeid M; Houseny, Asmaa M

    2017-10-01

    Two wild-type (WT) Aspergillus strains, A. flavus HAk1 and A. oryzae HAk2, were selected for kojic acid (KA) biosynthesis. Malt extract sucrose culture medium (MES) was the best culture medium for maximum production of KA. The maximum production of KA has been estimated at pH 4 after 7 days of incubation at 30 °C. Overproduction of KA was attained by mutagenesis of both A. flavus HAk1 and A. oryzae HAk2 through their exposer to different doses of gamma irradiation. The mutant strains (MT) A. flavus HAk1-M2 and A. oryzae HAk2-M26 were the most stable mutants for maximum production of KA through four generations. Yield of KA by A. oryzae HAk2-M26 and A. flavus HAk1-M2 has been 2.03-fold and 1.9-fold, respectively, higher than their wild-type strains. All WT and MT strains were used for KA production from different agricultural raw materials. Apple peel was the best waste for KA production by WT strains of A. flavus and A. oryzae, while orange peel and rice stalk are best material for KA production by MT strains, A. flavus HAk1-M2 and A. oryzae HAk2-M26, respectively. All experimental strains have the ability to produce considerable amounts of KA from sugarcane molasse (SCM) and sugar-beet molasse (SBM). SBM was better than SCM for KA production by all strains. The antioxidant activity of biosynthesizing KA was strongly affected with production conditions, where the highest antioxidant activity of all strains was recorded at the optimum environmental and nutritional conditions for KA production.

  17. Efficacy of two chemical coagulants and three different filtration media on removal of Aspergillus flavus from surface water.

    Science.gov (United States)

    Al-Gabr, Hamid Mohammad; Zheng, Tianling; Yu, Xin

    2014-02-01

    Aquatic fungi are common in various aqueous environments and play potentially crucial roles in nutrient and carbon cycling as well as interacting with other organisms. Species of Aspergillus are the most common fungi that occur in water. The present study was undertaken to elucidate the efficacy of two coagulants, aluminum sulfate and ferric chloride, used at different concentrations to treat drinking water, in removing Aspergillus flavus, as well as testing three different filtration media: sand, activated carbon, and ceramic granules, for their removal of fungi from water. The results revealed that both coagulants were effective in removing fungi and decreasing the turbidity of drinking water, and turbidity decreased with increasing coagulant concentration. Also, at the highest concentration of the coagulants, A. flavus was decreased by 99.6% in the treated water. Among ceramic granules, activated carbon, and sand used as media for water filtration, the sand and activated carbon filters were more effective in removing A. flavus than ceramic granules while simultaneously decreasing the turbidity levels in the test water samples. Post-treatment total organic carbon (TOC) and total nitrogen (TN) concentrations in the experimental water did not decrease; on the contrary, TN concentrations increased with the increasing dosage of coagulants. The filtration process had no effect in reducing TOC and TN in tested water.

  18. Achievements and Prospects in Electrochemical-Based Biosensing Platforms for Aflatoxin M1 Detection in Milk and Dairy Products

    Directory of Open Access Journals (Sweden)

    Ana-Maria Gurban

    2017-12-01

    Full Text Available Aflatoxins, which are mainly produced by Aspergillus flavus and parasiticus growing on plants and products stored under inappropriate conditions, represent the most studied group of mycotoxins. Contamination of human and animal milk with aflatoxin M1, the hydroxylated metabolite of aflatoxin B1, is an important health risk factor due to its carcinogenicity and mutagenicity. Due to the low concentration of this aflatoxin in milk and milk products, the analytical methods used for its quantification have to be highly sensitive, specific and simple. This paper presents an overview of the analytical methods, especially of the electrochemical immunosensors and aptasensors, used for determination of aflatoxin M1.

  19. Achievements and Prospects in Electrochemical-Based Biosensing Platforms for Aflatoxin M1 Detection in Milk and Dairy Products

    Science.gov (United States)

    Epure, Petru; Doni, Mihaela

    2017-01-01

    Aflatoxins, which are mainly produced by Aspergillus flavus and parasiticus growing on plants and products stored under inappropriate conditions, represent the most studied group of mycotoxins. Contamination of human and animal milk with aflatoxin M1, the hydroxylated metabolite of aflatoxin B1, is an important health risk factor due to its carcinogenicity and mutagenicity. Due to the low concentration of this aflatoxin in milk and milk products, the analytical methods used for its quantification have to be highly sensitive, specific and simple. This paper presents an overview of the analytical methods, especially of the electrochemical immunosensors and aptasensors, used for determination of aflatoxin M1. PMID:29257102

  20. Characterization of the Critical Amino Acids of an Aspergillus parasiticus Cytochrome P-450 Monooxygenase Encoded by ordA That Is Involved in the Biosynthesis of Aflatoxins B1, G1, B2, and G2

    Science.gov (United States)

    Yu, Jiujiang; Chang, Perng-Kuang; Ehrlich, Kenneth C.; Cary, Jeffrey W.; Montalbano, Beverly; Dyer, John M.; Bhatnagar, Deepak; Cleveland, Thomas E.

    1998-01-01

    The conversion of O-methylsterigmatocystin (OMST) and dihydro-O-methylsterigmatocystin to aflatoxins B1, G1, B2, and G2 requires a cytochrome P-450 type of oxidoreductase activity. ordA, a gene adjacent to the omtA gene, was identified in the aflatoxin-biosynthetic pathway gene cluster by chromosomal walking in Aspergillus parasiticus. The ordA gene was a homolog of the Aspergillus flavus ord1 gene, which is involved in the conversion of OMST to aflatoxin B1. Complementation of A. parasiticus SRRC 2043, an OMST-accumulating strain, with the ordA gene restored the ability to produce aflatoxins B1, G1, B2, and G2. The ordA gene placed under the control of the GAL1 promoter converted exogenously supplied OMST to aflatoxin B1 in Saccharomyces cerevisiae. In contrast, the ordA gene homolog in A. parasiticus SRRC 2043, ordA1, was not able to carry out the same conversion in the yeast system. Sequence analysis revealed that the ordA1 gene had three point mutations which resulted in three amino acid changes (His-400→Leu-400, Ala-143→Ser-143, and Ile-528→Tyr-528). Site-directed mutagenesis studies showed that the change of His-400 to Leu-400 resulted in a loss of the monooxygenase activity and that Ala-143 played a significant role in the catalytic conversion. In contrast, Ile-528 was not associated with the enzymatic activity. The involvement of the ordA gene in the synthesis of aflatoxins G1, and G2 in A. parasiticus suggests that enzymes required for the formation of aflatoxins G1 and G2 are not present in A. flavus. The results showed that in addition to the conserved heme-binding and redox reaction domains encoded by ordA, other seemingly domain-unrelated amino acid residues are critical for cytochrome P-450 catalytic activity. The ordA gene has been assigned to a new cytochrome P-450 gene family named CYP64 by The Cytochrome P450 Nomenclature Committee. PMID:9835571

  1. Aflatoxin Control in Maize by Trametes versicolor

    Directory of Open Access Journals (Sweden)

    Marzia Scarpari

    2014-12-01

    Full Text Available Aspergillus flavus is a well-known ubiquitous fungus able to contaminate both in pre- and postharvest period different feed and food commodities. During their growth, these fungi can synthesise aflatoxins, secondary metabolites highly hazardous for animal and human health. The requirement of products with low impact on the environment and on human health, able to control aflatoxin production, has increased. In this work the effect of the basidiomycete Trametes versicolor on the aflatoxin production by A. flavus both in vitro and in maize, was investigated. The goal was to propose an environmental loyal tool for a significant control of aflatoxin production, in order to obtain feedstuffs and feed with a high standard of quality and safety to enhance the wellbeing of dairy cows. The presence of T. versicolor, grown on sugar beet pulp, inhibited the production of aflatoxin B1 in maize by A. flavus. Furthermore, treatment of contaminated maize with culture filtrates of T. versicolor containing ligninolytic enzymes, showed a significant reduction of the content of aflatoxin B1.

  2. Isolation of Alkaline and Neutral Proteases from Aspergillus flavus var. columnaris, a Soy Sauce Koji Mold

    Science.gov (United States)

    Impoolsup, Attawut; Bhumiratana, Amaret; Flegel, Timothy W.

    1981-01-01

    Two different extracellular proteases, protease I (P-I), an alkaline protease, and protease II (P-II) a neutral protease, from Aspergillus flavus var. columnaris were partially purified by using (NH4)2SO4 precipitation, diethylaminoethyl-Sephadex A-50 chromatography, carboxymethylcellulose CM-52 chromatography, and Sephadex G-100 gel filtration. The degree of purity was followed using polyacrylamide gel electrophoresis. The activity of P-I was completely inhibited by 0.1 mM phenylmethylsulfonyl fluoride, and that of P-II was completely inhibited by 1 mM ethylenediaminetetraacetate. By using these inhibitors with extracts of wheat bran koji, the proportions of total activity that could be assigned to P-I and P-II were 80 and 20%, respectively. This compared favorably with activities estimated by using polyacrylamide gel electrophoresis slices (82 and 18%, respectively). Extracts from factory-run soybean koji gave comparable results. Both enzymes demonstrated maximum activity at 50 to 55°C and only small changes in activity between pH 6 and 11. For P-I, activity was somewhat higher from pH 8.0 to 11.0, whereas for P-II it was somewhat higher from pH 6 to 9. In the presence of 18% NaCl, the activities of both P-I and P-II dropped by approximately 90 and 85%, respectively. P-I was inferred to possess aminopeptidase activity since it could hydrolyze l-leucyl-p-nitroanilide hydrochloride. P-II was devoid of such activity. The ramifications of the results for factory-produced soy sauce koji are discussed. Images PMID:16345858

  3. Treatment of two postoperative endophthalmitis cases due to Aspergillus flavus and Scopulariopsis spp. with local and systemic antifungal therapy

    Directory of Open Access Journals (Sweden)

    Uyar Guliz

    2007-07-01

    Full Text Available Abstract Background Endophthalmitis is the inflammatory response to invasion of the eye with bacteria or fungi. The incidence of endophthalmitis after cataract surgery varies between 0.072–0.13 percent. Treatment of endophthalmitis with fungal etiology is difficult. Case Presentation Case 1: A 71-year old male diabetic patient developed postoperative endophthalmitis due to Aspergillus flavus. The patient was treated with topical amphotericin B ophthalmic solution, intravenous (IV liposomal amphotericin-B and caspofungin following vitrectomy. Case 2: A 72-year old male cachectic patient developed postoperative endophthalmitis due to Scopulariopsis spp. The patient was treated with topical and IV voriconazole and caspofungin. Conclusion Aspergillus spp. are responsible of postoperative fungal endophthalmitis. Endophthalmitis caused by Scopulariopsis spp. is a very rare condition. The two cases were successfully treated with local and systemic antifungal therapy.

  4. Dietary Factors and Hepatoma in Rainbow Trout (Salmo gairdneri). I. Aflatoxins in Vegetable Protein Feedstuffs

    Science.gov (United States)

    Sinnhuber, R.O.; Wales, J.H.; Ayers, J.L.; Engebrecht, R.H.; Amend, D.F.

    1968-01-01

    Aflatoxins (toxic metabolites of the mold Aspergillus flavus) were present in a commercial trout ration causing hepatoma in rainbow trout. Cottonseed meal and solvent extracts of cottonseed meal and of rations containing cottonseed meal and peanut meal were found by chemical assay and confirmed by duckling assay to contain aflatoxins. Diets containing these materials and a purified test diet to which aflatoxins had been added produced microscopic tumors in 6 months and gross lesions of hepatocarcinoma in 9 months. Similar diets without aflatoxin were negative.

  5. Use of Selected Essential Oils to Control Aflatoxin Contaminated Stored Cashew and Detection of Aflatoxin Biosynthesis Gene

    Directory of Open Access Journals (Sweden)

    Abeer R. M. Abd El-Aziz

    2015-01-01

    Full Text Available Aspergillus spp. associated with cashew from the regions of Riyadh, Dammam, and Abha were isolated and three different culture media were used to qualitatively measure aflatoxin production by Aspergillus via UV light (365 nm, which was expressed as positive or negative. The obtained data showed that six isolates of A. flavus and four isolates of A. parasiticus were positive for aflatoxin production, while all isolates of A. niger were negative. Five commercially essential oils (thyme, garlic, cinnamon, mint, and rosemary were tested to determine their influence on growth and aflatoxin production in A. flavus and A. parasiticus by performing high-performance liquid chromatography (HPLC. The results showed that the tested essential oils caused highly significant inhibition of fungal growth and aflatoxin production in A. flavus and A. parasiticus. The extent of the inhibition of fungal growth and aflatoxin production was dependent on the type and concentration of essential oils applied. The results indicate that cinnamon and thyme oils show strong antimicrobial potential. PCR was used with four sets of primer pairs for nor-1, omt-1, ver-1, and aflR genes, enclosed in the aflatoxin biosynthetic pathway. The interpretation of the results revealed that PCR is a rapid and sensitive method.

  6. Techniques used detection and quantification of aflatoxin M1 in milk

    Directory of Open Access Journals (Sweden)

    Adriana Frizzarin

    2012-02-01

    Full Text Available Aflatoxin is a group of toxic substances produced by fungi, mainly Aspergillus flavus and Aspergillus parasiticus. It can be developed in agriculture products such as grains or processed food, when environment conditions of humidity and air humidity are favorable. Aflatoxins can be presented as several forms. In Milk, are called M1 and M2, resulting from aflatoxins B1 and B2 metabolism. Aflatoxin M1 (AFM1 is classified as a possible carcinogen to humans, so the occurrence of aflatoxin M1 in milk of lactating cows is a public health issue, and because of its importance several techniques are used for its detection and quantification. These techniques include the physical-chemical as thin layer chromatography and high performance liquid chromatography and the biological techniques including immunoassays such as RIA and ELISA. This review aimed to present the techniques used to quantify aflatoxins M1 and M2 in milk and dairy products.

  7. Volatile metabolites associated with one aflatoxigenic and one nontoxigenic Aspergillus flavus strain grown on two different substrates

    Directory of Open Access Journals (Sweden)

    Z. Jurjevic

    2009-01-01

    Full Text Available Aflatoxigenic and non-toxigenic Aspergillus flavus strains were grown on corn and on peanut substrates. Microbial volatile organic compounds (MVOCS were collected by trapping headspace volatiles using thermal desorption tubes (TDT packed with Tenax® TA and Carbotrap™ B. Samples were collected at various fungal growth stages. Trapped compounds were thermally desorbed from the adsorbent tubes, separated by gas chromatography, and identified by mass spectrometry. The fungal stage did not have many differences in the MVOCs but the concentrations of some volatiles changed over time depending on the substrate. Volatiles that were associated with both the aflatoxigenic A. flavus strain and the nontoxigenic strain on both substrates included: ethanol, 1-propanol, butanal, 2-methyl-1-propanol, 3-methylfuran, ethyl acetate, 1-butanol, 3-methylbutanal, 3-methyl-1-butanol, propanoic acid-2-methyl-ethyl-ester, 2-methyl-1-butanol, 1-pentanol, 2-pentanol, 3-methyl-3-buten-1-ol, benzaldehyde, 3-octanone, 2-ethyl-1-hexanol and octane. Volatiles that were associated only with the aflatoxigenic A. flavus strain included: dimethyl disulfide and nonanal. Volatiles that were associated only with the nontoxigenic A. fl avus strain included: hexanal, 1-hexanol, 1-octene-3-ol, 1-octen-3-one and 2-pentyl furan.

  8. Chemical Composition and Antifungal Effect of Echinophora platyloba Essential Oil against Aspergillus flavus, Penicillium expansum and Fusarium graminearum

    Directory of Open Access Journals (Sweden)

    Mohammad Hashemi

    2016-03-01

    Full Text Available Molds are one of the most important causes of food spoilage that produce toxic substances called mycotoxins, which endanger the consumer health. The adverse effects of synthetic food preservatives consumption made researches to focus on application of natural preservatives in order to increase shelf life of food as well as prevention of harmful effects of chemical preservatives. The present study was conducted to investigate the effects of Echinophora platyloba essential oil on spore growth of Aspergillus flavus, Penicillium expansum and Fusarium graminearum. The essential oil composition of E. platyloba was analyzed by gas chromatography–mass spectrometry (GC-MS and its antifungal effect was evaluated by disk diffusion and micro dilution methods. Results revealed that the MIC values of essential oil for A. flavus, P. expansum and F. graminearum were 0.625 mg.mL-1, 0.625 mg.mL-1 and 0.3125 mg.mL-1 and the MFC values were 0.625 mg.mL-1, 1.250 mg.mL-1 and 0.625 mg.mL-1. The essential oil had the highest and the lowest anti-fungal effect on F. graminearum and A. flavus respectively. In conclusion, due to notable antifungal effects of E. platyloba essential oil, it can be practically applied as a natural alternative to chemical preservatives in food industry.

  9. Production and isolation of aflatoxin M1 for toxicological studies.

    Science.gov (United States)

    Hsieh, D P; Beltran, L M; Fukayama, M Y; Rice, D W; Wong, J J

    1986-01-01

    One hundred mg aflatoxin M1 was produced and purified for toxicological studies. Aspergillus flavus NRRL 3251 was cultured on rice to produce aflatoxins B1, B2, M1, and M2, B1 and B2 were separated from M1 and M2 by a normal phase low pressure liquid chromatography (LC) column. M1 was then separated from M2 by a reverse phase low pressure LC column. Recoveries of aflatoxins from the LC columns were about 90%. The purified M1 was confirmed by ultraviolet-visible spectrometry, mass spectrometry, nuclear magnetic resonance spectrometry, optical rotation, and its mutagenicity to Salmonella typhimurium TA98.

  10. Effects of Pistacia atlantica subsp. kurdica on Growth and Aflatoxin Production by Aspergillus parasiticus

    Science.gov (United States)

    Khodavaisy, Sadegh; Rezaie, Sassan; Noorbakhsh, Fatemeh; Baghdadi, Elham; Sharifynia, Somayeh; Aala, Farzad

    2016-01-01

    Background Aflatoxins are highly toxic secondary metabolites mainly produced by Aspergillus parasiticus. This species can contaminate a wide range of agricultural commodities, including cereals, peanuts, and crops in the field. In recent years, research on medicinal herbs, such as Pistacia atlantica subsp. kurdica, have led to reduced microbial growth, and these herbs also have a particular effect on the production of aflatoxins as carcinogenic compounds. Objectives In this study, we to examine P. atlantica subsp. kurdica as a natural compound used to inhibit the growth of A. parasiticus and to act as an anti-mycotoxin. Materials and Methods In vitro antifungal susceptibility testing of P. atlantica subsp. kurdica for A. parasiticus was performed according to CLSI document M38-A2. The rate of aflatoxin production was determined using the HPLC technique after exposure to different concentrations (62.5 - 125 mg/mL) of the gum. The changes in expression levels of the aflR gene were analyzed with a quantitative real-time PCR assay. Results The results showed that P. atlantica subsp. kurdica can inhibit A. parasiticus growth at a concentration of 125 mg/mL. HPLC results revealed a significant decrease in aflatoxin production with 125 mg/mL of P. atlantica subsp. kurdica, and AFL-B1 production was entirely inhibited. Based on quantitative real-time PCR results, the rate of aflR gene expression was significantly decreased after treatment with P. atlantica subsp. kurdica. Conclusions Pistacia atlantica subsp. kurdica has anti-toxic properties in addition to an inhibitory effect on A. parasiticus growth, and is able to decrease aflatoxin production effectively in a dose-dependent manner. Therefore, this herbal extract maybe considered a potential anti-mycotoxin agent in medicine or industrial agriculture. PMID:27800127

  11. Detection of aflatoxin-producing fungi isolated from Nile tilapia and fish feed.

    Science.gov (United States)

    Mohamed, Hams M A; Emeish, Walaa F A; Braeuning, Albert; Hammad, Seddik

    2017-01-01

    Contamination of fish by fungi and their mycotoxins poses major health concerns to human and animals. Therefore, our study was aimed to investigate Aspergillus flavus (A. flavus) infections and the levels of aflatoxins in Nile tilapia, Oreochromis niloticus (O. niloticus) , and fish feed. Samples from O. niloticus and fish feed (n=25 for each) were randomly collected from private fish farms at Qena province, Egypt, during the winter season. Different Aspergillus spp. were detected in 60 % and 64 % of O. niloticus and fish feed, respectively. HPLC-based analysis revealed aflatoxin-producing activity in 75 % and 83 % of A. flavus isolates from fish and fish feed, respectively. While 96 % of O. niloticus muscles and fish feed samples were contaminated with aflatoxins, the detected levels were below the permissible limits, i.e. 20 µg/kg. Moreover, experimental infection with toxicogenic A. flavus isolates was conducted to evaluate their pathogenicity in O. niloticus . Expectedly, experimental infections of O. niloticus with A. flavus were associated with several clinical symptoms reported in naturally infected fish, e.g. yellow coloration with skin ulceration, hemorrhagic ulcerative patches on gills and skin, corneal opacity, fin rot and abdominal distention. Furthermore, aflatoxicogenic A. flavus isolates from fish were sensitive to herbal clove oil. Even though the measured levels of aflatoxin were below permissible limits, effort should be placed on further reduction of exposure to genotoxic and carcinogenic mycotoxins.

  12. New Perspectives for the Application of Bioplastic Materials in the Biocontrol of Aspergillus flavus in Corn

    Science.gov (United States)

    Mycotoxins are secondary metabolities produced by certain filamentous fungi that can contaminate a large variety of agricultural commodities before and after harvest. Among different mycotoxins, aflatoxins and especially aflatoxin B1 are of particular concern because they are potent natural carcino...

  13. Occurrence of fungi and cytotoxicity of the species: Aspergillus ochraceus, Aspergillus niger and Aspergillus flavus isolated from the air of hospital wards.

    Science.gov (United States)

    Gniadek, Agnieszka; Krzyściak, Paweł; Twarużek, Magdalena; Macura, Anna B

    2017-03-30

    The basic care requirement for patients with weakened immune systems is to create the environment where the risk of mycosis is reduced to a minimum. Between 2007 and 2013 air samples were collected from various wards of a number of hospitals in Kraków, Poland, by means of the collision method using MAS-100 Iso MH Microbial Air Sampler (Merck Millipore, Germany). The air mycobiota contained several species of fungi, and almost 1/3 of it was made up of the species of the Aspergillus genus. Sixty-one strains of species other than A. fumigatus were selected for the research purposes, namely: 28 strains of A. ochraceus, 22 strains of A. niger and 11 strains of A. flavus species. Selected fungi underwent a cytotoxicity evaluation with the application of the MTT colorimetric assay (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide). The assay assesses cell viability by means of reducing the yellow tetrazolium salt to insoluble formazan. A semi-quantitative scale for cytotoxicity grading was adopted: low cytotoxic effect (+) with half maximal inhibitory concentration (IC50) for values ranging from 31.251 cm2/ml to 7.813 cm2/ml, medium cytotoxic effect (++) for values ranging from 3.906 cm2/ml to 0.977 cm2/ml and the high one (+++) for values ranging from 0.488 cm2/ml to 0.061 cm2/ml. The absence of cytotoxicity was determined when the IC50 values was at ≥ 50. For 48 samples the analyzed fungi displayed the cytotoxic effect with A. ochraceus in 26 out of 28 cases, with 11 strains displaying the high cytotoxic effect. The lowest cytotoxicity was displayed by fungi of A. niger in 13 out of 22 cases, and the major fungi of A. flavus species were toxic (9 out of 11 cases). A half of the fungi displayed the low cytotoxic effect. On the basis of the comparison of average cytotoxicity levels it was determined that there were significant differences in the levels of cytotoxicity of the analyzed fungi. However, such statement may not provide grounds for a definite

  14. Bioaktivitas Senyawa Asam Heksadekanoat dan ??-sitosterol Isolat dariHydroid Aglaophenia cupressina Lamoureoux sebagai BahanAntimikroba pada bakteri Staphilococcus aureus dan jamur Aspergillus flavus

    OpenAIRE

    Yohannes, Eva

    2014-01-01

    Saat ini sangat diperlukan sumber antibiotik baru yang lebih efektif untuk mengatasi Multi Drug Resistant (MDR), pada pengobatan penyakit infeksi yang disebabkan oleh mikroorganisme patogen. Penelitian ini bertujuan untuk mengetahui bioaktivitas senyawa asam heksadekanoat dan ??-sitosterol hasil isolat dari hydroid Aglaophenia cupressina Lamoureoux dalam menghambat atau mematikan bakteri Staphyloccocus aureus dan jamur Aspergillus flavus yang sering mencemari bahan pangan. Metode yang digunak...

  15. Effect of gamma radiation in peanuts for inhibition of Aspergillus flavus and nutritional composition; Irradiacao gama em amendoim para controle de Aspergillus flavus

    Energy Technology Data Exchange (ETDEWEB)

    Costa, L.F.; Silva, E.B. da, E-mail: lauryfrancis@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Oliveira, I.S. [Universidade Federal de Pernambuco (CAV/UFPE), Vitoria de Santo Antao, PE (Brazil). Centro Academico de Vitoria

    2013-08-15

    Care in food storage, controlling humidity and temperature, prevents fungal diseases in peanuts and the development of filamentous fungi in food and feed, which can result in the production of toxins known as mycotoxins. Ionizing radiation is a preventive method of food security, promoting inhibition of buds, delayed maturation, reduction of microbial load, elimination of pathogenic microorganisms, sterilization and disinfection in grains, cereals, fruits and spices. This work aimed to evaluate the effects of gamma radiation on the growth inhibition of aflatoxigenic fungi and on nutritional composition in peanut. Samples were collected directly from the producer (Petrolandia) and Supply Central of Pernambuco (CEASA-PE), and then grains inside / outside pods were packed and subjected to irradiation at doses of 6, 9, 12 and 15 kGy. Fungal growth and nutritional composition of the samples before and after irradiation were analyzed and statistical analysis using the Mann-Whitney-Wilcoxon. The results showed that the samples originated from CEASA-PE had the highest rates of contamination. The radiation was effective in the inhibition of aflatoxigenic fungi, achieving to eliminate the action of fungi, regardless of dose. Only one non-irradiated sample, originated from CEASA-PE, showed positive production of aflatoxins in the middle LCA. No significant difference in the values of the nutritional composition, with increasing radiation dose. The irradiation was shown to be an effective process for preserving peanuts, because it prevents the growth of fungi, particularly aflatoxin producer, making it safer for consumption, without changing its nutritional composition. (author)

  16. Occurrence of Aspergillus section Flavi and section Nigri and aflatoxins in raw cashew kernels (Anacardiumoccidentale L.) from Benin

    NARCIS (Netherlands)

    Lamboni, Y.; Frisvad, J.C.; Hell, K.; Linnemann, A.R.; Nout, M.J.R.; Tamo, M.; Nielsen, K.; Boekel, van M.A.J.S.; Smid, E.J.

    2016-01-01

    The objective of this study was to evaluate the presence of Aspergillus section Flavi and A. section Nigri in cashew nuts harvested in the Northern Guinea (NG) and Southern Sudanian (SS) agro-ecological zones of Benin. Also, the presence of aflatoxins was investigated. For detection of fungal

  17. Aflatoxins produced by Aspergillus nomius ASR3, a pathogen isolated from the leaf-cutter ant Atta sexdens rubropilosa

    Directory of Open Access Journals (Sweden)

    Eduardo Afonso da Silva-Junior

    Full Text Available ABSTRACT Aspergillus spp. cause economic impacts due to aflatoxins production. Although the toxicity of aflatoxins is already known, little information about their ecological roles is available. Here we investigated the compounds produced by Aspergillus nomius ASR3 directly from a dead leaf-cutter queen ant Atta sexdens rubropilosa and the fungal axenic culture. Chemical analyses were carried out by high-resolution mass spectrometry and tandem mass spectrometry techniques. Aflatoxins B1 and G1 were detected in both the axenic culture and in the dead leaf-cutter queen ant. The presence of these mycotoxins in the dead leaf-cutter queen ant suggests that these compounds can be related to the insect pathogenicity of A. nomius against A. sexdens rubropilosa.

  18. The potential inhibitory effect of cuminum cyminum, ziziphora clinopodioides and nigella sativa essential oils on the growth of Aspergillus fumigatus and Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    A.R Khosravi

    2011-03-01

    Full Text Available The goals of this study were to evaluate the effectiveness of Cuminum cyminum, Ziziphora clinopodioides and Nigella sativa essential oils to inhibit the growth of Aspergillus fumigatus and A. flavus and to evoke ultrastructural changes. The fungi were cultured into RPMI 1640 media in the presence of oils at concentrations of 8, 6, 5, 4, 3, 2, 1.5, 1.25, 1, 0.75 and 0.5 mg/ml in broth microdilution and 2, 1.5, 1 and 0.5 mg/ml in broth macrodilution methods with shaking for 48 h at 28ºC. Conidial and mycelial samples exposed to 0.25, 0.5, 1, 1.5 and 2 mg essential oils/ml for 5 days in 2% yeast extract granulated plus 15% Saccharose media were processed for transmission electron microscopy (TEM. Based on broth dilution methods, C. cyminum and to a lesser extent Z. clinopodioides oils exhibited the strongest activity against A. fumigatus and A. flavus with MIC90 ranging from 0.25 to 1.5 mg/ml, while the oil from N. sativa exhibited relatively moderate activity against two above fungi with MIC90 ranging from 1.5 to 2 mg/ml. The main changes observed by TEM were in the cell wall, plasma membrane and membranous organelles; in particular, in the nuclei and mitochondria. These modifications in fungal structure were associated with the interference of the essential oils with the enzymes responsible for cell wall synthesis, which disturbed normal growth. Moreover, the essential oils caused high vacuolation of the cytoplasm, detachment of fibrillar layer of cell wall, plasma membrane disruption and disorganization of the nuclear and mitochondrial structures. Aspergillus fumigatus and A. flavus growth inhibition induced by these oils were found to be well-correlated with subsequent morphological changes of the fungi exposed to different fungistatic concentrations of the oils. Our results show the anti-Aspergillus activities of C. cyminum, Z. clinopodioides and N. sativa essential oils, which strengthens the potential use of these substances as anti

  19. Molecular detection of mycobiota and aflatoxin contamination of chili

    Directory of Open Access Journals (Sweden)

    Gherbawy Youssuf A.

    2015-01-01

    Full Text Available Capsicum annuum grows in warm areas. Pepper production conditions require the drying of fruits by sunlight. During the drying processes, the crop is exposed to contamination by microorganisms, especially fungi. In this article, the isolation of mycobiota from retail markets and food restaurants of Taif city was studied. Crushed chili showed a high fungal load compared to chili sauce and chili powder, while chili powder showed a high occurrence of total aflatoxins (AFs. Aspergillus, Eurotium and Penicillium were the most common genera isolated from chili samples. Thirty-four samples (out of 60 were naturally contaminated with AFs ranging from 20 to 200 ppb. The total aflatoxin potential of 35 isolates of A. flavus, A. parasiticus and A. tamarri were studied. Seventy percent of A. flavus isolates were aflatoxigenic. The frequencies of aflatoxin biosynthesis genes aflR, nor-1, ver-1 and omtA were studied in aflatoxigenic and non-aflatoxigenic isolates of Aspergillus species collected in this study. All aflatoxigenic isolates (21 and 1 non-aflatoxigenic isolate of A. flavus showed DNA fragments that correspond to the complete set of the targeted genes. In conclusion, the high co-occurrence of Aspergillus species capable of producing aflatoxins, particularly in chili samples, suggests the need for more efficient control during processing and storage to reduce fungal contamination.

  20. Mycobiota and aflatoxins in raw materials and pet food in Brazil.

    Science.gov (United States)

    Campos, S G; Cavaglieri, L R; Fernández Juri, M G; Dalcero, A M; Krüger, C; Keller, L A M; Magnoli, C E; Rosa, C A R

    2008-06-01

    Commercial feedstuffs are a basic element in modern pet husbandry in the world. In dogs, the effect of mycotoxins is severe and can lead to death. Few reports on the influence of dietary mycotoxins were found in the scientific literature. The aims of this work were to isolate and identify the mycoflora and to determine the aflatoxins (AFs) natural occurrence in raw materials and ready dry pet food. Therefore, the aflatoxigenic capacity of Aspergillus flavus species was investigated. Aspergillus was the prevalent genera (65-89%) followed by Penicillium and Fusarium spp. Aspergillus flavus was the most prevalent species, followed by Aspergillus sydowii, Aspergillus fumigatus and Aspergillus versicolor. Aspergillus flavus frequencies ranged from 58% to 86% except in sorghum meal. All samples assayed (except corn grains and ready pet food) showed Fusarium spp. contamination. Corn meal and corn meal and gluten samples had 100% Fusarium verticillioides. Fusarium graminearum was isolated from sorghum meal. Aspergillus flavus strains (75%) isolated from raw materials and 57% from pet food were able to produce AFs. All samples showed AFs contamination percentages over 70%; corn and sorghum meal obtained the highest AFs levels. Ready pet food did not show quantitative levels of the tested toxins. This is the first report of the aflatoxigenic capacity by A. flavus from Brazilian pet food.

  1. In silico analysis of β-mannanases and β-mannosidase from Aspergillus flavus and Trichoderma virens UKM1

    Science.gov (United States)

    Yee, Chai Sin; Murad, Abdul Munir Abdul; Bakar, Farah Diba Abu

    2013-11-01

    A gene encoding an endo-β-1,4-mannanase from Trichoderma virens UKM1 (manTV) and Aspergillus flavus UKM1 (manAF) was analysed with bioinformatic tools. In addition, A. flavus NRRL 3357 genome database was screened for a β-mannosidase gene and analysed (mndA-AF). These three genes were analysed to understand their gene properties. manTV and manAF both consists of 1,332-bp and 1,386-bp nucleotides encoding 443 and 461 amino acid residues, respectively. Both the endo-β-1,4-mannanases belong to the glycosyl hydrolase family 5 and contain a carbohydrate-binding module family 1 (CBM1). On the other hand, mndA-AF which is a 2,745-bp gene encodes a protein sequence of 914 amino acid residues. This β-mannosidase belongs to the glycosyl hydrolase family 2. Predicted molecular weight of manTV, manAF and mndA-AF are 47.74 kDa, 49.71 kDa and 103 kDa, respectively. All three predicted protein sequences possessed signal peptide sequence and are highly conserved among other fungal β-mannanases and β-mannosidases.

  2. Spatial Patterns of Aflatoxin Levels in Relation to Ear-Feeding Insect Damage in Pre-Harvest Corn

    OpenAIRE

    Ni, Xinzhi; Wilson, Jeffrey P.; Buntin, G. David; Guo, Baozhu; Krakowsky, Matthew D.; Lee, R. Dewey; Cottrell, Ted E.; Scully, Brian T.; Huffaker, Alisa; Schmelz, Eric A.

    2011-01-01

    Key impediments to increased corn yield and quality in the southeastern US coastal plain region are damage by ear-feeding insects and aflatoxin contamination caused by infection of Aspergillus flavus. Key ear-feeding insects are corn earworm, Helicoverpa zea, fall armyworm, Spodoptera frugiperda, maize weevil, Sitophilus zeamais, and brown stink bug, Euschistus servus. In 2006 and 2007, aflatoxin contamination and insect damage were sampled before harvest in three 0.4-hectare corn fields usin...

  3. Molecular identification of Aspergillus and Eurotium species isolated from rice and their toxin-producing ability.

    Science.gov (United States)

    Yazdani, D; Zainal Abidin, M A; Tan, Y H; Kamaruzaman, S

    2011-01-01

    Thirty milled rice samples were collected from retailers in 4 provinces of Malaysia. These samples were evaluated for Aspergillus spp. infection by direct plating on malt extract salt agar (MESA). All Aspergillus holomorphs were isolated and identified using nucleotide sequences of ITS 1 and ITS 2 of rDNA. Five anamorphs (Aspergillus flavus, A. oryzae, A. tamarii, A. fumigatus and A. niger) and 5 teleomorphs (Eurotium rubrum, E. amstelodami, E. chevalieri, E. cristatum and E. tonophilum) were identified. The PCR-sequencing based technique for sequences of ITS 1 and ITS 2 is a fast technique for identification of Aspergillus and Eurotium species, although it doesn't work flawlessly for differentiation of Eurotium species. All Aspergillus and Eurotium isolates were screened for their ability to produce aflatoxin and ochratoxin A (OTA) by HPLC and TLC techniques. Only A. flavus isolate UPM 89 was able to produce aflatoxins B1 and B2.

  4. LAMP-based group specific detection of aflatoxin producers within Aspergillus section Flavi in food raw materials, spices, and dried fruit using neutral red for visible-light signal detection.

    Science.gov (United States)

    Niessen, Ludwig; Bechtner, Julia; Fodil, Sihem; Taniwaki, Marta H; Vogel, Rudi F

    2018-02-02

    Aflatoxins can be produced by 21 species within sections Flavi (16 species), Ochraceorosei (2), and Nidulantes (3) of the fungal genus Aspergillus. They pose risks to human and animal health due to high toxicity and carcinogenicity. Detecting aflatoxin producers can help to assess toxicological risks associated with contaminated commodities. Species specific molecular assays (PCR and LAMP) are available for detection of major producers, but fail to detect species of minor importance. To enable rapid and sensitive detection of several aflatoxin producing species in a single analysis, a nor1 gene-specific LAMP assay was developed. Specificity testing showed that among 128 fungal species from 28 genera, 15 aflatoxigenic species in section Flavi were detected, including synonyms of A. flavus and A. parasiticus. No cross reactions were found with other tested species. The detection limit of the assay was 9.03pg of A. parasiticus genomic DNA per reaction. Visual detection of positive LAMP reactions under daylight conditions was facilitated using neutral red to allow unambiguous distinction between positive and negative assay results. Application of the assay to the detection of A. parasiticus conidia revealed a detection limit of 211 conidia per reaction after minimal sample preparation. The usefulness of the assay was demonstrated in the analysis of aflatoxinogenic species in samples of rice, nuts, raisins, dried figs, as well as powdered spices. Comparison of LAMP results with presence/absence of aflatoxins and aflatoxin producing fungi in 50 rice samples showed good correlation between these parameters. Our study suggests that the developed LAMP assay is a rapid, sensitive and user-friendly tool for surveillance and quality control in our food industry. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Biological control of aflatoxin contamination and pests in U.S. crops using formulations of corn starch-based bioplastic

    Science.gov (United States)

    For many years, these laboratories have studied the use of biological control methods to reduce aflatoxin contamination in harvested corn using non-aflatoxigenic Aspergillus flavus isolates in grain-based granule and liquid formulations. More recently, research has focused on using various formulat...

  6. Aflatoxins in foods

    Directory of Open Access Journals (Sweden)

    Amedeo Pietri

    2007-03-01

    Full Text Available Aflatoxins are mycotoxins produced by Aspergillus flavus and A. parasiticus. The aflatoxin group is comprised of aflatoxin B1 (AFB1, B2, G1 and G2. In addition, aflatoxin M1 (AFM1, a hydroxylated metabolite of AFB1, is excreted in the milk of dairy cows consuming an AFB1-contaminated ration. AFB1 has shown extreme acute and chronic toxicity and carcinogenic activity in animals; the acute toxicity of AFM1 is nearly equal to that of AFB1, but its potential carcinogenic hazard is about one order of magnitude less than that of AFB1. The International Agency for Research on Cancer classified AFB1 as a human carcinogen (group 1 and AFM1 as a possible carcinogen (group 2A. Recently, the possibility of a synergistic carcinogenic interaction between HBV chronic infection and dietary exposure to AFB1 arose from the observation of their co-existence in countries with high incidences of HCC and was confirmed by further experimental and epidemiological studies. However, the carcinogenic potency of AFB1 is considered much lower in populations where chronic hepatitis infections are rare. For the first time in 2003, significant problems arose in Italy, due to the aflatoxin contamination of maize. The summer was extremely hot and dry and A. flavus is very competitive under these conditions as the plants are stressed. Maize grain is normally utilized in the food supply for dairy cows and as such led to the severe and widespread contamination of milk with AFM1. In the following years (2004-2006, different climatic conditions as well as better compliance with guidelines by farmers, led to a dramatic reduction of the problem.

  7. The Aspergillus flavus homeobox gene, hbx1, is required for development and aflatoxin production

    Science.gov (United States)

    Homeobox proteins are a class of transcription factors that are well conserved in many eukaryotes including fungi. Homeobox proteins regulate the expression of target genes, especially those involved in development. Studies in several filamentous fungi have shown that homeobox genes are required for...

  8. The Utilization of RNA Silencing Technology to Mitigate the Voriconazole Resistance of Aspergillus Flavus; Lipofectamine-Based Delivery

    Directory of Open Access Journals (Sweden)

    Sanam Nami

    2017-04-01

    Full Text Available Purpose: Introducing the effect of RNAi in fungi to downregulate essential genes has made it a powerful tool to investigate gene function, with potential strategies for novel disease treatments. Thus, this study is an endeavor to delve into the silencing potentials of siRNA on cyp51A and MDR1 in voriconazole-resistant Aspergillus flavus as the target genes. Methods: In this study, we designed three cyp51A-specific siRNAs and three MDR1-specific siRNAs and after the co-transfection of siRNA into Aspergillus flavus, using lipofectamine, we investigated the effect of different siRNA concentrations (5, 15, 25, 50nM on cyp51A and MDR1 expressions by qRT-PCR. Finally, the Minimum Inhibitory Concentrations (MICs of voriconazole for isolates were determined by broth dilution method. Results: Cyp51A siRNA induced 9, 22, 33, 40-fold reductions in cyp51A mRNA expres­sion in a voriconazole-resistant strain following the treatment of the cells with concentrations of 5, 15, 25, 50nM siRNA, respectively. Identically, the same procedure was applied to MDR1, even though it induced 2, 3, 4, 10-fold reductions. The results demonstrated a MIC for voriconazole in the untreated group (4µg per ml, when compared to the group treated with cyp51A-specific siRNA and MDR1-specific siRNA, both at concentrations of 25 and 50nM, yielding 2µg per ml and 1µg per ml when 25 nM was applied and 2µg per ml and 0.5µg per ml when the concentration doubled to 50 nM. Conclusion: In this study, we suggested that siRNA-mediated specific inhibition of cyp51A and MDR1 genes play roles in voriconazole-resistant A.flavus strain and these could be apt target genes for inactivation. The current study promises a bright prospect for the treatment of invasive aspergillosis through the effective deployment of RNAi and gene therapy.

  9. The Utilization of RNA Silencing Technology to Mitigate the Voriconazole Resistance of Aspergillus Flavus; Lipofectamine-Based Delivery.

    Science.gov (United States)

    Nami, Sanam; Baradaran, Behzad; Mansoori, Behzad; Kordbacheh, Parivash; Rezaie, Sasan; Falahati, Mehraban; Mohamed Khosroshahi, Leila; Safara, Mahin; Zaini, Farideh

    2017-04-01

    Purpose: Introducing the effect of RNAi in fungi to downregulate essential genes has made it a powerful tool to investigate gene function, with potential strategies for novel disease treatments. Thus, this study is an endeavor to delve into the silencing potentials of siRNA on cyp51A and MDR1 in voriconazole-resistant Aspergillus flavus as the target genes. Methods: In this study, we designed three cyp51A-specific siRNAs and three MDR1-specific siRNAs and after the co-transfection of siRNA into Aspergillus flavus, using lipofectamine, we investigated the effect of different siRNA concentrations (5, 15, 25, 50nM) on cyp51A and MDR1 expressions by qRT-PCR. Finally, the Minimum Inhibitory Concentrations (MICs) of voriconazole for isolates were determined by broth dilution method. Results: Cyp51A siRNA induced 9, 22, 33, 40-fold reductions in cyp51A mRNA expres-sion in a voriconazole-resistant strain following the treatment of the cells with concentrations of 5, 15, 25, 50nM siRNA, respectively. Identically, the same procedure was applied to MDR1, even though it induced 2, 3, 4, 10-fold reductions. The results demonstrated a MIC for voriconazole in the untreated group (4µg per ml), when compared to the group treated with cyp51A-specific siRNA and MDR1-specific siRNA, both at concentrations of 25 and 50nM, yielding 2µg per ml and 1µg per ml when 25 nM was applied and 2µg per ml and 0.5µg per ml when the concentration doubled to 50 nM. Conclusion: In this study, we suggested that siRNA-mediated specific inhibition of cyp51A and MDR1 genes play roles in voriconazole-resistant A.flavus strain and these could be apt target genes for inactivation. The current study promises a bright prospect for the treatment of invasive aspergillosis through the effective deployment of RNAi and gene therapy.

  10. Production of cellulase-free xylanase by Aspergillus flavus: Effect of ...

    African Journals Online (AJOL)

    Xylanase was found to be stable at 45°C with 100% of its original activity remaining after 2 h incubation. At 50°C, xylanase was stable for the first twenty minutes, and had half-life of 50 min. The pH stability for the xylanase from A. flavus was most stable in the range of pH 3.0-8.0 retaining more that 100% activity after 1 h.

  11. Citrate coated silver nanoparticles with modulatory effects on aflatoxin biosynthesis in Aspergillus parasiticus

    Science.gov (United States)

    Mitra, Chandrani

    The manufacture and usage of silver nanoparticles has drastically increased in recent years (Fabrega et al. 2011a). Hence, the levels of nanoparticles released into the environment through various routes have measurably increased and therefore are concern to the environment and to public health (Panyala, Pena-Mendez and Havel 2008). Previous studies have shown that silver nanoparticles are toxic to various organisms such as bacteria (Kim et al. 2007), fungi (Kim et al. 2008), aquatic plants (He, Dorantes-Aranda and Waite 2012a), arthropods (Khan et al. 2015), and mammalian cells (Asharani, Hande and Valiyaveettil 2009) etc. Most of the toxicity studies are carried out using higher concentrations or lethal doses of silver nanoparticles. However, there is no information available on how the fungal community reacts to the silver nanoparticles at nontoxic concentrations. In this study, we have investigated the effect of citrate coated silver nanoparticles (AgNp-cit) at a size of 20nm on Aspergillus parasiticus, a popular plant pathogen and well-studied model for secondary metabolism (natural product synthesis). A. parasiticus produces 4 major types of aflatoxins. Among other aflatoxins, aflatoxin B1 is considered to be one of most potent naturally occurring liver carcinogen, and is associated with an estimated 155,000 liver cancer cases globally (Liu and Wu 2010); therefore, contaminated food and feed are a significant risk factor for liver cancer in humans and animals (CAST 2003; Liu and Wu 2010). In this study, we have demonstrated the uptake of AgNp-cit (20nm) by A. parasiticus cells from the growth medium using a time course ICP-OES experiment. It was observed that the uptake of AgNp-cit had no effect on fungal growth and significantly decreased intracellular oxidative stress. It also down-regulated aflatoxin biosynthesis at the level of gene expression of aflatoxin pathway genes and the global regulatory genes of secondary metabolism. We also observed that the

  12. Efficacy of Bacillus subtilis and Bacillus amyloliquefaciens in the control of Aspergillus parasiticus growth and aflatoxins production on pistachio.

    Science.gov (United States)

    Siahmoshteh, Fatemeh; Siciliano, Ilenia; Banani, Houda; Hamidi-Esfahani, Zohreh; Razzaghi-Abyaneh, Mehdi; Gullino, Maria Lodovica; Spadaro, Davide

    2017-08-02

    Pistachio (Pistacia vera) is an important nut for its economic, nutritional and health aspects but it can be contaminated by aflatoxigenic fungi in the field and during storage. Biological control could be considered as an alternative to chemical treatment. In this study, we evaluated the antifungal and anti-mycotoxigenic capability of two Bacillus spp. both in vitro and on pistachio kernels. In in vitro conditions, both strains were able to reduce the mycelial growth and they were able to degrade the four aflatoxins during the first three days after inoculation. AFG1 and AFG2 were rapidly degraded within two days of incubation with the bacterial strains. No aflatoxin was found in the bacterial cell walls, permitting exclusion of mycotoxin adsorption and hypothesis of an in vitro biodegradation as a mode of action. The cultivar of pistachio most susceptible to fungal colonization was 'Ahmad-Aghaei', selected among four main Iranian cultivars. A. parasiticus was able to grow and produce aflatoxins on pistachios, but at longer inoculation periods, a natural decrease of aflatoxins was registered. Both strains were able to reduce the fungal incidence and number of spores on pistachio with a stronger effect during the first 5dpi. The effect on aflatoxin content in vivo was less pronounced than in vitro, with a maximum effect at 8dpi. At longer times, there was a contrasting effect due to the lower activity of Bacillus spp. in stationary phase and higher growth of Aspergillus species. This consideration could explain the lack of aflatoxin reduction at 12dpi. Both bacterial strains showed good antifungal activity and aflatoxin reduction in in vitro conditions and on pistachio kernels. Altogether, these results indicate that Bacillus species could be considered as potential biocontrol agents to combat toxigenic fungal growth and subsequent aflatoxin contamination of nuts and agricultural crops in practice. Copyright © 2017. Published by Elsevier B.V.

  13. Methods for Detection of Aflatoxins in Agricultural Food Crops

    Directory of Open Access Journals (Sweden)

    Alex P. Wacoo

    2014-01-01

    Full Text Available Aflatoxins are toxic carcinogenic secondary metabolites produced predominantly by two fungal species: Aspergillus flavus and Aspergillus parasiticus. These fungal species are contaminants of foodstuff as well as feeds and are responsible for aflatoxin contamination of these agro products. The toxicity and potency of aflatoxins make them the primary health hazard as well as responsible for losses associated with contaminations of processed foods and feeds. Determination of aflatoxins concentration in food stuff and feeds is thus very important. However, due to their low concentration in foods and feedstuff, analytical methods for detection and quantification of aflatoxins have to be specific, sensitive, and simple to carry out. Several methods including thin-layer chromatography (TLC, high-performance liquid chromatography (HPLC, mass spectroscopy, enzyme-linked immune-sorbent assay (ELISA, and electrochemical immunosensor, among others, have been described for detecting and quantifying aflatoxins in foods. Each of these methods has advantages and limitations in aflatoxins analysis. This review critically examines each of the methods used for detection of aflatoxins in foodstuff, highlighting the advantages and limitations of each method. Finally, a way forward for overcoming such obstacles is suggested.

  14. Aflatoxins: characteristics and impact on human health.

    Science.gov (United States)

    Kowalska, Anna; Walkiewicz, Katarzyna; Kozieł, Paweł; Muc-Wierzgoń, Małgorzata

    2017-05-05

    Some molds commonly occurring in the natural environment produce mycotoxins in the process of secondary metabolism. Aspergillus flavus and A. parasiticus are species of molds, which are responsible for the production of aflatoxins and are crucial in the pathogenesis of human diseases. Aspergillus species present in decaying plants, the soil and their spores are transferred via air currents and insects to crops and food storages. Aflatoxins B1, B2, G1, G2, M1 and M2 are the most common derivatives of aflatoxins. Ingestion of contaminated food is the main source of exposure to aflatoxins, which adversely affect the health of both humans and animals. The compounds can cause acute or chronic toxic effects of a teratogenic, mutagenic, carcinogenic, immunotoxic or hepatotoxic character. Molecular aflatoxins affect DNA mutations, postranslation peptids chains modification, proteins and nucleic acids methylation and the formation of free radicals. Due to aflatoxins carcinogenic features and frequent occurrence in food and forages they are routinely examinated in some groceries and agricultural products.

  15. The Shewanella algae strain YM8 produces volatiles with strong inhibition activity against Aspergillus pathogens and aflatoxins

    Directory of Open Access Journals (Sweden)

    Andong eGong

    2015-10-01

    Full Text Available Aflatoxigenic Aspergillus fungi and associated aflatoxins are ubiquitous in the production and storage of food/feed commodities. Controlling these pests is a challenge. In this study, the Shewanella algae strain YM8 was found to produce volatiles that have strong antifungal activity against Aspergillus pathogens. Gas chromatography-mass spectrometry profiling revealed 15 volatile organic compounds (VOCs emitted from YM8, of which dimethyl trisulfide was the most abundant. We obtained authentic reference standards for six of the VOCs; these all significantly reduced mycelial growth and conidial germination in Aspergillus; dimethyl trisulfide and 2,4-bis(1,1-dimethylethyl-phenol showed the strongest inhibitory activity. YM8 completely inhibited Aspergillus growth and aflatoxin biosynthesis in maize and peanut samples stored at different water activity levels, and scanning electron microscopy revealed severely damaged conidia and a complete lack of mycelium development and conidiogenesis. YM8 also completely inhibited the growth of eight other agronomically important species of phytopathogenic fungi: A. parasiticus, A. niger, Alternaria alternate, Botrytis cinerea, Fusarium graminearum, Fusarium oxysporum, Monilinia fructicola, and Sclerotinia sclerotiorum. This study demonstrates the susceptibility of Aspergillus and other fungi to VOCs from marine bacteria and indicates a new strategy for effectively controlling these pathogens and the associated mycotoxin production in the field and during storage.

  16. Perillaldehyde, a Promising Antifungal Agent Used in Food Preservation, Triggers Apoptosis through a Metacaspase-Dependent Pathway in Aspergillus flavus.

    Science.gov (United States)

    Tian, Jun; Wang, Yanzhen; Lu, Zhaoqun; Sun, Chunhui; Zhang, Man; Zhu, Aihua; Peng, Xue

    2016-10-05

    In the present study, we provide detailed insights into perillaldehyde (PAE)'s mechanisms of action on Aspergillus flavus and offer evidence in favor of the induction of an apoptosis-like phenotype. Specifically, PAE's antifungal mode of action was investigated through the detection of mitochondrial membrane potential (MtΔψ) and phosphatidylserine (PS) exposure, as well as intracellular Ca 2+ level, reactive oxygen species accumulation, and metacaspase activation. This was done by way of fluorometry, measuring DNA fragmentation, and condensation by fluorescent microscopy. Furthermore, we searched for phenotypic changes characteristic of apoptosis by transmission electron microscopy and flow cytometry, determining the amount of cytochrome c released using Western blotting. Results indicated that cultivation of A. flavus in the presence of PAE caused depolarization of MtΔψ, rapid DNA condensation, large-scale DNA fragmentation, and an elevation of intracellular Ca 2+ level. The percentage of early apoptotic cells with exposure of PS were 27.4% and 48.7%, respectively, after 9 h incubations with 0.25 and 0.5 μL/mL of PAE. The percentage of stained cells with activated intracellular metacaspases exposed to PAE at concentrations of 0.25 and 0.5 μL/mL compared with control subjects were increased by 28.4 ± 3.25% and 37.9 ± 4.24%, respectively. The above results has revealed that PAE induces fungal apoptosis through a caspase-dependent mitochondrial pathway. In all, our findings provide a novel mechanism for exploring a possible antifungal agent used in food preservation.

  17. Biosynthetic relationship among aflatoxins B1, B2, M1, and M2.

    Science.gov (United States)

    Dutton, M F; Ehrlich, K; Bennett, J W

    1985-01-01

    Aflatoxins are a family of toxic, acetate-derived decaketides that arise biosynthetically through polyhydroxyanthraquinone intermediates. Most studies have assumed that aflatoxin B1 is the biosynthetic precursor of the other aflatoxins. We used a strain of Aspergillus flavus which accumulates aflatoxin B2 to investigate the later stages of aflatoxin biosynthesis. This strain produced aflatoxins B2 and M2 but no detectable aflatoxin B1 when grown over 12 days in a low-salt, defined growth medium containing asparagine. Addition of dichlorvos to this growth medium inhibited aflatoxin production with concomitant accumulation of versiconal hemiacetal acetate. When mycelial pellets were grown for 24, 48, and 72 h in growth medium and then transferred to a replacement medium, only aflatoxin B2 and M2 were recovered after 96 h of incubation. Addition of sterigmatocystin to the replacement medium led to the recovery of higher levels of aflatoxins B2 and M2 than were detected in control cultures, as well as to the formation of aflatoxins B1 and M1 and O-methylsterigmatocystin. These results support the hypothesis that aflatoxins B1 and B2 can arise independently via a branched pathway. PMID:3925881

  18. Biosynthetic relationship among aflatoxins B1, B2, M1, and M2.

    Science.gov (United States)

    Dutton, M F; Ehrlich, K; Bennett, J W

    1985-06-01

    Aflatoxins are a family of toxic, acetate-derived decaketides that arise biosynthetically through polyhydroxyanthraquinone intermediates. Most studies have assumed that aflatoxin B1 is the biosynthetic precursor of the other aflatoxins. We used a strain of Aspergillus flavus which accumulates aflatoxin B2 to investigate the later stages of aflatoxin biosynthesis. This strain produced aflatoxins B2 and M2 but no detectable aflatoxin B1 when grown over 12 days in a low-salt, defined growth medium containing asparagine. Addition of dichlorvos to this growth medium inhibited aflatoxin production with concomitant accumulation of versiconal hemiacetal acetate. When mycelial pellets were grown for 24, 48, and 72 h in growth medium and then transferred to a replacement medium, only aflatoxin B2 and M2 were recovered after 96 h of incubation. Addition of sterigmatocystin to the replacement medium led to the recovery of higher levels of aflatoxins B2 and M2 than were detected in control cultures, as well as to the formation of aflatoxins B1 and M1 and O-methylsterigmatocystin. These results support the hypothesis that aflatoxins B1 and B2 can arise independently via a branched pathway.

  19. Effects of carbon, nitrogen and pH on the growth of Aspergillus parasiticus and aflatoxins production in water.

    Science.gov (United States)

    Al-Gabr, Hamid Moh; Ye, Chengsong; Zhang, Yongli; Khan, Sardar; Lin, Huirong; Zheng, Tianling

    2013-04-01

    Mycotoxins are considered as the most hazardous fungal metabolites for human, animals and plant health. Recently, more attention has been paid on the occurrence of this group of fungi in different water sources throughout the globe. In this study, Aspergillus parasiticus ATCC strain was used as representative strain producing aflatoxins in drinking water. This study aimed to investigate the activation of fungi in drinking water and their ability to produce aflatoxins (B1, B2, G1, and G2) in water under different ratios of C:N using different concentrations of total organic carbon (TOC) and total nitrogen (TN). Glucose and ammonium sulphate were used for changing the levels of TOC and TN in the selected water media. Similarly, the effects of different water pH levels from 4.5 to 8.2 on the growth of this group of fungi and aflatoxins production were also investigated. The results indicate that the growth of fungi was highest, at C:N ratio of 1:1 as compared to other selected ratios. Furthermore, the findings indicate that the pH levels 5.5-6.5 showed best growth of fungi as compared to other pH levels. Aflatoxin concentrations were measured in the water samples using HPLC technique, but selected fungi were not able to produce aflatoxins in water at applied concentrations of TOC and TN mimicking the ratios and concentrations present in the natural aquatic environment.

  20. Evaluation of the mycological status of luncheon meat with special reference to aflatoxigenic moulds and aflatoxin residues.

    Science.gov (United States)

    Ismail, M A; Zaky, Z M

    1999-01-01

    The luncheon meat samples analyzed, which were produced locally by the two main luncheon meat producing companies in Egypt were relatively highly contaminated either by moulds and yeasts in general, aflatoxigenic species and aflatoxin residues in particular. The most frequently encountered fungi from the samples were yeasts, Aspergillus niger, A. flavus, Penicillium chrysogenum, Rhizopus stolonifer, Mucor circinelloides. Less common were Cladosporium sphaerospermum, Alternaria alternata, Mycosphaerella tassiana, P. aurantiogriseum and P. oxalicum. The most important aflatoxigenic species, A. flavus, was isolated frequently. It was 10% of the total fungal isolates from both samples of the two companies. Seven luncheon meat samples out of 50 analyzed were positive for aflatoxin B1 or B1 and G1, while all samples were negative for aflatoxins B2, G2, M1 and M2. Aflatoxin B1 was detected only in 4 and 3 samples out of 25 analyzed from each of company A and B, respectively. The highest detectable level, 11.1 ppb, was recorded in a sample from company B and the least, 0.5 ppb, in a sample from company A. Aflatoxin G1, at concentration of 3.2 ppb, was detected in only one sample of the aflatoxin B1--contaminated 3 samples of company B: this sample also had the highest level of aflatoxin B1. Some luncheon meat samples had higher numbers of aflatoxigenic A. flavus than others, however these samples were negative for aflatoxins. The hazardous potential of such contamination will be discussed.

  1. Residues of aflatoxins B1 and M1 in different biological matrices of swine orally administered aflatoxin B1 and Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    L. Rizzi

    2010-01-01

    Full Text Available Mycotoxins are acutely toxic, carcinogenic, mutagenic, and oestrogenic secondary metabolites produced by moulds, mostly of the genera Aspergillus, Penicillum and Fusarium. Aflatoxins (AFs are dangerous molecules to animals and humans produced mostly by Aspergillus flavus and A. parasiticus (Marin et al., 2002. Aflatoxin B1 (AFB1 is the most potent of all aflatoxins and is of great concern because of its adverse effects to the health of humans and domestic animals, including also teratogenic and immunosuppressive effects (Eaton and Callagher, 1994. Aflatoxin M1 (AFM1 is a hydroxilated metabolite of AFB1 characterized by a rapid elimination through the milk and the urine, and by a lower toxicity than its parent compound.

  2. Effects of microwaves on the reduction of Aspergillus flavus and Aspergillus parasiticus on brown rice (Oryza sativa L.) and barley (Hordeum vulgare L.).

    Science.gov (United States)

    Lee, Seung-Hun; Park, Shin Young; Byun, Kye-Hwan; Chun, Hyang Sook; Ha, Sang-Do

    2017-07-01

    Aspergillus flavus and Aspergillus parasiticus are primary pathogen moulds on brown rice and barley. This study investigated the effects of microwave irradiation (MWI) (2450 MHz, 700 W, 10-50 s) on inactivation of A. flavus and A. parasiticus on brown rice and barley and the quality of these samples. The counts of both strains were significantly (p barley were 0.05 and 0.04 after 10 s; 1.06 and 1.05 after 20 s; 1.59 and 1.52 after 30 s; and 3.04 and 2.78 after 40 s. The log reductions of A. parasiticus on brown rice and barley were 0.06 and 0.10 after 10 s; 1.20 and 1.00 after 20 s; 2.04 and 1.61 after 30 s; and 2.89 and 2.90 after 40 s. Moreover, neither strain survived after 50 s of MWI. The Hunter colour 'L' gradually increased with increasing MWI treatment time. However, there were no significant differences in the 'L' of brown rice after 10-40 s of MWI treatment and of barley after 10-30 s of MWI treatment. The Hunter colour 'a' and 'b' gradually increased with increasing microwave time. No significant change was observed in the moisture content of either cereal treated with 10-20 s of MWI. The differences in the sensory quality (colour, appearance, flavour, texture and overall acceptability) after 0-30 s of MWI were not significant. However, values for colour, appearance, texture and overall acceptability were significantly reduced when treated with 40-50 s of MWI. Therefore, with 20 s of MWI at 2450 MHz, 700 W could be effective for > 90% reduction of mould without causing deleterious changes to the colour, moisture content and sensory qualities of these cereals.

  3. Assessment of aflatoxigenic Aspergillus and other fungi in millet and sesame from Plateau State, Nigeria

    Science.gov (United States)

    Ezekiel, C.N.; Udom, I.E.; Frisvad, J.C.; Adetunji, M.C.; Houbraken, J.; Fapohunda, S.O.; Samson, R.A.; Atanda, O.O.; Agi-Otto, M.C.; Onashile, O.A.

    2014-01-01

    Sixteen fonio millet and 17 sesame samples were analysed for incidence of moulds, especially aflatoxigenic Aspergillus species, in order to determine the safety of both crops to consumers, and to correlate aflatoxin levels in the crops with levels produced by toxigenic isolates on laboratory medium. Diverse moulds including Alternaria, Aspergillus, Cercospora, Fusarium, Mucor, Penicillium, Rhizopus and Trichoderma were isolated. Aspergillus was predominantly present in both crops (46–48%), and amongst the potentially aflatoxigenic Aspergillus species, A. flavus recorded the highest incidence (68% in fonio millet; 86% in sesame kernels). All A. parvisclerotigenus isolates produced B and G aflatoxins in culture while B aflatoxins were produced by only 39% and 20% of A. flavus strains isolated from the fonio millet and sesame kernels, respectively. Aflatoxin concentrations in fonio millet correlated inversely (r = −0.55; p = 0.02) with aflatoxin levels produced by toxigenic isolates on laboratory medium, but no correlation was observed in the case of the sesame samples. Both crops, especially sesame, may not be suitable substrates for aflatoxin biosynthesis. This is the first report on A. parvisclerotigenus in sesame. PMID:24772370

  4. Efficacy of a coating composed of chitosan from Mucor circinelloides and carvacrol to control Aspergillus flavus and the quality of cherry tomato fruits.

    Science.gov (United States)

    de Souza, Evandro L; Sales, Camila V; de Oliveira, Carlos E V; Lopes, Laênia A A; da Conceição, Maria L; Berger, Lúcia R R; Stamford, Thayza C M

    2015-01-01

    Cherry tomato (Lycopersicon esculentum Mill) fruits are susceptible to contamination by Aspergillus flavus, which may cause the development of fruit rot and significant postharvest losses. Currently there are significant drawbacks for the use of synthetic fungicides to control pathogenic fungi in tomato fruits, and it has increased the interest in exploring new alternatives to control the occurrence of fungal infections in these fruits. This study evaluated the efficacy of chitosan (CHI) from Mucor circinelloides in combination with carvacrol (CAR) in inhibiting A. flavus in laboratory media and as a coating on cherry tomato fruits (25°C, 12 days and 12°C, 24 days). During a period of storage, the effect of coatings composed of CHI and CAR on autochthonous microflora, as well as on some quality characteristics of the fruits such as weight loss, color, firmness, soluble solids, and titratable acidity was evaluated. CHI and CAR displayed MIC valuesof 7.5 mg/mL and 10 μL/mL, respectively, against A. flavus. The combined application of CHI (7.5 or 3.75 mg/mL) and CAR (5 or 2.5 μL/mL) strongly inhibited the mycelial growth and spore germination of A. flavus. The coating composed of CHI (3.75 mg/mL) and CAR (2.5 or 1.25 μL/mL) inhibited the growth of A. flavus in artificially contaminated fruits, as well as the native fungal microflora of the fruits stored at room or low temperature. The application of the tested coatings preserved the quality of cherry tomato fruits as measured by some physicochemical attributes. From this, composite coatings containing CHI and CAR offer a promising alternative to control postharvest infection caused by A. flavus or native fungal microflora in fresh cherry tomato fruits without negatively affecting their quality over storage.

  5. Fungal Biodeterioration, Aflatoxin Contamination, and Nutrient Value of “Suya Spices”

    Directory of Open Access Journals (Sweden)

    Segun Gbolagade Jonathan

    2016-01-01

    Full Text Available This work aimed to analyze the nutrient values, examine the biodeteriorating fungi biota, and analyze the mycotoxin contents of “Suya spices.” Fungi with highest percentage occurrence on all the samples are Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Fusarium sp., Rhizopus stolonifer, yeast, and Trichoderma koningii. Nutrient composition of the samples is significantly different statistically (P<0.05 with high protein (9.53% to 13.17%, fiber (9.27 to 13.17%, carbohydrate (46.27% to 50.90%, and ash (8.47% to 9.70% contents but low moisture (9.03% to 9.47% and fat (9.77% to 13.53% contents. Aflatoxin analysis of the samples revealed that they all contain aflatoxin in varying amount but no detectible aflatoxin content in the control. 59.54% of the detected aflatoxin is aflatoxin B1 with highest recorded in Agbowo, Mokola, and Sango samples (i.e., 28.03, 22.44, and 13.8 μg/kg, resp.. 4.78% of the aflatoxin is aflatoxin B2 which is only found in Sango and Mokola samples (3.59 and 2.6 μg/kg, resp.. 32.76% of aflatoxin is aflatoxin G1 with the highest found in Agbowo and Mokola samples (i.e., 18.63 and 10.41 μg/kg, resp.. 2.93% of the aflatoxin is aflatoxin G2 which is only detected in Sango and Agbowo samples (i.e., 1.19 and 2.65 μg/kg, resp..

  6. α--AMYLASES OF Aspergillus flavus var. oryzae AND Bacillus subtilis: THE SUBSTRATE SPECIFICITY AND RESISTANCE TO A NUMBER OF CHEMICALLY ACTIVE SUBSTANCES

    Directory of Open Access Journals (Sweden)

    K. V. Avdiyuk

    2013-06-01

    Full Text Available The ability of Aspergillus flavus var. oryzae 80428 and Bacillus subtilis 147 α-amylases to split different carbohydrate-containing substrates, such as maltose, sucrose, trehalose, dextrin, α- and β-cyclodextrin, amylose, amylopectin, glycogen, pullulan, soluble starch, insoluble starch, corn starch, wheat starch, dextran 500 has been studied. It was shown that investigated enzymes differ by substrate specificity. α-Amylase of A. flavus var. oryzae 80428 rapidly hydrolysed soluble potato and wheat starch, while the α-amylase of B. subtilis 147 — only wheat starch. Both enzymes don’t cleave maltose, α-cyclodextrin and dextran 500. A. flavus var. oryzae 80428 α-amylase display very small ability to hydrolyze pullulan, while α-amylase of B. subtilis 147 it does not act in general. The lowest values of Michaelis constant for both enzymes at splitting of glycogen have been obtained, indicating that enzymes have the greatest affinity to this substrate. The studies of influence of chemically active substances on activity of A. flavus var. oryzae 80428 and B. subtilis 147 ?-amylases show there are resistant to urea, deoxycholic acid, Tween-80, Triton X-100 and hydrogen peroxide. It’s indicate the enzymes tested may be competitive in compare with earlier described in literature enzymes. The obtained results give a possibility to propose in future usage these enzymes in different fields of industry, foremost in detergent industry.

  7. Sexuality generates diversity in the aflatoxin gene cluster: evidence on a global scale.

    Directory of Open Access Journals (Sweden)

    Geromy G Moore

    Full Text Available Aflatoxins are produced by Aspergillus flavus and A. parasiticus in oil-rich seed and grain crops and are a serious problem in agriculture, with aflatoxin B₁ being the most carcinogenic natural compound known. Sexual reproduction in these species occurs between individuals belonging to different vegetative compatibility groups (VCGs. We examined natural genetic variation in 758 isolates of A. flavus, A. parasiticus and A. minisclerotigenes sampled from single peanut fields in the United States (Georgia, Africa (Benin, Argentina (Córdoba, Australia (Queensland and India (Karnataka. Analysis of DNA sequence variation across multiple intergenic regions in the aflatoxin gene clusters of A. flavus, A. parasiticus and A. minisclerotigenes revealed significant linkage disequilibrium (LD organized into distinct blocks that are conserved across different localities, suggesting that genetic recombination is nonrandom and a global occurrence. To assess the contributions of asexual and sexual reproduction to fixation and maintenance of toxin chemotype diversity in populations from each locality/species, we tested the null hypothesis of an equal number of MAT1-1 and MAT1-2 mating-type individuals, which is indicative of a sexually recombining population. All samples were clone-corrected using multi-locus sequence typing which associates closely with VCG. For both A. flavus and A. parasiticus, when the proportions of MAT1-1 and MAT1-2 were significantly different, there was more extensive LD in the aflatoxin cluster and populations were fixed for specific toxin chemotype classes, either the non-aflatoxigenic class in A. flavus or the B₁-dominant and G₁-dominant classes in A. parasiticus. A mating type ratio close to 1∶1 in A. flavus, A. parasiticus and A. minisclerotigenes was associated with higher recombination rates in the aflatoxin cluster and less pronounced chemotype differences in populations. This work shows that the reproductive nature of

  8. Influence of the antimicrobial compound allyl isothiocyanate against the Aspergillus parasiticus growth and its aflatoxins production in pizza crust.

    Science.gov (United States)

    Quiles, Juan M; Manyes, Lara; Luciano, Fernando; Mañes, Jordi; Meca, Giuseppe

    2015-09-01

    Aflatoxins (AFs) are secondary metabolites produced by different species of Aspergillus, such as Aspergillus flavus and Aspergillus parasiticus, which possess mutagenic, teratogenic and carcinogenic activities in humans. In this study, active packaging devices containing allyl isothiocyanate (AITC) or oriental mustard flour (OMF) + water were tested to inhibit the growth of A. parasiticus and AFs production in fresh pizza crust after 30 d. The antimicrobial and anti-aflatoxin activities were compared to a control group (no antimicrobial treatment) and to a group added with commercial preservatives (sorbic acid + sodium propionate). A. parasiticus growth was only inhibited after 30 d by AITC in filter paper at 5 μL/L and 10 μL/L, AITC sachet at 5 μL/L and 10 μL/L and OMF sachet at 850 mg + 850 μL of water. However, AFs production was inhibited by all antimicrobial treatments in a dose-dependent manner. More importantly, AITC in a filter paper at 10 μL/L, AITC sachet at 10 μL/L, OMF sachet at 850 mg + 850 μL of water and sorbic acid + sodium propionate at 0.5-2.0 g/Kg completely inhibited AFs formation. The use of AITC in active packaging devices could be a natural alternative to avoid the growth of mycotoxinogenic fungi in refrigerated bakery products in substitution of common commercial preservatives. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Rifampin Enhances the Activity of Amphotericin B against Fusarium solani Species Complex and Aspergillus flavus Species Complex Isolates from Keratitis Patients.

    Science.gov (United States)

    He, Yi; Zhou, Lutan; Gao, Chuanwen; Han, Lei; Xu, Yan

    2017-04-01

    The in vitro activities of amphotericin B in combination with rifampin were assessed against 95 ocular fungal isolates. The interactions between amphotericin B and rifampin at 4, 8, 16, and 32 μg/ml were synergistic for 11.8%, 51.0%, 90.2%, and 94.1%, respectively, of Fusarium solani species complex isolates and for 13.6%, 45.5%, 93.2%, and 95.5%, respectively, of Aspergillus flavus species complex isolates. Antagonism was never observed for the amphotericin B-rifampin combinations. Copyright © 2017 American Society for Microbiology.

  10. Measurement and assessment of aflatoxin B1 and its producing molds in Iranian sausages and burgers

    Directory of Open Access Journals (Sweden)

    Siavash Maktabi

    2016-09-01

    Full Text Available Abstract Introduction: Aflatoxin B1 (AFB1 is one of the most well-known hepatocarcinogens in humans. Contamination of raw materials, used in the production of sausages and burgers, with aflatoxin producing molds can lead to increased level of aflatoxin in the final products and can impose hazards to human health. Unfortunately, aflatoxin is resistant to heating and freezing processes, etc. and can remain in these products untile consumption. Methods: During a six-month period, 45 sausage and 53 burger samples from valid brands across the country were randomly purchased from the stores. The samples were analyzed for AFB1 by ELISA technique. Meanwhile, the number of molds was calculated and aflatoxin producing molds were identified by direct and slide culture methods. Results: The findings showed that 2 susage samples (4.9% and 3 burger samples (6.3% were contaminated with >1 ng/g aflatoxin. Moreover, 4 burger samples (8.9% contaminated with mold included aspergillus flavus, aspergillus niger, mucor, and penicillium while, none of the susage samples showed mold contamination. Conclusion: The Iranian meat products had a relative aflatoxin B1 contamination during the study period, but the contamination rate was low and in allowable range. Standard hygienic preparation and packaging of meat products molds is recommended to reduce fungal contamination, especially aflatoxin-producing molds.

  11. Inorganic composition determination and evaluation of the biological activity of Peperomia pellucida in the Aspergillus flavus growth; Estudo da composicao inorganica e avaliacao da atividade biologica de Peperomia pellucida no crescimento de Aspergillus flavus

    Energy Technology Data Exchange (ETDEWEB)

    Sussa, Fabio Vitorio

    2011-07-01

    oil, ethanolic and hexane extracts of Peperomia pellucida were tested for antifungal activity against Aspergillus flavus in vitro on Petri plates. The antifungal activity was based on the inhibition zone and IC{sub 50} values against the pathogen on Petri plates assays. Also, the essential oil chemical composition was determined by GC-MS. (author)

  12. Characterization of small RNA populations in non-transgenic and aflatoxin-reducing-transformed peanut.

    Science.gov (United States)

    Power, Imana L; Dang, Phat M; Sobolev, Victor S; Orner, Valerie A; Powell, Joseph L; Lamb, Marshall C; Arias, Renee S

    2017-04-01

    Aflatoxin contamination is a major constraint in food production worldwide. In peanut (Arachis hypogaea L.), these toxic and carcinogenic aflatoxins are mainly produced by Aspergillus flavus Link and A. parasiticus Speare. The use of RNA interference (RNAi) is a promising method to reduce or prevent the accumulation of aflatoxin in peanut seed. In this study, we performed high-throughput sequencing of small RNA populations in a control line and in two transformed peanut lines that expressed an inverted repeat targeting five genes involved in the aflatoxin-biosynthesis pathway and that showed up to 100% less aflatoxin B 1 than the controls. The objective was to determine the putative involvement of the small RNA populations in aflatoxin reduction. In total, 41 known microRNA (miRNA) families and many novel miRNAs were identified. Among those, 89 known and 10 novel miRNAs were differentially expressed in the transformed lines. We furthermore found two small interfering RNAs derived from the inverted repeat, and 39 sRNAs that mapped without mismatches to the genome of A. flavus and were present only in the transformed lines. This information will increase our understanding of the effectiveness of RNAi and enable the possible improvement of the RNAi technology for the control of aflatoxins. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Dynamic variation of bioactive compounds and aflatoxins in contaminated Radix Astragali during extraction process.

    Science.gov (United States)

    Hu, Yichen; Kong, Weijun; Luo, Hongli; Zhao, Lianhua; Yang, Meihua

    2016-03-30

    Although increasing attention has been paid to the health threat caused by mycotoxins in commodities such as food or medicines, mycotoxin transfer processes from crude material to products have raised little concern so far. Radix Astragali is a commonly used edible and medicinal herbal plant that is susceptible to contamination with aflatoxins from Aspergillus flavus. There have been no studies on mycotoxin transfer into pharmaceutical preparations or derivative products. To facilitate the aflatoxin reduction and bioactivity retention, the dynamic variations of aflatoxins as well as herbal compounds, namely calycosin-7-glucoside, astragaloside and formononetin, in Radix Astragali contaminated by A. flavus during water decoction and ethanol refluxing treatments were evaluated simultaneously by an ultra-fast liquid chromatography-triple quadrupole linear ion trap mass spectrometry method. After the extraction processes, although the amount of alfatoxins was reduced remarkably, aflatoxin residuals in preparation still exceed recommended limits, manifesting the great need to establish a limit for aflatoxins in herbal extractions or derivative products. Meanwhile, due to the hydrolysis of glucoside, water decoction period should be no longer than 4 h. This investigation would benefit from the determination of the dynamic variation of aflatoxins in infected herbs in preparation treatments, in order to further develop aflatoxin limits in herbal preparations. © 2015 Society of Chemical Industry.

  14. Aflatoxins: biosynthesis, occurrence, toxicity, and remedies.

    Science.gov (United States)

    Abrar, Muhammad; Anjum, Faqir Muhammad; Butt, Masood Sadiq; Pasha, Imran; Randhawa, Muhammad Atif; Saeed, Farhan; Waqas, Khalid

    2013-01-01

    Food contagion with aflatoxins is the modern concern and has received a great awareness during the last few decades. The intermittent incidence of these toxins in agricultural commodities has negative role on the economy of the affected regions where harvest and postharvest techniques for the prevention of mold growth, are seldom practiced. Aflatoxins are difuranocoumarin derivatives produced by a polyketide pathway by the fungus Aspergillus flavus and Aspergillus parasiticus via polyketide pathway which are highly hepatotoxic, hepatocarcinogenic, teratogenic, and mutagenic in nature and contaminate a wide variety of important agricultural commodities before, during, and after harvest in various environmental conditions. The production of aflatoxins in innate substrates depends upon the various factors, that is, type of substrate, fungal species, moisture contents of the substrate, minerals, humidity, temperature, and physical damage of the kernels. These toxins cause several ailments such as cancer, hepatitis, mutation abnormalities, and reproduction disorders. Minimization and inactivation of aflatoxins contaminants through proper crop management at farm level and with physical, chemical, and biological techniques are the limelight of the article.

  15. Bioprocess and biotechnology: effect of xylanase from Aspergillus niger and Aspergillus flavus on pulp biobleaching and enzyme production using agroindustrial residues as substract

    National Research Council Canada - National Science Library

    Nelciele Cavalieri de Alencar Guimaraes; Michele Sorgatto; Simone de Carvalho Peixoto-Nogueira; Jorge Henrique Almeida Betini; Fabiana Fonseca Zanoelo; Maria Rita Marques; Maria de Lourdes Teixeira de Moraes Polizeli; Giovana C Giannesi

    2013-01-01

      This study compares two xylanases produced by filamentous fungi such as A. niger and A. flavus using agroindustrial residues as substract and evaluated the effect of these enzymes on cellulose pulp biobleaching process...

  16. Inhibitory effect of eugenol on aflatoxin B1 production in Aspergillus parasiticus by downregulating the expression of major genes in the toxin biosynthetic pathway.

    Science.gov (United States)

    Jahanshiri, Zahra; Shams-Ghahfarokhi, Masoomeh; Allameh, Abdolamir; Razzaghi-Abyaneh, Mehdi

    2015-07-01

    Aflatoxin contamination of grains and agro-products is a serious food safety issue and a significant economic concern worldwide. In the present study, the effects of eugenol on Aspergillus parasiticus growth and aflatoxin production were studied in relation to the expression of some essential genes involved in aflatoxin biosynthetic pathway. The fungus was cultured in presence of serial two-fold concentrations of eugenol (15.62-500 μg mL(-1)) for 3 days at 28 °C. Mycelia dry weight was determined as an index of fungal growth, while aflatoxin production was assessed by high performance liquid chromatography. The expression of aflatoxin biosynthetic genes including ver-1, nor-1, pksA, omtA and aflR were evaluated by real-time PCR. Eugenol strongly inhibited A. parasiticus growth in the range of 19.16-95.83 % in a dose-dependent manner. Aflatoxin B1 production was also inhibited by the compound in the range of 15.07-98.0 %. The expressions of ver-1, nor-1, pksA, omtA and aflR genes were significantly suppressed by eugenol at concentrations of 62.5 and 125 μg mL(-1). These results indicate that eugenol may be considered as a good candidate to control toxigenic fungal growth and the subsequent contamination of food, feed and agricultural commodities by carcinogenic aflatoxins.

  17. Microbiological and aflatoxin evaluation of Brazil nut pods and the effects of unit processing operations.

    Science.gov (United States)

    Arrus, Katia; Blank, Greg; Clear, Randall; Holley, Richard A; Abramson, David

    2005-05-01

    Harvesting of Brazil nuts not only helps to preserve the Amazon rainforest but also provides income to individuals who would otherwise have little means of making a livelihood. Recently, the European Community has tightened the quality requirements for Brazil nuts, particularly with regard to aflatoxin levels and microbiological contamination. The objectives of this research were to gain a better understanding of the origin of aflatoxins on Brazil nuts and to microbiologically evaluate some of the operations involved in processing. In this regard, five Brazil nut pods were aseptically picked from trees located in each of three concessions of the Peruvian Amazon rainforest (Madre de Dios province). The exteriors of the pods and the nuts were examined for yeast and molds, including Aspergillus flavus and Aspergillus parasiticus, and for bacteria, including Salmonella and Escherichia coli. Brazil nuts obtained from various commercial process operations located in Peru were similarly evaluated. Exteriors of all Brazil nut pods did not contain A. parasiticus, and only pods from one concession yielded A. flavus isolates. All isolates tested were aflatoxigenic (630 to 915 ppb total aflatoxin). Coliforms, E. coli, and salmonellae were not recovered from any of the pods. Whole, in-shell nuts obtained after opening the pods yielded no A. flavus or A. parasiticus. Aflatoxins were not detected (detection limit 1.75 ppb) in any of the nuts. Whole, in-shell and shelled nuts from various process operations were all positive for A. flavus but negative for E. coli and salmonellae. Soaking of whole, in-shell nuts before cracking or shelling increased coliform numbers, whereas levels of A. flavus decreased. In order to gain a better understanding of the sanitary performance of the unit process operations, additional evaluations should be conducted on product lots processed on different days. Also, the microbiology of product processed from common lots should be followed through the

  18. Aflatoxin-producing fungi in maize field soils from sea level to over 2000 masl: a three year study in Sonora, Mexico.

    Science.gov (United States)

    Ortega-Beltran, Alejandro; Jaime, Ramon; Cotty, Peter J

    2015-04-01

    Aflatoxins, highly toxic carcinogens produced by several members of Aspergillus section Flavi, contaminate crops in temperate zones. In the state of Sonora, Mexico, maize is cultivated from 0 to 2100 masl with diverse cultivation practices. This is typical of the nation. In order to design better sampling strategies across Mexico, aflatoxin-producing fungal communities associated with maize production during 2006, 2007, and 2008 in Sonora were investigated in four agro-ecological zones (AEZ) at varying elevation. Fungal communities were dominated by the Aspergillus flavus L strain morphotype (46%), but variation occurred between years and among AEZ. Several atoxigenic isolates with potential to be used as biocontrol agents for aflatoxin mitigation were detected in all AEZ. The characteristics of each AEZ had minimal influences on fungal community structure and should not be a major consideration for future sampling designs for Mexico. Insights into the dynamics and stability of aflatoxin-producing fungal communities across AEZ are discussed. Published by Elsevier Ltd.

  19. Evaluation of ELISA screening test for detecting aflatoxin in biogenic dust samples

    Energy Technology Data Exchange (ETDEWEB)

    Durant, J.T.

    1996-05-01

    Aflatoxin is a carcinogenic chemical that is sometimes produced when agricultural commodities are infested by the fungi Aspergillus flavus and A. Parasiticus. Aflatoxin has been found to be present in air samples taken around persons handling materials likely to be contaminated. The purpose of this investigation was to demonstrate the feasibility of using an Enzyme Linked Immunosorbent Assay (ELISA) test kit that was developed to screen for aflatoxin in bulk agricultural commodities, to an air sample. Samples were taken from two environments likely to be contaminated with aflatoxin, a dairy farm feed mixing operation and a peanut bagging operation. The dust collected from these environments was considered to be biogenic, in that it originated primarily from biological materials.

  20. Survey the Relation between Rice Consumption with Aflatoxin M1 Excretion Rate in Yazd Women of using Biomarkers

    Directory of Open Access Journals (Sweden)

    B Hajimohammadi

    2016-03-01

    Full Text Available Introduction: Aflatoxins are usually produced from Aspergillus Flavus and Aspergillus Parasiticus. This toxin is found in the most of foods, such as rice. The aim of this study was to survey the relation between rice consumption with Aflatoxin M1 excretion rate in women of Yazd using biomarkers. Methods: This was a cross sectional-descriptive study that was done in 2014. Eighty five women were selected among women who referred to health centers of Yazd. ELISA method was used to measure Aflatoxin M1 in urine samples. Results: The results show that from total number of 85 women, 94% were excreted Aflatoxin M1. There was a significant difference between rice consumption (p=0.015 and type of consumed rice (p= 0.023 with excretion of Aflatoxin M1. Conclusion: According to the results it can be concluded that with increasing rice consumption, daily intake of Aflatoxin increases. Therefore the amount of Aflatoxin in rice consumption by women of Yazd is high and a lot of people are exposed to high concentration of Aflatoxin and health hazards related to it.

  1. Nanoparticle-based immunosensors and immunoassays for aflatoxins

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xu; Niessner, Reinhard [Institute of Hydrochemistry and Chair of Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, D-81377 München (Germany); Tang, Dianping [Key Laboratory of Analysis and Detection for Food Safety, MOE & Fujian Province, Department of Chemistry, Fuzhou University, Fuzhou 350108 (China); Knopp, Dietmar, E-mail: dietmar.knopp@ch.tum.de [Institute of Hydrochemistry and Chair of Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, D-81377 München (Germany)

    2016-03-17

    Aflatoxins are naturally existing mycotoxins produced mainly by Aspergillus flavus and Aspergillus parasiticus, present in a wide range of food and feed products. Because of their extremely high toxicity and carcinogenicity, strict control of maximum residue levels of aflatoxins in foodstuff is set by many countries. In daily routine, different chromatographic methods are used almost exclusively. As supplement, in several companies enzyme immunoassay-based sample testing as primary screening is performed. Recently, nanomaterials such as noble metal nanoparticles, magnetic particles, carbon nanomaterials, quantum dots, and silica nanomaterials are increasingly utilized for aflatoxin determination to improve the sensitivity and simplify the detection. They are employed either as supports for the immobilization of biomolecules or as electroactive or optical labels for signal transduction and amplification. Several nanoparticle-based electrochemical, piezoelectric, optical, and immunodipstick assays for aflatoxins have been developed. In this review, we summarize these recent advances and illustrate novel concepts and promising applications in the field of food safety. - Highlights: • Novel concepts and promising applications of nanoparticle-based immunological methods for the determination of aflatoxins. • Inclusion of most important nanomaterials and hybrid nanostructures. • Inclusion of electrochemical, optical and mass-sensitive biosensors as well as optical and immunochromatographic assays.

  2. Expression Profiling of Non-Aflatoxigenic Aspergillus parasiticus Mutants Obtained by 5-Azacytosine Treatment or Serial Mycelial Transfer

    Directory of Open Access Journals (Sweden)

    Jiujiang Yu

    2011-08-01

    Full Text Available Aflatoxins are carcinogenic secondary metabolites produced by the fungi Aspergillus flavus and Aspergillus parasiticus. Previous studies found that repeated serial mycelial transfer or treatment of A. parasiticus with 5-azacytidine produced colonies with a fluffy phenotype and inability to produce aflatoxins. To understand how these treatments affect expression of genes involved in aflatoxin production and development, we carried out expressed sequence tag (EST-based microarray assays to identify genes in treated clones that are differentially expressed compared to the wild-type. Expression of 183 genes was significantly dysregulated. Of these, 38 had at least two-fold or lower expression compared to the untreated control and only two had two-fold or higher expression. The most frequent change was downregulation of genes predicted to encode membrane-bound proteins. Based on this result we hypothesize that the treatments cause changes in the structure of cellular and organelle membranes that prevent normal development and aflatoxin biosynthesis.

  3. Relationship between Aflatoxin Contamination and Physiological Responses of Corn Plants under Drought and Heat Stress

    Directory of Open Access Journals (Sweden)

    Nacer Bellaloui

    2012-11-01

    Full Text Available Increased aflatoxin contamination in corn by the fungus Aspergillus flavus is associated with frequent periods of drought and heat stress during the reproductive stages of the plants. The objective of this study was to evaluate the relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress. The study was conducted in Stoneville, MS, USA under irrigated and non-irrigated conditions. Five commercial hybrids, P31G70, P33F87, P32B34, P31B13 and DKC63-42 and two inbred germplasm lines, PI 639055 and PI 489361, were evaluated. The plants were inoculated with Aspergillus flavus (K-54 at mid-silk stage, and aflatoxin contamination was determined on the kernels at harvest. Several physiological measurements which are indicators of stress response were determined. The results suggested that PI 639055, PI 489361 and hybrid DKC63-42 were more sensitive to drought and high temperature stress in the non-irrigated plots and P31G70 was the most tolerant among all the genotypes. Aflatoxin contamination was the highest in DKC63-42 and PI 489361 but significantly lower in P31G70. However, PI 639055, which is an aflatoxin resistant germplasm, had the lowest aflatoxin contamination, even though it was one of the most stressed genotypes. Possible reasons for these differences are discussed. These results suggested that the physiological responses were associated with the level of aflatoxin contamination in all the genotypes, except PI 639055. These and other physiological responses related to stress may help examine differences among corn genotypes in aflatoxin contamination.

  4. Application of a modified culture medium for the simultaneous counting of molds and yeasts and detection of aflatoxigenic strains of Aspergillus flavus and Aspergillus parasiticus.

    Science.gov (United States)

    Jaimez, J; Fente, C A; Franco, C M; Cepeda, A; Vázquez, B I

    2003-02-01

    Molds and yeasts from 91 samples of feed and raw materials used in feed formulation were enumerated on a new culture medium to which a beta cyclodextrin (beta-W7M 1.8-cyclodextrin) had been added. This medium was compared with other media normally used in laboratories for the routine analysis of fungi, such as Sabouraud agar, malt agar supplemented with 2% dextrose, and potato dextrose agar. When a t test for paired data (0.05 significance level, 95% confidence interval) was applied, no statistically significant differences between the results obtained with the new culture medium and those obtained with the other media used to enumerate molds and yeasts were found. For the evaluation of contamination due to aflatoxin for all of the samples, Sabouraud agar and yeast extract agar, both supplemented with 0.3% beta-W7M 1.8-cyclodextrin, and APA (aflatoxin-producing ability) medium were used. Aflatoxin was detected in 21% of the feed samples and in 23% of the raw-material samples analyzed, with maximal amounts of 2.8 and 6.0 microg of aflatoxin B1 per kg, respectively, being detected. In any case, the aflatoxin contents found exceeded the legally stipulated limits. The t test for paired data (0.05 significance level, 95% confidence interval) did not show statistically significant differences between the results obtained with the different culture media used for the detection of aflatoxins. The advantage of the new medium developed (Sabouraud agar with 0.3% beta-W7M 1.8-cyclodextrin) is that it allows simultaneous fungal enumeration and determination (under UV light) of the presence of aflatoxin-producing strains without prior isolation and culture procedures involving expensive and/or complex specific media and thus saves work, time, and money.

  5. Utilization of agro-wastes to inhibit aflatoxins synthesis by Aspergillus parasiticus: A biotreatment of three cereals for safe long-term storage.

    Science.gov (United States)

    Sultana, B; Naseer, R; Nigam, Poonam

    2015-12-01

    The growth of Aspergillus parasiticus and aflatoxins production were inhibited during storage of three important cereals (wheat, maize and rice) using leaves of neem (Azadirachta indica) and kikar (Acacia nilotica). Cereals were inoculated with mould spores and stabilized by neem and kikar leaves-powder. Test samples with moisture levels of 21% were stored at 30°C for a period of 9months. Aflatoxins were quantified at different time intervals in stored cereals. Neem leaves fully inhibited all types of aflatoxins synthesis for 4months in wheat and for 2months in maize while in rice inhibited synthesis of only B2, G1 and G2 aflatoxin for 3months. Kikar leaves fully inhibited aflatoxin B2, G1 and G2 for 3months in wheat, and for 2months in maize. Among two investigated plants, neem leaves were found more effective for preventing the production of all types of aflatoxins in cereals' long-term storage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Efficacy of the combined application of chitosan and Locust Bean Gum with different citrus essential oils to control postharvest spoilage caused by Aspergillus flavus in dates.

    Science.gov (United States)

    Aloui, Hajer; Khwaldia, Khaoula; Licciardello, Fabio; Mazzaglia, Agata; Muratore, Giuseppe; Hamdi, Moktar; Restuccia, Cristina

    2014-01-17

    This study reports the efficacy of the combined application of chitosan (CH) and Locust Bean Gum (LBG) in combination with different citrus essential oils (EOs) to inhibit Aspergillus flavus in vitro and on artificially infected dates for a storage period of 12 days. The effect of these treatments on the fruits' sensory characteristics was evaluated to verify the complete absence of off-odours and off-flavours. Bergamot EO was the most effective in reducing mycelial growth, followed by bitter orange EO. Both bergamot and bitter orange oils significantly reduced conidial germination and a complete inhibition was obtained at concentrations higher than 2%. The mixtures based on CH-2% (v/v) bergamot EO or CH-2% (v/v) bitter orange EO proved to be the most effective coatings to reduce conidial germination resulting in an 87-90% inhibition compared with the control. In fruit decay assays coatings based on CH incorporating citrus oils were able to reduce fungal decay in the range of 52-62% at day 12. The study results and the complete absence of off-flavours and off-odours demonstrate the potential of CH coatings carrying citrus EOs at sub-inhibitory concentrations to control postharvest growth of A. flavus in dates. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Biosorption characteristics of Aspergillus flavus biomass for removal of Pb(II) and Cu(II) ions from an aqueous solution.

    Science.gov (United States)

    Akar, Tamer; Tunali, Sibel

    2006-10-01

    The Pb(II) and Cu(II) biosorption characteristics of Aspergillus flavus fungal biomass were examined as a function of initial pH, contact time and initial metal ion concentration. Heat inactivated (killed) biomass was used in the determination of optimum conditions before investigating the performance of pretreated biosorbent. The maximum biosorption values were found to be 13.46 +/- 0.99 mg/g for Pb(II) and 10.82 +/- 1.46 mg/g for Cu(II) at pH 5.0 +/- 0.1 with an equilibrium time of 2 h. Detergent, sodium hydroxide and dimethyl sulfoxide pretreatments enhanced the biosorption capacity of biomass in comparison with the heat inactivated biomass. The biosorption data obtained under the optimum conditions were well described by the Freundlich isotherm model. Competitive biosorption of Pb(II) and Cu(II) ions was also investigated to determine the selectivity of the biomass. The results indicated that A. flavus is a suitable biosorbent for the removal of Pb(II) and Cu(II) ions from aqueous solution.

  8. Vitality Stains and Real Time PCR Studies to Delineate the Interactions of Pichia anomala and Aspergillus flavus

    Science.gov (United States)

    The objectives of this study were to probe the effect of the yeast, P. anomala against A flavus by using real time RT-PCR technique and vitality fluorescent stains. Yeast and fungi were inoculated into a 250 ml-flask containing 50 ml potato dextrose broth (PDB) at yeast to fungus (Y : F) ratios of ...

  9. Pharmacodynamics of Voriconazole against Wild-Type and Azole-Resistant Aspergillus flavus Isolates in a Nonneutropenic Murine Model of Disseminated Aspergillosis.

    Science.gov (United States)

    Rudramurthy, Shivaprakash M; Seyedmousavi, Seyedmojtaba; Dhaliwal, Manpreet; Chakrabarti, Arunaloke; Meis, Jacques F; Mouton, Johan W

    2017-01-01

    Invasive aspergillosis (IA) due to Aspergillus flavus is associated with high mortality. Although voriconazole (VRC) is widely recommended as the first-line treatment for IA, emergence of azole resistance in Aspergillus spp. is translating to treatment failure. We evaluated the efficacy of voriconazole in a nonneutropenic murine model of disseminated A. flavus infection using two voriconazole-resistant isolates (one harboring the Y319H substitution in the cyp51C gene) and two wild-type isolates without mutations. All isolates exhibited a dose-response relationship, and voriconazole treatment improved mouse survival in a dose-dependent manner. At 40 mg/kg of body weight, 100% efficacy was observed for 1 susceptible isolate and 1 resistant isolate (with mutation), whereas for another susceptible isolate and resistant isolate (without mutation), survival rates were 81% and 72%, respectively. The Hill equation with a variable slope fitted the relationship between the area under the concentration-time curve (AUC)/MIC ratio and 14-day survival well for each strain. An F test showed the 50% effective doses to be significantly different from each other (P = 0.0023). However, contrary to expectation, there was a significant difference in exposure-response relationships between strains, and it appeared that the susceptible strains required a relatively higher exposure than the resistant ones to result in the same treatment effect, the 50% effective pharmacokinetic/pharmacodynamic (PK/PD) index (EI 50 ) required being negatively and log-linearly related to the MIC (P = 0.04). We conclude that the efficacy of voriconazole depended on drug exposure and the voriconazole MIC of the isolates, but lower exposures are required for strains with higher MICs. These findings may have profound significance in clinical practice with respect to dosing and drug choice. Copyright © 2016 American Society for Microbiology.

  10. Innovative technologies to manage aflatoxins in foods and feeds and the profitability of application - A review.

    Science.gov (United States)

    Udomkun, Patchimaporn; Wiredu, Alexander Nimo; Nagle, Marcus; Müller, Joachim; Vanlauwe, Bernard; Bandyopadhyay, Ranajit

    2017-06-01

    Aflatoxins are mainly produced by certain strains of Aspergillus flavus, which are found in diverse agricultural crops. In many lower-income countries, aflatoxins pose serious public health issues since the occurrence of these toxins can be considerably common and even extreme. Aflatoxins can negatively affect health of livestock and poultry due to contaminated feeds. Additionally, they significantly limit the development of international trade as a result of strict regulation in high-value markets. Due to their high stability, aflatoxins are not only a problem during cropping, but also during storage, transport, processing, and handling steps. Consequently, innovative evidence-based technologies are urgently required to minimize aflatoxin exposure. Thus far, biological control has been developed as the most innovative potential technology of controlling aflatoxin contamination in crops, which uses competitive exclusion of toxigenic strains by non-toxigenic ones. This technology is commercially applied in groundnuts maize, cottonseed, and pistachios during pre-harvest stages. Some other effective technologies such as irradiation, ozone fumigation, chemical and biological control agents, and improved packaging materials can also minimize post-harvest aflatoxins contamination in agricultural products. However, integrated adoption of these pre- and post-harvest technologies is still required for sustainable solutions to reduce aflatoxins contamination, which enhances food security, alleviates malnutrition, and strengthens economic sustainability.

  11. Mycobiota and mycotoxins (aflatoxins and ochratoxin) associated with some Saudi date palm fruits.

    Science.gov (United States)

    Gherbawy, Youssuf A; Elhariry, Hesham M; Bahobial, Abdul Aziz S

    2012-06-01

    This study aimed to determine the mycological profile of the retail date fruits distributed in different markets at Taif, Saudi Arabia. The presence of aflatoxins and ochratoxin A was also measured. Twenty-two fungal species belonging to 12 genera were isolated from 50 different date samples. Aspergillus flavus, A. niger, Penicillium chrysogenum, and Rhizopus stolonifer were the most prevalent species among isolated fungi. Eighty isolates of A. flavus and 36 of A. niger were detected for their aflatoxins and ochratoxin production potentials using thin layer chromatography. Toxicity test using Artimia larvae indicated that seven out of 18 A. flavus isolates had aflatoxins potentials, while nine out of 36 isolates of A. niger were ochratoxigenic. The quadruplex polymerase chain reaction using specific primers demonstrated the presence of four genes: nor A, ver 1, omt A, and avf A in seven A. flavus toxigenic isolates. Nine A. niger toxigenic isolates showed positive results for the presence of the PKS gene. In conclusion, the present study highlighted the potential hazards of mycotoxins on human health from consuming raw dates. Rapid molecular detection methods described here might help the food authorities to assure the safety of raw dates distributed in local markets.

  12. Toxigenic Potential of Aspergillus Species Occurring on Maize Kernels from Two Agro-Ecological Zones in Kenya

    Directory of Open Access Journals (Sweden)

    Vesa Joutsjoki

    2012-10-01

    Full Text Available Two agro-ecological zones in Kenya were selected to compare the distribution in maize of Aspergillus spp. and their toxigenicity. These were Nandi County, which is the main maize growing region in the country but where no human aflatoxicoses have been reported, and Makueni County where most of the aflatoxicosis cases have occurred. Two hundred and fifty-five households were sampled in Nandi and 258 in Makueni, and Aspergillus was isolated from maize. Aspergillus flavus and A. parasiticus isolates were tested for the presence of aflD and aflQ genes. Positive strains were induced to produce aflatoxins on yeast extract sucrose and quantified using liquid chromatography-tandem mass spectrometry (LCMSMS. Aspergillus flavus was the most common contaminant, and the incidence of occurrence in Nandi and Makueni was not significantly different (82.33% and 73.26%, respectively. Toxigenic strains were more prevalent than non-toxigenic strains. All the toxigenic strains from Makueni were of the S-type while those from Nandi belonged to the l-type. Quantitative differences in aflatoxin production in vitro between isolates and between strains were detected with S strains producing relatively larger amounts of total aflatoxins, B toxins and lower values for G toxins. This was in accord with the frequent aflatoxicosis outbreaks in Makueni. However some L strains produced considerable amounts of B toxins. Given the widespread distribution of toxigenic strains in both regions, the risk of aflatoxin poisoning is high when favorable conditions for toxin production occur.

  13. Effect of ozone on aflatoxins detoxification and nutritional quality of peanuts.

    Science.gov (United States)

    Chen, Ran; Ma, Fei; Li, Pei-Wu; Zhang, Wen; Ding, Xiao-Xia; Zhang, Qi; Li, Min; Wang, Yan-Ru; Xu, Bao-Cheng

    2014-03-01

    Aflatoxins are a group of secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus with carcinogenicity, teratogenicity, and mutagenicity. Aflatoxins may be found in a wide range of agri-products, especially in grains, oilseeds, corns, and peanuts. In this study, the conditions for detoxifying peanuts by ozonation were optimised. Aflatoxins in peanuts at moisture content of 5% (w/w) were sensitive to ozone and easily degraded when reacted with 6.0mg/l of ozone for 30min at room temperature. The detoxification rates of the total aflatoxins and aflatoxin B1 (AFB1) were 65.8% and 65.9%, respectively. The quality of peanut samples was also evaluated in this research. No significant differences (P>0.05) were found in the polyphenols, resveratrol, acid value (AV), and peroxide value (PV) between treated and untreated samples. The results suggested that ozonation was a promising method for aflatoxin detoxification in peanuts. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. VeA is associated with the response to oxidative stress in the aflatoxin producer Aspergillus flavus

    Science.gov (United States)

    Survival of fungal species depends on the ability of these organisms to respond to environmental stresses. Osmotic stress or high levels of reactive oxygen species (ROS) can cause stress in fungi resulting in growth inhibition. Both eukaryotic and prokaryotic cells have developed numerous mechanisms...

  15. Mycoflora and aflatoxin/fumonisin production by fungal isolates from freshly harvested corn hybrids

    Directory of Open Access Journals (Sweden)

    Almeida Adriana P.

    2000-01-01

    Full Text Available The mycoflora of 3 hybrids of freshly harvested corn grains collected from three regions of the state of São Paulo, Brazil (Assis, Capão Bonito and Ribeirão Preto was investigated. A total of 66 samples were analyzed focusing on the influence of abiotic factors (moisture content, water activity, temperature and rainfall on both the prevalence of Aspergillus flavus and Fusarium moniliforme, and the ability of these genera isolates to produce aflatoxins and fumonisins, respectively. In the three surveyed regions, the fungal population comprised mainly Fusarium spp., Penicillium spp., Aspergillus spp. and 2 others filamentous fungal genera, which were isolated from corn kernels showing water activity of 0.30 to 0.99 and moisture content of 5.0% to 20.2%. Among the genera Fusarium and Aspergillus, the most frequent species were F. moniliforme and A. flavus, respectively. Concerning the toxigenic potential of F. moniliforme, all isolated strains (40 produced fumonisins at 20 mug/g to 2168 mug/g (FB1 and/or 10 mug/g to 380 mug/g (FB2. From the 10 A. flavus isolates, 6 strains (60.0% produced aflatoxins at 615 mug/kg to 30.750 mug/kg (AFB1 and/or 11 mug/kg to 22 mug/kg (AFB2.

  16. Determination of aflatoxins and zearalenone in different culture media.

    Science.gov (United States)

    Bueno, Dante Javier; Oliver, Guillermo

    2004-01-01

    Some molds produce desirable changes in food, but most are merely esthetically undesirable. There has also been an increasing awareness that certain metabolic products of some molds commonly found on foods and feed are dangerous to humans and animals. These toxin substances, mycotoxins, are secondary metabolites produced by different fungi, especially Aspergillus, Penicillium, Fusarium, and, to a lesser degree, Alternaria. The most important toxins for humans are aflatoxins, ochratoxin A, fumonisins, certain trichothecenes, and zearalenone. Aflatoxins are fungal metabolites produced by different Aspergillus species: A. flavus, A. parasiticus, and A. nomius. The most commonly encountered aflatoxins are B1, B2, G1, G2, M1, and M2, but aflatoxin B1 is the most frequently found in contaminated samples, and aflatoxins B2, G1, and G2 are generally not reported in the absence of AFB1. The International Agency for Research on Cancer (IARC) considers that aflatoxins are carcinogenic (hepatocarcinogenic) to humans (group 1) and animals. Zearalenone is an estrogenic mycotoxin produced by several species of Fusarium (F. acuminatum, F. culmorum, F. equiseti, F. graminearum, F. verticilliodes, F. oxysporum, F. poae, F. rosum, F. solani, F. semitectum, and F. sporotrichioides) that primarily colonize different cereal grains. Several reports were noted on the occurrence of ZEA along with various combinations of group B trichothecenes, fumonisins, aflatoxins, and ochratoxins. In most cases, the levels of ZEA were considered to be low; however, the toxicological significance is not known. This toxin is not classifiable as to carcinogenicity in humans (group 3) by the IARC, but ZEA was implied in precocious sexual development in children in Puerto Rico and a breast enlargement in young boys in Italy.

  17. Mycobiota and Natural Incidence of Aflatoxins, Ochratoxin A, and Citrinin in Indian Spices Confirmed by LC-MS/MS

    Directory of Open Access Journals (Sweden)

    Punam Jeswal

    2015-01-01

    Full Text Available Nine different Indian spices (red chilli, black pepper, turmeric, coriander, cumin, fennel, caraway, fenugreek, and dry ginger commonly cultivated and highly used in India were analysed for natural occurrence of toxigenic mycoflora and aflatoxins (AFs, ochratoxin A (OTA, and citrinin (CTN contamination. Aspergillus flavus and Aspergillus niger were the most dominant species isolated from all types of spices. Red chilli samples were highly contaminated with aflatoxins (85.4% followed by dry ginger (77.7%. 56% Aspergillus flavus from red chilli and 45% Aspergillus ochraceus from black pepper were toxigenic and produced aflatoxins and ochratoxin A, respectively. Qualitative detection and quantitative detection of mycotoxins in spices were analyzed by ELISA and further confirmed by LC-MS/MS. Penicillium citrinum produced citrinin in red chilli, black pepper, coriander, cumin, fenugreek, and dry ginger samples. The highest amount of AFs was found in red chilli (219.6 ng/g, OTA was in black pepper (154.1 ng/g, and CTN was in dry ginger samples (85.1 ng/g. The results of this study suggest that the spices are susceptible substrate for growth of mycotoxigenic fungi and further mycotoxin production. This is the first report of natural occurrence of citrinin in black pepper and dry ginger from India.

  18. Nanoparticle-based immunosensors and immunoassays for aflatoxins.

    Science.gov (United States)

    Wang, Xu; Niessner, Reinhard; Tang, Dianping; Knopp, Dietmar

    2016-03-17

    Aflatoxins are naturally existing mycotoxins produced mainly by Aspergillus flavus and Aspergillus parasiticus, present in a wide range of food and feed products. Because of their extremely high toxicity and carcinogenicity, strict control of maximum residue levels of aflatoxins in foodstuff is set by many countries. In daily routine, different chromatographic methods are used almost exclusively. As supplement, in several companies enzyme immunoassay-based sample testing as primary screening is performed. Recently, nanomaterials such as noble metal nanoparticles, magnetic particles, carbon nanomaterials, quantum dots, and silica nanomaterials are increasingly utilized for aflatoxin determination to improve the sensitivity and simplify the detection. They are employed either as supports for the immobilization of biomolecules or as electroactive or optical labels for signal transduction and amplification. Several nanoparticle-based electrochemical, piezoelectric, optical, and immunodipstick assays for aflatoxins have been developed. In this review, we summarize these recent advances and illustrate novel concepts and promising applications in the field of food safety. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Perfil bioquímico do soro de frangos de corte alimentados com dieta suplementada com alfa-amilase de Cryptococcus flavus e Aspergillus niger HM2003 Biochemichal serum profile of broilers fed diets suplemented with alfa-amylase from Cryptococcus flavus and Aspergillus niger HM2003

    Directory of Open Access Journals (Sweden)

    Cibele Silva Minafra

    2010-12-01

    Full Text Available Avaliou-se o perfil bioquímico do soro de frangos de corte alimentados com a enzima α-amilase produzida por dois microrganismos. Produziram-se dois extratos, um com a-amilase obtida a partir de Cryptococcus flavus em meio de levedura comercial e outro com Aspergillus niger HM2003 em meio de proteína de soja e amido comercial, com atividade de 9,58 U/mL e 10,0 U/mL, respectivamente. Utilizaram-se 360 pintos de corte Cobb 500 de 1 dia de idade e com 49,72 ± 0,68 g de peso vivo inicial. As aves foram alojadas em baterias e foram criadas até os 21 dias de idade. Foram utilizados três dietas, cada uma com cinco repetições de 12 aves, em delineamento inteiramente casualizado. A primeira dieta (basal foi formulada sem adição de enzima e as outras duas receberam a suplementação de a-amilase produzida por cultivo de Cryptococcus flavus e Aspergillus niger HM2003. Dietas à base de milho e soja foram formuladas em duas fases: pré-inicial (1-7 dias e inicial (8-21 dias. Na fase pré-inicial, foram observados os seguintes valores médios para cálcio (6,90 e 5,99 mg/dL, proteína plasmática (2,0 e 2,50 g/dL e fosfatase alcalina (979,98 e 974,66 UI/L, respectivamente para Cryptococcus flavus e Aspergillus niger HM2003. A dieta acrescida de a-amilase obtida a partir de Aspergillus niger HM2003 determinou maior concentração sérica de fósforo. Na fase inicial, os resultados significativos relacionaram-se a potássio quando avaliadas dietas com adição de a-amilase pelas duas fontes. A incorporação das enzimas testadas não proporciona alterações metabólicas ou toxicidade nos animais.It was evaluated the biochemical serum profile of broilers fed rations supplemented with α-amylase produced by two microorganisms. Two extracts were produced, one was produced with a-amylase obtained from Cryptococcus flavus in a commercial yeast-based medium and the other with Aspergillus niger HM2003 produced in soybean protein and commercial starch medium

  20. Detoxification of Aflatoxin-Contaminated Maize by Neutral Electrolyzed Oxidizing Water

    Directory of Open Access Journals (Sweden)

    Samantha Jardon-Xicotencatl

    2015-10-01

    Full Text Available Aflatoxins, a group of extremely toxic mycotoxins produced by Aspergillus flavus, A. parasiticus and A. nomius, can occur as natural contaminants of certain agricultural commodities, particularly maize. These toxins have been shown to be hepatotoxic, carcinogenic, mutagenic and cause severe human and animal diseases. The effectiveness of neutral electrolyzed oxidizing water (NEW on aflatoxin detoxification was investigated in HepG2 cells using several validation methodologies such as the 3-(4,5-dimethylthiazol-2-yl-2,5- diphenyltetrazolium bromide assay, the induction of lipid peroxidation, the oxidative damage by means of glutathione modulation, the Ames test and the alkaline Comet assay. Our results showed that, after the aflatoxin-contaminated maize containing 360 ng/g was soaked in NEW (60 mg/L available chlorine, pH 7.01 during 15 min at room temperature, the aflatoxin content did not decrease as confirmed by the immunoaffinity column and ultra performance liquid chromatography methods. Aflatoxin fluorescence strength of detoxified samples was similar to untreated samples. However, aflatoxin-associated cytotoxicity and OPEN ACCESS Toxins 2015, 7 4295 genotoxicity effects were markedly reduced upon treatment. According to these results, NEW can be effectively used to detoxify aflatoxin-contaminated maize.

  1. Detoxification of Aflatoxin-Contaminated Maize by Neutral Electrolyzed Oxidizing Water

    Science.gov (United States)

    Jardon-Xicotencatl, Samantha; Díaz-Torres, Roberto; Marroquín-Cardona, Alicia; Villarreal-Barajas, Tania; Méndez-Albores, Abraham

    2015-01-01

    Aflatoxins, a group of extremely toxic mycotoxins produced by Aspergillus flavus, A. parasiticus and A. nomius, can occur as natural contaminants of certain agricultural commodities, particularly maize. These toxins have been shown to be hepatotoxic, carcinogenic, mutagenic and cause severe human and animal diseases. The effectiveness of neutral electrolyzed oxidizing water (NEW) on aflatoxin detoxification was investigated in HepG2 cells using several validation methodologies such as the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the induction of lipid peroxidation, the oxidative damage by means of glutathione modulation, the Ames test and the alkaline Comet assay. Our results showed that, after the aflatoxin-contaminated maize containing 360 ng/g was soaked in NEW (60 mg/L available chlorine, pH 7.01) during 15 min at room temperature, the aflatoxin content did not decrease as confirmed by the immunoaffinity column and ultra performance liquid chromatography methods. Aflatoxin fluorescence strength of detoxified samples was similar to untreated samples. However, aflatoxin-associated cytotoxicity and genotoxicity effects were markedly reduced upon treatment. According to these results, NEW can be effectively used to detoxify aflatoxin-contaminated maize. PMID:26512692

  2. Inhibitory Activities of Alkyl Syringates and Related Compounds on Aflatoxin Production

    Directory of Open Access Journals (Sweden)

    Tomohiro Furukawa

    2016-06-01

    Full Text Available Inhibitors of aflatoxin production of aflatoxigenic fungi are useful for preventing aflatoxin contamination in crops. As methyl syringate weakly inhibits aflatoxin production, aflatoxin production inhibitory activities of additional alkyl syringates with alkyl chains from ethyl to octyl were examined. Inhibitory activity toward aflatoxin production of Aspergillus flavus became stronger as the length of the alkyl chains on the esters became longer. Pentyl, hexyl, heptyl, and octyl syringates showed strong activity at 0.05 mM. Heptyl and octyl parabens, and octyl gallate also inhibited aflatoxin production as strongly as octyl syringate. Alkyl parabens and alkyl gallates inhibit the complex II activity of the mitochondrial respiration chain; thus, whether alkyl syringates inhibit complex II activity was examined. Inhibitory activities of alkyl syringates toward complex II also became stronger as the length of the alkyl chains increased. The complex II inhibitory activity of octyl syringate was comparable to that of octyl paraben and octyl gallate. These results suggest that alkyl syringates, alkyl parabens, and alkyl gallates, including commonly used food additives, are useful for aflatoxin control.

  3. Natural occurrence of aflatoxins in peanuts and peanut butter from Bulawayo, Zimbabwe.

    Science.gov (United States)

    Mupunga, I; Lebelo, S L; Mngqawa, P; Rheeder, J P; Katerere, D R

    2014-10-01

    Mycotoxins are toxic secondary metabolites produced by filamentous fungi that may contaminate food and pose a health risk, especially in developing countries, where there is a lack of food security and quality is subsumed by food insufficiency. Aflatoxins are the most toxic known mycotoxins and are a significant risk factor for liver and kidney cancer, teratogenicity, undernutrition, and micronutrient malabsorption in both humans and animals. The main aim of the study was to determine the extent of fungal and aflatoxin contamination in peanuts and peanut butter being sold in both the formal and informal markets in Bulawayo, Zimbabwe. Eighteen peanut samples and 11 peanut butter samples were purchased from retail shops and the informal market. Fungal contamination was determined using standard mycology culture methods, while aflatoxin contamination was determined using high-performance liquid chromatography-fluorescence detection. Four of the six peanut samples tested for fungal contamination were infected with Aspergillus flavus/parasiticus, ranging from 3 to 20% of the kernels examined, while 27% (3 of 11) of the peanut butter samples were infected with A. flavus/parasiticus. Ninety-one percent (10 of 11) of the peanut butter samples were contaminated with aflatoxins (mean, 75.66 ng/g, and range, 6.1 to 247 ng/g), and aflatoxin B1 was the most prevalent (mean, 51.0 ng/g, and range, 3.7 to 191 ng/g). Three of the 18 peanut samples were contaminated with aflatoxins (range, 6.6 to 622 ng/g). The commercial peanut butter samples had very high aflatoxin levels, and manufacturers should be sensitized to the detrimental effects of aflatoxins and measures to reduce contamination.

  4. The biodiversity of Aspergillus section Flavi and aflatoxins in the Brazilian peanut production chain

    DEFF Research Database (Denmark)

    Martins, Ligia Manoel; de Souza Sant'Ana, Anderson; Pelegrinelli Fungaro, Maria Helena

    2017-01-01

    A total of 119 samples of peanut were collected throughout the peanut production chain in Sao Paulo State, Brazil. The peanut samples were directly plated for determination of percentages of infection and a polyphasic approach was used to identify Aspergillus section Flavi species. Further, the p...

  5. High sequence variations in the region containing genes encoding a cellular morphogenesis protein and the repressor of sexual development help to reveal origins of Aspergillus oryzae.

    Science.gov (United States)

    Chang, Perng-Kuang; Scharfenstein, Leslie L; Solorzano, Cesar D; Abbas, Hamed K; Hua, Sui-Sheng T; Jones, Walker A; Zablotowicz, Robert M

    2015-05-04

    Aspergillus oryzae and Aspergillus flavus are closely related fungal species. The A. flavus morphotype that produces numerous small sclerotia (S strain) and aflatoxin has a unique 1.5 kb deletion in the norB-cypA region of the aflatoxin gene cluster (i.e. the S genotype). Phylogenetic studies have indicated that an isolate of the nonaflatoxigenic A. flavus with the S genotype is the ancestor of A. oryzae. Genome sequence comparison between A. flavus NRRL3357, which produces large sclerotia (L strain), and S-strain A. flavus 70S identified a region (samA-rosA) that was highly variable in the two morphotypes. A third type of samA-rosA region was found in A. oryzae RIB40. The three samA-rosA types were later revealed to be commonly present in A. flavus L-strain populations. Of the 182 L-strain A. flavus field isolates examined, 46%, 15% and 39% had the samA-rosA type of NRRL3357, 70S and RIB40, respectively. The three types also were found in 18 S-strain A. flavus isolates with different proportions. For A. oryzae, however, the majority (80%) of the 16 strains examined had the RIB40 type and none had the NRRL3357 type. The results suggested that A. oryzae strains in the current culture collections were mostly derived from the samA-rosA/RIB40 lineage of the nonaflatoxigenic A. flavus with the S genotype. Published by Elsevier B.V.

  6. Lactic acid bacteria as functional probiotic isolates for inhibiting the growth of Aspergillus flavus, A. parasiticus, A. niger and Penicillium chrysogenum.

    Science.gov (United States)

    Abbaszadeh, S; Tavakoli, R; Sharifzadeh, A; Shokri, H

    2015-12-01

    The aim of this study was to assess the potential of lactic acid bacteria (LAB) such as Lactobacillus acidophilus, L. rhamnosus, L. casei, L. paracasei and Bifidobacterium bifidum to inhibit the outgrowth of some common food-spoiling fungi including Aspergillus niger, A. flavus, A. parasiticus and Penicillium chrysogenum. Bacterial isolates were cultured on Mann Rogosa Sharpe (MRS) broth and liquid cultures and supernatants were prepared. The antifungal activity was tested using the agar well diffusion method. Both liquid culture and supernatant of L. casei isolate exhibited high antifungal activity, followed by L. acidophilus and L. paracasei isolates. The least activity was recorded for the isolates B. bifidum, while the isolate L. rhamnosus was moderately active against tested fungi. The antifungal activity of the supernatants obtained from all probiotic isolates against fungi was significantly less than that of liquid cultures (Pprobiotic bacteria, followed by P. chrysogenum, A. niger and A. parasiticus. These results suggest that probiotic bacteria strains have the ability to prevent the growth of pathogenic and mycotoxigenic fungi as antifungal agents for various biomedical applications. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  7. Mycetoma in South India: retrospective analysis of 13 cases and description of two cases caused by unusual pathogens: Neoscytalidium dimidiatum and Aspergillus flavus.

    Science.gov (United States)

    Padhi, Somanath; Uppin, Shantveet G; Uppin, Megha S; Umabala, P; Challa, Sundaram; Laxmi, V; Prasad, V B N

    2010-11-01

    Mycetoma is a chronic suppurative and/or granulomatous inflammatory lesion of skin, subcutaneous tissue, fascia, and tendons caused by the traumatic inoculation of either fungal (eumycotic) or bacterial (actinomycotic) organisms present in the soil. The disease is characterized by triad of tumefaction, discharging sinuses, and grains. Thirteen new cases of biopsy proven mycetomas were analyzed, retrospectively, from January 2000 to October 2009. Clinical parameters, bone involvement, microbiological properties, and histopathological features were evaluated. Categorization into eumycotic or actinomycotic was based upon features on hematoxylin and eosin stained sections with special stains. Therapeutic outcome was presented wherever available. There were eight actinomycetomas and five eumycetoma cases including 11 men and two women. Foot and lower extremities were the most common site of involvement (9 of 13, 69%). Culture results were available in 8 of 13 cases (61.5%). Madurella mycetomatis, Neoscytalidium dimidiatum, and Aspergillus flavus were the isolates among eumycetomas whereas Acinomadura madurae, Actinomadura pelletieri, and Nocardia species were the isolates among actinomycetomas. Two cases had underlying bone involvement. On follow-up, four of five eumycetoma cases showed partial improvement following surgery and antifungal therapy, one had amputation of the lower leg. Of the actinomycetomas, six of eight had dramatic improvement following sulfamethoxazole-trimethoprim based therapy, one had complete cure, and one was lost to follow-up. Strong clinical suspicion, exact categorization of lesion into eumycotic or actinomycotic along with culture correlation, is essential for prognosis and effective therapy. © 2010 The International Society of Dermatology.

  8. Large crystal growth by thermal control allows combined X-ray and neutron crystallographic studies to elucidate the protonation states in Aspergillus flavus urate oxidase.

    Science.gov (United States)

    Oksanen, E; Blakeley, M P; Bonneté, F; Dauvergne, M T; Dauvergne, F; Budayova-Spano, M

    2009-10-06

    Urate oxidase (Uox) catalyses the oxidation of urate to allantoin and is used to reduce toxic urate accumulation during chemotherapy. X-ray structures of Uox with various inhibitors have been determined and yet the detailed catalytic mechanism remains unclear. Neutron crystallography can provide complementary information to that from X-ray studies and allows direct determination of the protonation states of the active-site residues and substrate analogues, provided that large, well-ordered deuterated crystals can be grown. Here, we describe a method and apparatus used to grow large crystals of Uox (Aspergillus flavus) with its substrate analogues 8-azaxanthine and 9-methyl urate, and with the natural substrate urate, in the presence and absence of cyanide. High-resolution X-ray (1.05-1.20 A) and neutron diffraction data (1.9-2.5 A) have been collected for the Uox complexes at the European Synchrotron Radiation Facility and the Institut Laue-Langevin, respectively. In addition, room temperature X-ray data were also collected in preparation for joint X-ray and neutron refinement. Preliminary results indicate no major structural differences between crystals grown in H(2)O and D(2)O even though the crystallization process is affected. Moreover, initial nuclear scattering density maps reveal the proton positions clearly, eventually providing important information towards unravelling the mechanism of catalysis.

  9. Single aflatoxin contaminated corn kernel analysis with fluorescence hyperspectral image

    Science.gov (United States)

    Yao, Haibo; Hruska, Zuzana; Kincaid, Russell; Ononye, Ambrose; Brown, Robert L.; Cleveland, Thomas E.

    2010-04-01

    Aflatoxins are toxic secondary metabolites of the fungi Aspergillus flavus and Aspergillus parasiticus, among others. Aflatoxin contaminated corn is toxic to domestic animals when ingested in feed and is a known carcinogen associated with liver and lung cancer in humans. Consequently, aflatoxin levels in food and feed are regulated by the Food and Drug Administration (FDA) in the US, allowing 20 ppb (parts per billion) limits in food and 100 ppb in feed for interstate commerce. Currently, aflatoxin detection and quantification methods are based on analytical tests including thin-layer chromatography (TCL) and high performance liquid chromatography (HPLC). These analytical tests require the destruction of samples, and are costly and time consuming. Thus, the ability to detect aflatoxin in a rapid, nondestructive way is crucial to the grain industry, particularly to corn industry. Hyperspectral imaging technology offers a non-invasive approach toward screening for food safety inspection and quality control based on its spectral signature. The focus of this paper is to classify aflatoxin contaminated single corn kernels using fluorescence hyperspectral imagery. Field inoculated corn kernels were used in the study. Contaminated and control kernels under long wavelength ultraviolet excitation were imaged using a visible near-infrared (VNIR) hyperspectral camera. The imaged kernels were chemically analyzed to provide reference information for image analysis. This paper describes a procedure to process corn kernels located in different images for statistical training and classification. Two classification algorithms, Maximum Likelihood and Binary Encoding, were used to classify each corn kernel into "control" or "contaminated" through pixel classification. The Binary Encoding approach had a slightly better performance with accuracy equals to 87% or 88% when 20 ppb or 100 ppb was used as classification threshold, respectively.

  10. Assessment of aflatoxins B

    African Journals Online (AJOL)

    These results show that people in Swaziland are being exposed to aflatoxins through feeding on contaminated maize. There is a growing urgency for the Swaziland government to come up with strategies of teaching the people about food safety. Keywords: aflatoxins, Aspergillus, maize, contamination, carcinogen, toxin, ...

  11. Production of thermostable glucoamylase by newly isolated Aspergillus flavus A 1.1 and Thermomyces lanuginosus A 13.37 Produção e glucoamilase por Aspergillus flavus A1.1 e Thermomyces lanuginosus A13.37

    Directory of Open Access Journals (Sweden)

    Eleni Gomes

    2005-03-01

    Full Text Available Thirteen thermophilic fungal strains were isolated from agricultural soil, tubers and compost samples in tropical Brazil. Two strains were selected based on of their ability to produce considerable glucoamylase activity while growing in liquid medium at 45ºC with starch as the only carbon source. They were identified as Aspergillus flavus A1.1 and Thermomyces lanuginosus A 13.37 Tsiklinsky. The experiment to evaluate the effect of carbon source, temperature and initial pH of the medium on enzyme production was developed in a full factorial design (2x2x3. Enzyme productivity was influenced by the type of starch used as carbon source. Cassava starch showed to be a better substrate than corn starch for glucoamylase production by A. flavus but for T. lanuginosus the difference was not significant. Enzyme activities were determined using as substrates 0.3% soluble starch, 0.3% maltose or 0.3% of starch plus 0.1% maltose. The enzymes from A. flavus A1.1 hydrolyzed soluble starch preferentially but also exhibited a significant maltase activity. Moreover higher quantities of glucose were released when the substrate used was a mixture of starch and maltose, suggesting that this fungus produced two types of enzyme. In the case T. lanuginosus A 13.37, the substrate specificity test indicated that the enzyme released also hydrolyzed starch more efficiently than maltose, but there was no increase in the liberation of glucose when a mixture of starch and maltose was used as substrate, suggesting that only one type of enzyme was secreted. Glucoamylases produced from A. flavus A1.1 and T. lanuginous A.13-37 have high optimum temperature (65ºC and 70ºC and good thermostability in the absence of substrate (maintaining 50% of activity for 5 and 8 hours, respectively, at 60ºC and are stable over in a wide pH range. These new strains offer an attractive alternative source of enzymes for industrial starch processing.Entre 13 linhagens de fungos filamentosos

  12. Interacções de estirpes de Aspergillus flavus não-toxígenas com Aspergillus parasiticus na produção de aflatoxinas

    Directory of Open Access Journals (Sweden)

    Hermínia Marina Martins

    2000-12-01

    Full Text Available A produção de aflatoxinas é afetada por parâmetros abióticos, bióticos e genéticos. As condições eugenésicas e disgenésicas da aflatoxinogênese estão relativamente bem estudadas, tal como as influências ecológicas (temperatura, pH, Aw, tensão de oxigênio, pressão osmótica, nutrientes e substâncias fungistáticas. Contudo, é muito escasso o conhecimento relativo aos mecanismos reguladores endógenos, à cinética do anabolismo e à interação dos fungos produtores com a restante microflora presente em substratos eutrofizantes. O principal objetivo deste estudo é avaliar a interação de cinco estirpes indígenas de A. flavus, comprovadamente atoxígenas, com uma geneticamente apta (A. parasiticus ATCC 15517, cultivadas simultaneamente em dois substratos: um natural (milho triturado e outro sintético (Caldo de Czapeck-Dox Modificado. A quantificação das aflatoxinas foi efetuada no 8º e 12º dias de incubação, por Cromatografia Líquida de Alta Resolução (HPLC. Os resultados demonstraram que todas as estirpes foram sinérgicas, aumentando o rendimento da produção entre 5,6 e 106,5%, quando comparados com os valores das testemunhas.

  13. Improvement of the antifungal activity of Litsea cubeba vapor by using a helium-neon (He-Ne) laser against Aspergillus flavus on brown rice snack bars.

    Science.gov (United States)

    Suhem, Kitiya; Matan, Narumol; Matan, Nirundorn; Danworaphong, Sorasak; Aewsiri, Tanong

    2015-12-23

    The aim of this study was to improve the antifungal activity of the volatile Litsea cubeba essential oil and its main components (citral and limonene) on brown rice snack bars by applying He-Ne laser treatment. Different volumes (50-200 μL) of L. cubeba, citral or limonene were absorbed into a filter paper and placed inside an oven (18 L). Ten brown rice snack bars (2 cm wide × 4 cm long × 0.5 cm deep) were put in an oven and heated at 180 °C for 20 min. The shelf-life of the treated snack bars at 30 °C was assessed and sensory testing was carried out to investigate their consumer acceptability. A count of total phenolic content (TPC) and Fourier transform infrared spectroscopy (FTIR) on the properties of essential oil, citral, and limonene before and after the laser treatment was studied for possible modes of action. It was found that the laser treatment improved the antifungal activity of the examined volatile L. cubeba and citral with Aspergillus flavus inhibition by 80% in comparison with those of the control not treated with the laser. L. cubeba vapor at 100 μL with the laser treatment was found to completely inhibit the growth of natural molds on the snack bars for at least 25 days; however, without essential oil vapor and laser treatment, naturally contaminating mold was observed in 3 days. Results from the sensory tests showed that the panelists were unable to detect flavor and aroma differences between essential oil treatment and the control. Laser treatment caused an increase in TPC of citral oil whereas the TPC in limonene showed a decrease after the laser treatment. These situations could result from the changing peak of the aliphatic hydrocarbons that was revealed by the FTIR spectra. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. MicroCommentary: A New Role for Coenzyme F420 in Aflatoxin Reduction by Soil Mycobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Graham, David E [ORNL

    2010-01-01

    Hepatotoxic aflatoxins have found a worthy adversary in two new families of bacterial oxidoreductases. These enzymes use the reduced coenzyme F420 to initiate the degradation of furanocoumarin compounds, including the major mycotoxin products of Aspergillus flavus. Along with pyridoxalamine 5 -phosphate oxidases and aryl nitroreductases, these proteins form a large and versatile superfamily of flavin and deazaflavin-dependent oxidoreductases. F420-dependent members of this family appear to share a common mechanism of hydride transfer from the reduced deazaflavin to the electron-deficient ring systems of their substrates.

  15. Effect of gamma radiation on the inactivation of aflatoxin B1 in food and feed crops

    OpenAIRE

    Ghanem, I.; Orfi, M.; Shamma, M

    2008-01-01

    Samples of food crops (peanut, peeled pistachio, unpeeled pistachio, rice, and corn) and feed (barley, bran, corn) were autoclave-sterilized, and inoculated with 10(6) of spore suspension of an isolate of Aspergillus flavus fungus known to produce aflatoxin B1 (AFB1) . Following a 10-day period of incubation at 27 C to allow for fungal growth, food and feed samples were irradiated with gamma radiation at the doses 4, 6, and 10 kGy. Results indicated that degradation of AFB1 was positively cor...

  16. Stimulation of aflatoxin B1 and T-2 toxin production by sorbic acid.

    OpenAIRE

    Gareis, M; Bauer, J; von Montgelas, A; Gedek, B

    1984-01-01

    Aspergillus flavus grown on yeast extract-sucrose medium produced higher amounts of aflatoxin B1 in the presence of 0.025% sorbic acid than without this chemical with a maximum at 17 days of incubation. Addition of 0.05 to 0.0125% sorbic acid stimulated T-2 toxin production of Fusarium acuminatum cultures grown on maize meal. The highest amounts of the mycotoxin were detected in 14-day-old cultures containing 0.025% sorbic acid. It is assumed that certain amounts of sorbic acid near the minim...

  17. Role of pencycuron in aflatoxin production and cotton seed protection.

    Science.gov (United States)

    Hasan, H A

    2001-05-01

    The research is conducted on the effect of pencycuron and pencycuron-c on cotton seed mycoflora, aflatoxin production and viability. At 8% seed moisture content (mc), pencycuron and pencycuron-c promoted Aspergillus niger, A. flavus, and Penicillium corylophilum growth count at 1 g/kg, but exerted inhibitory effect at 3 and 5 g/kg. At 15% mc, pencycuron enhanced seed-borne fungi at all three doses after most treatment periods (1, 2, 3, 4, and 5 months), whereas pencycuron-c induced inhibition effect. The A. niger utilized pencycuron as nitrogen source more than pencycuron-c. Seeds with 15% mc lost their viability faster than that at 8%, and this was more evident as storage time increased. Such loss occurred faster when seed was treated with pencycuron, whereas pencycuron-c exerted significant activation in the viability compared to the control. The fungal species have high biodegradation activity and produce aflatoxin in different parts of cotton boll (fiber, valves, and seeds). Pencycuron and pencycuron-c inhibited aflatoxin B1 and B2 production in seeds, but did not affect aflatoxin G1 and G2.

  18. Use of electron beam on aflatoxins degradation in coconut agar

    Energy Technology Data Exchange (ETDEWEB)

    Rogovschi, Vladimir D.; Nunes, Thaise C.F.; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: vrogovschi@ipen.br; Aquino, Simone; Goncalez, Edlayne [Instituto Biologico (IB-SP), Sao Paulo, SP (Brazil); Correa, Benedito [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Ciencias Biomedicas

    2009-07-01

    The fungi Aspergillus flavus are capable of producing toxic metabolites, such as aflatoxin, that is one of the most important human carcinogens, according to the 'International Agency for Research on Cancer'. The aim of this study was to compare the effect of electron beam irradiation on degradation of aflatoxin B1 present in laboratorial residues with a dose of 0 kGy and 5.0 kGy. The fungi were cultivated in potato dextrose agar (PDA) for 7 days and transferred to a coconut agar medium, incubated at a temperature of 25 deg C for 14 days to produce the laboratorial wastes (coconut agar) containing aflatoxins. The samples were conditioned in petri dish for radiation treatment of contaminated material and processed in the Electron Accelerator with 0 kGy and 5.0 kGy. Aflatoxin B{sub 1} was extracted with chloroform and separated on a thin layer chromatography plate (TLC) with chloroform: acetone (9:1). All the control and irradiated samples were analyzed in a Shimadzu Densitometer. The detection limit of this methodology is 0.1{mu}g kg{sup -1}. The results indicate that the irradiated samples had a reduction of 75.49 % in the analyzed dose. (author)

  19. Purification of aflatoxin B1 antibody for the development of aflatoxin biosensor

    Science.gov (United States)

    Prihantoro, E. A. B.; Saepudin, E.; Ivandini, T. A.

    2017-07-01

    Aflatoxin B1 (AFB1) is produced from agricultural products especially peanuts overgrown with aspergillus flavus during the post-harvest process. Aflatoxin is classified as a highly toxic and carcinogenic substance to humans by the International Agency for Research on Cancer (IARC), WHO. This research was conducted to develop the AFB1 biosensor using antibody that specifically binds to aflatoxin B1. This antibody was produced by injecting an AFB1 hapten-protein (immunogen) to a rabbit. Antibody was obtained from rabbit's blood serum and purified using Protein A affinity chromatography and precipitation at the isoelectric point. The result showed that purification using protein A contains antibody of 4.0 mg/mL, whereas purification using precipitation at isoelectric pH contains antibody of 0.3 mg/mL. The pure antibody was tested for its specificity against AFB1, tetrahydrofuran (THF), dimethyl formamide (DMF), bovine serum albumin (BSA), and ethanol. The result revealed that THF, BSA, and ethanol were bound to antibody, while DMF showed no interaction. It was concluded that the polyclonal antibody which have been successfully purified from rabbit's blood serum using protein A affinity chromatography and precipitation methods showed an unspecific identification.

  20. Analysis of aflatoxins in nonalcoholic beer using liquid-liquid extraction and ultraperformance LC-MS/MS.

    Science.gov (United States)

    Khan, Mohammad R; Alothman, Zeid A; Ghfar, Ayman A; Wabaidur, Saikh M

    2013-02-01

    Aflatoxins AFB1, AFB2, AFG1, and AFG2 are toxic secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus and posses a potential threat to food safety. In the present work, liquid-liquid extraction and ultraperformance LC-MS/MS method has been applied for the determination of four naturally occurring aflatoxins AFB1, AFB2, AFG1, and AFG2 in nonalcoholic beer. Aflatoxins extraction from nonalcoholic beer was carried out using liquid-liquid extraction procedure. The effects of solvent-types were studied to obtain maximum recovery of the target analytes with minimum contamination. Among different solvents, the aflatoxins extraction was best achieved using ethyl acetate. The obtained recoveries were ranged from 85 to 96% with good quality parameters: LOD values between 0.001 and 0.003 ng/mL, linearity of the calibration curve (r(2) > 0.999), and repeatability (run-to-run) and reproducibility (day-to-day) precisions with RSDs lower than 5% (n = 5) achieved at 0.50 ng/mL concentration. The optimized liquid-liquid extraction in combination with ultraperformance LC-MS/MS was applied successfully to the analysis of AFB1, AFB2, AFG1, and AFG2 aflatoxins in 11 nonalcoholic beers and were detected up to 15.31 ng/L in some of the samples. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Description of Aspergillus flavus growth under the influence of different factors (water activity, incubation temperature, protein and fat concentration, pH, and cinnamon essential oil concentration) by kinetic, probability of growth, and time-to-detection models.

    Science.gov (United States)

    Kosegarten, Carlos E; Ramírez-Corona, Nelly; Mani-López, Emma; Palou, Enrique; López-Malo, Aurelio

    2017-01-02

    A Box-Behnken design was used to determine the effect of protein concentration (0, 5, or 10g of casein/100g), fat (0, 3, or 6g of corn oil/100g), aw (0.900, 0.945, or 0.990), pH (3.5, 5.0, or 6.5), concentration of cinnamon essential oil (CEO, 0, 200, or 400μL/kg) and incubation temperature (15, 25, or 35°C) on the growth of Aspergillus flavus during 50days of incubation. Mold response under the evaluated conditions was modeled by the modified Gompertz equation, logistic regression, and time-to-detection model. The obtained polynomial regression models allow the significant coefficients (p0.967) the studied mold responses. After 50days of incubation, every tested model system was classified according to the observed response as 1 (growth) or 0 (no growth), then a binary logistic regression was utilized to model A. flavus growth interface, allowing to predict the probability of mold growth under selected combinations of tested factors. The time-to-detection model was utilized to estimate the time at which A. flavus visible growth begins. Water activity, temperature, and CEO concentration were the most important factors affecting fungal growth. It was observed that there is a range of possible combinations that may induce growth, such that incubation conditions and the amount of essential oil necessary for fungal growth inhibition strongly depend on protein and fat concentrations as well as on the pH of studied model systems. The probabilistic model and the time-to-detection models constitute another option to determine appropriate storage/processing conditions and accurately predict the probability and/or the time at which A. flavus growth occurs. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Volatile profiles of healthy and aflatoxin contaminated pistachios.

    Science.gov (United States)

    Georgiadou, M; Gardeli, Chr; Komaitis, M; Tsitsigiannis, D I; Paplomatas, E J; Sotirakoglou, K; Yanniotis, S

    2015-08-01

    The volatile profile of four different groups of dried pistachios namely: H: healthy, NC: naturally contaminated with aflatoxin, AC: artificially contaminated with aflatoxigenic strains of the fungi Aspergillus flavus and ANT: artificially contaminated with non-toxigenic strains of the fungi A. flavus, was determined. The volatiles were isolated by the HS-SPME method and determined by GC-FID and GC-MS, whereas aflatoxin by HPLC. Seventy two volatile compounds were identified almost equally distributed among the above four studied groups. The predominant chemical compounds were monoterpenes, alcohols, ketones, aldehydes, esters and hydrocarbons. The monoterpenes, mainly determined as α-pinene and α-terpinolene were detected in all samples. Even though the general volatile profile was similar among groups, some differences were detected between healthy and contaminated groups of samples. When some key volatiles such as eight-carbon and seven-carbon alcohols and aldehydes were used along with the species-specific sesquiterpenes and the other terpenes detected, a correct classification was obtained in H, NC, AC and ANT groups, as was demonstrated by cluster and discriminant analyses. This evidence provides a potential tool for distinguishing contaminated samples on the basis of characteristic volatile patterns. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Aflatoxin effect on erythrocyte profile and histopathology of broilers given different additives

    Science.gov (United States)

    Karimy, M. F.; Sutrisno, B.; Agus, A.; Suryani, A. E.; Istiqomah, L.; Damayanti, E.

    2017-12-01

    The aim of this study was to evaluate erythrocyte profile and microscopic changes effect of AF induces by low level (57.18 ppb) and chronic exposure (34 days) with administration of additive (Lactobacillus plantarum G7 and methionine). Aflatoxin-contaminated corn was prepared by inoculate Aspergillus flavus FNCC 6002 on corn. Total number of 576 broiler Lohman strain (MB202) unsexed DOC were allocated completely randomized into four treatments and 12 replicates, with 12 broiler chicks each. The treatments as follows: T1 = aflatoxin-contaminated diet, T2 = aflatoxin-contaminated diet + 1% of LAB (w/w), T3 = aflatoxin-contaminated diet + 0.8% of methionine (w/w), and T4 = aflatoxin-contaminated diet + 1% of LAB + 0.8% of methionine (w/w). The effect of treatments was evaluated using ANOVA and the difference among mean treatments were analyzed using DMRT. The result showed that administration of additives had no significant effect (P>0.05) on erythrocyte profile, liver, and bursa of Fabricius. The dose of additive in each treatment (T2, T3, T4) were insufficient to reduce adverse effect of chronic aflatoxicosis. It was concluded that the LAB dose for binding AF (57.18%) should be evaluated and the dose for methionine should be reduced for chronic treatment of aflatoxicosis.

  4. Classification of corn kernels contaminated with aflatoxins using fluorescence and reflectance hyperspectral images analysis

    Science.gov (United States)

    Zhu, Fengle; Yao, Haibo; Hruska, Zuzana; Kincaid, Russell; Brown, Robert; Bhatnagar, Deepak; Cleveland, Thomas

    2015-05-01

    Aflatoxins are secondary metabolites produced by certain fungal species of the Aspergillus genus. Aflatoxin contamination remains a problem in agricultural products due to its toxic and carcinogenic properties. Conventional chemical methods for aflatoxin detection are time-consuming and destructive. This study employed fluorescence and reflectance visible near-infrared (VNIR) hyperspectral images to classify aflatoxin contaminated corn kernels rapidly and non-destructively. Corn ears were artificially inoculated in the field with toxigenic A. flavus spores at the early dough stage of kernel development. After harvest, a total of 300 kernels were collected from the inoculated ears. Fluorescence hyperspectral imagery with UV excitation and reflectance hyperspectral imagery with halogen illumination were acquired on both endosperm and germ sides of kernels. All kernels were then subjected to chemical analysis individually to determine aflatoxin concentrations. A region of interest (ROI) was created for each kernel to extract averaged spectra. Compared with healthy kernels, fluorescence spectral peaks for contaminated kernels shifted to longer wavelengths with lower intensity, and reflectance values for contaminated kernels were lower with a different spectral shape in 700-800 nm region. Principal component analysis was applied for data compression before classifying kernels into contaminated and healthy based on a 20 ppb threshold utilizing the K-nearest neighbors algorithm. The best overall accuracy achieved was 92.67% for germ side in the fluorescence data analysis. The germ side generally performed better than endosperm side. Fluorescence and reflectance image data achieved similar accuracy.

  5. Stimulation of aflatoxin B1 and T-2 toxin production by sorbic acid.

    Science.gov (United States)

    Gareis, M; Bauer, J; von Montgelas, A; Gedek, B

    1984-01-01

    Aspergillus flavus grown on yeast extract-sucrose medium produced higher amounts of aflatoxin B1 in the presence of 0.025% sorbic acid than without this chemical with a maximum at 17 days of incubation. Addition of 0.05 to 0.0125% sorbic acid stimulated T-2 toxin production of Fusarium acuminatum cultures grown on maize meal. The highest amounts of the mycotoxin were detected in 14-day-old cultures containing 0.025% sorbic acid. It is assumed that certain amounts of sorbic acid near the minimal inhibitory concentration reduce the activity of the tricarboxylic acid cycle; this may lead to an accumulation of acetyl coenzyme A, which is an essential intermediate in the biosynthesis of aflatoxin B1 and T-2 toxin. PMID:6424567

  6. Spatial Patterns of Aflatoxin Levels in Relation to Ear-Feeding Insect Damage in Pre-Harvest Corn

    Directory of Open Access Journals (Sweden)

    Alisa Huffaker

    2011-07-01

    Full Text Available Key impediments to increased corn yield and quality in the southeastern US coastal plain region are damage by ear-feeding insects and aflatoxin contamination caused by infection of Aspergillus flavus. Key ear-feeding insects are corn earworm, Helicoverpa zea, fall armyworm, Spodoptera frugiperda, maize weevil, Sitophilus zeamais, and brown stink bug, Euschistus servus. In 2006 and 2007, aflatoxin contamination and insect damage were sampled before harvest in three 0.4-hectare corn fields using a grid sampling method. The feeding damage by each of ear/kernel-feeding insects (i.e., corn earworm/fall armyworm damage on the silk/cob, and discoloration of corn kernels by stink bugs, and maize weevil population were assessed at each grid point with five ears. The spatial distribution pattern of aflatoxin contamination was also assessed using the corn samples collected at each sampling point. Aflatoxin level was correlated to the number of maize weevils and stink bug-discolored kernels, but not closely correlated to either husk coverage or corn earworm damage. Contour maps of the maize weevil populations, stink bug-damaged kernels, and aflatoxin levels exhibited an aggregated distribution pattern with a strong edge effect on all three parameters. The separation of silk- and cob-feeding insects from kernel-feeding insects, as well as chewing (i.e., the corn earworm and maize weevil and piercing-sucking insects (i.e., the stink bugs and their damage in relation to aflatoxin accumulation is economically important. Both theoretic and applied ramifications of this study were discussed by proposing a hypothesis on the underlying mechanisms of the aggregated distribution patterns and strong edge effect of insect damage and aflatoxin contamination, and by discussing possible management tactics for aflatoxin reduction by proper management of kernel-feeding insects. Future directions on basic and applied research related to aflatoxin contamination are also

  7. Spatial patterns of aflatoxin levels in relation to ear-feeding insect damage in pre-harvest corn.

    Science.gov (United States)

    Ni, Xinzhi; Wilson, Jeffrey P; Buntin, G David; Guo, Baozhu; Krakowsky, Matthew D; Lee, R Dewey; Cottrell, Ted E; Scully, Brian T; Huffaker, Alisa; Schmelz, Eric A

    2011-07-01

    Key impediments to increased corn yield and quality in the southeastern US coastal plain region are damage by ear-feeding insects and aflatoxin contamination caused by infection of Aspergillus flavus. Key ear-feeding insects are corn earworm, Helicoverpa zea, fall armyworm, Spodoptera frugiperda, maize weevil, Sitophilus zeamais, and brown stink bug, Euschistus servus. In 2006 and 2007, aflatoxin contamination and insect damage were sampled before harvest in three 0.4-hectare corn fields using a grid sampling method. The feeding damage by each of ear/kernel-feeding insects (i.e., corn earworm/fall armyworm damage on the silk/cob, and discoloration of corn kernels by stink bugs), and maize weevil population were assessed at each grid point with five ears. The spatial distribution pattern of aflatoxin contamination was also assessed using the corn samples collected at each sampling point. Aflatoxin level was correlated to the number of maize weevils and stink bug-discolored kernels, but not closely correlated to either husk coverage or corn earworm damage. Contour maps of the maize weevil populations, stink bug-damaged kernels, and aflatoxin levels exhibited an aggregated distribution pattern with a strong edge effect on all three parameters. The separation of silk- and cob-feeding insects from kernel-feeding insects, as well as chewing (i.e., the corn earworm and maize weevil) and piercing-sucking insects (i.e., the stink bugs) and their damage in relation to aflatoxin accumulation is economically important. Both theoretic and applied ramifications of this study were discussed by proposing a hypothesis on the underlying mechanisms of the aggregated distribution patterns and strong edge effect of insect damage and aflatoxin contamination, and by discussing possible management tactics for aflatoxin reduction by proper management of kernel-feeding insects. Future directions on basic and applied research related to aflatoxin contamination are also discussed.

  8. Ação fungitóxica do óleo essencial de Tanaecium nocturnum (Barb. Rodr. Bur. e K. Shum sobre o Aspergillus flavus isolado da castanha-do-Brasil (Bertholletia excelsa Fungitoxic action of the essential oil of Tanaecium nocturnum (Barb. Rodr. Bur. and K. Shum on Aspergillus flavus isolated from the Brazil nut (Bertholletia excelsa

    Directory of Open Access Journals (Sweden)

    Flávio Araújo Pimentel

    2010-03-01

    Full Text Available Neste trabalho, avaliou-se a capacidade fungitóxica do óleo essencial de folhas frescas de Tanaecium nocturnum sobre o Aspergillus flavus isolado da castanha-do-brasil, por meio das técnicas de contato e fumigação. Pelos resultados dos bioensaios realizados até 10 dias de incubação, verificou-se que a inibição total do crescimento micelial ocorreu quando se utilizou o óleo essencial nas concentrações de 782 ppm (técnica de contato e 1000 ppm (técnica de fumigação. Em ambas as técnicas, o óleo essencial inibiu a esporulação a partir da concentração de 500 ppm. Observou-se que nos cinco primeiros dias de incubação não houve diferença significativa nos resultados apresentados pelas duas técnicas estudadas, havendo a partir daí uma redução da atividade do óleo essencial nas concentrações inferiores a 1000 ppm pelo teste de fumigação. A ação fungitóxica do óleo essencial sobre o microrganismo estudado pode ser atribuída à presença do benzaldeído (composto majoritário do óleo essencial estudado, em associação com outros compostos também presentes nesse óleo essencial, tais como; álcool benzílico, benzoato de benzila e mandelonitrila.The present work sought to evaluate the fungitoxic activity of the essential oil from fresh Tanaecium nocturnum fresh leaves on Aspergillus flavus isolated from Brazil nuts, using contact and fumigation techniques. The results of bioassays performed up to 10 days of incubation demonstrated that total inhibition of mycelial growth occurred when using the essential oil at concentrations of 782 ppm (contact technique and 1000 ppm (fumigation technique. In both techniques, the essential oil inhibited the formation of spores at the concentration of 500 ppm. No significant difference in the results presented by the two techniques was observed in the first five days of incubation. After this period, the essential oil showed a reduction in activity at concentrations lower than

  9. Association between Aflatoxin M1 and Liver Disease in HBV/HCV Infected Persons in Ghana

    Directory of Open Access Journals (Sweden)

    Clarrisa Afum

    2016-03-01

    Full Text Available Aflatoxins are produced by the fungi Aspergillus flavus and Aspergillus parasiticus and are common food contaminants in tropical developing countries. Extensive aflatoxin consumption has been shown to be highly associated with liver disease. A case-control study was conducted to determine the association between aflatoxin and liver disease in Kumasi, Ghana. A questionnaire was administered to examine socio-demographic characteristics and food storage and consumption practices, and urine samples were collected to measure levels of the aflatoxin metabolite (AFM1. Two hundred and seventy-six people participated in the study; 38 had liver disease (cases, 136 had neither hepatitis B/C nor liver disease (negative controls, and 102 were hepatitis B/C positive without liver cancer (positive controls. A much higher percent of participants in each group was male (76% of cases, 88% of negative controls and 65% of positive controls. Multivariate analysis showed that age was a significant predictor for being a case when cases were compared to negative controls. The odds of being a case was 70% less for participants aged 25–34 years (odds ratios (OR 0.30; 95% confidence interval (CI 0.10–0.88 compared to those ≥45 years. For cases; Akans were seven times more likely to have AFM1 levels below the median when compared to other ethnic groups (OR 7; CI 1.41–34.68. When cases were compared to positive controls, they were 2.29 times more likely to report awareness of aflatoxin contamination of groundnuts (95% CI 1.06–4.91. Cases were also two times more likely to report awareness of aflatoxin contamination of maize than all controls combined (95% CI 1.02–4.11. However, most cases reported that aflatoxin contamination does not cause sickness in humans. This shows that there is awareness of aflatoxin contamination without proper understanding of the serious potential adverse health impacts among these study participants. These findings indicate that

  10. Rapid detection of aflatoxin producing fungi in food by real-time quantitative loop-mediated isothermal amplification.

    Science.gov (United States)

    Luo, Jie; Vogel, Rudi F; Niessen, Ludwig

    2014-12-01

    Aflatoxins represent a serious risk for human and animal health. They are mainly produced by Aspergillus flavus and Aspergillus parasiticus but also by Aspergillus nomius. Three species specific turbidimeter based real-time LAMP (loop-mediated isothermal amplification) assays were developed to quantify the three species individually in conidial solutions and to define contamination levels in samples of shelled Brazil nuts, maize, and peanuts. Standard curves relating spore numbers to time to threshold (Tt) values were set up for each of the species. Assays had detection limits of 10, 100 and 100 conidia per reaction of A. flavus, A. parasiticus, and A. nomius, respectively. Analysis of contaminated sample materials revealed that the A. nomius specific real-time LAMP assay detected a minimum of 10 conidia/g in Brazil nuts while assays specific for A. flavus and A. parasiticus had detection limits of 10(2) conidia/g and 10(5) conidia/g, respectively in peanut samples as well as 10(4) conidia/g and 10(4) conidia/g, respectively in samples of maize. The real-time LAMP assays developed here appear to be promising tools for the prediction of potential aflatoxigenic risk at an early stage and in all critical control points of the food and feed production chain. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Persistence of Aflatoxin During the Fermentation of Soy Sauce

    Science.gov (United States)

    Maing, Il-Young; Ayres, J. C.; Koehler, P. E.

    1973-01-01

    Aflatoxin was produced by Aspergillus parasiticus NRRL 2999 but not by A. oryzae during fermentation of soy sauce. Little aflatoxin was degraded within 6 weeks unless Lactobacillus delbrueckii also was present. PMID:4736791

  12. Confirmation and Fine Mapping of a Major QTL for Aflatoxin Resistance in Maize Using a Combination of Linkage and Association Mapping

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2016-09-01

    Full Text Available Maize grain contamination with aflatoxin from Aspergillus flavus (A. flavus is a serious health hazard to animals and humans. To map the quantitative trait loci (QTLs associated with resistance to A. flavus, we employed a powerful approach that differs from previous methods in one important way: it combines the advantages of the genome-wide association analysis (GWAS and traditional linkage mapping analysis. Linkage mapping was performed using 228 recombinant inbred lines (RILs, and a highly significant QTL that affected aflatoxin accumulation, qAA8, was mapped. This QTL spanned approximately 7 centi-Morgan (cM on chromosome 8. The confidence interval was too large for positional cloning of the causal gene. To refine this QTL, GWAS was performed with 558,629 single nucleotide polymorphisms (SNPs in an association population comprising 437 maize inbred lines. Twenty-five significantly associated SNPs were identified, most of which co-localised with qAA8 and explained 6.7% to 26.8% of the phenotypic variation observed. Based on the rapid linkage disequilibrium (LD and the high density of SNPs in the association population, qAA8 was further localised to a smaller genomic region of approximately 1500 bp. A high-resolution map of the qAA8 region will be useful towards a marker-assisted selection (MAS of A. flavus resistance and a characterisation of the causal gene.

  13. Evaluation of Nephrotoxic Effects of Aflatoxins on Common Carp (Cyprinus carpio

    Directory of Open Access Journals (Sweden)

    Somayeh Taheri

    2017-02-01

    Full Text Available Background: We investigated the effects of different dose of aflatoxins, secondary toxic metabolites produced by Aspergillus flavus, on some biochemical parameters in kidney of common carp (Cyprinus carpio. Methods: This study was done in Aquaculture and Biology Laboratory of Behbahn Khatam Alanbia University of Technology, Behbahan, Iran in 2015. Fishes were distributed into five groups: Group I-III was fed contaminated diets with 0.5, 0.7 and 1.4 mg kg-1 feed, respectively. Group IV was fed contaminated diets with extraction solution (methanol, acetone, and diluted water as a positive control. Control group received normal feed (Group V. After 21 d of experiment, activities of cellular enzymes and oxidative stress biomarker were evaluated. Results: Aflatoxins (0.7 and 1.4 mg kg-1 caused a significant increase in ALT activity. Although, significant increase of LDH activity (P<0.05 were found in kidney of fish fed diet contaminated with 0.5 mg kg-1 of aflatoxins, LDH activity was significantly decreased in kidney of fish fed diet contaminated with 0.7 and 1.4 mg kg-1 of aflatoxins. A significant increase (P<0.05 were observed in MDA levels and CAT activity in kidney of fish fed diet contaminated with different concentrations of aflatoxins for 21 d. The total antioxidant levels, AST and ALP activities in kidney of fish were significantly reduced (P<0.05 on the 21st day following aflatoxins administration. Conclusion: Diets containing certain concentrations of aflatoxins (0.5, 0.7 and 1.4 mg kg-1 feed made oxidative damage to kidney tissue, including changes in oxidative stress biomarker and biochemical parameters.

  14. Contaminação por Aspergillus flavus e A. fumigatus em sementes de girassol (Helianthus annuus utilizados na alimentação de psitacídeos

    Directory of Open Access Journals (Sweden)

    Alexsandro Machado Conceição

    2010-04-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2010v23n2p145 Amplamente difundido na alimentação de psitacídeos em razão do preço baixo, elevada palatabilidade, e por razões culturais, o Helianthus annuus, conhecido como girassol, vem se mostrando importante na clínica aviária em decorrência do excesso de calorias, e da alta incidência na contaminação por alguns fungos, principalmente do gênero Aspergillus, especificamente A. flavus e A. fumigatus. O objetivo deste estudo foi avaliar a contaminação por Aspegillus ssp. em sementes de girassol destinada à alimentação de psitacídeos comercializadas em Aracaju, estado de Sergipe. As análises foram realizadas no Laboratório de Microbiologia, do Hospital Veterinário Dr. Vicente Borreli, na Faculdade Pio Décimo. Avaliaram-se quatro amostras de sementes de girassol, sendo uma comercializada no mercado público municipal, de forma granel e três marcas comerciais, envasadas e de diferentes hipermercados, processadas segundo Forsythe (2002. De acordo com a pesquisa realizada, foi possível observar um elevado desenvolvimento de A. flavus e A. fumigatus nas sementes de girassol. Esta contaminação pode estar relacionada a vários fatores: colheita e fases de secagem, beneficiamento e armazenamento do grão inadequado. Além disso, é importante destacar a necessidade de que haja um melhor armazenamento de grãos, com controle de temperatura e umidade relativa, visando reduzir a possibilidade de contaminação por Aspergillus spp. que causa prejuízos na alimentação de psitacídeos, e de outras espécies animais.

  15. Aflatoxin, proximate composition and mineral profile of stored broiler feed treated with medicinal plant leaves.

    Science.gov (United States)

    Hassan, S M; Sultana, B; Atta, A; Qureshi, N; Iqbal, M; Abbas, M

    2017-09-01

    In the present investigation, the Morus alba (M. alba), Vitis vinifera (V. vinifera), Ficus religiosa (F. religiosa) and Citrus paradisi (C. paradisi) leaves anti-aflatoxigenic activities were evaluated in Aspergillus flavus (A. flavus) inoculated feed. The broiler feed inoculated with A. flavus was treated with selected medicinal plant leaf powder (5%, 10% and 15% w/w) and stored for the period of six months at 28°C and 16% moisture. The aflatoxins (AFTs) were estimated at the end of each month by Reversed Phase High Performance Liquid Chromatography (RP-HPLC) method along with proximate composition and mineral contents. Plant leaves controlled AFTs efficiently without affecting the feed proximate composition and mineral contents. The M. alba leaves completely inhibition (100%) the AFTs (B1 and B2) in feed at very low concentration (5%). Other plants also showed significant (Pleaves, A. flavus produced AFTs could possibly be controlled in stored poultry feed. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Occurrence of aflatoxin contamination in maize kernels and ...

    African Journals Online (AJOL)

    Occurrence of aflatoxin contamination in maize kernels and molecular characterization of the producing organism, Aspergillus. Muthusamy Karthikeyan, Arumugam Karthikeyan, Rethinasamy Velazhahan, Srinivasan Madhavan, Thangamuthu Jayaraj ...

  17. Occurrence of B1 Aflatoxin in diet and M1 Aflatoxin in bovine milk

    OpenAIRE

    Adriana Frizzarin; Thiago Pereira Motta; Thamires Martins; Livia Castelani; Heloisa Solda de Azevedo; Cláudia Rodrigues Pozzi

    2012-01-01

    Ensuring food quality is one of the principles of food safety. Food for dairy cattle may be contaminated by fungi of the genus Aspergillus, which produce aflatoxins. The B1 aflatoxin, when ingested by animals, is biotransformed in liver in several other toxic metabolites, including M1 aflatoxin which is excreted in milk. M1 aflatoxin has a carcinogenic effect, which the presence in milk poses a serious risk to public health because milk and dairy products are consumed mainly by children, preg...

  18. Production of Aflatoxin on Soybeans

    Science.gov (United States)

    Gupta, S. K.; Venkitasubramanian, T. A.

    1975-01-01

    Probable factors influencing resistance to aflatoxin synthesis in soybeans have been investigated by using cultures of Aspergillus parasiticus NRRL 3240. Soybeans contain a small amount of zinc (0.01 μg/g) bound to phytic acid. Autoclaving soybeans at 15 pounds (6803.88 g) for 15 min increases the aflatoxin production, probably by making zinc available. Addition of zinc to both autoclaved and nonautoclaved soybeans promotes aflatoxin production. However, addition of varying levels of phytic acid at a constant concentration of zinc depresses aflatoxin synthesis with an increase in the added phytic acid. In a synthetic medium known to give good yields of aflatoxin, the addition of phytic acid (10 mM) decreases aflatoxin synthesis. PMID:1171654

  19. Reduction of Aspergillus spp. and aflatoxins in peanut sauce processing by oil-less frying of chilli powder and retort processing.

    Science.gov (United States)

    Farawahida, A H; Jinap, S; Nor-Khaizura, M A R; Samsudin, N I P

    2017-12-01

    Among the many roles played by small and medium enterprises (SMEs) in the food industry is the production of heritage foods such as peanut sauce. Unfortunately, the safety of peanut sauce is not always assured as the processing line is not controlled. Peanut sauce is usually made of peanuts and chilli, and these commodities are normally contaminated with Aspergillus spp. and aflatoxins (AFs). Hence, the objective of this study was to evaluate the practices related to reduction of AF hazard and the effect of interventions in peanut sauce processing. Peanut samples were collected from each step of peanut sauce processing from a small peanut sauce company according to four designs: (1) control; (2) oil-less frying of chilli powder; (3) addition of retort processing; and (4) combination of oil-less frying of chilli powder and retort processing. Oil-less frying of chilli powder (Design 2) reduced total AFs by 33-41%, retort processing (Design 3) reduced total AFs by 49%, while combination of these two thermal processes (Design 4) significantly reduced total AFs, by 57%. The present work demonstrated that Design 4 yielded the highest reduction of total AFs and is therefore recommended to be employed by SME companies.

  20. Study of the Effect of Methyl Jasmonate Concentration on Aflatoxin B1 Biosynthesis by Aspergillus parasiticus in Yeast Extract Sucrose Medium

    Science.gov (United States)

    Meimaroglou, Dido Maria; Galanopoulou, Dia; Markaki, Panagiota

    2009-01-01

    Aflatoxin B1 (AFB1) is a carcinogenic metabolite produced by certain Aspergillus species on agricultural commodities. AFB1 biosynthesis is affected by jasmonic acid and also by its methylester (MeJA), a plant growth regulator derived from linoleic acid. This study reports the effect of MeJA on the growth of A. parasiticus and AFB1 output in yeast extract sucrose (YES) medium when added at three different concentrations; namely, 10−2 M, 10−4 M, and 10−6 M. AFB1 determination was performed by immunoaffinity and HPLC. MeJA at 10−4 and 10−6 M concentrations had no significant effect on mycelial growth but did affect AFB1 production after the 7th day of incubation; on the 12th day, AFB1 production was increased by 212.7% and 141.6% compared to the control samples (addition of 10−6 M and 10−4 M MeJA, resp.). Treatment of A. parasiticus cultures with 10−2 M MeJA inhibited mycelial growth and AFB1 production as well. These results suggest that the effect of MeJA on AFB1 biosynthesis by A. parasiticus depends on the MeJA concentration used. PMID:20016812

  1. Study of the Effect of Methyl Jasmonate Concentration on Aflatoxin B1 Biosynthesis by Aspergillus parasiticus in Yeast Extract Sucrose Medium

    Directory of Open Access Journals (Sweden)

    Panagiota Markaki

    2009-01-01

    Full Text Available Aflatoxin B1 (AFB1 is a carcinogenic metabolite produced by certain Aspergillus species on agricultural commodities. AFB1 biosynthesis is affected by jasmonic acid and also by its methylester (MeJA, a plant growth regulator derived from linoleic acid. This study reports the effect of MeJA on the growth of A. parasiticus and AFB1 output in yeast extract sucrose (YES medium when added at three different concentrations; namely, 10−2 M, 10−4 M, and 10−6 M. AFB1 determination was performed by immunoaffinity and HPLC. MeJA at 10−4 and 10−6 M concentrations had no significant effect on mycelial growth but did affect AFB1 production after the 7th day of incubation; on the 12th day, AFB1 production was increased by 212.7% and 141.6% compared to the control samples (addition of 10−6 M and 10−4 M MeJA, resp.. Treatment of A. parasiticus cultures with 10−2 M MeJA inhibited mycelial growth and AFB1 production as well. These results suggest that the effect of MeJA on AFB1 biosynthesis by A. parasiticus depends on the MeJA concentration used.

  2. Chemical Composition and Antifungal Activity of Cuminum cyminum L. Essential Oil From Alborz Mountain Against Aspergillus species

    Science.gov (United States)

    Mohammadpour, Hossein; Moghimipour, Eskandar; Rasooli, Iraj; Fakoor, Mohammad Hadi; Alipoor Astaneh, Shakiba; Shehni Moosaie, Sara; Jalili, Zeynab

    2012-01-01

    Background Aflatoxin B1 (AFB1) is a highly toxic and hepatocarcinogenic metabolite produced by Aspergillus species. Some natural products are known to kill fungi and destroy toxins and toxin-producing agents. Objectives The purpose of this study is to provide experimental data on the antifungal activity of cumin oils and their components that could be considered suitable for application in foods and drugs. Materials and Methods The essential oil (EO) of Cuminum cyminum L. collected from Alborz Mountain, Iran, was obtained by hydro-distillation. The oil was analyzed by gas chromatography (GC) and chromatography/mass spectrophotometry (GC/MS). The antifungal activity of the oil was studied with regard to the inhibition of the growth of Aspergillus flavus PICC-AF39 , Aspergillus flavus PICC-AF24, Aspergillus parasiticus NRRL-2999 and Aspergillus niger. The minimal inhibitory (MIC) and minimal fungicidal (MFC) concentrations of the oil were determined. Results α–Pinene (29.2%), limonene (21.7%), 1,8-cineole (18.1%), linalool (10.5%), linalyl acetate (4.8%), and α-terpineole (3.17%) were the major components of the essential oil from C. cyminum L., and the oil showed a strong inhibitory effect on fungal growth. Conclusions Essential oils could be safely used as preservatives in pharmaceuticals as well as health and food products to protect them against toxigenic fungal infections. PMID:24624154

  3. [Aflatoxins--health risk factors].

    Science.gov (United States)

    Miliţă, Nicoleta Manuela; Mihăescu, Gr; Chifiriuc, Carmen

    2010-01-01

    Aflatoxins are secondary metabolites produced by a group of strains, mainly Aspergillus and Penicillium species. These mycotoxins are bifurano-coumarin derivatives group with four major products B1, B2, G1 and G2 according to blue or green fluorescence emitted in ultraviolet light and according to chromatographic separation. After metabolism of aflatoxin B1 and B2 in the mammalian body, result two metabolites M1 and M2 as hydroxylated derivatives of the parent compound. Aflatoxins have high carcinogenic potential, the most powerful carcinogens in different species of animals and humans. International Agency for Research on Cancer has classified aflatoxin B1 in Group I carcinogens. The target organ for aflatoxins is the liver. In chronic poisoning, aflatoxin is a risk to health, for a long term causing cancer (hepatocellular carcinoma), and in acute intoxications aflatoxin is lethal. This work purpose to discuss aflatoxins issue: the synthesis, absorption and elimination of aflatoxins, the toxicity mechanisms, and measures to limit the content of aflatoxins in food

  4. Selected plant essential oils and their main active components, a promising approach to inhibit aflatoxigenic fungi and aflatoxin production in food.

    Science.gov (United States)

    Gómez, José Vicente; Tarazona, Andrea; Mateo-Castro, Rufino; Gimeno-Adelantado, José Vicente; Jiménez, Misericordia; Mateo, Eva M

    2018-01-17

    Recent research has showed that Aspergillus flavus and Aspergillus parasiticus are aflatoxigenic species that can become very competitive in the framework of climate change. Aflatoxins show carcinogenic, mutagenic, immunotoxic and teratogenic effects on human and animals. Effective and sustainable measures to inhibit these species and aflatoxins in food are required. Origanum vulgare and Cinnamomum zeylanicum essential oils (EOs) and their major active constituents, carvacrol and cinnamaldehyde, respectively, were assayed for inhibiting these species and aflatoxin production in maize extract medium under different environmental conditions. Doses of 10-1000 mg l -1 were assayed and the effective doses for 50 (ED 50 ) and 90% (ED 90 ) growth inhibition were determined. The ED 50 of cinnamaldehyde, carvacrol, oregano EO, and cinnamon EO against A. flavus were in the ranges 49-52.6, 98-145, 152-505, 295-560 mg l -1 and against A. parasiticus in the ranges 46-55.5, 101-175, 260-425 and 490-675 mg l -1 , respectively, depending on environmental conditions. In A. flavus treatments ED 90 were in the ranges 89.7-90.5, 770-860 and 820->1000 mg l -1 for cinnamaldehyde, carvacrol and cinnamon EO, and in A. parasiticus treatments in the ranges 89-91, 855->1000 and 900->1000 mg l -1 , respectively. ED 90 values for oregano EO against both species were >1000 mg l -1 . Growth rates of both species were higher at 37 than at 25°C and at 0.99 than at 0.96 a w . Aflatoxin production was higher at 25 than at 37°C. Stimulation of aflatoxin production was observed at low doses except for cinnamaldehyde treatments. The effectiveness of EOs and their main constituents to inhibit fungal growth and aflatoxin production in contact assays was lower than in vapour phase assays using bioactive EVOH-EO films previously reported.

  5. Efficacy of chemically characterized Foeniculum vulgare Mill seed essential oil in protection of raw tobacco leaves during storage against fungal and aflatoxin contamination.

    Science.gov (United States)

    Kedia, A; Dwivedy, A K; Pandey, A K; Kumar, R R; Regmi, P; Dubey, N K

    2015-10-01

    To report fungal and aflatoxin contamination in stored tobacco leaves and the potential of Foeniculum vulgare (fennel) seed essential oil (EO) as a plant-based preservative in protection of tobacco during storage. Mycological analysis of tobacco samples was done by surface sterilization and serial dilution tests. The Aspergillus flavus isolates were screened for their toxigenicity. Both in vivo and in vitro tests were done to evaluate antifungal and antiaflatoxigenic efficacy of chemically characterized EO. The mycoflora analysis revealed 108 fungal colonies belonging to five genera and nine species. All A. flavus isolates were found aflatoxigenic during screening. Gas chromatography and mass spectrometry analysis of EO identified 19 components (99·66%); estragole being the major component (47·49%). The EO showed broad fungitoxicity at 1·25 μl ml(-1) and 100% inhibition to AFB1 production as well as ergosterol synthesis at 1·0 μl ml(-1) concentration. EO showed 100% protection of stored tobacco samples from aflatoxin B1 contamination. The fennel EO can thus be formulated as a plant-based preservative for food items. The present investigation comprises the first report on antiaflatoxin efficacy of fennel oil and its potency in the protection of tobacco leaves from fungal and aflatoxin contamination during storage. © 2015 The Society for Applied Microbiology.

  6. Hepatitis infections, aflatoxin and hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Pierre Hainaut

    2007-02-01

    Full Text Available

    The incidence rates of hepatocellular carcinoma (HCC show large geographic variations, globally reflecting the prevalence of two main aetiologic factors, hepatitis B (HBV and/or C (HCV virus infection and exposure to high levels of aflatoxin in the diet (Chen et al. 1997. The highest incidence rates are observed in regions where most of the population is exposed to both factors, such as in parts of eastern Asia and in sub-Saharan Africa (Parkin et al. 2001. These high incidences are consistent with the fact that HBV chronicity and exposure to aflatoxin have a multiplicative effect of risk for HCC. Depending on aetiology and geographic area, mutations in TP53 show striking differences in prevalence and pattern. In Europe and the US, where alcohol is a major risk factor in addition to viral infections, mutations occur in about 25% of HCC and show as much diversity in their type and codon position as in most other epithelial cancers. However, in high incidence areas such as Mozambique, Senegal, The Gambia (Africa and Qidong county (China, TP53 is mutated in over 50% of the cases and the vast majority of these mutations are a single missense, hotspot mutation at codon 249, AGG to AGT, resulting in the substitution of arginine into serine (249ser. This mutation is uncommon in regions where aflatoxin is not present at significant levels in the diet. In areas of intermediate exposure to aflatoxin, as for example in Thailand, the prevalence of the 249ser mutation is intermediate between high- and low-incidence areas. Thus, there is a dose-dependent relationship between exposure to aflatoxin, incidence of HCC and prevalence of 249ser mutation. Aflatoxins are toxic and carcinogenic metabolites produced by several varieties of molds, mainly Aspergillus flavus and Aspergillus parasiticum. These molds contaminate a wide range of traditional agricultural products in countries

  7. Movilidad de Aspergillus flavus link ex fries en mazorcas de cinco genotipos de maiz (Zea Mays L. empleando tres métodos de inoculación (ING

    Directory of Open Access Journals (Sweden)

    Néstor Villalobos

    2016-03-01

    Full Text Available Three inoculation techniques for evaluating reaction of corn to kernel infection by Aspergillus flavus were tested in the field of five different genotypes. Inoculations were made 20 days after midsilk stage, using 0.5 ml of 105 conidial suspensions. The methods were: a injection of small amounts of inoculum in each kernel of a vertical row (M1; b injection in the first well developed kernels around the top part of the ear (M2; c injection of inoculum in the kernels at the lower part of the ear, forming a semicircle (M3. Two weeks after inoculation ears were harvested, and kernels not wounded were separated according to its position to the inoculated kernels, then surface sterilized and planted on PDA, to determine the infection percentage. M1 and M2 were found very efficient because they produced higher infection levels. M1 is considered the best because it provided a larger number of kernels for assay and was easy to use. No statistical difference was found among genotypes.

  8. Occurrence of aflatoxins in oilseeds providing cocoa-butter substitutes.

    Science.gov (United States)

    Kershaw, S J

    1982-01-01

    Four oilseeds providing cocoa-butter substitutes--shea, pentadecima, illipe, and salseed--when tested as substrates for aflatoxin production by two strains of Aspergillus parasiticus, gave varying levels of aflatoxin. Aflatoxins were found at low levels occurring naturally in moldy shea-nuts, but none of 21 commercial shea-nut samples contained greater than 20 micrograms of aflatoxin B1 per kg. PMID:6808919

  9. Mycoflora and Aflatoxin levels of Left-over Harvest in some Farms, South West of Nigeria

    Directory of Open Access Journals (Sweden)

    Flora Oluwafemi

    2015-08-01

    Full Text Available More than ninety percent of the ruminant livestock in Nigeria lies in the hands of herders who keep them under extensive and semi-intensive management systems, whereby the animals rely only on natural pasture and crop residues for survival. In this work, the mycoflora and aflatoxin levels of ten farms were determined by sampling crop residues on farms grazed by cattle. Samples of the remains of farm harvest were surface-disinfected and cultured using standard microbiological techniques while aflatoxins in the left over harvest were determined using High Performance Liquid Chromatography (HPLC with fluorescence detection. Fungal counts in leftover harvest ranged from 1.2 x 106 to 3.8 x106cfu/g. Aspergillus flavus, A. terreus, A.parasiticus, Rhizopus sp and a yeast, Candida sp were most prevalent on all the investigated crop residues. Aflatoxin B1 (AFB1 on the crop residues ranged between 3.0 and 13.30 μg/Kg, while the levels of AFG1 were between 2.30 and 4.50 μg/Kg. Results of the present study is indicative that the accumulation of these doses of AFB1 can lead to transfer of AFB1 into cattle and subsequently into milk. So there is an urgent need to control the feeding pattern of cattle in order to protect the health of the consuming public.

  10. Influência da calagem, da época de colheita e da secagem na incidência de fungos e aflatoxinas em grãos de amendoim armazenados Storage peanut kernels fungal contamination and aflatoxin as affected by liming, harvest time and drying

    Directory of Open Access Journals (Sweden)

    Claudia Antonia Vieira Rossetto

    2005-04-01

    Full Text Available O objetivo deste trabalho foi avaliar a contaminação e o potencial para síntese de aflatoxinas pelos isolados do grupo Aspergillus flavus em grãos armazenados de amendoim (Arachis hypogaea L., que foram produzidos com distintos procedimentos de calagem, de colheita e de secagem. Para isto, foram avaliadas doze amostras de grãos de amendoim, cv. Botutatu, provenientes de plantas cultivadas em área que recebeu ou não a aplicação de calcário, colhidas aos 104, 114 e 124 dias após a semeadura e secas em condições ambientais e em estufa. Aos 12 e 18 meses de armazenamento, os grãos foram tratados com hipoclorito de sódio e incubados em BDA, a 20°C, por cinco dias. As espécies do grupo Aspergillus flavus foram identificadas após incubação em meio ADM. Posteriormente, o potencial toxígeno foi avaliado pelo método da cromatografia de camada delgada. A análise da freqüência de fungos revelou que os grãos de amendoim armazenados estavam contaminados por Aspergillus spp., Penicillium spp. e Fusarium spp. Os grãos de amendoim, provenientes da colheita antecipada, apresentaram maior contaminação pelo grupo Aspergillus flavus, sendo menor a proporção destes com potencial toxígeno.The objective of this work was to evaluate the effect of the storage on the potential of aflatoxin production by isolates from Aspergillus flavus group in peanut (Arachis hypogaea L.. These kernels were obtained from a field experiment with two areas (with or without lime, three times of harvest (104, 114 and 124 days after planting and two types of dryer conditions (ambient and chamber with forced air. After 12 and 18 months of storage, the kernels were treated with sodium hypochloride and incubated in a PDA at 20°C during five days. The isolates from Aspergillus flavus group were identified after incubation in ADM culture medium. The toxigenic potential was analyzed by thin layer chromatography. The genera detected were Aspergillus, Penicillium and

  11. Aflatoxin B1 invokes apoptosis via death receptor pathway in hepatocytes.

    Science.gov (United States)

    Mughal, Muhammad Jameel; Xi, Peng; Yi, Zhou; Jing, Fang

    2017-01-31

    The fungal metabolites produced by Aspergillus flavus and Aspergillus parasiticus cause detrimental health effects on humans and animals. Particularly aflatoxin B1 (AFB1) is the most studied and a well-known global carcinogen, producing hepatotoxic, genotoxic and immunotoxic effects in multiple species. AFB1 is shown to provoke liver dysfunctioning by causing hepatocytes apoptosis and disturbing cellular enzymatic activities. In liver, AFB1 causes apoptosis via extrinsic mechanism because of high expression of death receptor pathway. The detailed mechanism of AFB1 induced hepatocytes apoptosis, via death receptor pathway still remains elusive. So the present study was conducted to explore apoptotic mechanism initiated by death receptors and associated genes in aflatoxin B1 induced liver apoptosis in chickens fed with AFB1 for 3 weeks. Results from the present study displayed histopathological and ultrastructural changes in liver such as hydropic degeneration, fatty vacuolar degeneration and proliferation of bile duct in hepatocytes in AFB1 group, along with imbalance between reactive oxygen species (ROS) and antioxidant defense system upon AFB1 ingestion. Moreover, AFB1 intoxicated chickens showed upregulation of death receptors FAS, TNFR1 and associated genes and downregulation of inhibitory apoptotic proteins XIAP and BCL-2. The results obtained from this novel and comprehensive study including histopathological, ultrastructural, flow cytometrical and death receptor pathway gene expression profiles, will facilitate better understanding of mechanisms and involvement of death receptor pathway in hepatocytes apoptosis induced by AFB1 and ultimately may be helpful in bringing down the toxigenic potential of AFB1.

  12. Adaptation and mitigation options to manage aflatoxin contamination in food with a climate change perspective

    DEFF Research Database (Denmark)

    Wambui, J. M.; Karuri, E. G.; Ojiambo, J. A.

    2016-01-01

    for an integrated management of aflatoxins in a changing climate was proposed. The management practices in the framework are divided into agronomic, post-harvest and institutional levels. Given the multiple points of application, coordination amongst stakeholders along the chain is fundamental. We therefore......Understanding the impact of climate change remains vital for food safety and public health. Of particular importance is the influence of climatic conditions on the growth of Aspergillus flavus and production of their toxins. Nevertheless, little is known about the actual impact of climate change...... on the issue. Setting up of relevant measures to manage the impact has therefore become a daunting task especially in developing nations. Therefore, this study aimed at providing adaptation and mitigation options to manage this risk with a special focus on Kenya where cases of aflatoxicosis have been recurrent...

  13. Development and evaluation of an up-converting phosphor technology-based lateral flow assay for rapid and quantitative detection of aflatoxin B1 in crops.

    Science.gov (United States)

    Zhao, Yong; Liu, Xiao; Wang, Xiaochen; Sun, Chongyun; Wang, Xinrui; Zhang, Pingping; Qiu, Jingfu; Yang, Ruifu; Zhou, Lei

    2016-12-01

    Contamination of grains and other crops by aflatoxin B1 (AFB1), a highly toxic aflatoxin produced by Aspergillus flavus and Aspergillus parasiticus, poses a serious threat to human health and is an important food safety issue. In this study, a competitive up-converting phosphor technology-based lateral flow (AFB1-UPT-LF) assay was developed for rapid detection of AFB1. Detection sensitivity of the proposed assay can reach 0.03ngmL -1 for standard AFB1 solutions, with the coefficients of variation (CV) less than 10% (from 1.0 to 9.4%). A good linearity (r=0.9889) was observed for quantification of AFB1 from 0.03 to 1000ngmL -1 . Except for aflatoxin M1, no cross-reactivity was found with the abrin, ricin, ochratoxin A, botulinum toxin, shiga toxin 1, shiga toxin 2, and staphylococcal enterotoxin B, even at high concentrations of 100 or 1000ngmL - 1 . After optimizing the extraction of AFB1, the assay showed good tolerance to various crop samples, with the detection limit (from 0.1 to 5ngg - 1 ) lower than the corresponding maximum residue level (MRL) set in China. The AFB1-UPT-LF assay provides a promising tool for rapid on-site detection of AFB1 because of its high sensitivity, specificity, and sample tolerance. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Contaminação endógena por Aspergillus spp. em milho pós-colheita no Estado do Paraná Endogenous Aspergillus spp. contamination of postharvest corn in Paraná State, Brazil

    Directory of Open Access Journals (Sweden)

    ANTONIO XAVIER DE FARIAS

    2000-03-01

    metabolics in peanut agar medium and in wheat grits. The kernel contamination varied from 0 to 100% and the prevalent genera detected were Aspergillus, Penicillium and Fusarium. A. flavus was the predominant species (64%, followed by E. amstelodami (19%, E. chevalieri (10% and A. parasiticus (7%. From 109 A. flavus species isolated, 73 strains synthesized aflatoxins B1 and B2, 20 synthesized B1, seven synthesized B1 and G1, three synthesized B1, B2 and G1 and in six strains aflatoxin production was not detected. All A. parasiticus species produced, simultaneously, B1, B2, G1 and G2. Sterigmatocystin synthesis was not detected in any condition by E. amstelodami and E. chevalieri.

  15. Effect of gamma radiation on the inactivation of aflatoxin B1 in food and feed crops Efeito da radiação gama na inativação de aflatoxina B1 em alimentos e ração

    OpenAIRE

    Ghanem, I.; Orfi, M.; Shamma, M

    2008-01-01

    Samples of food crops (peanut, peeled pistachio, unpeeled pistachio, rice, and corn) and feed (barley, bran, corn) were autoclave-sterilized, and inoculated with 10(6) of spore suspension of an isolate of Aspergillus flavus fungus known to produce aflatoxin B1 (AFB1) . Following a 10-day period of incubation at 27 C to allow for fungal growth, food and feed samples were irradiated with gamma radiation at the doses 4, 6, and 10 kGy. Results indicated that degradation of AFB1 was positively cor...

  16. On-Farm Demonstrations with a Set of Good Agricultural Practices (GAPs Proved Cost-Effective in Reducing Pre-Harvest Aflatoxin Contamination in Groundnut

    Directory of Open Access Journals (Sweden)

    Vijayaraju Parimi

    2018-01-01

    Full Text Available Aflatoxin contamination in groundnut is an important qualitative issue posing a threat to food safety. In our present study, we have demonstrated the efficacy of certain good agricultural practices (GAPs in groundnut, such as farmyard manure (5 t/ha, gypsum (500 kg/ha, a protective irrigation at 90 days after sowing (DAS, drying of pods on tarpaulins after harvest in farmers’ fields. During 2013–2015, 89 on-farm demonstrations were conducted advocating GAPs, and compared with farmers’ practices (FP plots. Farmers’ awareness of GAPs, and knowledge on important aspects of groundnut cultivation, were also assessed during our experimentation in the selected villages under study. Pre-harvest kernel infection by Aspergillus flavus, aflatoxin contamination, and pod yields were compared in GAPs plots, vis-à-vis FP plots. The cost of cultivation in both the plots was calculated and compared, based on farmer’s opinion surveys. Results indicate kernel infections and aflatoxins were significantly lower, with 13–58% and 62–94% reduction, respectively, in GAPs plots over FP. Further, a net gain of around $23 per acre was realized through adoption of GAPs by farmers besides quality improvement of groundnuts. Based on our results, it can be concluded that on-farm demonstrations were the best educative tool to convince the farmers about the cost-effectiveness, and adoptability of aflatoxin management technologies.

  17. Effect of powdered spice treatments on mycelial growth, sporulation and production of aflatoxins by toxigenic fungi Efeito de tratamentos com condimentos em pó sobre o crescimento micelial, esporulação e produção de aflatoxinas por fungos toxigênicos

    Directory of Open Access Journals (Sweden)

    Sára Maria Chalfoun

    2004-08-01

    Full Text Available The effect of ten powdered spice plants was evaluated at the concentration of 1, 2, 3 and 4% to observe the mycelial growth and sporulation of Aspergillus niger and Eurotium repens. The spices were added to the culture media PDA and CYA20S. Clove completely inhibited the mycelial growth of the tested fungi. The other spices: cinnamon, garlic, thyme, mint, anis, oregano and onion were, in a decreasing order, promising antifungals. Bay leaf and basil did not show a pronounced fungistatic effect. The antitoxigenic potential of the spices was tested against one aflatoxin-producing strain of AspergiIIus flavus. The spices were tested at the same concentrations previously mentioned and were added to the culture medium YES, appropriate for the production of those metabolites. Clove completely inhibited the mycelial growth of Aspergillus flavus. Cinnamon and anis totally inhibited the production of Bl and B2 aflatoxin. Both bay leaf and basil inhibited the synthesis of aflatoxin starting from the concentration of 2%. The other spices did not have a pronounced antiaflatoxigenic effect.O efeito de dez plantas condimentares em pó foi avaliado nas concentrações de 1, 2, 3 e 4%, para observar o desenvolvimento micelial e esporulação de Aspergillus niger e Eurotium repens. Os condimentos foram adicionados aos meios de cultura BDA e CYA 20S. O cravo inibiu completamente o desenvolvimento micelial dos fungos testados. Os outros condimentos: canela, alho, tomilho, menta, erva-doce, orégano e cebola foram, em ordem decrescente, antifúngicos promissores. Louro e manjericão não apresentaram um efeito fungistático pronunciado. O potencial antitoxigênico dos condimentos foi testado contra uma cepa de Aspergillus flavus, produtora de aflatoxina. Os condimentos foram testados nas mesmas concentrações previamente mencionadas e foram adicionados ao meio de cultura YES, apropriado para a produção daqueles metabólitos. O cravo inibiu completamente o

  18. Efficacy of corn silage inoculants on the fermentation quality under farm conditions and their influence on Aspergillus parasitucus, A. flavus and A. fumigatus determined by q-PCR.

    Science.gov (United States)

    Dogi, Cecilia A; Pellegrino, Matías; Poloni, Valeria; Poloni, Luis; Pereyra, Carina M; Sanabria, Analía; Pianzzola, María Julia; Dalcero, Ana; Cavaglieri, Lilia

    2015-01-01

    Laboratory-scale silos were prepared to evaluate the efficacy of two different lactic acid bacteria (LAB) on the fermentation quality and mycobiota of corn silage. Their influence on Aspergillus species' variability by using the q-PCR technique was studied. Silage inoculated with Lactobacillus rhamnosus RC007 or L. plantarum RC009 were compared with uninoculated silage. Silos were opened after 1, 7, 45, 90 and 120 days after ensiling. At the end of the ensiling period, silos were left open for 7 days to evaluate aerobic stability. Rapid lactic acid production and decline in pH values were seen in the early stages of fermentation in silage inoculated with L. rhamnosus RC007. After aerobic exposure, a significant decline in lactic acid content was observed in untreated and L. plantarum RC009-inoculated silages. Counts for yeasted and toxigenic fungus remained lower, after aerobic exposure, in L. rhamnosus RC007-inoculated silage, in comparison with L. plantarum RC009 and uninoculated silages. Comparing the influence exerted by both BAL, it was observed that L. rhamnosus RC007 was more efficient at inhibiting the three fungal species tested whose DNA concentrations, determined by q-PCR, oscillated near the initial value (pre-ensiling maize). The ability of L. rhamnosus RC007 to produce lactic acid rapidly and the decline in pH values in the early stages of the fermentation along with the reduction of yeast and mycotoxicogenic fungus after aerobic exposure shows its potential as a bio-control inoculant agent in animal feed.

  19. [Investigation of aflatoxin M1 levels in raw and market milks in Mersin Province, Turkey].

    Science.gov (United States)

    Delialioğlu, Nuran; Otağ, Feza; Ocal, N Didem; Aslan, Gönül; Emekda, Görol

    2010-01-01

    Aflatoxin M1 (AFM1) which is produced by some Aspergillus species, mainly Aspergillus flavus, is the hydroxylated metabolite of aflatoxin B1 (AFB1) and can be found in milk and dairy products of livestock fed with contaminated feed. AFM1 is a potential threat to human health owing to its toxic and carcino- genic effects. This study was aimed to investigate the level of AFM1 in raw and ultra-high-temperature pasteurized (UHT) milk samples. A total of 137 milk specimens (39 from goats, 53 from cows, and 45 from UHT marketmilks) were included to the study, and AFM1 levels were analyzed by high performance liquid chromatography (HPLC; Aflaprep M immunoaffinity column; R-Biopharm Rhone Ltd., Glasgow) method. AFM1 positivity was detected in 14 (35.8%) goat milk samples, in 46 (86.7%) cow milk samples and 33 (73.3%) UHT milk samples, with the levels ranging from 0.0021 microg/l to 0.8666 microg/I in raw milk, and from 0.001 microg/I to 0.059 microg/I in UHT milk samples. In 10.2% (4/39) of goat milk, 73.5% (39/53) of cow milk, and 2.2% (1/45) of UHT milk samples, the toxin levels were found to be above the officially reasonable limit value (> 0.05 microg/l) recommended by Turkish Food Codex Regulation. Since AFM1 levels were found to be significantly high in the raw milk samples collected in Mersin province (located on Mediterranean part of Turkey), it was concluded that people dealing with feed, milk and dairy products should be informed about the importance of aflatoxins and the preventive measures to get protected from AFB1 and AFM1.

  20. Characterization of Aspergillus species associated with ...

    African Journals Online (AJOL)

    Results also reveal that only A. flavus showed amplification with all the three aflatoxigenic primers apa-2, ver-1 and omt-1, which means that only A. flavus was identified as aflatoxigenic and other Aspergillus species as non-toxigenic after PCR analysis. Hence, morphological, microscopic and molecular methods are ...

  1. Aflatoxins and fumonisins in rice and maize staple cereals in Northern Vietnam and dietary exposure in different ethnic groups

    DEFF Research Database (Denmark)

    Bui, Huong Mai; Tuyen, Le Dahn; Do, Tran Thanh

    2016-01-01

    risk factors for AF’s and FB contamination. Based on daily food consumption data, the estimated average exposure dose of aflatoxin B1(AFB1) from rice was 21.7 ng/kg bw/day for adults and 33.7 ng/kg bw/day for children. For FB, the rice based average exposure amounted to 536 ng/kg bw/day for adults......Mycotoxins in food are increasingly a food safety hazard concern in particular in developing countries. This study was performed to determine the occurrence and determinants of aflatoxin and fumonisin contamination in rice and maize and to assess health risks through dietary intake exposure among...... ethnic minority groups in northern Vietnam. A total of 111 rice and 102 maize samples, were tested for occurrence of fungi and mycotoxins, i.e. aflatoxins (AF’s) and fuminisin B (FB). Results showed that 107 (96.4%) rice and 84 (82.4%) maize samples were contaminated by fungi. Aspergillus flavus...

  2. Enzymatic Formation of G-Group Aflatoxins and Biosynthetic Relationship between G- and B-Group Aflatoxins

    Science.gov (United States)

    Yabe, Kimiko; Nakamura, Miki; Hamasaki, Takashi

    1999-01-01

    We detected biosynthetic activity for aflatoxins G1 and G2 in cell extracts of Aspergillus parasiticus NIAH-26. We found that in the presence of NADPH, aflatoxins G1 and G2 were produced from O-methylsterigmatocystin and dihydro-O-methylsterigmatocystin, respectively. No G-group aflatoxins were produced from aflatoxin B1, aflatoxin B2, 5-methoxysterigmatocystin, dimethoxysterigmatocystin, or sterigmatin, confirming that B-group aflatoxins are not the precursors of G-group aflatoxins and that G- and B-group aflatoxins are independently produced from the same substrates (O-methylsterigmatocystin and dihydro-O-methylsterigmatocystin). In competition experiments in which the cell-free system was used, formation of aflatoxin G2 from dihydro-O-methylsterigmatocystin was suppressed when O-methylsterigmatocystin was added to the reaction mixture, whereas aflatoxin G1 was newly formed. This result indicates that the same enzymes can catalyze the formation of aflatoxins G1 and G2. Inhibition of G-group aflatoxin formation by methyrapone, SKF-525A, or imidazole indicated that a cytochrome P-450 monooxygenase may be involved in the formation of G-group aflatoxins. Both the microsome fraction and a cytosol protein with a native mass of 220 kDa were necessary for the formation of G-group aflatoxins. Due to instability of the microsome fraction, G-group aflatoxin formation was less stable than B-group aflatoxin formation. The ordA gene product, which may catalyze the formation of B-group aflatoxins, also may be required for G-group aflatoxin biosynthesis. We concluded that at least three reactions, catalyzed by the ordA gene product, an unstable microsome enzyme, and a 220-kDa cytosol protein, are involved in the enzymatic formation of G-group aflatoxins from either O-methylsterigmatocystin or dihydro-O-methylsterigmatocystin. PMID:10473388

  3. Thermolysed and active yeast to reduce the toxicity of aflatoxin Formas termolisada e viva de leveduras na redução de toxicidade causada por aflatoxinas

    Directory of Open Access Journals (Sweden)

    Antonio Sampaio Baptista

    2002-06-01

    Full Text Available Aflatoxins are hepatotoxic metabolites produced by Aspergillus flavus and A. parasiticus on a number of agricultural commodities. This research was carried out to evaluate the ability of thermolysed and active Saccharomyces cerevisiae to attenuate liver damage caused by aflatoxin. Diets were prepared containing 0 aflatoxin; 400 mug kg-1 aflatoxin; 400 mug kg-1 aflatoxin plus 1% of dehydrated active yeast, and 400 mug kg-1 aflatoxin plus 1% of thermolysed yeast. A bioassay with Wistar rats was conducted for 28 days, and body organs were weighted and analyses of the liver tissue of the animals were performed. The relative weight of heart, kidneys and liver from animals submitted to the different treatments did not show any difference, and liver tissue of animals feeding on the aflatoxin-free diet was adopted as a toxicity-free pattern. Hepatic tissue of animals feeding on diets containing 400 mug kg-1 aflatoxin or the diet supplemented with 1% thermolysed yeast showed clear signs of toxicity and damage. Hepatic tissue of animals feeding on the diet containing 1% of dehydrated active yeast showed less toxicity signs and damage than those receiving the diet containing 400 mug kg-1 aflatoxin. Active, dehydrated yeast had the ability to reduce toxic effects caused by aflatoxin, but thermolysed yeast was not able to alleviate the effects of aflatoxin toxicity.As aflatoxinas são metabólitos hepatotóxicos produzidos por algumas linhagens de Aspergillus flavus, A. parasiticus e, eventualmente, por A. nomius sobre grande número de produtos agrícolas. Esta pesquisa foi conduzida para avaliar a capacidade de Saccharomyces cerevisiae, nas formas termolisada e desidratada viva, em reduzir os danos causados por aflatoxinas. Para tal, foi preparada uma dieta básica e desta se obtiveram quatro formulações: uma como controle; as demais contaminadas com aflatoxinas na concentração de 400 mig kg-1, sendo duas com posterior adição de 1% de leveduras, uma

  4. Aspergillus species as mycotoxin producers in agricultural products in central Europe

    Directory of Open Access Journals (Sweden)

    Kočube Šandor

    2013-01-01

    Full Text Available Aspergillus species are able to produce a range of mycotoxins, includ­ing e.g. aflatoxins, ochratoxins, fumonisins and patulin. Aflatoxins are mainly produced by members of Aspergillus section Flavi, and they contaminate various agricultural products in several parts of the world. Several recent reports have indicated that aflatoxin-producing fungi and consequently aflatoxin contamination occur in agricultural commodities in a number of European countries which have not been faced with this problem before. Indeed, recent surveys have clarified that concentrations of aflatoxins in maize products and milk has been exceeding the EU limit in several regions of Central Europe including Serbia, Slovenia, Croatia, Northern Italy and Romania. However, aflatoxin contamination and aflatoxin-producing Aspergillus species have not been identified yet in maize in Hungary. We examined the presence of potential aflatoxin-producing Aspergilli in maize samples collected in southern parts of Hungary. Several A. flavus isolates were identified, and pre­liminary results indicated that some of the isolates were able to produce aflatoxins. Con­tamination of other agricultural products with aflatoxins can also pose problems in Central Europe due to global warming. Ochratoxin contamination of grapes and grape-derived products is usually caused by black Aspergilli, especially by A. carbonarius and A. niger, although these species have been rare in Central European vineyards due to climatic fac­tors. Ochratoxin contamination of other agricultural products including spices and cereals was also observed in the region. Besides, ochratoxin producing Aspergilli are frequently isolated from imported products including coffee beans, dried fruits and spices, and ochra­toxin contamination of these samples was also observed. Fumonisins are produced mainly by Fusarium species, and by the recently identified producers Aspergillus niger and A. awamori. We examined fumonisin

  5. Survey of aflatoxins in tomato products Aflatoxinas em produtos de tomate

    Directory of Open Access Journals (Sweden)

    Lilian Regina Barros Mariutti

    2009-06-01

    Full Text Available Tomatoes are highly susceptible to fungi contamination in the field, during transportation, processing, and storage. Aspergillus flavus and Aspergillus parasiticus have been isolated from tomatoes and tomato products, and both fungi species can produce aflatoxin, mycotoxin with hepatotoxic, carcinogenic, teratogenic, and mutagenic effects on all animal species tested so far. In order to verify a possible aflatoxin contamination of tomato products commercialized in Brazil, 63 samples of tomato products (pulp, paste, purée, ketchup, dehydrated tomatoes, and dried tomatoes preserved in oil produced in 5 Brazilian states and 1 imported sample (ketchup, totalizing 29 brands, were analyzed by thin layer chromatography. The analytical method showed an average recovery of 86% for all aflatoxins at two spiking levels. The limits of detection for the aflatoxins B1, B2, G1, and G2 varied with the type of the product ranging from 2 to 7 µg/kg. Aflatoxins were not detected in any evaluated sample indicating that they did not pose a risk to human health since there was no invasion of raw materials by toxigenic fungi or no conditions for toxin production.Os tomates são frutos altamente susceptíveis à contaminação fúngica tanto no campo como durante o transporte, processamento e armazenamento. Aspergillus flavus e Aspergillus parasiticus têm sido isolados em tomate e em produtos de tomate e ambas as espécies são produtoras de aflatoxinas, potentes micotoxinas que apresentam efeitos hepatotóxicos, carcinogênicos, teratogênicos e mutagênicos para todas as espécies animais testadas até o momento. Para verificar a possível contaminação por estas micotoxinas em produtos de tomate comercializados no Brasil, amostras de 63 produtos de tomate (polpa, pasta, purê, catchup, tomate desidratado e tomate seco conservado em óleo provenientes de 5 Estados brasileiros e uma do exterior (catchup, compreendendo a 29 marcas, foram analisadas por

  6. Effect of mint (Mentha piperita L. and caraway (Carum carvi L. on the growth of some toxigenic aspergillus species and aflatoxin B1 production

    Directory of Open Access Journals (Sweden)

    Škrinjar Marija M.

    2009-01-01

    Full Text Available An inhibitory effect of various concentrations (0.0, 0.5, 1.0, 1.5 and 2,0% of mint (Mentha piperita L. and caraway (Carvum carvi L. on the growth of A. fumigatus, A. flavus and A. ochraceus was examined during 10 days of cultivation in YES medium at temperature of 25°C. Mint showed stronger inhibitory effect than caraway. Total dry weight (g/l after 10 days of the growth of A. fumigatus in YES medium with 0.5% of mint decreased by about 95%, A. flavus by 97% and A. ochraceus by about 82%. Addition of higher concentrations of mint (1.0, 1.5 and 2.0% reduced the growth of all tested species. It was poor and hardly visible. pH values of the media increased with the increase of mint concentrations. A. fumigatus showed the highest sensitivity towards caraway and A. flavus the lowest. Total dry weight (g/l after 10 days of growth of A. fumigatus in medium with 0.5% of caraway decreased by about 72% in comparison to the control. In media with higher concentrations of caraway, its growth was found to be very poor. Concentration of 1.0% of caraway reduced A. flavus growth by 15% and of 1.5% by 92%, in regard to the control. In medium with 2.0% of caraway the growth of A. flavus was observed as poor and hardly visible. The growth of A. ochraceus in medium with 0.5% of caraway decreased by about 85% comparing with control and further decrease was noticed by the increase of concentrations. In medium with 1.5% of caraway a reduction of about 95% of growth was found and under 2.0% of caraway it was poor. pH of the media also increased with the increase of caraway concentrations. Applied concentrations of mint and caraway inhibited completely the production of AB1 by A. flavus.

  7. The Bioload and Aflatoxin Content of Herbal Medicines from ...

    African Journals Online (AJOL)

    , EHEC, Streptococcus and other coliforms) and 6 fungal genera (Aspergillus, Penicillium, Rhizopus, Cladosporium, Geotricum and Candida) were isolated. Aflatoxin B1, B2 and G1 were detected in varying concentrations in the samples ...

  8. Aflatoxin B1content in patients with hepatic diseases Aflatoxina B1 en pacientes con enfermedades hepáticas

    Directory of Open Access Journals (Sweden)

    Clara López

    2002-08-01

    Full Text Available Aflatoxins are toxic metabolites of some Aspergillus flavus, A. parasiticus and A. nomius strains that occur in many foods and feeds. There are four major natural occurring aflatoxins: B1, B2, G1 and G2. These toxins can cause illness in human beings and animals. Aflatoxin B1 is the most abundant and toxic member of the family, and it is also the most potent hepatocarcinogen known. In order to estimate the potential human health risk of AFB1, it is useful to measure blood concentration. The presence of aflatoxin B1 in patients was evaluated by high-performance liquid chromatography, in serum samples, obtained from 20 patient volunteers with hepatic disease. Out of the 20 patients, the presence of AFB1 was detected in only one of them, in a concentration of 0.47 ng/cm³. Nevertheless, this result should draw the attention of control organizations in Argentina to the need for a thorough food and feed inspection.Las aflatoxinas son metabolitos tóxicos producidos por cepas de Aspergillus flavus, A. parasiticus y A. nomius, presentes en alimentos y piensos. Las cuatro aflatoxinas principales son: aflatoxina B1, B2, G1 y G2. Dichas toxinas pueden causar enfermedades tanto en seres humanos como en animales. La aflatoxina B1 es la más abundante y la más tóxica del grupo y es también el más potente hepatocarcinógeno conocido. El objetivo de este trabajo fue detectar la presencia de aflatoxina B1 en sangre humana para estimar el riesgo potencial de la salud. La determinación de aflatoxina B1 fue realizada por cromatografía líquida de alto rendimiento, en suero de 20 pacientes voluntarios con enfermedades hepáticas. En sólo uno de estos pacientes se detectó la presencia de aflatoxina B1, en una concentración de 0.47ng/cm³. Estos resultados deberían ser tenidos en cuenta por los responsables de la vigilancia y control de los alimentos en la Argentina.

  9. Detoxification of Aflatoxin B₁ by Zygosaccharomyces rouxii with Solid State Fermentation in Peanut Meal.

    Science.gov (United States)

    Zhou, Guanghui; Chen, Yujie; Kong, Qing; Ma, Yunxiao; Liu, Yang

    2017-01-20

    Aflatoxins are highly carcinogenic, teratogenetic, and morbigenous secondary metabolites of Aspergillus flavus and A. parasiticus that can contaminate multiple staple foods, such as peanut, maize, and tree nuts. In this study, Zygosaccharomyces rouxii was screened out and identified from fermented soy paste-one kind of traditional Chinese food-to detoxify aflatoxin B₁ (AFB₁) by aerobic solid state fermentation in peanut meal. The optimal degradation condition was chosen from single factor experiment, and the most effective detoxification rate was about 97%. As for liquid fermentation, we tested the binding ability of Z. rouxii, and the highest binding rate reached was 74.3% (nonviable cells of Z. rouxii) in phosphate-buffered saline (PBS). Moreover, the biotransformation of AFB₁ through fermentation of Z. rouxii in peanut meal was further verified by liquid chromatography/mass spectrometry (LC/MS). According to TIC scan, after fermentation by Z. rouxii, the AFB₁ in peanut meal was prominently degraded to the lowering peaks of AFB₁. Additionally, m/s statistics demonstrated that AFB₁ may be degraded to some new products whose structural properties may be different from AFB₁, or the degradation products may be dissolved in the aqueous phase rather than the organic phase. As far as we know, this is the first report indicating that the safe strain of Z. rouxii has the ability to detoxify AFB₁.

  10. Detoxification of Aflatoxin B1 by Zygosaccharomyces rouxii with Solid State Fermentation in Peanut Meal

    Directory of Open Access Journals (Sweden)

    Guanghui Zhou

    2017-01-01

    Full Text Available Aflatoxins are highly carcinogenic, teratogenetic, and morbigenous secondary metabolites of Aspergillus flavus and A. parasiticus that can contaminate multiple staple foods, such as peanut, maize, and tree nuts. In this study, Zygosaccharomyces rouxii was screened out and identified from fermented soy paste—one kind of traditional Chinese food—to detoxify aflatoxin B1 (AFB1 by aerobic solid state fermentation in peanut meal. The optimal degradation condition was chosen from single factor experiment, and the most effective detoxification rate was about 97%. As for liquid fermentation, we tested the binding ability of Z. rouxii, and the highest binding rate reached was 74.3% (nonviable cells of Z. rouxii in phosphate-buffered saline (PBS. Moreover, the biotransformation of AFB1 through fermentation of Z. rouxii in peanut meal was further verified by liquid chromatography/mass spectrometry (LC/MS. According to TIC scan, after fermentation by Z. rouxii, the AFB1 in peanut meal was prominently degraded to the lowering peaks of AFB1. Additionally, m/s statistics demonstrated that AFB1 may be degraded to some new products whose structural properties may be different from AFB1, or the degradation products may be dissolved in the aqueous phase rather than the organic phase. As far as we know, this is the first report indicating that the safe strain of Z. rouxii has the ability to detoxify AFB1.

  11. Radiation degradation of biological waste (aflatoxins) produced in food laboratory; Degradacao por radiacao de residuos biologicos (aflatoxinas) produzidos em laboratorio de alimentos

    Energy Technology Data Exchange (ETDEWEB)

    Rogovschi, Vladimir Dias

    2009-07-01

    Many filamentous fungi can produce secondary metabolites, called mycotoxins, which can be found in food and agricultural products. One of the main genera of myco toxigenic fungi related to the food chain is the Aspergillus spp. There are over 400 mycotoxins described in the literature, the most common the aflatoxins B1, B2, G1 and G2. The mycotoxins are commonly found in foods and are considered one of the most dangerous contaminants. The aflatoxin B1 is classified in group one by the International Agency of Research on Cancer. Aflatoxins resisting for more than one hour in autoclave making it necessary to other means of degradation of these toxins. This work aimed to observe the effects of gamma radiation of {sup 60}Co and electron beams in the degradation of aflatoxins and compare the damage caused on the morphology of the Aspergillus flavus. The fungus was grown on potato dextrose agar (PDA) for 10 days and was subsequently transferred to coconut agar medium, and maintained for 14 days at 25 degree C. After this step the coconut agar was ground to become a homogeneous pasty and was irradiated with doses of 2.5, 5.0, 10 and 20 kGy. The samples used in scanning electron microscopy were irradiated with doses of 0, 2.5, 5.0, 10 and 20 kGy with sources of {sup 60}Co and electron beams. Irradiation with electron accelerator showed a slightly higher degradation to gamma radiation, reducing 29.93 %, 34.50 %, 52.63 % and 72.30 % for doses of 2.5, 5.0, 10 and 20 kGy, respectively. The Scanning Electron Microscopy showed that doses of 2.5 to 10 kGy did not cause damage to the fungus, but with a dose of 20 kGy it can be observed fungal damage to structures. (author)

  12. Influences of climate on aflatoxin producing fungi and aflatoxin contamination.

    Science.gov (United States)

    Cotty, Peter J; Jaime-Garcia, Ramon

    2007-10-20

    Aflatoxins are potent mycotoxins that cause developmental and immune system suppression, cancer, and death. As a result of regulations intended to reduce human exposure, crop contamination with aflatoxins causes significant economic loss for producers, marketers, and processors of diverse susceptible crops. Aflatoxin contamination occurs when specific fungi in the genus Aspergillus infect crops. Many industries frequently affected by aflatoxin contamination know from experience and anecdote that fluctuations in climate impact the extent of contamination. Climate influences contamination, in part, by direct effects on the causative fungi. As climate shifts, so do the complex communities of aflatoxin-producing fungi. This includes changes in the quantity of aflatoxin-producers in the environment and alterations to fungal community structure. Fluctuations in climate also influence predisposition of hosts to contamination by altering crop development and by affecting insects that create wounds on which aflatoxin-producers proliferate. Aflatoxin contamination is prevalent both in warm humid climates and in irrigated hot deserts. In temperate regions, contamination may be severe during drought. The contamination process is frequently broken down into two phases with the first phase occurring on the developing crop and the second phase affecting the crop after maturation. Rain and temperature influence the phases differently with dry, hot conditions favoring the first and warm, wet conditions favoring the second. Contamination varies with climate both temporally and spatially. Geostatistics and multiple regression analyses have shed light on influences of weather on contamination. Geostatistical analyses have been used to identify recurrent contamination patterns and to match these with environmental variables. In the process environmental conditions with the greatest impact on contamination are identified. Likewise, multiple regression analyses allow ranking of

  13. Variation in fungal microbiome (mycobiome) and aflatoxins during simulated storage of in-shell peanuts and peanut kernels.

    Science.gov (United States)

    Xing, Fuguo; Ding, Ning; Liu, Xiao; Selvaraj, Jonathan Nimal; Wang, Limin; Zhou, Lu; Zhao, Yueju; Wang, Yan; Liu, Yang

    2016-05-16

    Internal transcribed spacer 2 (ITS2) sequencing was used to characterize the peanut mycobiome during 90 days storage at five conditions. The fungal diversity in in-shell peanuts was higher with 110 operational taxonomic units (OTUs) and 41 genera than peanut kernels (91 OTUs and 37 genera). This means that the micro-environment in shell is more suitable for maintaining fungal diversity. At 20-30 d, Rhizopus, Eurotium and Wallemia were predominant in in-shell peanuts. In peanut kernels, Rhizopus (>30%) and Eurotium (>20%) were predominant at 10-20 d and 30 d, respectively. The relative abundances of Rhizopus, Eurotium and Wallemia were higher than Aspergillus, because they were xerophilic and grew well on substrates with low water activity (aw). During growth, they released metabolic water, thereby favoring the growth of Aspergillus. Therefore, from 30 to 90 d, the relative abundance of Aspergillus increased while that of Rhizopus, Eurotium and Wallemia decreased. Principal Coordinate Analysis (PCoA) revealed that peanuts stored for 60-90 days and for 10-30 days clustered differently from each other. Due to low aw values (0.34-0.72) and low levels of A. flavus, nine of 51 samples were contaminated with aflatoxins.

  14. Validation of a liquid chromatography/tandem mass spectrometry method for the detection of aflatoxin B1 residues in broiler liver.

    Science.gov (United States)

    Magnoli, Alejandra P; González Pereyra, María L; Monge, María P; Cavaglieri, Lilia R; Chiacchiera, Stella M

    2017-11-14

    Aflatoxin B1 is a carcinogenic and mutagenic mycotoxin produced mainly by Aspergillus flavus and Aspergillus parasiticus. It is the predominant mycotoxin found in raw materials used for the manufacture of broiler feeds. The aim of the present study was to develop a new and optimized method for the detection and quantification of aflatoxin B1 (AFB1) residues in broiler liver using solid phase extraction (SPE) clean-up and liquid chromatography-electrospray ionization/tandem mass spectrometry (LC-ESI-MS/MS) detection. The method was validated for linearity, accuracy, precision, limit of detection (LOD) and limit of quantification (LOQ). The validation parameters indicated satisfactory linearity (r2>0.99), accuracy and precision (4.57% intra-day RSD; 14.65% inter-day RSD) a very high recovery (99±13%) and high sensitivity achieved for AFB1 in animal samples (LOD=0.017 and LOQ=0.050ng/g). The method was effective for the detection and quantification of AFB1 residues in broiler liver and could also be potentially used for detecting AFB1 in other edible animal tissues after natural or experimental AFB1 exposure with high sensitivity and precision. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Health economic impacts and cost-effectiveness of aflatoxin reduction strategies in Africa: Case studies in biocontrol and postharvest interventions

    Science.gov (United States)

    Wu, Felicia; Khlangwiset, Pornsri

    2010-01-01

    Advances in health economics have proven useful in evaluating the cost-effectiveness of interventions, where the benefit usually takes the form of improved health outcomes rather than market outcomes. We perform health-based cost-effectiveness analyses of two potential aflatoxin control strategies in Africa: 1) pre-harvest biocontrol, using atoxigenic strains of Aspergillus flavus to competitively exclude toxigenic strains from colonizing maize in Nigeria, and 2) postharvest interventions in a package to reduce aflatoxin accumulation in groundnuts in Guinea. We describe how health benefits gained from each intervention, in terms of fewer aflatoxin-induced hepatocellular carcinoma (HCC) cases, can be compared with costs of implementing the interventions. We find that both interventions would be extremely cost-effective if applied widely in African agriculture. That is, the monetized value of lives saved and quality of life gained by reducing aflatoxin-induced HCC far exceeds the cost of either biocontrol or the postharvest intervention package to achieve those health benefits. The estimated cost-effectiveness ratio (CER; gross domestic product multiplied by disability-adjusted life years saved per unit cost) for biocontrol in Nigerian maize ranges from 5.10 to 24.8; while the estimated CER for the postharvest intervention package in Guinean groundnuts ranges from 0.21 to 2.08. Any intervention with a CER greater than 1 is considered by the World Health Organization to be “very cost-effective,” while an intervention with a CER greater than 0.33 is considered “cost-effective.” Aside from cost-effectiveness, public health interventions must be readily accepted by the public, and must have financial and infrastructural support to be feasible in the parts of the world where they are most needed. PMID:20234965

  16. Phenotypic differentiation of species from Aspergillus section Flavi on neutral red desiccated coconut agar

    DEFF Research Database (Denmark)

    Atanda, O. O.; Adetunji, M. C.; Ezekiel, C. N.

    2014-01-01

    isolates produced aflatoxins in the culture medium in varying quantities. Plates of aflatoxigenic A. flavus L strains fluoresced bluish purple/lavender around the colony on the obverse and pastel blue on the reverse side due to aflatoxin B production while those of A. minisclerotigenes, A. parasiticus...... characteristics, and grouping of species into B and B+G aflatoxin producers within 5 days thus obviating the need for chemical analysis of the culture....

  17. PENURUNAN KADAR AFLATOKSIN B1 PADA SARI KEDELAI OLEH SEL HIDUP DAN SEL MATI Lactobacillus acidophilus SNP-2 [Reduction of Aflatoxin B1 in Soymilk by Viable and Heat-killed Lactobacillus acidophilus SNP-2

    Directory of Open Access Journals (Sweden)

    Tyas Utami1*

    2012-06-01

    Full Text Available Aflatoxins are carcinogenic mycotoxins that commonly contaminate foods and feed. There are many different forms of aflatoxin and its metabolites. Of these, aflatoxin B1 (AFB1 is the most prevalent and toxic. Lactobacillus acidophilus SNP-2 has previously been shown to remove AFB1 from liquid solution of phosphate saline buffer. However, the ability of lactic acid bacteria to reduce AFB1 content in soymilk has not been studied yet. The objective of this study was to investigate the ability of viable and heat-killed cells of L. acidophilus SNP-2 to reduce AFB1 in soymilk and fermented soymilk. Soymilk contaminated with Aspergillus flavus was inoculated with culture of L. acidophilus SNP-2, and incubated at 37C for 12 hours. Fermented soymilk, then, was heat sterilized and stored at cool room (4°C. Heat-killed cells were introduced to soy milk and then kept at cool room for 3 days. During soymilk fermentation, there was reduction of AFB1 content in soymilk related to the growth of lactic acid bacteria and the reduction of pH. The initial concentration of AFB1 in the soymilk was 4.9 ppb. Lactobacillus acidophilus SNP-2 reduced 67.58% of AFB1 in the soymilk after 12 hoursof fermentation. In cool environment, the binding of AFB1 to heat-killed cell after soymilk fermentation was relatively more stable than that of soymilk without fermentation.

  18. Health economic impacts and cost-effectiveness of aflatoxin-reduction strategies in Africa: case studies in biocontrol and post-harvest interventions.

    Science.gov (United States)

    Wu, F; Khlangwiset, P

    2010-04-01

    Advances in health economics have proven useful in evaluating the cost-effectiveness of interventions, where the benefit usually takes the form of improved health outcomes rather than market outcomes. The paper performs health-based cost-effectiveness analyses of two potential aflatoxin control strategies in Africa: (1) pre-harvest biocontrol, using atoxigenic strains of Aspergillus flavus competitively to exclude toxigenic strains from colonizing maize in Nigeria; and (2) post-harvest interventions in a package to reduce aflatoxin accumulation in groundnuts in Guinea. It is described how health benefits gained from each intervention, in terms of fewer aflatoxin-induced hepatocellular carcinoma cases, can be compared with the costs of implementing the interventions. It is found that both interventions would be extremely cost-effective if applied widely in African agriculture. That is, the monetized value of lives saved and quality of life gained by reducing aflatoxin-induced hepatocellular carcinoma far exceeds the cost of either biocontrol or the post-harvest intervention package to achieve those health benefits. The estimated cost-effectiveness ratio (CER; gross domestic product multiplied by disability-adjusted life years saved per unit cost) for biocontrol in Nigerian maize ranged from 5.10 to 24.8; while the estimated CER for the post-harvest intervention package in Guinean groundnuts ranged from 0.21 to 2.08. Any intervention with a CER > 1 is considered by the World Health Organization (WHO) to be 'very cost-effective', while an intervention with a CER > 0.33 is considered 'cost-effective'. Aside from cost-effectiveness, public health interventions must be readily accepted by the public, and must have financial and infrastructural support to be feasible in the parts of the world where they are most needed.

  19. Occurrence of aflatoxin M1 in human milk samples in Vojvodina, Serbia: Estimation of average daily intake by babies.

    Science.gov (United States)

    Radonić, Jelena R; Kocić Tanackov, Sunčica D; Mihajlović, Ivana J; Grujić, Zorica S; Vojinović Miloradov, Mirjana B; Škrinjar, Marija M; Turk Sekulić, Maja M

    2017-01-02

    The objectives of the study were to determine the aflatoxin M1 content in human milk samples in Vojvodina, Serbia, and to assess the risk of infants' exposure to aflatoxins food contamination. The growth of Aspergillus flavus and production of aflatoxin B1 in corn samples resulted in higher concentrations of AFM1 in milk and dairy products in 2013, indicating higher concentrations of AFM1 in human milk samples in 2013 and 2014 in Serbia. A total number of 60 samples of human milk (colostrum and breast milk collected 4-8 months after delivery) were analyzed for the presence of AFM1 using the Enzyme Linked Immunosorbent Assay method. The estimated daily intake of AFM1 through breastfeeding was calculated for the colostrum samples using an average intake of 60 mL/kg body weight (b.w.)/day on the third day of lactation. All breast milk collected 4-8 months after delivery and 36.4% of colostrum samples were contaminated with AFM1. The greatest percentage of contaminated colostrum (85%) and all samples of breast milk collected 4-8 months after delivery had AFM1 concentration above maximum allowable concentration according to the Regulation on health safety of dietetic products. The mean daily intake of AFM1 in colostrum was 2.65 ng/kg bw/day. Results of our study indicate the high risk of infants' exposure, who are at the early stage of development and vulnerable to toxic contaminants.

  20. Aflatoxin-exposure of Vibrio gazogenes as a novel system for the generation of aflatoxin synthesis inhibitors

    Directory of Open Access Journals (Sweden)

    Phani M Gummadidala

    2016-06-01

    Full Text Available Aflatoxin is a mycotoxin and a secondary metabolite, and the most potent known liver carcinogen that contaminates several important crops, and represents a significant threat to public health and the economy. Available approaches reported thus far have been insufficient to eliminate this threat, and therefore provide the rational to explore novel methods for preventing aflatoxin accumulation in the environment. Many terrestrial plants and microbes that share ecological niches and encounter the aflatoxin producers have the ability to synthesize compounds that inhibit aflatoxin synthesis. However, reports of natural aflatoxin inhibitors from marine ecosystem components that do not share ecological niches with the aflatoxin producers are rare. Here we show that a non-pathogenic marine bacterium, Vibrio gazogenes, when exposed to low non-toxic doses of aflatoxin B1, demonstrates a shift in its metabolic output and synthesizes a metabolite fraction that inhibits aflatoxin synthesis without affecting hyphal growth in the model aflatoxin producer, Aspergillus parasiticus. The molecular mass of the predominant metabolite in this fraction was also different from the known prodigiosins, which are the known antifungal secondary metabolites synthesized by this Vibrio. Gene expression analyses using RT-PCR demonstrate that this metabolite fraction inhibits aflatoxin synthesis by down-regulating the expression of early-, middle- and late- growth stage aflatoxin genes, the aflatoxin pathway regulator, aflR and one global regulator of secondary metabolism, LaeA. Our study establishes a novel system for generation of aflatoxin synthesis inhibitors, and emphasizes the potential of the under-explored Vibrio’s silent genome for generating new modulators of fungal secondary metabolism.

  1. A colorimetric and spectrophotometric method for in vitro susceptibility testing of Aspergillus species against caspofungin.

    NARCIS (Netherlands)

    Dorsthorst, D.T.A. te; Zwaaftink, R.B.; Rijs, A.J.M.M.; Meletiadis, J.; Verweij, P.E.

    2007-01-01

    The in vitro susceptibility of 45 Aspergillus fumigatus, Aspergillus flavus and Aspergillus terreus isolates against caspofungin (CAS) was assessed by the CLSI reference method with spectrophotometric reading and by a colorimetric method that employed the dye MTT. Perfect agreement was found between

  2. Inhibitory Effects of Respiration Inhibitors on Aflatoxin Production

    Directory of Open Access Journals (Sweden)

    Shohei Sakuda

    2014-03-01

    Full Text Available Aflatoxin production inhibitors, which do not inhibit the growth of aflatoxigenic fungi, may be used to control aflatoxin without incurring a rapid spread of resistant strains. A respiration inhibitor that inhibits aflatoxin production was identified during a screening process for natural, aflatoxin-production inhibitors. This prompted us to evaluate respiration inhibitors as potential aflatoxin control agents. The inhibitory activities of four natural inhibitors, seven synthetic miticides, and nine synthetic fungicides were evaluated on aflatoxin production in Aspergillus parasiticus. All of the natural inhibitors (rotenone, siccanin, aptenin A5, and antimycin A inhibited fungal aflatoxin production with IC50 values around 10 µM. Among the synthetic miticides, pyridaben, fluacrypyrim, and tolfenpyrad exhibited strong inhibitory activities with IC50 values less than 0.2 µM, whereas cyflumetofen did not show significant inhibitory activity. Of the synthetic fungicides, boscalid, pyribencarb, azoxystrobin, pyraclostrobin, and kresoxim-methyl demonstrated strong inhibitory activities, with IC50 values less than 0.5 µM. Fungal growth was not significantly affected by any of the inhibitors tested at concentrations used. There was no correlation observed between the targets of respiration inhibitors (complexes I, II, and III and their IC50 values for aflatoxin-production inhibitory activity. This study suggests that respiration inhibitors, including commonly used pesticides, are useful for aflatoxin control.

  3. Inhibitory Effects of Respiration Inhibitors on Aflatoxin Production

    Science.gov (United States)

    Sakuda, Shohei; Prabowo, Diyan Febri; Takagi, Keiko; Shiomi, Kazuro; Mori, Mihoko; Ōmura, Satoshi; Nagasawa, Hiromichi

    2014-01-01

    Aflatoxin production inhibitors, which do not inhibit the growth of aflatoxigenic fungi, may be used to control aflatoxin without incurring a rapid spread of resistant strains. A respiration inhibitor that inhibits aflatoxin production was identified during a screening process for natural, aflatoxin-production inhibitors. This prompted us to evaluate respiration inhibitors as potential aflatoxin control agents. The inhibitory activities of four natural inhibitors, seven synthetic miticides, and nine synthetic fungicides were evaluated on aflatoxin production in Aspergillus parasiticus. All of the natural inhibitors (rotenone, siccanin, aptenin A5, and antimycin A) inhibited fungal aflatoxin production with IC50 values around 10 µM. Among the synthetic miticides, pyridaben, fluacrypyrim, and tolfenpyrad exhibited strong inhibitory activities with IC50 values less than 0.2 µM, whereas cyflumetofen did not show significant inhibitory activity. Of the synthetic fungicides, boscalid, pyribencarb, azoxystrobin, pyraclostrobin, and kresoxim-methyl demonstrated strong inhibitory activities, with IC50 values less than 0.5 µM. Fungal growth was not significantly affected by any of the inhibitors tested at concentrations used. There was no correlation observed between the targets of respiration inhibitors (complexes I, II, and III) and their IC50 values for aflatoxin-production inhibitory activity. This study suggests that respiration inhibitors, including commonly used pesticides, are useful for aflatoxin control. PMID:24674936

  4. Expression of a Human Cytochrome P450 in Yeast Permits Analysis of Pathways for Response to and Repair of Aflatoxin-Induced DNA Damage†

    Science.gov (United States)

    Guo, Yingying; Breeden, Linda L.; Zarbl, Helmut; Preston, Bradley D.; Eaton, David L.

    2005-01-01

    Aflatoxin B1 (AFB1) is a human hepatotoxin and hepatocarcinogen produced by the mold Aspergillus flavus. In humans, AFB1 is primarily bioactivated by cytochrome P450 1A2 (CYP1A2) and 3A4 to a genotoxic epoxide that forms N7-guanine DNA adducts. A series of yeast haploid mutants defective in DNA repair and cell cycle checkpoints were transformed with human CYP1A2 to investigate how these DNA adducts are repaired. Cell survival and mutagenesis following aflatoxin B1 treatment was assayed in strains defective in nucleotide excision repair (NER) (rad14), postreplication repair (PRR) (rad6, rad18, mms2, and rad5), homologous recombinational repair (HRR) (rad51 and rad54), base excision repair (BER) (apn1 apn2), nonhomologous end-joining (NHEJ) (yku70), mismatch repair (MMR) (pms1), translesion synthesis (TLS) (rev3), and checkpoints (mec1-1, mec1-1 rad53, rad9, and rad17). Together our data suggest the involvement of homologous recombination and nucleotide excision repair, postreplication repair, and checkpoints in the repair and/or tolerance of AFB1-induced DNA damage in the yeast model. Rev3 appears to mediate AFB1-induced mutagenesis when error-free pathways are compromised. The results further suggest unique roles for Rad5 and abasic endonuclease-dependent DNA intermediates in regulating AFB1-induced mutagenicity. PMID:15988000

  5. Expression of a human cytochrome p450 in yeast permits analysis of pathways for response to and repair of aflatoxin-induced DNA damage.

    Science.gov (United States)

    Guo, Yingying; Breeden, Linda L; Zarbl, Helmut; Preston, Bradley D; Eaton, David L

    2005-07-01

    Aflatoxin B1 (AFB1) is a human hepatotoxin and hepatocarcinogen produced by the mold Aspergillus flavus. In humans, AFB1 is primarily bioactivated by cytochrome P450 1A2 (CYP1A2) and 3A4 to a genotoxic epoxide that forms N7-guanine DNA adducts. A series of yeast haploid mutants defective in DNA repair and cell cycle checkpoints were transformed with human CYP1A2 to investigate how these DNA adducts are repaired. Cell survival and mutagenesis following aflatoxin B1 treatment was assayed in strains defective in nucleotide excision repair (NER) (rad14), postreplication repair (PRR) (rad6, rad18, mms2, and rad5), homologous recombinational repair (HRR) (rad51 and rad54), base excision repair (BER) (apn1 apn2), nonhomologous end-joining (NHEJ) (yku70), mismatch repair (MMR) (pms1), translesion synthesis (TLS) (rev3), and checkpoints (mec1-1, mec1-1 rad53, rad9, and rad17). Together our data suggest the involvement of homologous recombination and nucleotide excision repair, postreplication repair, and checkpoints in the repair and/or tolerance of AFB1-induced DNA damage in the yeast model. Rev3 appears to mediate AFB1-induced mutagenesis when error-free pathways are compromised. The results further suggest unique roles for Rad5 and abasic endonuclease-dependent DNA intermediates in regulating AFB1-induced mutagenicity.

  6. Revitalization of a forward genetic screen identifies three new regulators of fungal secondary metabolism in the genus Aspergillus

    Science.gov (United States)

    Brandon T. Pfannenstiel; Xixi Zhao; Jennifer Wortman; Philipp Wiemann; Kurt Throckmorton; Joseph E. Spraker; Alexandra A. Soukup; Xingyu Luo; Daniel L. Lindner; Fang Yun Lim; Benjamin P. Knox; Brian Haas; Gregory J. Fischer; Tsokyi Choera; Robert A. E. Butchko; Jin-Woo Bok; Katharyn J. Affeldt; Nancy P. Keller; Jonathan M. Palmer; B. Gillian Turgeon

    2017-01-01

    The study of aflatoxin in Aspergillus spp. has garnered the attention of many researchers due to aflatoxin's carcinogenic properties and frequency as a food and feed contaminant. Significant progress has been made by utilizing the model organism Aspergillus nidulans to characterize the regulation of sterigmatocystin (ST),...

  7. Combining ability and heritability for host resistance to Aspergillus ...

    African Journals Online (AJOL)

    We generated 144 three-way test crosses and screened them together with their parental inbred lines and 4 single cross testers for host resistance to A. flavus and reduced aflatoxin accumulation. Using line by tester analysis, we identified 5 resistant inbred lines and 7 hybrids. We used the resistant inbred lines to make ...

  8. Occupational Exposure to Aflatoxin B1 in a Portuguese Poultry Slaughterhouse.

    Science.gov (United States)

    Viegas, Susana; Veiga, Luísa; Almeida, Ana; dos Santos, Mateus; Carolino, Elisabete; Viegas, Carla

    2016-03-01

    Aflatoxin B1 (AFB1) is a secondary metabolite produced by the fungi Aspergillus flavus and is the most potent hepatocarcinogen known in mammals and has been classified by the International Agency of Research on Cancer as Group 1 carcinogen. Although dietary exposure to AFB1 has been extensively documented, there are still few studies dedicated to the problem of occupational exposure. Considering recent findings regarding AFB1 occupational exposure in poultry production, it was considered relevant to clarify if there is also exposure in poultry slaughterhouses. Occupational exposure assessment to AFB1 was done with a biomarker of internal dose that measures AFB1 in the serum by enzyme-linked immunosorbent assay. Thirty workers from a slaughterhouse were enrolled in this study. A control group (n = 30) was also considered in order to know AFB1 background levels for Portuguese population. Fourteen workers (47.0%) showed detectable levels of AFB1 with values from 1.06 to 4.03ng ml(-1), with a mean value of 1.73ng ml(-1). No AFB1 was detected in serum of individuals used as controls. Despite uncertainties regarding the exposure route that is contributing more to exposure (inhalation or dermal) is possible to state that exposure to AFB1 is occurring in the slaughterhouse studied. It seems that reducing AFB1 contamination in poultry production can have a positive result in this occupational setting. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  9. Chemistry and Biology of Aflatoxin-DNA Adducts

    Energy Technology Data Exchange (ETDEWEB)

    Stone, Michael P.; Banerjee, Surajit; Brown, Kyle L.; Egli, Martin (Vanderbilt)

    2012-03-27

    Aspergillus flavus is a fungal contaminant of stored rice, wheat, corn, and other grainstuffs, and peanuts. This is of concern to human health because it produces the mycotoxin aflatoxin B{sub 1} (AFB{sub 1}), which is genotoxic and is implicated in the etiology of liver cancer. AFB{sub 1} is oxidized in vivo by cytochrome P450 to form aflatoxin B{sub 1} epoxide, which forms an N7-dG adduct (AFB{sub 1}-N7-dG) in DNA. The latter rearranges to a formamidopyrimidine (AFB{sub 1}-FAPY) derivative that equilibrates between {alpha} and {beta} anomers of the deoxyribose. In DNA, both the AFB{sub 1}-N7-dG and AFB{sub 1}-{beta}-FAPY adducts intercalate above the 5'-face of the damaged guanine. Each produces G {yields} T transversions in Escherichia coli, but the AFB{sub 1}-{beta}-FAPY adduct is more mutagenic. The Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) provides a model for understanding error-prone bypass of the AFB{sub 1}-N7-dG and AFB{sub 1}-{beta}-FAPY adducts. It bypasses the AFB{sub 1}-N7-dG adduct, but it conducts error-prone replication past the AFB{sub 1}-FAPY adduct, including mis-insertion of dATP, consistent with the G {yields} T mutations characteristic of AFB{sub 1} mutagenesis in E. coli. Crystallographic analyses of a series of binary and ternary complexes with the Dpo4 polymerase revealed differing orientations of the N7-C8 bond of the AFB{sub 1}-N7-dG adduct as compared to the N{sup 5}-C8 bond in the AFB{sub 1}-{beta}-FAPY adduct, and differential accommodation of the intercalated AFB{sub 1} moieties within the active site. These may modulate AFB{sub 1} lesion bypass by this polymerase.

  10. Mycotoxin production on rice, pulses and oilseeds

    Science.gov (United States)

    Begum, Fouzia; Samajpati, N.

    Mycotoxin-producing fungi were isolated from contaminated grains of rice, pulses and oilseeds sold in the local markets of Calcutta for human consumption. It was found that aflatoxin B1 was produced by Aspergillus flavus and Aspergillus parasiticus, aflatoxin G1 by A. flavus, ochratoxin by Aspergillus ochraceous, sterigmatocystin by Aspergillus japonicus and citrinin by Penicillium citrinum. Aflatoxin B1 (333-10416μg/kg) was produced by Aspergillus spp. in rice, pulses and oilseeds.

  11. Pulmonary aspergillosis and aflatoxins in chronic lung diseases.

    Science.gov (United States)

    Ali, Sana; Malik, Abida; Shahid, Mohd; Bhargava, Rakesh

    2013-10-01

    Fungal infections of lung have become increasingly common during the last few decades. Aspergillosis and the role of aflatoxins in various chronic lung diseases have not been extensively studied. Bronchoalveolar lavage (BAL) samples and sera from 40 patients of chronic lung diseases were analyzed for galactomannan antigen (GM) and aflatoxin by enzyme-linked immunosorbent assay. Direct microscopy and culture of BAL samples were also done to detect the Aspergillus species. Results revealed that 15 (37.5 %) of the 40 patients had growth of Aspergillus on BAL culture. Out of these culture-positive cases, 13 (86.7 %) patients were positive for galactomannan antigen also. About 62.5 % cases did not show growth of Aspergillus in BAL culture. However, galactomannan antigen could be detected in 20 % of these patients. Overall, 20 % patients were diagnosed as proven invasive fungal disease (IFD), 32.5 % were of probable IFD, 17.5 % of possible IFD. Aspergillus growth was observed in 100 % of proven and 53.8 % of probable IFD cases. Galactomannan antigen was found in 100 % cases of proven and 76.9 % of probable IFD. Ten (25 %) patients were found to be positive for aflatoxins. It was detected in 6 (40 %) of culture-positive cases. About 62.5 % of the cases with proven IFD and 46.1 % of probable IFD had aflatoxin in their samples. Aflatoxin positivity was found to be more in patients with proven IFD than in probable IFD, and higher level of aflatoxins was detected in cases with proven IFD. Significant difference was observed in aflatoxin positivity among food grain workers when compared to other occupations.

  12. Biosynthesis of silver nanoparticles synthesized by Aspergillus ...

    Indian Academy of Sciences (India)

    In the present study, biosynthesis of silver nanoparticles and its antioxidant, antimicrobial and cytotoxic activities were investigated. Silver nanoparticles were extracellularly synthesized using Aspergillus flavus and the formation of nanoparticles was observed after 72 h of incubation. The results recorded from colour ...

  13. Biosynthesis of silver nanoparticles synthesized by Aspergillus ...

    Indian Academy of Sciences (India)

    agents. Keywords. Aspergillus flavus; silver nanoparticles; antimicrobial; antioxidant; cytotoxicity. 1. Introduction. Nanoparticles with controlled size and composition are of fundamental and technological interest as they provide solu- tions to technological and environmental challenges in the areas of solar energy conversion ...

  14. Identificação de Aspergillus spp: toxigênico em arroz Identification of toxigenic Aspergillus spp: in rice

    Directory of Open Access Journals (Sweden)

    Ívina Catarina de Oliveira Guimarães

    2010-05-01

    Full Text Available A composição química e o modo de cultivo do arroz o tornam susceptível à contaminação fúngica e, consequentemente, por micotoxinas. Considerando-se o expressivo consumo de arroz e a possibilidade de ser potencial fonte de micotoxinas, especial atenção deve ser dispensada quanto à qualidade do produto adquirido. Assim, o presente trabalho teve como objetivo avaliar espécies do gênero Aspergillus quanto à capacidade toxigênica, em diferentes subgrupos de arroz. As amostras constituíram-se de 31 marcas de arroz referentes aos subgrupos branco polido (21 e parboilizado (10, mais comumente comercializadas na cidade de Lavras - MG. Ao contrário dos outros subgrupos, a incidência de Aspergillus flavus e Aspergillus niger em amostras de arroz branco polido aumentou significativamente após a desinfecção. Pôde-se observar que, 50% dos Aspergillus flavus e 50% dos Aspergillus niger encontrados, foram considerados toxigênicos para o subgrupo branco polido. Na amostra de arroz parboilizado, 67% dos Aspergillus flavus eram potenciais produtores. O Aspergillus ochraceus não se revelou como toxigênico. Este estudo permitiu concluir que, apesar de trabalhos isolados, a presença de fungos toxigênicos em arroz é verídico, o que se torna relevante por se tratar de um cereal importante no cenário mundial.The chemical composition and its methods of cultivation, make rice plants susceptible to fungi and consequently to mycotoxins contamination. Considering the expressive rice consumption and given the possibility that it maybe a potential source of mycotoxins, special attention should be devoted to its quality. Thus, this study was carried out to evaluate the Aspergillus species as to its toxigenic capacities in different rice subgroups. Thirty one and rice brands among the most popular brands sold in the city of Lavras - MG, were collected as samples, (21 polished white and (10 parboiled, respectively. Unlike other subgroups, the

  15. Occurrence of B1 Aflatoxin in diet and M1 Aflatoxin in bovine milk

    Directory of Open Access Journals (Sweden)

    Adriana Frizzarin

    2012-12-01

    Full Text Available Ensuring food quality is one of the principles of food safety. Food for dairy cattle may be contaminated by fungi of the genus Aspergillus, which produce aflatoxins. The B1 aflatoxin, when ingested by animals, is biotransformed in liver in several other toxic metabolites, including M1 aflatoxin which is excreted in milk. M1 aflatoxin has a carcinogenic effect, which the presence in milk poses a serious risk to public health because milk and dairy products are consumed mainly by children, pregnant women and elderly. The objective of this study was to detect the presence of B1 aflatoxin in feed supplied to dairy cows and the presence of M1 aflatoxin in milk. Samples were collected from complete diet (corn silage and concentrate from a batch of 15 lactating cows from a dairy farm in the Campinas region. Two samples of diets were collected directly into the troughs in intervals of 24 hours at every 15 days, totalizing a period of 45 days. Milk samples of those cows were collected 24 hours after diet collection, directly from sample valves in the glass jars.. B1 and M1 aflatoxins were detected by the technique of High Performance Liquid Chromatography after extraction and purification on immunoaffinity columns. From the 40 samples of diets evaluated, 40% were contaminated with B1 aflatoxin, and the levels found ranged from 1.93 to 43.78μg/Kg. One sample showed result higher than the maximum recommended for grain and animal feed in Brazil (20μg/Kg. From the 75 milk samples analyzed, the presence of M1 aflatoxin was detected in 13.3% with levels ranging from 0.03 to 0.16μg/L, not exceeding the maximum permitted for marketing in the country of 0.5μg/L, however 80% of contaminated samples had values above the maximum permissible levels of 0.05μg/L, value found among countries with abundant milk production... The presence of aflatoxins highlights the importance of monitoring the production, the storage and the importance of handling food and

  16. Aflatoxinas: um risco a saúde humana e animal / Aflatoxins: a risk animal and human health

    OpenAIRE

    Helder Ferreira; Elaine Pittner; Hermes Francisco Sanches; Marta Chagas Monteiro

    2006-01-01

    O Aspergillus flavus e a subespécie próxima relacionada parasiticus têm sido reconhecidas por muito tempo como contaminadores principais de produtos orgânicos e inorgânicos. A. flavus, um fungo comum do solo, pode infestar uma larga escala de produtos agrícolas. Algumas variedades de A. flavus produzem as aflatoxinas, que são toxinas neoplásicas capazes de induzir neoplasia hepática em animais de laboratório. O crescimento de A. flavus e a biossíntese da aflatoxina depende da carcaça, da umid...

  17. Diversity in secondary metabolites including mycotoxins from strains of aspergillus section nigri isolated from raw cashew nuts from benin, west africa

    NARCIS (Netherlands)

    Lamboni, Yendouban; Nielsen, Kristian F.; Linnemann, Anita R.; Gezgin, Yué Ksel; Hell, Kerstin; Nout, Rob; Smid, Eddy J.; Tamo, Manuele; Boekel, van M.A.J.S.; Hoof, Jakob Blñsbjerg; Frisvad, Jens Christian

    2016-01-01

    In a previous study, raw cashew kernels were assayed for the fungal contamination focusin on strains belonging to the genus Aspergillus and on aflatoxins producers. These sample showed high contamination with Aspergillus section Nigri species and absence o aflatoxins. To investigate the diversity

  18. Inhibitory effect of essential oil on aflatoxin activities

    African Journals Online (AJOL)

    STORAGESEVER

    2010-04-19

    Apr 19, 2010 ... Inhibitory effects of Thyme oils on growth and aflatoxin production by Aspergillus parasiticus. Food Control,15: 479-483. Rasoli I, Fakoor MH, Yadegarinia D, Gachkar L, Allameh A, Rezaei MB. (2008). Antimycotoxigenic characteristics of Rosmarinus officinalis and Trachyspermum copticum L. essential oils.

  19. Natural occurrence of aflatoxins in bread in Nigeria | Efuntoye ...

    African Journals Online (AJOL)

    A study was conducted in Nigeria on samples of brown bread for growth of moulds and natural occurrence of aflatoxins. Mycological analysis showed the presence of six genera of filamentous fungi, Aspergillus, Rhizopus, Mucor, Penicillium, Alternaria and Geotrichum. Thin layer chromatography (TLC) analysis of bread ...

  20. Biodiversity of Aspergillus species in some important agricultural products

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Susca, A.,; Cozzi, G.

    2007-01-01

    . flavus and A. parasiticus, and ochratoxinogenic A. niger, A. ochraceus and A. carbonarius species are frequently encountered in agricultural products. Studies on the biodiversity of toxigenic Aspergillus species is useful to clarify molecular, ecological and biochemical characteristics of the different...... species in relation to their different adaptation to environmental and geographical conditions, and to their potential toxigenicity. Here we analyzed the biodiversity of ochratoxin producing species occurring on two important crops: grapes and coffee, and the genetic diversity of A. flavus populations...

  1. Identification by Molecular Methods and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry and Antifungal Susceptibility Profiles of Clinically Significant Rare Aspergillus Species in a Referral Chest Hospital in Delhi, India

    NARCIS (Netherlands)

    Masih, A.; Singh, P.K.; Kathuria, S.; Agarwal, K.; Meis, J.F.G.M.; Chowdhary, A.

    2016-01-01

    Aspergillus species cause a wide spectrum of clinical infections. Although Aspergillus fumigatus and Aspergillus flavus remain the most commonly isolated species in aspergillosis, in the last decade, rare and cryptic Aspergillus species have emerged in diverse clinical settings. The present study

  2. Gene duplication, modularity and adaptation in the evolution of the aflatoxin gene cluster

    Directory of Open Access Journals (Sweden)

    Jakobek Judy L

    2007-07-01

    Full Text Available Abstract Background The biosynthesis of aflatoxin (AF involves over 20 enzymatic reactions in a complex polyketide pathway that converts acetate and malonate to the intermediates sterigmatocystin (ST and O-methylsterigmatocystin (OMST, the respective penultimate and ultimate precursors of AF. Although these precursors are chemically and structurally very similar, their accumulation differs at the species level for Aspergilli. Notable examples are A. nidulans that synthesizes only ST, A. flavus that makes predominantly AF, and A. parasiticus that generally produces either AF or OMST. Whether these differences are important in the evolutionary/ecological processes of species adaptation and diversification is unknown. Equally unknown are the specific genomic mechanisms responsible for ordering and clustering of genes in the AF pathway of Aspergillus. Results To elucidate the mechanisms that have driven formation of these clusters, we performed systematic searches of aflatoxin cluster homologs across five Aspergillus genomes. We found a high level of gene duplication and identified seven modules consisting of highly correlated gene pairs (aflA/aflB, aflR/aflS, aflX/aflY, aflF/aflE, aflT/aflQ, aflC/aflW, and aflG/aflL. With the exception of A. nomius, contrasts of mean Ka/Ks values across all cluster genes showed significant differences in selective pressure between section Flavi and non-section Flavi species. A. nomius mean Ka/Ks values were more similar to partial clusters in A. fumigatus and A. terreus. Overall, mean Ka/Ks values were significantly higher for section Flavi than for non-section Flavi species. Conclusion Our results implicate several genomic mechanisms in the evolution of ST, OMST and AF cluster genes. Gene modules may arise from duplications of a single gene, whereby the function of the pre-duplication gene is retained in the copy (aflF/aflE or the copies may partition the ancestral function (aflA/aflB. In some gene modules, the

  3. Occurrence of Aspergillus section Flavi and section Nigri and aflatoxins in raw cashew kernels (Anacardium occidentale L.) from Benin

    DEFF Research Database (Denmark)

    Lamboni, Yendouban; Frisvad, Jens Christian; Hell, Kerstin

    2016-01-01

    contamination, a total of 100 kernels/sample (with disinfection) and 40 kernels/sample (without disinfection) were plated. Seventy samples from fourteen villages were used. Aflatoxins occurrence was analysed on 84 samples by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS...... predominant, in NG and SS zones (90.2% and 87.2%) respectively. When non disinfected kernels were plated, A. section Nigri was predominant in both NG and SS zones, with percentages of 89.7% and 93.4%, respectively. None of the 84 nuts samples were positive for natural occurrence of aflatoxins with a detection...

  4. Radiation degradation of biological residues (Aflatoxins) produced in food laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Rogovschi, Vladimir D.; Aquino, Simone; Nunes, Thaise C.F.; Trindade, Reginaldo A.; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (brazil)]. E-mails: vladrogo@yahoo.com.br; villavic@ipen.br; Zorzete, Patricia; Correa, Benedito [Universidade de Sao Paulo, SP (Brazil). Inst. de Ciencias Biomedicas]. E-mail: correabe@usp.br

    2007-07-01

    Some molds have the capacity to produce substances that are toxic and generally cancer-causing agents, such as aflatoxins, that stand between the most important carcinogenic substances (class one of the agents which are certainly carcinogenous for human people according to the International Agency for Research on Cancer). Aspergillus spp. is present in world-wide distribution, with predominance in tropical and subtropical regions growing in any substratum. The aim of this work is establish a minimum dose of radiation that degrades aflatoxins produced by fungi Aspergillus spp. The Aspergillus spp. colonies will be cultivated in coconut agar medium and the samples will be conditioned in appropriate bags for irradiation treatment of contaminated material and processed in the Gammacell 220 with dose of 20 kGy. (author)

  5. Aflatoxin M1 in raw milk and binding of aflatoxin by lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Aflatoxin M1 in raw milk and binding of aflatoxin by lactic acid bacteria

    2010-12-01

    Full Text Available Aflatoxin M1 (AFM1 is potential human carcinogen. Its presence in milk and dairy products represents risk for human health. Therefore, this study was carried out in order to determine thedegree of microbiological contamination by mold, and the potential presence of aflatoxin M1 in 60 raw milk samples, randomly taken from individual producers from different regions of the continental Croatia. The most common genera isolated fungi were Geotrichum (78.3 %, Aspergillus (32.4 % and Penicillium (27.0 %. From total of 60 studied milk samples, 86.66 % were positive for the presence of aflatoxin M1, and 6.66 % of samples were above the prescribed limits. Lactic acid bacteria used in fermented dairy products as a starter culture may play a role in reduction of aflatoxin in foods and nutrients. In this paper the ability of lactic acid bacteria: Lactobacillus rhamnosus GG (ATCC 53103, Lactobacillus delbrueckii S1 and Lactobacillus plantarum A1 to bind aflatoxin M1 was investigated. Standard strain L. rhamnosus GG (ATCC 53103 and L. delbrueckii S1 can significantly (P50 % compared to L. plantarum A1, which binds AFM1 between 18.7 to 28.7 %.

  6. Occurrence of ochratoxin A- and aflatoxin B1-producing fungi in Lebanese grapes and ochratoxin a content in musts and finished wines during 2004.

    Science.gov (United States)

    El Khoury, André; Rizk, Toufic; Lteif, Roger; Azouri, Hayat; Delia, Marie-Line; Lebrihi, Ahmed

    2006-11-15

    This paper reports the results of an extensive survey on the occurrence of filamentous fungi isolated from wine-grapes in Lebanon and to test their ability to produce ochratoxin A (OTA) and aflatoxin B1 (AFB1) on CYA culture medium, in order to assess their potential for producing these mycotoxins on grapes. From the 470 grapes samples taken during season 2004, 550 fungi strains were isolated with 490 belonging to Aspergillus spp. and 60 belonging to Penicillium spp. All these isolated fungi starins were tested for their ability to produce OTA and AFB1. Aspergillus carbonarius shows that it is the only species able to produce OTA with a production percentage reaching 100% and a maximum concentration of 52.8 microg/g of Czapek yeast extract agar (CYA). In its turn, Aspergillus flavus was considered as the only AFB1-producing species with production percentage of 45.3% and a maximum concentration reaching 40 microg/g CYA. A total of 47 handmade musts produced from the collected grapes were also analyzed in order to correlate the presence of OTA in must and the occurrence of filamentous fungi on grapes; 57.4% were contaminated with OTA at low level with concentrations ranging between 0.011 and 0.221 microg OTA L(-1). The analysis of these must samples was not performed with regard to AFB1. Seventy samples of finish red wine were also assayed for OTA content. The results showed that 42 of the tested samples (60%) were found to be positive for OTA with low levels (0.012-0.126 microg OTA L(-1)).

  7. Detection of Aspergillus in lung and other tissue samples using the MycAssay Aspergillus real-time PCR kit.

    Science.gov (United States)

    Lass-Flörl, C; Follett, S A; Moody, A; Denning, D W

    2011-09-01

    The MycAssay™ Aspergillus real-time PCR kit was tested on tissues from patients with invasive fungal infections. Tissue samples from nine organ transplant recipients and 33 patients with haematological malignancy were from lung (n = 30), skin (n = 4), and others. Samples were preprocessed with proteinase K and lyticase, followed by DNA extraction and real-time PCR. For all samples, the sensitivity of the MycAssay Aspergillus test was 82% and specificity 79% relative to microscopy and 90% and 64%, respectively, compared with Aspergillus culture. The positive predictive value and negative predictive values compared with culture were 69% and 88% and were 88% and 69% compared with microscopy, respectively. The MycAssay Aspergillus test detected tissue invasive infections with Aspergillus fumigatus , Aspergillus flavus , and Aspergillus terreus.

  8. Septic arthritis due to tubercular and Aspergillus co-infection

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar

    2016-01-01

    Full Text Available Aspergillus septic arthritis is a rare and serious medical and surgical problem. It occurs mainly in immunocompromised patients. Aspergillus fumigatus is the most common causative organism followed by Aspergillus flavus. The most common site affected is knee followed by shoulder, ankle, wrist, hip and sacroiliac joint. Debridement and voriconazole are primary treatment of articular aspergilosis. To the best of our knowledge, there are no reported cases of co-infection of tuberculosis (TB and Aspergillus infecting joints. We report a case of co-infection of TB and A. flavus of hip and knee of a 60-year-old male, with type 2 diabetes mellitus. He was treated with debridement, intravenous voriconazole, and antitubercular drugs.

  9. Diversity in Secondary Metabolites Including Mycotoxins from Strains of Aspergillus Section Nigri Isolated from Raw Cashew Nuts from Benin, West Africa

    DEFF Research Database (Denmark)

    Lamboni, Leo Yendouban; Nielsen, Kristian Fog; Linnemann, Anita R.

    2016-01-01

    In a previous study, raw cashew kernels were assayed for the fungal contamination focusing on strains belonging to the genus Aspergillus and on aflatoxins producers. These samples showed high contamination with Aspergillus section Nigri species and absence of aflatoxins. To investigate the divers...

  10. Preparation of Labeled Aflatoxins with High Specific Activities

    Science.gov (United States)

    Hsieh, D. P. H.; Mateles, R. I.

    1971-01-01

    Resting cells of Aspergillus parasiticus ATCC 15517 were used to prepare highly labeled aflatoxins from labeled acetate. High synthetic activity in growing cells was evidenced only during 40 to 70 hr of incubation. Glucose was required for high incorporation efficiency, whereas the concentration of the labeled acetate determined the specific activity of the product. When labeled acetate was continuously added to maintain a concentration near but not exceeding 10 mm, in a culture containing 30 g of glucose per liter, 2% of its labels could be recovered in the purified aflatoxins which have a specific activity more than three times that of the labeled acetate. PMID:4329435

  11. ASPERGILLUS NIGER ASPERGILLUS NIGER

    African Journals Online (AJOL)

    eobe

    Additives such as low molecular weight alcohols, trace metals, phytate, lipids etc have been reported to stimulate citric acid production. Hence the objective of this study was to investigate the effect of stimulating the metabolic activity of activity of Aspergillus niger for the purpose of improved citric acid production from ...

  12. [Aflatoxin contamination level in artisanal and industrial peanut butter food in Dakar (Senegal)].

    Science.gov (United States)

    Diop, Y M; Ndiaye, B; Fall, M; Diouf, A; Sall, A; Ciss, M; Ba, D

    2000-01-01

    Aflatoxins are mycotoxins produced by some strains of fungus (Aspergillus) which develop in peanut seeds. Peanut oil and past are very used up in Senegal, then the aflatoxin poisoning risk is very actual. The aim of this study was to determinate the aflatoxin level in artisanal and industrial peanut pastry food from Dakar (Sénégal). High Performance Liquid Chromatography (HPLC) analysis of the different samples showed that the most contaminated by aflatoxins are artisanal pastry sold in different market of Dakar (Sénégal). Indeed, 40% of these samples contained mean values of aflatoxin B1 (the most dangerous) widely over allowable EEC specifications (5ppb). Furthermore, most of industrial and domestic peanut pastry were cleaned and could be consumed without risk.

  13. Aflatoxins: A Global Concern for Food Safety, Human Health and Their Management.

    Science.gov (United States)

    Kumar, Pradeep; Mahato, Dipendra K; Kamle, Madhu; Mohanta, Tapan K; Kang, Sang G

    2016-01-01

    The aflatoxin producing fungi, Aspergillus spp. , are widely spread in nature and have severely contaminated food supplies of humans and animals, resulting in health hazards and even death. Therefore, there is great demand for aflatoxins research to develop suitable methods for their quantification, precise detection and control to ensure the safety of consumers' health. Here, the chemistry and biosynthesis process of the mycotoxins is discussed in brief along with their occurrence, and the health hazards to humans and livestock. This review focuses on resources, production, detection and control measures of aflatoxins to ensure food and feed safety. The review is informative for health-conscious consumers and research experts in the fields. Furthermore, providing knowledge on aflatoxins toxicity will help in ensure food safety and meet the future demands of the increasing population by decreasing the incidence of outbreaks due to aflatoxins.

  14. Effect of gamma radiation on the inactivation of aflatoxin B1 in food and feed crops.

    Science.gov (United States)

    Ghanem, I; Orfi, M; Shamma, M

    2008-10-01

    Samples of food crops (peanut, peeled pistachio, unpeeled pistachio, rice, and corn) and feed (barley, bran, corn) were autoclave-sterilized, and inoculated with 10(6) of spore suspension of an isolate of Aspergillus flavus fungus known to produce aflatoxin B1 (AFB1) . Following a 10-day period of incubation at 27 C to allow for fungal growth, food and feed samples were irradiated with gamma radiation at the doses 4, 6, and 10 kGy. Results indicated that degradation of AFB1 was positively correlated with the increase in the applied dose of gamma ray for each tested sample. At a dose of 10 kGy percentages of AFB1 degradation reached highest values at 58.6, 68.8, 84.6, 81.1 and 87.8% for peanuts, peeled pistachios, unpeeled pistachios, corn and rice samples, respectively. In feed samples percentages of AFB1 degradation were 45, 66, and 90% in barley, 47, 75, and 86% in bran, and 31, 72, and 84% in corn for the doses of 4, 6, and 10 kGy, respectively. AFB1 degradation in food samples correlated negatively with oil content in irradiated samples. Thus, in peanuts, which contained the highest oil content, percentage of AFB1 degradation at 10 kGy was not more than 56.6%, whereas, the corresponding value in corn, which contained the lowest oil content, reached as high as 80%. The above results indicate the possibility of using gamma radiation as a means of degradation of AFB1 in food and feed crops to levels lower than the maximum allowed levels.

  15. Biological control of post harvest disease caused by Aspergillus ...

    African Journals Online (AJOL)

    Biological control of post harvest disease caused by Aspergillus flavus on stored lemon fruits. ... Erwinia chrysanthemi RK-67 and Bacillus subtilis RK-6 treatments reduced disease severity on both lemon cultivars. Furthermore, both the cell suspension and culture filtrates of Burkholderia cepacia strain RK- 277 reduced ...

  16. Biological control of post harvest disease caused by Aspergillus ...

    African Journals Online (AJOL)

    Antagonistic activity of 24 selected bacterial strains detected by previous microbiological studies to Aspergillus flavus was tested in vitro and in vivo conditions. Within 24 strains, only ten strains showed remarkable inhibition zone (6-34 mm) against the pathogen in assays carried out in Petri plates. Both cell suspension and ...

  17. Dietary exposure to aflatoxin from maize and groundnut in young children from Benin and Togo, West Africa.

    Science.gov (United States)

    Egal, S; Hounsa, A; Gong, Y Y; Turner, P C; Wild, C P; Hall, A J; Hell, K; Cardwell, K F

    2005-10-15

    Aflatoxins are a family of fungal toxins that are carcinogenic to man and cause immunosuppression, cancer and growth reduction in animals. We conducted a cross-sectional study among 480 children (age 9 months to 5 years) across 4 agro-ecological zones (SS, NGS, SGS and CS) in Benin and Togo to identify the effect of aflatoxin exposure on child growth and assess the pattern of exposure. Prior reports on this study [Gong, Y.Y.,Cardwell, K., Hounsa, A., Egal, S., Turner, Hall, A.J., Wild, C.P., 2002. Dietary aflatoxin exposure and impaired growth in young children from Benin and Togo: cross sectional study. British Medical Journal 325, 20-21, Gong, Y.Y., Egal, S., Hounsa, A., Turner, P.C., Hall, A.J., Cardwell, K., Wild, C.P., 2003. Determinants of aflatoxin exposure in young children from Benin and Togo, West Africa: the critical role of weaning and weaning foods. International Journal of Epidemiology, 32, 556-562] showed that aflatoxin exposure among these children is widespread (99%) and that growth faltering is associated with high blood aflatoxin-albumin adducts (AF-alb adducts), a measure of recent past exposure. The present report demonstrates that consumption of maize is an important source of aflatoxin exposure for the survey population. Higher AF-alb adducts were correlated with higher A. flavus (CFU) infestation of maize (p=0.006), higher aflatoxin contamination (ppb) of maize (phigher consumption frequencies of maize (p=0.053). The likelihood of aflatoxin exposure from maize was particularly high in agro-ecological zones where the frequency of maize consumption (SGS and CS), the presence of aflatoxin in maize (SGS) or the presence of A. flavus on maize (NGS and SGS) was relatively high. Socio-economic background did not affect the presence of A. flavus and aflatoxin in maize, but better maternal education was associated with lower frequencies of maize consumption among children from the northernmost agro-ecological zone (SS) (p=0.001). The impact of

  18. Photodynamic inactivation of Aspergillus flavus mediated by Bidens ...

    African Journals Online (AJOL)

    Occurrence of mycotoxins in food and animal feeds poses major health risks to human and animals, and effective control requires integration of crop management strategies both in the field and during post-harvest storage and processing. Photodynamic inactivation is a novel light-based approach which offers a promising ...

  19. Ocorrência de aflatoxinas em arroz consumido por militares do Exército Brasileiro por cromatografia em camada delgada e cromatografia líquida de alta eficiência Incidence of aflatoxins in rice to be consumed by militaries in the brazilian army by thin layer chromatography and high performance liquid chromatography methods

    Directory of Open Access Journals (Sweden)

    Jader Oliveira da Silva

    2008-08-01

    Full Text Available Fungos do gênero Aspergillus como A. flavus e A. parasiticus são capazes de produzir metabólitos secundários tóxicos denominados aflatoxinas. Estas espécies podem se desenvolver rapidamente em cereais sob condições favoráveis. A partir do conhecimento dos riscos à saúde decorrentes da presença de aflatoxinas em alimentos, foi realizado um levantamento para avaliar a presença de aflatoxinas em arroz beneficiado polido tipo I, destinado ao consumo dos militares do Exército Brasileiro. As amostras foram coletadas no armazém do 5º Batalhão de Suprimento do Exército Brasileiro, Curitiba-PR no período de novembro de 2003 a fevereiro de 2004 e avaliada a ocorrência de aflatoxinas B1, B2, G1 e G2, utilizando-se as técnicas de Cromatografia em Camada Delgada (CCD e Cromatografia Líquida de Alta Eficiência (CLAE. Objetivou-se, neste trabalho, contribuir com o controle de qualidade dos alimentos consumidos pelos militares da 5º Região Militar do Exército Brasileiro, no que se refere ao controle dos níveis de aflatoxinas e comparar as técnicas de CCD e CLAE. Do total de 30 amostras analisadas por cromatografia em camada delgada, não foi verificada em nenhuma a presença de aflatoxinas. De 26 amostras analisadas por cromatografia líquida de alta eficiência, seis (23,07% apresentaram positividade para aflatoxina B1 (AFB1, com níveis entre 0,54 e 2,04µg/kg e uma (3,84% apresentou presença de aflatoxina B2 (AFB2 com 1,84µg/kg.Aspergillus are fungal species like a A flavus and A parasiticus and they are able to develop secondary metabolites called mycotoxins. They grow quickly under ideal conditions. From the moment one discovered its danger for health resulted from the presence of aflatoxins in foods, an achievement was carried out to evaluate the presence of a mycotoxins lifiting in benefited polished rice type 1, used by Brazilian army. The samples were collected at " 5º Batalhão de Suprimento" (army departament from

  20. Post-operative Aspergillus mediastinitis in a man who was immunocompetent: a case report

    Directory of Open Access Journals (Sweden)

    Orfanos Stylianos

    2010-09-01

    Full Text Available Abstract Introduction Aspergillus spp. infections mainly affect patients who are immunocompromised, and are extremely rare in immunocompetent individuals. Case presentation Aspergillus post-operative mediastinitis is considered to be a devastating infection, usually affecting patients undergoing cardiothoracic surgery with specific predisposing factors. We describe the case of an immunocompetent 68-year-old Caucasian man with severe chronic thromboembolic pulmonary hypertension, who underwent pulmonary thromboendarterectomy and developed post-operative mediastinitis due to Aspergillus flavus. The environmental control did not reveal the source of A. flavus infection and, despite combined antifungal therapy, our patient died as a result of septic shock and multiple organ failure. Conclusion Aspergillus mediastinitis mainly affects patients after cardiosurgery operations with predisposing factors, and it is unusual in patients who are immunocompetent. The identification of the Aspergillus spp. source is often difficult, and there are no guidelines for the administration of pre-emptive therapy in this population of at-risk patients.

  1. Rapid detection of aflatoxigenic Aspergillus sp. in herbal specimens by a simple, bendable, paper-based lab-on-a-chip.

    Science.gov (United States)

    Chaumpluk, Piyasak; Plubcharoensook, Pattra; Prasongsuk, Sehanat

    2016-06-01

    Postharvest herbal product contamination with mycotoxins and mycotoxin-producing fungi represents a potentially carcinogenic hazard. Aspergillus flavus is a major cause of this issue. Available mold detection methods are PCR-based and rely heavily on laboratories; thus, they are unsuitable for on-site monitoring. In this study, a bendable, paper-based lab-on-a-chip platform was developed to rapidly detect toxigenic Aspergillus spp. DNA. The 3.0-4.0 cm(2) chip is fabricated using Whatman™ filter paper, fishing line and a simple plastic lamination process and has nucleic acid amplification and signal detection components. The Aspergillus assay specifically amplifies the aflatoxin biosynthesis gene, aflR, using loop-mediated isothermal amplification (LAMP); hybridization between target DNA and probes on blue silvernanoplates (AgNPls) yields colorimetric results. Positive results are indicated by the detection pad appearing blue due to dispersed blue AgNPls; negative results are indicated by the detection pad appearing colorless or pale yellow due to probe/target DNA hybridization and AgNPls aggregation. Assay completion requires less than 40 min, has a limit of detection (LOD) of 100 aflR copies, and has high specificity (94.47%)and sensitivity (100%). Contamination was identified in 14 of 32 herbal samples tested (43.75%). This work demonstrates the fabrication of a simple, low-cost, paper-based lab-on-a-chip platform suitable for rapid-detection applications. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Control of Aspergillus niger with garlic, onion and leek extracts

    African Journals Online (AJOL)

    Administrator

    2007-02-19

    Feb 19, 2007 ... Condiments Chemistry,Microbiology ,Technology.Academic Press,. San Fransisco,pp 35-305. Rasooli I, Abyaneh MR (2004).Inhibitory effects of thyme oils on growth and aflatoxin production by Aspergillus parasiticus. Food Control. 15: 479-483. Rivlin RS (2001). Historical perspective on the use of garlic.

  3. Impact of bioactive packaging systems based on EVOH films and essential oils in the control of aflatoxigenic fungi and aflatoxin production in maize.

    Science.gov (United States)

    Mateo, Eva M; Gómez, José V; Domínguez, Irene; Gimeno-Adelantado, Jose V; Mateo-Castro, Rufino; Gavara, Rafael; Jiménez, Misericordia

    2017-08-02

    Aspergillus flavus and A. parasiticus are the most common fungal species associated with aflatoxin (AF) contamination of cereals, especially maize, and other agricultural commodities. AFB 1, the most frequent and toxic metabolite, is a powerful hepatotoxic, teratogenic and mutagenic compound. Effective strategies to control these fungal species and AFs in food and feed are required. Active packaging film containing essential oils (EO) is one of the most innovative food packaging concepts. In this study, ethylene-vinyl alcohol (EVOH) copolymer films incorporating EO from Origanum vulgare (ORE), Cinnamomum zeylanicum (CIN) or their major active constituents, carvacrol (CAR) and cinnamaldehyde (CINHO), respectively, were developed and assayed to control growth of A. flavus and A. parasiticus and AF production in maize grains under different a w and temperature regimens. EO doses assayed in cultures were in the range 0.25-4.0mg/Petri dish. The factors a w , temperature, type of EVOH-EO film and fungal species significantly influenced the ED 50 values of all assayed films. Growth rate (GR) of both species was usually higher at 0.99 than at 0.96 a w and at 37°C than at 25°C. However, the contrary was found with regard to AF production. The order of efficacy of EVOH-EO films to control growth of both species and AF production was EVOH-CINHO>EVOH-CAR>EVOH-ORE>EVOH-CIN. The effective dose (ED 50 ) (mg EO/plate) for EVOH-CINHO and EVOH-CIN films against A. flavus were in the ranges of 0.125 and 2.475-3.500 and against A. parasiticus in the ranges of 0.121-0.133 and 2.275-3.625, respectively. Under the assayed conditions, the ED 90 for EVOH-CINHO film were 0.22-0.23mg/plate for both species. It was the most effective bioactive film to control fungal growth (vapour phase) and AF production, regardless of a w and temperature. This is the first study about the impact that interacting environmental conditions and bioactive EVOH-CINHO, EVOH-ORE, EVOH-CIN EVOH-CAR films have on

  4. Aflatoxin-free transgenic maize using host-induced gene silencing.

    Science.gov (United States)

    Thakare, Dhiraj; Zhang, Jianwei; Wing, Rod A; Cotty, Peter J; Schmidt, Monica A

    2017-03-01

    Aflatoxins, toxic secondary metabolites produced by some Aspergillus species, are a universal agricultural economic problem and a critical health issue. Despite decades of control efforts, aflatoxin contamination is responsible for a global loss of millions of tons of crops each year. We show that host-induced gene silencing is an effective method for eliminating this toxin in transgenic maize. We transformed maize plants with a kernel-specific RNA interference (RNAi) gene cassette targeting the aflC gene, which encodes an enzyme in the Aspergillus aflatoxin biosynthetic pathway. After pathogen infection, aflatoxin could not be detected in kernels from these RNAi transgenic maize plants, while toxin loads reached thousands of parts per billion in nontransgenic control kernels. A comparison of transcripts in developing aflatoxin-free transgenic kernels with those from nontransgenic kernels showed no significant differences between these two groups. These results demonstrate that small interfering RNA molecules can be used to silence aflatoxin biosynthesis in maize, providing an attractive and precise engineering strategy that could also be extended to other crops to improve food security.

  5. Aspergillus parasiticus communities associated with sugarcane in the Rio Grande Valley of Texas: implications of global transport and host association within Aspergillus section Flavi.

    Science.gov (United States)

    Garber, N P; Cotty, P J

    2014-05-01

    In the Rio Grande Valley of Texas (RGV), values of maize and cottonseed crops are significantly reduced by aflatoxin contamination. Aflatoxin contamination of susceptible crops is the product of communities of aflatoxin producers and the average aflatoxin-producing potentials of these communities influence aflatoxin contamination risk. Cropping pattern influences community composition and, thereby, the epidemiology of aflatoxin contamination. In 2004, Aspergillus parasiticus was isolated from two fields previously cropped to sugarcane but not from 23 fields without recent history of sugarcane cultivation. In 2004 and 2005, A. parasiticus composed 18 to 36% of Aspergillus section Flavi resident in agricultural soils within sugarcane-producing counties. A. parasiticus was not detected in counties that do not produce sugarcane. Aspergillus section Flavi soil communities within sugarcane-producing counties differed significantly dependent on sugarcane cropping history. Fields cropped to sugarcane within the previous 5 years had greater quantities of A. parasiticus (mean = 16 CFU/g) than fields not cropped to sugarcane (mean = 0.1 CFU/g). The percentage of Aspergillus section Flavi composed of A. parasiticus increased to 65% under continuous sugarcane cultivation and remained high the first season of rotation out of sugarcane. Section Flavi communities in fields rotated to non-sugarcane crops for 3 to 5 years were composed of history averaged only 0.2% A. parasiticus. The section Flavi community infecting RGV sugarcane stems ranged from 95% A. parasiticus in billets prepared for commercial planting to 52% A. parasiticus in hand-collected sugarcane stems. Vegetative compatibility assays and multilocus phylogenies verified that aflatoxin contamination of raw sugar was previously attributed to similar A. parasiticus in Japan. Association of closely related A. parasiticus genotypes with sugarcane produced in Japan and RGV, frequent infection of billets by these genotypes

  6. Use of Probiotics to Control Aflatoxin Production in Peanut Grains

    Science.gov (United States)

    da Silva, Juliana Fonseca Moreira; Peluzio, Joenes Mucci; Madeira, Jovita Eugênia Gazzinelli Cruz; Silva, Marize Oliveira; de Morais, Paula Benevides; Rosa, Carlos Augusto; Pimenta, Raphael Sanzio; Nicoli, Jacques Robert

    2015-01-01

    Probiotic microorganisms (Saccharomyces cerevisiae var. boulardii, S. cerevisiae UFMG 905, and Lactobacillus delbrueckii UFV H2b20) were evaluated as biological control agents to reduce aflatoxin and spore production by Aspergillus parasiticus IMI 242695 in peanut. Suspensions containing the probiotics alone or in combinations were tested by sprinkling on the grains followed by incubation for seven days at 25°C. All probiotic microorganisms, in live and inactivated forms, significantly reduced A. parasiticus sporulation, but the best results were obtained with live cells. The presence of probiotics also altered the color of A. parasiticus colonies but not the spore morphology. Reduction in aflatoxin production of 72.8 and 65.8% was observed for S. boulardii and S. cerevisiae, respectively, when inoculated alone. When inoculated in pairs, all probiotic combinations reduced significantly aflatoxin production, and the best reduction was obtained with S. boulardii plus L. delbrueckii (96.1%) followed by S. boulardii plus S. cerevisiae and L. delbrueckii plus S. cerevisiae (71.1 and 66.7%, resp.). All probiotics remained viable in high numbers on the grains even after 300 days. The results of the present study suggest a different use of probiotics as an alternative treatment to prevent aflatoxin production in peanut grains. PMID:26221629

  7. Use of Probiotics to Control Aflatoxin Production in Peanut Grains

    Directory of Open Access Journals (Sweden)

    Juliana Fonseca Moreira da Silva

    2015-01-01

    Full Text Available Probiotic microorganisms (Saccharomyces cerevisiae var. boulardii, S. cerevisiae UFMG 905, and Lactobacillus delbrueckii UFV H2b20 were evaluated as biological control agents to reduce aflatoxin and spore production by Aspergillus parasiticus IMI 242695 in peanut. Suspensions containing the probiotics alone or in combinations were tested by sprinkling on the grains followed by incubation for seven days at 25°C. All probiotic microorganisms, in live and inactivated forms, significantly reduced A. parasiticus sporulation, but the best results were obtained with live cells. The presence of probiotics also altered the color of A. parasiticus colonies but not the spore morphology. Reduction in aflatoxin production of 72.8 and 65.8% was observed for S. boulardii and S. cerevisiae, respectively, when inoculated alone. When inoculated in pairs, all probiotic combinations reduced significantly aflatoxin production, and the best reduction was obtained with S. boulardii plus L. delbrueckii (96.1% followed by S. boulardii plus S. cerevisiae and L. delbrueckii plus S. cerevisiae (71.1 and 66.7%, resp.. All probiotics remained viable in high numbers on the grains even after 300 days. The results of the present study suggest a different use of probiotics as an alternative treatment to prevent aflatoxin production in peanut grains.

  8. Evidence for an association in corn between stress tolerance and ...

    African Journals Online (AJOL)

    Aflatoxins are carcinogenic secondary metabolites produced mainly by Aspergillus flavus during infection of susceptible crops, such as corn. A. flavus infection and subsequent aflatoxin contamination is a serious issue in the southern US, especially during a drought. Field studies demonstrate that reduction of drought stress ...

  9. Aspergillus triggers phenazine production in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib

    Aspergillus species. Methods: A suspension of fungal spores was streaked onto WATM agar plates. After 24 hours incubation at 37 °C, a P. aeruginosa overnight culture was streaked out perpendicular to the fungal streak. The plates were incubated at 37 °C for five days, examined and plugs were extracted...... for HPLC-DAD and HPLC-DAD-MS analysis. Results: P. aeruginosa PAO1 suppressed growth of A. fumigatus, A. niger, A. flavus, A. oryzae, A. terreus and Emericella nidulans. HPLC and HPLC-DAD-MS results showed an increase in phenazine-1-carboxylic acid and phenazine-1-carboxamide production by P. aeruginosa...

  10. Suppression of Aspergillus by Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib

    culture plates. After 24 hours incubation at 37 °C, a P. aeruginosa overnight culture diluted to 108 CFU/ml was streaked out perpendicular to the fungal streak. The plates were incubated at 37 °C for 5 days, examined and plugs were extracted for HPLC and LC-DAD-MS analysis. Results: P. aeruginosa PAO1...... suppressed growth of A. fumigatus, A. niger, A. flavus, A. oryzae, A. terreus and E. nidulans. HPLC and LC-DAD-MS results showed an increase in phenazine-1-carboxylic acid and phenazine-1-carboxamide production by P. aeruginosa in the contact area of Aspergillus. Different quinolones were also identified...

  11. Biosynthesis and Characterization of Silver Nanoparticles by Aspergillus Species

    OpenAIRE

    Zomorodian, K.; Pourshahid, S; Sadatsharifi, A; Mehryar, P; Pakshir, K.; Rahimi, MJ; Monfared, AA

    2016-01-01

    Currently, researchers turn to natural processes such as using biological microorganisms in order to develop reliable and ecofriendly methods for the synthesis of metallic nanoparticles. In this study, we have investigated extracellular biosynthesis of silver nanoparticles using four Aspergillus species including A. fumigatus, A. clavatus, A. niger, and A. flavus. We have also analyzed nitrate reductase activity in the studied species in order to determine the probable role of this enzyme in ...

  12. Static Hot Air and Infrared Rays Roasting are Efficient Methods for Aflatoxin Decontamination on Hazelnuts.

    Science.gov (United States)

    Siciliano, Ilenia; Dal Bello, Barbara; Zeppa, Giuseppe; Spadaro, Davide; Gullino, Maria Lodovica

    2017-02-21

    Aflatoxins are a group of secondary metabolites produced by members of Aspergillus Section Flavi that are dangerous to humans and animals. Nuts can be potentially contaminated with aflatoxins, often over the legal threshold. Food processes, including roasting, may have different effects on mycotoxins, and high temperatures have proven to be very effective in the reduction of mycotoxins. In this work, two different roasting methods-traditional static hot air roasting and infra-red rays roasting-were applied and compared for the detoxification of hazelnuts from Italy and Turkey. At the temperature of 140 °C for 40 min of exposure, detoxification was effective for both roasting techniques. Residual aflatoxins after infra-red rays treatments were lower compared to static hot air roasting. On Italian hazelnuts, residual aflatoxins were lower than 5%, while for Turkish hazelnuts they were lower than 15% after 40 min of exposure to an infra-red rays roaster. After roasting, the perisperm was detached from the nuts and analyzed for aflatoxin contents. Residual aflatoxins in the perisperm ranged from 80% up to 100%. After roasting, the lipid profile and the nutritional quality of hazelnuts were not affected. Fatty acid methyl esters analyses showed a similar composition for Italian and Turkish hazelnuts.

  13. Static Hot Air and Infrared Rays Roasting are Efficient Methods for Aflatoxin Decontamination on Hazelnuts

    Directory of Open Access Journals (Sweden)

    Ilenia Siciliano

    2017-02-01

    Full Text Available Aflatoxins are a group of secondary metabolites produced by members of Aspergillus Section Flavi that are dangerous to humans and animals. Nuts can be potentially contaminated with aflatoxins, often over the legal threshold. Food processes, including roasting, may have different effects on mycotoxins, and high temperatures have proven to be very effective in the reduction of mycotoxins. In this work, two different roasting methods—traditional static hot air roasting and infra-red rays roasting—were applied and compared for the detoxification of hazelnuts from Italy and Turkey. At the temperature of 140 °C for 40 min of exposure, detoxification was effective for both roasting techniques. Residual aflatoxins after infra-red rays treatments were lower compared to static hot air roasting. On Italian hazelnuts, residual aflatoxins were lower than 5%, while for Turkish hazelnuts they were lower than 15% after 40 min of exposure to an infra-red rays roaster. After roasting, the perisperm was detached from the nuts and analyzed for aflatoxin contents. Residual aflatoxins in the perisperm ranged from 80% up to 100%. After roasting, the lipid profile and the nutritional quality of hazelnuts were not affected. Fatty acid methyl esters analyses showed a similar composition for Italian and Turkish hazelnuts.

  14. Microclimatic conditions of Lasius flavus ant mounds

    Science.gov (United States)

    Véle, Adam; Holuša, Jaroslav

    2017-05-01

    Like other organisms, ants require suitable microclimatic conditions for their development. Thus, ant species inhabiting colder climates build nest mounds that rise above the soil surface, presumably to obtain heating from solar radiation. Although some ant species construct mounds of organic materials, which generate substantial heat due to microbial metabolism, Lasius flavus mounds consists mostly of soil, not organic material. The use of artificial shading in the current study demonstrated that L. flavus depends on direct solar radiation to regulate the temperature in its mound-like nests. Temperatures were much lower in shaded mounds than in unshaded mounds and were likely low enough in shaded mounds to reduce ant development and reproduction. In areas where L. flavus and similar ants are undesirable, they might be managed by shading.

  15. UJAS 21.pmd

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    23. Host resistance to Aspergillus flavus and Aflatoxin accumulation combining ability (SCA) and heritability for. A. flavus resistance, and (iii) determining the relationship between A. flavus infection and agronomic traits. Screening for resistance involved artificial field inoculation followed by laboratory assessment of infection ...

  16. Density and Molecular Epidemiology of Aspergillus in Air and Relationship to Outbreaks of Aspergillus Infection

    Science.gov (United States)

    Leenders, Alexander C. A. P.; van Belkum, Alex; Behrendt, Myra; Luijendijk, Ad; Verbrugh, Henri A.

    1999-01-01

    After five patients were diagnosed with nosocomial invasive aspergillosis caused by Aspergillus fumigatus and A. flavus, a 14-month surveillance program for pathogenic and nonpathogenic fungal conidia in the air within and outside the University Hospital in Rotterdam (The Netherlands) was begun. A. fumigatus isolates obtained from the Department of Hematology were studied for genetic relatedness by randomly amplified polymorphic DNA (RAPD) analysis. This was repeated with A. fumigatus isolates contaminating culture media in the microbiology laboratory. The density of the conidia of nonpathogenic fungi in the outside air showed a seasonal variation: higher densities were measured during the summer, while lower densities were determined during the fall and winter. Hardly any variation was found in the numbers of Aspergillus conidia. We found decreasing numbers of conidia when comparing air from outside the hospital to that inside the hospital and when comparing open areas within the hospital to the closed department of hematology. The increase in the number of patients with invasive aspergillosis could not be explained by an increase in the number of Aspergillus conidia in the outside air. The short-term presence of A. flavus can only be explained by the presence of a point source, which was probably patient related. Genotyping A. fumigatus isolates from the department of hematology showed that clonally related isolates were persistently present for more than 1 year. Clinical isolates of A. fumigatus obtained during the outbreak period were different from these persistent clones. A. fumigatus isolates contaminating culture media were all genotypically identical, indicating a causative point source. Knowledge of the epidemiology of Aspergillus species is necessary for the development of strategies to prevent invasive aspergillosis. RAPD fingerprinting of Aspergillus isolates can help to determine the cause of an outbreak of invasive aspergillosis. PMID:10325319

  17. The comparison of total fumonisin and total aflatoxin levels in biscuit and cookie samples in babol city, northern iran.

    Science.gov (United States)

    Gholamour Azizi, Issa; Rouhi, Samaneh

    2013-01-01

    Fumonisins and aflatoxins are mycotoxins that are produced by Fusarium and Aspergillus genus respectively. Due to the toxicity of aflatoxin and fumonisin and its effects on human and animals' health, the purpose of this study was analysis of total fumonisin and total aflatoxin contamination in biscuit and cookie samples in Babol City, Northern Iran. Thirty biscuit (n=15) and cookie (n=15) samples were randomly collected at supermarkets in Babol City in winter 2011. Competitive ELISA was conducted for total fumonisin and total aflatoxin separately. Out of 30 biscuit and cookie samples, 28 (93.4%) samples were contaminated with 4ppm of total fumonisin. From 30 samples, 26 (86.7%) were contaminated with cookies are extensively used among all ages of humans, consumption of contaminated food causes different diseases in human. Therefore, determination, management, and prevention of mycotoxins according to the climatic conditions should be considered.

  18. Production of M-/GM-group aflatoxins catalyzed by the OrdA enzyme in aflatoxin biosynthesis.

    Science.gov (United States)

    Yabe, Kimiko; Chihaya, Naomi; Hatabayashi, Hidemi; Kito, Masako; Hoshino, Sachiko; Zeng, Hongmei; Cai, Jingjing; Nakajima, Hiromitsu

    2012-09-01

    Aspergillus parasiticus produces the minor aflatoxins M(1) (AFM(1)), M(2) (AFM(2)), GM(1) (AFGM(1)), and GM(2) (AFGM(2)), as well as the major aflatoxins B(1) (AFB(1)), B(2) (AFB(2)), G(1) (AFG(1)), and G(2) (AFG(2)). Feeding of A. parasiticus with aspertoxin (12c-hydroxyOMST) caused AFM(1) and AFGM(1), and cell-free experiments using the microsomal fraction of A. parasiticus and aspertoxin caused production of AFM(1), indicating that aspertoxin is a precursor of AFM(1) and AFGM(1). Feeding of the same fungus with O-methylsterigmatocystin (OMST) caused AFM(1) and AFGM(1) together with AFB(1) and AFG(1); feeding with dihydroOMST (DHOMST) caused AFM(2) and AFGM(2) together with AFB(2) and AFG(2). Incubation of either the microsomal fraction or OrdA enzyme-expressing yeast with OMST caused production of aspertoxin together with AFM(1) and AFB(1). These results demonstrated that the OrdA enzyme catalyzes both 12c-hydroxylation reaction from OMST to aspertoxin and the successive reaction from aspertoxin to AFM(1). In contrast, feeding of the fungus with AFB(1) did not produce any AFM(1), demonstrating that M-/GM-aflatoxins are not produced from B-/G-aflatoxins. Furthermore, AFM(1) together with AFB(1) and AFG(1) was also produced from 11-hydroxyOMST (HOMST) in feeding experiment of A. parasiticus, whereas no aflatoxins were produced when used the ordA deletion mutant. These results demonstrated that OrdA enzyme can also catalyze 12c-hydroxylation of HOMST to produce 11-hydroxyaspertoxin, which serves as a precursor for the production of AFM(1) and AFGM(1). The same pathway may work for the production of AFM(2) and AFGM(2) from DHOMST and dihydroHOMST through the formation of dihydroaspertoxin and dihydro-11-hydroxyaspertoxin, respectively. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. The comparison of CHCA solvent compositions for improving LC-MALDI performance and its application to study the impact of aflatoxin B1 on the liver proteome of diabetes mellitus type 1 mice.

    Directory of Open Access Journals (Sweden)

    Fuu-Jen Tsai

    Full Text Available In nanoflow liquid chromatography-matrix-assisted laser desorption/ionization tandem time-of-flight (nanoLC-MALDI-TOF/TOF approaches, it is critical to directly apply small amounts of the sample elutes on the sample target using a nanoLC system due to its low flow rate of 200 ~ 300 nl/min. It is recommended to apply a sheath liquid containing a matrix with a several μL/min flow rate at the end of the nanoLC column to ensure a larger co-eluted droplet for more reproducible sample spotting and avoid the laborious task of post-manual matrix spotting. In this study, to achieve a better nanoLC-MALDI performance on sample spotting, we first compared α-Cyano-4-hydroxycinnamic acid (CHCA solvent composition for efficiently concentrating nanoLC elutes on an anchor chip. The solvent composition of isopropanol (IPA: acetonitrile (ACN:acetone:0.1% Trifluoroacetic acid (TFA (2:7:7:2 provided strong and homogeneous signals with higher peptide ion yields than the other solvent compositions. Then, nanoLC-MALDI-TOF/TOF was applied to study the impact of aflatoxin B1 on the liver proteome from diabetes mellitus type 1 mice. Aflatoxin B1 (AFB1, produced by Aspergillus flavus and Aspergillus parasiticus is a carcinogen and a known causative agent of liver cancer. To evaluate the effects of long-term exposure to AFB1 on type 1 diabetes mellitus (TIDM, the livers of T1DM control mice and mice treated with AFB1 were analyzed using isotope-coded protein labeling (ICPL-based quantitative proteomics. Our results showed that gluconeogenesis, lipid, and oxidative phosphorylation mechanisms, normally elevated in T1DM, were disordered following AFB1 treatment. In addition, major urinary protein 1 (MUP1, an indicator of increased insulin sensitivity, was significantly decreased in the T1DM/AFB1 group and may have resulted in higher blood glucose levels compared to the T1DM group. These results indicate that T1DM patients should avoid the AFB1 intake, as they could lead to

  20. Emericella venezuelensis, a new species with stellate ascospores producing sterigmatocystin and aflatoxin B-1

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Samson, R.A.

    2004-01-01

    Emericella venezuelensis is a new species, differing from two other species with stellate ascospores, E. variecolor and E. pluriseminata, by triangular flaps on the convex sides of the ascospores, and further from E. variecolor by producing an Aspergillus anamorph only on unconventional growth...... media. The three species also differ in their profiles of extrolites (secondary metabolites). Emericella venezuelensis produces aflatoxin B-1, sterigmatocystin, and terrein and compounds with chromophores of the shamixanthone, emerin and desertorin type of compounds. F. variecolor produces asteltoxin......, variecoxanthone A, B, C, isoemericellin, kojic acid, varitriol, varioxiran, dihydroterrein, 7-hydroxyemodin, avariquinone and stromemycin. E. pluriseminata produces several unknown specific extrolites. E. venezuelensis is the first organism of marine origin reported to produce aflatoxin. Aflatoxin production by E...