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Sample records for control aspergillus flavus

  1. 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): ...

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

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... the biocontrol agents tested, culture filtrate of Rhodococcus erythropolis completely inhibited the A. ... major risk factor, and according to the Food and .... Kernel infection and aflatoxin production in peanut (Arachis hypogaea L) by Aspergillus flavus in presence of geocarpospheric bacteria. J. Food Sci.

  3. Aspergillus flavus: the major producer of aflatoxin.

    Science.gov (United States)

    Klich, Maren A

    2007-11-01

    SUMMARY Aspergillus flavus is an opportunistic pathogen of crops. It is important because it produces aflatoxin as a secondary metabolite in the seeds of a number of crops both before and after harvest. Aflatoxin is a potent carcinogen that is highly regulated in most countries. In the field, aflatoxin is associated with drought-stressed oilseed crops including maize, peanut, cottonseed and tree nuts. Under the right conditions, the fungus will grow and produce aflatoxin in almost any stored crop seed. In storage, aflatoxin can be controlled by maintaining available moisture at levels below that which will support growth of A. flavus. A number of field control measures are being utilized or explored, including: modification of cultural practices; development of resistant crops through molecular and proteomic techniques; competitive exclusion using strains that do not produce aflatoxin; and development of field treatments that would block aflatoxin production. Aspergillus flavus Link (teleomorph unknown) kingdom Fungi, phyllum Ascomycota, order Eurotiales, class Eurotiomycetes, family Trichocomaceae, genus Aspergillus, species flavus. Aspergillus flavus has a broad host range as an opportunistic pathogen/saprobe. It is an extremely common soil fungus. The major concern with this fungus in agriculture is that it produces highly carcinogenic toxins called aflatoxins which are a health hazard to animals. In the field, A. flavus is predominantly a problem in the oilseed crops maize, peanuts, cottonseed and tree nuts. Under improper storage conditions, A. flavus is capable of growing and forming aflatoxin in almost any crop seed. It also is a pathogen of animals and insects. In humans it is predominantly an opportunistic pathogen of immunosuppressed patients. http://www.aspergillusflavus.org, http://www.aflatoxin.info/health.asp, plantpathology.tamu.edu/aflatoxin, http://www.aspergillus.org.uk.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

    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.

  5. Aflatoxin biosynthesis control produced by Aspergillus flavus in layer hens feed during storage period of six months.

    Science.gov (United States)

    Hassan, S M; Sultana, B; Iqbal, M

    2017-06-01

    Aflatoxins (AFTs) are a group of closely related toxins that are produced by different fungus species. Food and feed contamination with AFT is a worldwide health-related problem. As a result of fungal attack, the food and feed resulted in a principal socioeconomic loss and toxins produced in feed and food items harm the humans and animals in different ways. The anti-aflatoxigenic effect Psidium guajava, Ficus benghalensis, Gardenia radicans, Punica granatum and Ziziphus jujuba leaves were evaluated against aflatoxins (AFTs), produced by Aspergillus flavus in layer feed during storage. Among the investigated medicinal plant leaves, P. granatum showed highly promising anti-aflatoxigenic activity and completely inhibited the AFTs (B1 and B2) production over storage period without compromising the nutritive quality of feed (ash, protein, fat, fiber, Fe, Ca, P and K contents). Leaves of F. benghalensis and Z. jujuba were also effective however, higher concentration (15%) inhibited the AFTs production up to 99% and also maintained nutritive quality of feed. G. radicans was found least effective in controlling the AFTs production. Results revealed that all plant leaves were effective in controlling AFTs production in layer feed over the storage period of six months and these plants are potential candidate to replace the fungicides used to protect feed and other agricultural commodities from AFTs production during storage. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Aspergillus Flavus Keratitis after Deep Anterior Lamellar Keratoplasty

    Directory of Open Access Journals (Sweden)

    Mohammad-Reza Jafarinasab

    2012-01-01

    Full Text Available Purpose: To report the clinical, microbiologic, confocal scan and histopathologic features of Aspergillus flavus keratitis which developed immediately after deep anterior lamellar keratoplasty (DALK. Case Report: A 28-year-old woman underwent DALK using the big-bubble technique for keratoconus. The operation was uneventful, yielding a bare Descemet′s membrane (DM followed by transplantation of a corneal graft devoid of DM and endothelium. Four days after keratoplasty, mild infiltrates were noticed in the inferonasal margin of the graft, which rapidly progressed to involve the adjacent recipient cornea. Confocal scan findings suggested filamentous fungal keratitis, leading to initiation of topical and systemic antifungal medications followed by immediate replacement of the graft. Histopathologic examination disclosed keratitis caused by a filamentous fungus, which was determined by microbiologic cultures to be Aspergillus flavus. Early diagnosis and appropriate management resulted in complete recovery from this potentially devastating infection. Conclusion: Aspergillus Flavus can cause graft ulcers immediately after DALK. Confocal scan proved to be a valuable tool for early diagnosis and prompt intervention to control this otherwise devastating infection.

  7. 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.

  8. 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...

  9. 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.

  10. Studies on the control of fungal contamination and aflatoxin production by Aspergillus flavus link in a cereal grain by the combination treatment of heat and irradiation

    NARCIS (Netherlands)

    Odamtten, G.T.

    1986-01-01

    Traditional storage of maize in tropical countries such as Ghana results in the rapid development of numerous fungi, including potential mycotoxin producers such as Aspergillus flavus (aflatoxins), A. ochraceus (ochratoxins, penicillic acid),

  11. Control of Aspergillus flavus growth and aflatoxin production in transgenic maize kernels expressing a tachyplesin-derived synthetic peptide, AGM182

    Science.gov (United States)

    Aspergillus flavus (A. flavus) is an opportunistic, saprophytic fungus that infects maize and other fatty acid-rich food and feed crops and produces toxic and carcinogenic secondary metabolites known as aflatoxins. Contamination of maize with aflatoxin poses a serious threat to human health in addit...

  12. Control of Aspergillus flavus growth and aflatoxin production in transgenic maize kernels expressing a tachyplesin-derived synthetic peptide, AGM182.

    Science.gov (United States)

    Rajasekaran, Kanniah; Sayler, Ronald J; Sickler, Christine M; Majumdar, Rajtilak; Jaynes, Jesse M; Cary, Jeffrey W

    2018-05-01

    Aspergillus flavus is an opportunistic, saprophytic fungus that infects maize and other fatty acid-rich food and feed crops and produces toxic and carcinogenic secondary metabolites known as aflatoxins. Contamination of maize with aflatoxin poses a serious threat to human health in addition to reducing the crop value leading to a substantial economic loss. Here we report designing a tachyplesin1-derived synthetic peptide AGM182 and testing its antifungal activity both in vitro and in planta. In vitro studies showed a five-fold increase in antifungal activity of AGM182 (vs. tachyplesin1) against A. flavus. Transgenic maize plants expressing AGM182 under maize Ubiquitin-1 promoter were produced through Agrobacterium-mediated transformation. PCR products confirmed integration of the AGM182 gene, while RT-PCR of maize RNA confirmed the presence of AGM182 transcripts. Maize kernel screening assay using a highly aflatoxigenic A. flavus strain (AF70) showed up to 72% reduction in fungal growth in the transgenic AGM182 seeds compared to isogenic negative control seeds. Reduced fungal growth in the AGM182 transgenic seeds resulted in a significant reduction in aflatoxin levels (76-98%). The results presented here show the power of computational and synthetic biology to rationally design and synthesize an antimicrobial peptide against A. flavus that is effective in reducing fungal growth and aflatoxin contamination in an economically important food and feed crop such as maize. Published by Elsevier B.V.

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

    African Journals Online (AJOL)

    Cellulase Production by Aspergillus flavus Linn Isolate NSPR 101 fermented in sawdust, bagasse and corncob. Tunde Victor Ojumu, Bamidele Ogbe Solomon, Eriola Betiku, Stephen Kolawole Layokun, Bamikole Amigun ...

  14. Nutrient environment influences competition among Aspergillus flavus genotypes

    Science.gov (United States)

    Structures of Aspergillus flavus populations, shaped by intraspecific competition, influence the incidences and severities of crop aflatoxin contamination. Competition for nutrients may be one factor modulating intraspecific interactions, but influences of specific types and concentrations of nutrie...

  15. 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.

  16. 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.

  17. 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...

  18. 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 ...

  19. 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)

  20. 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.

  1. 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.

  2. Experimental study of Aspergillus flavus fungus from uranium mines

    International Nuclear Information System (INIS)

    Kusak, V.

    1982-01-01

    Cultivation is discussed of fungus strain Aspergillus flavus obtained from materials from uranium mines. It was found that an addition of 0.6 g of uranium in form of uranyl acetate or of 0.6 g of thorium in form on thorium nitrate in 1000 ml of the standard medium had stimulating effects on the growth and sporulation of Aspergillus flavus. Irradiating the cultivated fungus through a polyethylene foil did not show a stimulating effect. It is stated that uranium and its daughters must be directly present in the culture medium for their stimulating effect on growth and sporulation to manifest itself. (H.S.)

  3. 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.

  4. 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.

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

    African Journals Online (AJOL)

    USER

    Abstract. 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.

  6. 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) ...

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

    African Journals Online (AJOL)

    Administrator

    One ml aqueous concentrations at 0.1, 0.25, 0.5, 1.0, and 5.0 mg/ml of laboratory extracts of. Hypogymnia physodes and Ramalina farinacea (Lichens), and Bentex-T, were incorporated separately in a basal broth culture medium inside conical flasks. Mycelial dry weight of Aspergillus flavus, grown on the medium with the ...

  8. Aspergillus flavus secondary metabolites: more than just aflatoxins

    Science.gov (United States)

    Aspergillus flavus is best known for producing the family of potent carcinogenic secondary metabolites known as aflatoxins. However, this opportunistic plant and animal pathogen also produces numerous other secondary metabolites, many of which have also been shown to be toxic. While about forty of t...

  9. 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 ...

  10. Photodynamic inactivation of Aspergillus flavus mediated by Bidens ...

    African Journals Online (AJOL)

    An experimental study was conducted to assess the effectiveness of photoinactivation of Aspergillus flavus, a major aflatoxin-producing fungal species, by photosensitization mediated by an extract of the tropical plant Bidens pilosa. Photosensitization was conducted on fungal spores and hyphae in solution using of 420 nm ...

  11. 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...

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

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... However, 65% of the strains produced AFB1 on Czapek's agar, 53% of the strains on potato dextrose agar (PDA) and none of the strains on Aspergillus flavus and parasiticus agar media (AFPA). The strain, DRAf 009 produced maximum AFB1 (4.0 – 40 µg/g agar) on all the agar media tested. Five strains of ...

  13. 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.

  14. 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.

  15. 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...

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

    OpenAIRE

    Chellapandi, P.

    2010-01-01

    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 f...

  17. 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...

  18. Effect of Plant Essential Oils and Gamma Irradiation on Growth and Aflatoxin Production by Aspergillus Flavus Isolated from Wheat Grains

    International Nuclear Information System (INIS)

    Salem, E.A.; Shalaby, Kh.

    2016-01-01

    The antifungal potential of essential oils of Thyme (Thymus vulgaris L.) and camphor ( Eucalyptus rostrata L.) was determined on Aspergillus flavus link isolated from wheat grains on Potato dextrose agar (PDA). They inhibited completely mycelia growth of the fungus at 1000 and 2000 ppm, and prevented aflatoxin production at sub lethal dose 500 and 1000 ppm respectively. Gamma radiation was used to control mycelia growth of Aspergillus flavus Link and inhibiting aflatoxin production. A dose level of 3.5 KGy gamma radiation prevented the fungal growth and aflatoxin production by A. flavus link, where a dose of 2.5 K Gy ( the sub lethal dose) prevented about 85% of aflatoxin production

  19. 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.

  20. 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 ...

  1. Production and characterization of novel self-assembling biosurfactants from Aspergillus flavus.

    Science.gov (United States)

    Ishaq, U; Akram, M S; Iqbal, Z; Rafiq, M; Akrem, A; Nadeem, M; Shafi, F; Shafiq, Z; Mahmood, S; Baig, M A

    2015-10-01

    This work was conducted to produce, purify and characterize biosurfactants from Aspergillus flavus AF612 isolated from citrus fruit. Biosurfactant named 'Uzmaq' was isolated from A. flavus AF612. The chemical characterization of the biosurfactant was conducted. Biosurfactant Uzmaq produced by A. flavus, was composed of methoxy phenyl oxime glycosides. Two molecular forms of the biosurfactant, Uzmaq-A and Uzmaq-B were isolated. Biological properties (antifungal activity) were evaluated. The fractions of the biosurfactant were isolated and their surface properties were analysed. Uzmaq-A and Uzmaq-B had critical micelle concentration (CMC) around 170 and 80 mg l(-1) , and lowered surface tension of water up to 20 and 25 m Nm(-1) respectively. The biosurfactants were stable at pH 3-12 and temperature up to 80°C. Growth and biosurfactant production kinetics were also analysed. Novel biosurfactant Uzmaq was produced from A. flavus, which was composed of methoxy phenyl oxime glycosides. The surface activity of Uzmaq was better than the maximum values of synthetic chemical surfactants. The biosurfactant showed antifungal activity and self-assembling properties. Aspergillus flavus AF612 can be used for commercial production of Uzmaq that may be employed for controlled drug release applications and bioremediation. © 2015 The Society for Applied Microbiology.

  2. 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.

  3. Indole-Diterpene Gene Cluster from Aspergillus flavus

    Science.gov (United States)

    Zhang, Shuguang; Monahan, Brendon J.; Tkacz, Jan S.; Scott, Barry

    2004-01-01

    Aflatrem is a potent tremorgenic mycotoxin produced by the soil fungus Aspergillus flavus and is a member of a large structurally diverse group of secondary metabolites known as indole-diterpenes. By using degenerate primers for conserved domains of fungal geranylgeranyl diphosphate synthases, we cloned two genes, atmG and ggsA (an apparent pseudogene), from A. flavus. Adjacent to atmG are two other genes, atmC and atmM. These three genes have 64 to 70% amino acid sequence similarity and conserved synteny with a cluster of orthologous genes, paxG, paxC, and paxM, from Penicillium paxilli which are required for indole-diterpene biosynthesis. atmG, atmC, and atmM are coordinately expressed, with transcript levels dramatically increasing at the onset of aflatrem biosynthesis. A genomic copy of atmM can complement a paxM deletion mutant of P. paxilli, demonstrating that atmM is a functional homolog of paxM. Thus, atmG, atmC, and atmM are necessary, but not sufficient, for aflatrem biosynthesis by A. flavus. This provides the first genetic evidence for the biosynthetic pathway of aflatrem in A. flavus. PMID:15528556

  4. 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.

  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. Studies on the control of fungal contamination and aflatoxin production by Aspergillus flavus link in a cereal grain by the combination treatment of heat and irradiation

    International Nuclear Information System (INIS)

    Odamtten, G.T.

    1986-01-01

    Traditional storage of maize in tropical countries such as Ghana results in the rapid development of numerous fungi, including potential mycotoxin producers such as Aspergillus flavus (aflatoxins), A. ochraceus (ochratoxins, penicillic acid), Fusarium moniliforme (moniliformin), Paecilomyces varioti and Penicillium expansum (patulin). Treatment of maize with a combination of moist heat (30 min. at 60 0 C and relative humidity > 85%) and gamma irradiation (4.0 kGy) proved to be effective in inactivating the resident population of fungal spores. This result was confirmed by in vitro studies with spores of Aspergillus flavus NRRL 5906. In a comparative study of packaging materials it was found that food commodities stored in woven polypropylene bags for six months at 85% R.H. had mould and yeast counts which were 2-3 log cycles lower than those of products kept in jute bags. Also, the viability of the seeds was better preserved in polypropylene sacks. It is recommended that the combination treatment be carried out on good quality grains, and that woven polypropylene sacks are used in packaging prior to irradiation, for maximum extension of shelf-life. (Auth.)

  7. Inhibitory activity of compounds isolated from Polymnia sonchifolia on aflatoxin production by Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Pak Adriana

    2006-01-01

    Full Text Available Polymnia sonchifolia, commonly known as ";yacon";, was originally cultivated at Andes moutains in South America. Recently, the specie attracted worldwide attention because of its wide range of uses, for example in the control of diabetes melitus, besides the antifungal and pesticidal compounds were found in the leaves. This study describes the identification of two flavonoids: 3', 5, 7 trihydroxy-3, 4'-dimethoxyflavone (compound 1 and 3', 4', 5- trihydroxy-7-methoxy flavanone (compound 2 and two sesquiterpenes lactones: enhydrin (compound 3 and a mixture of enhydrin and uvedalin (compound 4 isolated from Polymnia sonchifolia leaves and their effects on the aflatoxin production by Aspergillus flavus. The identification of the compounds were achieved by ¹H and 13C NMR. All compounds were tested in different concentration, to evaluate the growth of Aspergillus flavus culture and the production of aflatoxin. The compound 1, at the concentration 15 mug/mL, inhibited 25% of the aflatoxin B1 production (p<0.01. The compound 4 inhibited 34% and 76% of the fungal growth and AFB1 production respectively. These results show that Polymnia sonchifolia can be used for the development of agents to control aflatoxin B1 production by Aspergillus flavus.

  8. EFEK BAKTERI PELARUT FOSFAT TERHADAP PERTUMBUHAN ASPERGILLUS FLAVUS PADA PERKECAMBAHAN KACANG TANAH

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    Sholeh Avivi, Ida Sugeng Suyani & Sugeng Winarso .

    2011-11-01

    Full Text Available Effect of phosphate solubilizing microorganism to Aspergillus flavus development on peanut germination.  Phosphate solubilizing microorganisms (PSM are microorganisms which could increase the available P in plant media.   The aim of this research is to determine the effect of PSM on A. flavus growth, and to identify it’s effects on the growth dynamics of  A. flavus as long as the peanut germination.  The research were conducted in the Laboratory of Plant Diseases Department, Faculty of Agriculture, University of Jember, from August 2005 to May 2006 and divided in 2 stages: in vitro and germination stage.  Base on in-vitro stage we concluded that Bacillus subtilis strain SK had better inhibition toward the growth of A. flavus than Pseudomonas fluorescent strain GM.  B. subtilis strain SK could inhibit A. flavus as much as 74%, whereas P. fluorescent strain GM was only reached 60% compared to control.  Base on the germination stage, B. subtilis in the desiccator supernatant (BsDS could increase the dry weight of root up to 24.1 g better than P. fluorescens strain GM and control.  We also found that B. subtilis strain SK was more effective to change the availability of P on plant media.

  9. Genetic variability of Aspergillus flavus isolates from a Mississippi corn field.

    Science.gov (United States)

    Solorzano, Cesar D; Abbas, Hamed K; Zablotowicz, Robert M; Chang, Perng-Kuang; Jones, Walker A

    2014-01-01

    A nontoxigenic Aspergillus flavus strain, K49, is currently being tested as a biological control agent in corn fields in the Mississippi Delta. However, little is known about the overall genetic diversity of A. flavus from year to year in corn fields and specifically in Mississippi. Our objective was to assess the genetic variability of A. flavus isolates from different seasons, inoculum sources, and years, from a no-till corn field. Of the 175 A. flavus isolates examined, 74 and 97 had the typical norB-cypA type I (1.5 kb) and type II (1.0 kb) deletion patterns, respectively. Variability in the sequence of the omtA gene of the majority of the field isolates (n = 118) was compared to strain K49. High levels of haplotypic diversity (24 omtA haplotypes; Hd = 0.61 ± 0.04) were found. Among the 24 haplotypes, two were predominant, H1 (n = 71), which consists of mostly toxigenic isolates, and H49 (n = 18), which consists of mostly atoxigenic isolates including K49. Toxigenic isolates were prevalent (60%) in this natural population. Nonetheless, about 15% of the population likely shared the same ancestral origin with K49. This study provides valuable information on the diversity of A. flavus. This knowledge can be further used to develop additional biological control strains.

  10. Genetic Variability of Aspergillus flavus Isolates from a Mississippi Corn Field

    Directory of Open Access Journals (Sweden)

    Cesar D. Solorzano

    2014-01-01

    Full Text Available A nontoxigenic Aspergillus flavus strain, K49, is currently being tested as a biological control agent in corn fields in the Mississippi Delta. However, little is known about the overall genetic diversity of A. flavus from year to year in corn fields and specifically in Mississippi. Our objective was to assess the genetic variability of A. flavus isolates from different seasons, inoculum sources, and years, from a no-till corn field. Of the 175 A. flavus isolates examined, 74 and 97 had the typical norB-cypA type I (1.5 kb and type II (1.0 kb deletion patterns, respectively. Variability in the sequence of the omtA gene of the majority of the field isolates (n=118 was compared to strain K49. High levels of haplotypic diversity (24 omtA haplotypes; Hd = 0.61 ± 0.04 were found. Among the 24 haplotypes, two were predominant, H1 (n=71, which consists of mostly toxigenic isolates, and H49 (n=18, which consists of mostly atoxigenic isolates including K49. Toxigenic isolates were prevalent (60% in this natural population. Nonetheless, about 15% of the population likely shared the same ancestral origin with K49. This study provides valuable information on the diversity of A. flavus. This knowledge can be further used to develop additional biological control strains.

  11. Reduction of aflatoxin production by Aspergillus flavus and Aspergillus parasiticus in interaction with Streptomyces.

    Science.gov (United States)

    Verheecke, C; Liboz, T; Anson, P; Diaz, R; Mathieu, F

    2015-05-01

    The aim of this study is to investigate aflatoxin gene expression during Streptomyces-Aspergillus interaction. Aflatoxins are carcinogenic compounds produced mainly by Aspergillus flavus and Aspergillus parasiticus. A previous study has shown that Streptomyces-A. flavus interaction can reduce aflatoxin content in vitro. Here, we first validated this same effect in the interaction with A. parasiticus. Moreover, we showed that growth reduction and aflatoxin content were correlated in A. parasiticus but not in A. flavus. Secondly, we investigated the mechanisms of action by reverse-transcriptase quantitative PCR. As microbial interaction can lead to variations in expression of household genes, the most stable [act1, βtub (and cox5 for A. parasiticus)] were chosen using geNorm software. To shed light on the mechanisms involved, we studied during the interaction the expression of five genes (aflD, aflM, aflP, aflR and aflS). Overall, the results of aflatoxin gene expression showed that Streptomyces repressed gene expression to a greater level in A. parasiticus than in A. flavus. Expression of aflR and aflS was generally repressed in both Aspergillus species. Expression of aflM was repressed and was correlated with aflatoxin B1 content. The results suggest that aflM expression could be a potential aflatoxin indicator in Streptomyces species interactions. Therefore, we demonstrate that Streptomyces can reduce aflatoxin production by both Aspergillus species and that this effect can be correlated with the repression of aflM expression. © 2015 The Authors.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. Aspergillus flavus Blast2GO gene ontology database: elevated growth temperature alters amino acid metabolism

    Science.gov (United States)

    The availability of a representative gene ontology (GO) database is a prerequisite for a successful functional genomics study. Using online Blast2GO resources we constructed a GO database of Aspergillus flavus. Of the predicted total 13,485 A. flavus genes 8,987 were annotated with GO terms. The mea...

  17. Green Fluorescent Protein as a Reporter To Monitor Gene Expression and Food Colonization by Aspergillus flavus

    OpenAIRE

    Du, Wanglei; Huang, Zhengyu; Flaherty, Joseph E.; Wells, Kevin; Payne, Gary A.

    1999-01-01

    Transformants of Aspergillus flavus containing the Aequorea victoria gfp gene fused to a viral promoter or the promoter region and 483 bp of the coding region of A. flavus aflR expressed green fluorescence detectable without a microscope or filters. Expression of green fluorescent protein fluorescence was correlated with resistance to aflatoxin accumulation in five corn genotypes inoculated with these transformants.

  18. 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.

  19. Detection of Aflatoxin Producing Aspergillus flavus in Post-harvest Contaminated Vigna ungulculata Seeds

    OpenAIRE

    Ajay Kumar Gautam

    2014-01-01

    The present study was carried out with a specific objective to study postharvest spoilage of Lobhiya (Vigna unguiculata) seeds contaminated with Aspergillus flavus. Infected seeds were collected and cultured on potato dextrose agar (PDA) media, at 25±2 °C. Aspergillus flavus isolates were primarily characterized by its morphological and microscopic characteristics. Collected fungal isolates were also screened for their afaltoxigenic nature on preliminary basis and at molecul...

  20. 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.

  1. Inhibitory Effects of Thai Essential Oils on Potentially Aflatoxigenic Aspergillus parasiticus and Aspergillus flavus.

    Science.gov (United States)

    Jantapan, Kittika; Poapolathep, Amnart; Imsilp, Kanjana; Poapolathep, Saranya; Tanhan, Phanwimol; Kumagai, Susumu; Jermnak, Usuma

    2017-01-01

     The antiaflatoxigenic and antifungal activities of essential oils (EOs) of finger root (Boesenbergia rotunda (L.) Mansf.), pine (Pinus pinaster), rosewood (Aniba rosaedora), Siam benzoin (Styrax tonkinensis), Thai moringa (Moringa oleifera), and ylang ylang (Cananga odorata) were tested for Aspergillus parasiticus and Aspergillus flavus in potato dextrose broth. Aflatoxin B 1 (AFB 1 ) was extracted from culture using a QuEChERS-based extraction procedure and analyzed with high performance liquid chromatography (HPLC) coupled to a fluorescence detector. EO of pine showed the greatest inhibition of growth and AFB 1 production of A. parasiticus, followed by EOs of rosewood, finger root, Siam benzoin, and ylang ylang. EO of finger root gave the best inhibitory effects on A. flavus, followed by EOs of rosewood, pine, ylang ylang, and Siam benzoin. EO of Thai moringa did not show any significant inhibition of aflatoxigenic fungi. The antiaflatoxigenic activities of EOs correlated with their antifungal activities in the dosedependent manner. Comparison of the application of the five selected EOs in peanut pods by direct and vapor exposure indicated that the AFB 1 production inhibitory effects of the five EOs by direct exposure were faster and more effective than by vapor exposure. EO of finger root showed the best inhibition of AFB 1 production of A. flavus in peanut pods by direct exposure, followed by EOs of pine, rosewood, ylang ylang, and Siam benzoin.

  2. Modelling Aspergillus flavus growth and aflatoxins production in pistachio nuts.

    Science.gov (United States)

    Marín, Sonia; Ramos, Antonio J; Sanchis, V

    2012-12-01

    Aflatoxins (AFs) are the main contaminants in pistachio nuts. AFs production in pistachio has been attributed to Aspergillus flavus. The aim of this study was to apply existing models to predict growth and AFs production by an A. flavus isolated from pistachios as a function of moisture content and storage temperature of pistachios in order to test their usefulness and complementarities. A full factorial design was used: the moisture content levels assayed were 10, 15, 20, 25 and 30% and incubation temperatures were 10, 15, 20, 25, 30, 37 and 42 °C. Both kinetic and probability models were built to predict growth of the strain under the assayed conditions. Among the assayed models, cardinal ones gave a good quality fit for radial growth rate data. Moreover, the progressive approach, which was developed based on a reduced number of experimental points led to an improved prediction in the validation step. This is quite significant as may allow for improved experimental designs, less costly than full factorial ones. Probability model proved to be concordant in 91% of the calibration set observations. Even though the validation set included conditions around the growth/no-growth interface, there was a 100% agreement in the predictions from the data set (n = 16, cut off = 0.5) after 60 days. Similarly, the probability for AF presence was rightly predicted in 89% of the cases. According to our results EC maximum aflatoxin levels would be surpassed in a period as short as 1 month if pistachio nuts reach 20 °C, unless %mc is ≤10%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Identification of the predominant volatile compounds produced by Aspergillus flavus.

    Science.gov (United States)

    Kamiński, E; Libbey, L M; Stawicki, S; Wasowicz, E

    1972-11-01

    A culture of Aspergillus flavus grown on moistened wheat meal was homogenized with a blendor, and the resulting slurry was vacuum-distilled at 5 mm of Hg and 35 C. The aqueous distillate was collected in traps cooled to -10 to -80 C. The culture volatiles were extracted from the distillate with CH(2)Cl(2), and, after removal of the bulk of the solvent, the concentrated volatiles were examined by packed-column gas chromatography. Nineteen peaks were observed, and coupled gas chromatography-mass spectrometry was employed to identify the larger components. The compounds identified were: 3-methyl-butanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and cis-2-octen-1-ol. The two octenols were the predominant compounds, and sufficient sample was trapped from the gas chromatograph for infrared analyses; this confirmed the mass spectral identifications and permitted the assignment of the cis designation to 2-octen-1-ol. Both oct-1-en-3-ol and cis-2-octen-1-ol are thought to be responsible for the characteristic musty-fungal odor of certain fungi; the latter compound may be a useful chemical index of fungal growth.

  4. Purification and characterization of mycoferritin from Aspergillus flavus MTCC 873.

    Science.gov (United States)

    Vakdevi, V; Sashidhar, R B; Deshpande, Vijay

    2009-10-01

    The fungus Aspergillus flavus MTCC 873, a non-toxigenic isolate demonstrated its capability to synthesize mycoferritin (MF) upon induction with iron in yeast extract sucrose (YES) medium. The molecular mass, yield, iron and carbohydrate contents of the MF were 440 kDa, 0.015 mg/g of wet mycelia, 0.8 and 30.4%, respectively. Native gel-electrophoresis revealed a band corresponding to dimeric form of equine spleen ferritin (ESF). Subunit analysis by SDS-PAGE revealed a single protein band with an apparent molecular mass of 24 kDa, suggesting similar sized subunits in the structure of apoferritin shell. Immunological cross-reactivity was observed with the anti-fish liver ferritin. Transmission electron microscopy (TEM) revealed an apparent particle size of 100 A. N-terminal amino acid sequence of MF revealed a sequence of SLPLQDYA, which showed identities with other eukaryotic ferritin sequences. The spectral characteristics (UV/VIS, fluorescence and circular dichroic spectra) were similar to ESF. The fungus, unlike A. parasilicus 255 (non-toxigenic) was incapable of producing allatoxins, when grown in YES media.

  5. Interactions in solution and crystallization of Aspergillus flavus urate oxidase

    Science.gov (United States)

    Bonneté, F.; Vivarès, D.; Robert, Ch.; Colloc'h, N.

    2001-11-01

    Interparticle interactions of urate oxidase from Aspergillus flavus have been studied by small-angle X-ray scattering to determine crystallization conditions. This enzyme is a homotetramer with a total molecular weight of 128 kDa. It is a slightly basic protein (pI between 7.5 and 8). The interaction potentials have been studied as a function of the main thermodynamic and chemical parameters: temperature, protein concentration, pH, salt nature and concentration, addition of polyols. In 10 mM sodium carbonate at pH 10.5, the interactions are slightly repulsive and become less repulsive with a pH closer to pI. With the addition of carbonate, the protein loses its tetrameric structure for a dimeric one; with formate, the tetrameric structure remains stable. We also studied the effect of polyethylene glycols as it had been done with high molecular weight proteins. With the addition of PEG 8 K, the interactions became less repulsive and even turned attractive with the addition of both PEG 8 K and salt. Protein crystals of urate oxidase were observed in slightly repulsive conditions (second virial coefficient A2 about +10 -5 mol ml g -2 instead of -2 to -8×10 -4 mol ml g -2 for low molecular weight proteins).

  6. The Aspergillus flavus Homeobox Gene, hbx1, Is Required for Development and Aflatoxin Production

    Directory of Open Access Journals (Sweden)

    Jeffrey W. Cary

    2017-10-01

    Full Text Available Homeobox proteins, a class of well conserved transcription factors, regulate the expression of targeted genes, especially those involved in development. In filamentous fungi, homeobox genes are required for normal conidiogenesis and fruiting body formation. In the present study, we identified eight homeobox (hbx genes in the aflatoxin-producing ascomycete, Aspergillus flavus, and determined their respective role in growth, conidiation and sclerotial production. Disruption of seven of the eight genes had little to no effect on fungal growth and development. However, disruption of the homeobox gene AFLA_069100, designated as hbx1, in two morphologically different A. flavus strains, CA14 and AF70, resulted in complete loss of production of conidia and sclerotia as well as aflatoxins B1 and B2, cyclopiazonic acid and aflatrem. Microscopic examination showed that the Δhbx1 mutants did not produce conidiophores. The inability of Δhbx1 mutants to produce conidia was related to downregulation of brlA (bristle and abaA (abacus, regulatory genes for conidiophore development. These mutants also had significant downregulation of the aflatoxin pathway biosynthetic genes aflC, aflD, aflM and the cluster-specific regulatory gene, aflR. Our results demonstrate that hbx1 not only plays a significant role in controlling A. flavus development but is also critical for the production of secondary metabolites, such as aflatoxins.

  7. 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.

  8. The Aspergillus flavus Homeobox Gene, hbx1, is Required for Development and Aflatoxin Production.

    Science.gov (United States)

    Cary, Jeffrey W; Harris-Coward, Pamela; Scharfenstein, Leslie; Mack, Brian M; Chang, Perng-Kuang; Wei, Qijian; Lebar, Matthew; Carter-Wientjes, Carol; Majumdar, Rajtilak; Mitra, Chandrani; Banerjee, Sourav; Chanda, Anindya

    2017-10-12

    Homeobox proteins, a class of well conserved transcription factors, regulate the expression of targeted genes, especially those involved in development. In filamentous fungi, homeobox genes are required for normal conidiogenesis and fruiting body formation. In the present study, we identified eight homeobox ( hbx ) genes in the aflatoxin-producing ascomycete, Aspergillus flavus , and determined their respective role in growth, conidiation and sclerotial production. Disruption of seven of the eight genes had little to no effect on fungal growth and development. However, disruption of the homeobox gene AFLA_069100, designated as hbx1 , in two morphologically different A. flavus strains, CA14 and AF70, resulted in complete loss of production of conidia and sclerotia as well as aflatoxins B₁ and B₂, cyclopiazonic acid and aflatrem. Microscopic examination showed that the Δ hbx1 mutants did not produce conidiophores. The inability of Δ hbx1 mutants to produce conidia was related to downregulation of brlA (bristle) and abaA (abacus), regulatory genes for conidiophore development. These mutants also had significant downregulation of the aflatoxin pathway biosynthetic genes aflC , aflD , aflM and the cluster-specific regulatory gene, aflR . Our results demonstrate that hbx1 not only plays a significant role in controlling A. flavus development but is also critical for the production of secondary metabolites, such as aflatoxins.

  9. Effects of Gamma and Electron Beam Radiation on Brazil Nuts Artificially Inoculated with Aspergillus flavus.

    Science.gov (United States)

    Assunção, Ednei; Reis, Tatiana Alves; Baquião, Arianne Costa; Corrêa, Benedito

    2015-07-01

    The aim of this study was to evaluate the effects of gamma radiation (GR) and electron beam (EB) on Brazil nut samples contaminated with Aspergillus flavus. Fifty samples were spread with an A. flavus suspension and incubated at 30°C and a relative humidity of 93%. After 15 days of incubation, mycobiota and aflatoxin analysis were performed. The samples were divided into three groups (control, group 1, and group 2) that received radiation doses of 0 kGy (control) and 5 and 10 kGy each of GR and EB (groups 1 and 2). Noninoculated samples were irradiated with the same doses for sensory evaluation. The results showed that after 15 days of incubation, the average water activity of the samples was 0.80. The irradiation with GR and EB at doses of 5 and 10 kGy was able to eliminate A. flavus in Brazil nut samples. Aflatoxin analysis showed that EB doses of 5 and 10 kGy reduced aflatoxin B1 levels by 53.32 and 65.66%, respectively, whereas the same doses of GR reduced the levels of this toxin by 70.61 and 84.15% compared with the level in the control groups. Sensory evaluation demonstrated that the texture and odor of irradiated Brazil nut samples were acceptable. The taste evaluation indicated that 5 kGy of GR was judged acceptable. The results highlight that both irradiation processes (5- and 10-kGy doses) showed efficiency in A. flavus and aflatoxin elimination. GR and EB treatments resulted in some alterations in the sensory attributes of samples with the doses used in this study; however, Brazil nut samples irradiated with 5-kGy GR doses were considered acceptable.

  10. 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.

  11. 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.

  12. Dry heat and radiation combination effects on Aspergillus flavus Link. infecting cocoa beans

    International Nuclear Information System (INIS)

    Amoako-Atta, B.; Meier, H.; Odamtten, G.T.

    1981-01-01

    The paper deals with the effect of heat and radiation combination treatments on the control of microbial spoilage of cocoa beans caused by toxigenic Aspergillus flavus Link. The heat and radiation sources were from dry air oven heat and 60 Co gammacell 220 irradiator, respectively. The radiation doses used were either 0, 50, 100, 150 or 200 krad, with combined heat temperatures of 30, 60 or 90 0 C. At each temperature level three different exposure time intervals of either 15 min, 30 min or 60 min respectively, were used. Two reversible sequential heat/radiation combination effects were evaluated. The first sequence involved cocoa beans inoculated with A. flavus spores exposed first to dry heat at pre-determined temperature heat exposure time, followed by radiation treatment, then retention of samples in a constant humidity environmental chamber set at 80% for daily observation up to forty days post-treatment. The second sequence involved exposure of the inoculated beans first to radiation, then to heat before retention under fixed RH for observation. From their results, the authors arrive at four conclusions: first, that there is a critical radiation/heat combination range (200, 150 and 100 krad/90 0 C for 15 min) that significantly decontaminates (less than 5% mouldiness) A. flavus infected cocoa beans even under high relative humidity (80% RH) environment; second, that a temperature level of 90 0 C combined with 200, 150 or 100 krad maximizes such effect but the heat exposure time is a major factor; third, that low heat temperature ranges of 30 or 60 0 C, combined with low radiation dosages of 150 krad or below, enhance the rate of A. flavus spoilage effects of cocoa beans; and, lastly, that the sequence of exposure of the inoculated cocoa beans to heat/radiation combination influenced the spore germination; exposure to heat before radiation would sensitize the spores (200 krad/90 0 C) but results in an increased radioresistance. (author)

  13. Dry Heat and Radiation Combination Effects on Aspergillus Flavus Link. Infecting Cocoa Beans

    International Nuclear Information System (INIS)

    Amoako-Atta, B.; Meier, H.; Odamtten, G.T.

    1981-01-01

    The paper deals with the effect of heat and radiation combination treatments on the control of microbial spoilage of cocoa beans caused by toxigenic Aspergillus flavus Link. The heat and radiation sources were from dry air oven heat and 60 Co gammaceli 220 irradiator, respectively. The radiation doses used were either 0, 50, 100, 150 or 200 krad, with combined heat temperatures of 30, 60 or 90°C. At each temperature level three different exposure time intervals of either 15 min, 30 min or 60 min respectively, were used. Two reversible sequential heat/radiation combination effects were evaluated.. The first sequence involved cocoa beans inoculated with A. flavus spores exposed first to dry heat at pre-determined temperature heat exposure time, followed by radiation treatment, then retention of samples in a constant humidity environmental chamber set at 80% for daily observation up to forty days post-treatment. The second sequence involved exposure of the inoculated beans first to radiation, then to heat before retention under fixed RH for observation. From their results, the authors arrive at four conclusions: first, that there is a critical radiation/heat combination range (200, 150 and 100 krad/90°C for 15 min) that significantly decontaminates (less than 5% mouldiness) A. flavus infected cocoa beans even under high relative humidity (80% RH) environment; second, that a temperature level of 90°C combined with 200, 150 or 100 krad maximizes such effect but the heat exposure time is a major factor; third, that low heat temperature ranges of 30 or 60°C, combined with low radiation dosages of 150 krad or below, enhance the rate of A. flavus spoilage effects of cocoa beans; and, lastly, that the sequence of exposure of the inoculated cocoa beans to heat/radiation combination influenced the spore germination; exposure to heat before radiation would sensitize the spores (200 krad/90°C) but results in an increased radioresistance. (author)

  14. Inhibition of aflatoxin B production of Aspergillus flavus, isolated from soybean seeds by certain natural plant products.

    Science.gov (United States)

    Krishnamurthy, Y L; Shashikala, J

    2006-11-01

    The inhibitory effect of cowdung fumes, Captan, leaf powder of Withania somnifera, Hyptis suaveolens, Eucalyptus citriodora, peel powder of Citrus sinensis, Citrus medica and Punica granatum, neem cake and pongamia cake and spore suspension of Trichoderma harzianum and Aspergillus niger on aflatoxin B(1) production by toxigenic strain of Aspergillus flavus isolated from soybean seeds was investigated. Soybean seed was treated with different natural products and fungicide captan and was inoculated with toxigenic strain of A. flavus and incubated for different periods. The results showed that all the treatments were effective in controlling aflatoxin B(1) production. Captan, neem cake, spore suspension of T. harzianum, A. niger and combination of both reduced the level of aflatoxin B(1) to a great extent. Leaf powder of W. somnifera, H. suaveolens, peel powder of C. sinensis, C. medica and pongamia cake also controlled the aflatoxin B(1) production. All the natural product treatments applied were significantly effective in inhibiting aflatoxin B(1) production on soybean seeds by A. flavus. These natural plant products may successfully replace chemical fungicides and provide an alternative method to protect soybean and other agricultural commodities from aflatoxin B(1) production by A. flavus.

  15. Aflatoxin production by Aspergillus Flavus on irradiated and non-irradiated stored egyptian bread

    International Nuclear Information System (INIS)

    Elbazza, Z.E.; Mahmoud, M.I.; Fahd, M.E.; Abu Seif, F.A.

    1986-01-01

    Aflatoxins production by Aspergillus Flavus isolate on several types of egyptian bread samples through a period of 45 days at different temperatures reveled that there was detectable fungal growth but no aflatoxins were produced at 5±1 degree or 37 degree. At 25 degree or 30 degree aflatoxin were produced after 5-6 days on the different bread types. Gamma irradiation of kaiser bread, previously inoculated with Aspergillus Flavus, reduced the amount of aflatoxins produced on subsequent storage for 8 weeks at 26±1 degree. The 5 KGy dose eliminated fungal growth and aflatoxin production. 4 tab

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

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

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    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.

  2. Detection of Aflatoxin Producing Aspergillus flavus in Post-harvest Contaminated Vigna ungulculata Seeds

    Directory of Open Access Journals (Sweden)

    Ajay Kumar Gautam

    2014-07-01

    Full Text Available The present study was carried out with a specific objective to study postharvest spoilage of Lobhiya (Vigna unguiculata seeds contaminated with Aspergillus flavus. Infected seeds were collected and cultured on potato dextrose agar (PDA media, at 25±2 °C. Aspergillus flavus isolates were primarily characterized by its morphological and microscopic characteristics. Collected fungal isolates were also screened for their afaltoxigenic nature on preliminary basis and at molecular level. For preliminary screening, 5 mm disc of fungal culture was soaked with few drops of liquid ammonia. Color change from yellow pigment to plum-red with different intensities showed the mycotoxic nature of the fungus. DNA from fungal isolates was isolated and amplified using PCR with aflatoxin specific primers, apa-2, ver-1 and omt-1. Amplicons of 1032 bp, 895 bp and 596 bp were obtained in most of the isolates regardless of primer set used which was useful to differentiate between mycotoxic and nontoxic isolates of A. flavus. The isolation of aflatoxigenic strains of A. flavus during post-harvest period of lobhiya seeds raise a serious concern over the quality of seeds and a threat to heath of consumers. It was concluded that Aspergillus flavus is responsible for postharvest spolilage of Lobhiya (Vigna unguiculata.

  3. Genetic isolation among sympatric vegetative compatibility groups of the aflatoxin-producing fungus Aspergillus flavus.

    Science.gov (United States)

    Grubisha, L C; Cotty, P J

    2010-01-01

    Aspergillus flavus, a fungal pathogen of animals and both wild and economically important plants, is most recognized for producing aflatoxin, a cancer-causing secondary metabolite that contaminates food and animal feed globally. Aspergillus flavus has two self/nonself recognition systems, a sexual compatibility system and a vegetative incompatibility system, and both play a role in directing gene flow in populations. Aspergillus flavus reproduces clonally in wild and agricultural settings, but whether a cryptic sexual stage exists in nature is currently unknown. We investigated the distribution of genetic variation in 243 samples collected over 4 years from three common vegetative compatibility groups (VCGs) in Arizona and Texas from cotton using 24 microsatellite loci and the mating type locus (MAT) to assess population structure and potential gene flow among A. flavus VCGs in sympatric populations. All isolates within a VCG had the same mating type with OD02 having MAT1-2 and both CG136 and MR17 having MAT1-1. Our results support the hypothesis that these three A. flavus VCGs are genetically isolated. We found high levels of genetic differentiation and no evidence of gene flow between VCGs, including VCGs of opposite mating-type. Our results suggest that these VCGs diverged before domestication of agricultural hosts (>10,000 yr bp).

  4. 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.

  5. Gene expression profiles of Aspergillus flavus isolates responding to oxidative stress in different culture media

    Science.gov (United States)

    Aflatoxin contamination of peanut by Aspergillus flavus is exacerbated by drought stress. Drought also stimulates the production of reactive oxygen species (ROS) in plant tissues implying a correlation between ROS and aflatoxin production. Here, we performed gene expression analysis by RNAseq of tox...

  6. Comparative transcriptome analysis of Aspergillus flavus isolates under different oxidative stresses and culture media

    Science.gov (United States)

    Aspergillus flavus and aflatoxin contamination in the field are known to be influenced by numerous stress factors, particularly drought and heat stress. However, the purpose of aflatoxin production is unknown. Here, we report transcriptome analyses comprised of 282.6 Gb of sequencing data describing...

  7. 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...

  8. Orientation of navel orangeworm larvae and adults (Amyelois transitella: Lepidoptera: Pyralidae) toward Aspergillus flavus.

    Science.gov (United States)

    The navel orangeworm (Amyelois transitella), a pest of California tree nuts, is associated with the fungus Aspergillus flavus, and mounting evidence suggests that these two species are facultative mutualists. Navel orangeworm larvae exhibit improved growth and survival on diets containing this fungu...

  9. Intraspecific competition during infection by Aspergillus flavus is influenced by plant host species

    Science.gov (United States)

    Communities of Aspergillus flavus are composed of diverse genotypes that collectively influence incidence and severity of crop aflatoxin contamination. Isolates vary in competitive ability on maize, but empirical data on the extent to which host-specific influences determine outcomes of competition ...

  10. 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

  11. 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...

  12. Microsatellite Typing To Trace Aspergillus flavus Infections in a Hematology Unit ▿

    Science.gov (United States)

    Hadrich, Inès; Makni, Fattouma; Ayadi, Ali; Ranque, Stéphane

    2010-01-01

    Assessing the relatedness of strains isolated from patients and their environment is instrumental in documenting the source of preventable health care-associated life-threatening Aspergillus flavus human infection clusters. The present study aimed at identifying and selecting suitable microsatellite markers for A. flavus typing. This typing scheme was then applied to investigate the A. flavus epidemiology within a hematology unit in Sfax, Tunisia. Use of a combination of five markers made it possible to discern clusters of isolates and to substantiate the genetic diversity of A. flavus within clusters. Isolates from Tunisia and Marseille, France, displayed distinct haplotypes, indicating a highly significant geographical structuring of A. flavus. The typing of clinical and environmental A. flavus isolates in a hematology unit provided insights into its hospital epidemiology. From a heterogeneous genetic background, a cluster indicative of a clonal propagation episode within the unit could be identified. In two patients with invasive aspergillosis, the same genotype was found in clinical and environmental isolates, indicating hospital-acquired colonization and infection. In further studies, this novel microsatellite typing scheme might be instrumental in illuminating important epidemiological issues about A. flavus population genetics or epidemiology, including tracing the sources and routes of transmission. PMID:20410353

  13. 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.

  14. 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.

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

    African Journals Online (AJOL)

    ajl yemi

    2011-11-28

    Nov 28, 2011 ... by many approaches like, heating, drying and particular agricultural practice, but the development of crop species with high resistance to afla-toxigenic molds is the greatest potential way (Rustom, 1997). Screening of A. flavus resistant mutants in peanut mutation breeding programs is the most challenged ...

  16. The Master Transcription Factor mtfA Governs Aflatoxin Production, Morphological Development and Pathogenicity in the Fungus Aspergillus flavus

    OpenAIRE

    Zhenhong Zhuang; Jessica M. Lohmar; Timothy Satterlee; Jeffrey W. Cary; Ana M. Calvo

    2016-01-01

    Aspergillus flavus produces a variety of toxic secondary metabolites; among them, the aflatoxins (AFs) are the most well known. These compounds are highly mutagenic and carcinogenic, particularly AFB1. A. flavus is capable of colonizing a number of economically-important crops, such as corn, cotton, peanut and tree nuts, and contaminating them with AFs. Molecular genetic studies in A. flavus could identify novel gene targets for use in strategies to reduce AF contamination and its adverse imp...

  17. 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...

  18. 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

    2018-03-01

    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.

  19. Characterization of AFLAV, a Tf1/Sushi retrotransposon from Aspergillus flavus.

    Science.gov (United States)

    Hua, Sui-Sheng T; Tarun, Alice S; Pandey, Sonal N; Chang, Leo; Chang, Perng-Kuang

    2007-02-01

    The plasmid, pAF28, a genomic clone from Aspergillus flavus NRRL 6541, has been used as a hybridization probe to fingerprint A. flavus strains isolated in corn and peanut fields. The insert of pAF28 contains a 4.5 kb region which encodes a truncated retrotransposon (AfRTL-1). In search for a full-length and intact copy of retrotransposon, we exploited a novel PCR cloning strategy by amplifying a 3.4 kb region from the genomic DNA of A. flavus NRRL 6541. The fragment was cloned into pCR 4-TOPO. Sequence analysis confirmed that this region encoded putative domains of partial reverse transcriptase, RNase H, and integrase of the predicted retrotransposon. The two flanking long terminal repeats (LTRs) and the sequence between them comprise a putative full-length LTR retrotransposon of 7799 bp in length. This intact retrotransposon sequence is named AFLAV (A. flavus Retrotransposon). The order of the predicted catalytic domains in the polyprotein (Pol) placed AFLAV in the Tf1/sushi subgroup of the Ty3/gypsy retrotransposon family. Primers derived from AFLAV sequence were used to screen this retrotransposon in other strains of A. flavus. More than fifty strains of A. flavus isolated from different geological origins were surveyed and the results show that many strains have extensive deletions in the regions encoding the capsid (Gag) and Pol.

  20. 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.

  1. Genome Sequence of Aspergillus flavus NRRL 3357, a Strain That Causes Aflatoxin Contamination of Food and Feed

    OpenAIRE

    Nierman, William C.; Yu, Jiujiang; Fedorova-Abrams, Natalie D.; Losada, Liliana; Cleveland, Thomas E.; Bhatnagar, Deepak; Bennett, Joan W.; Dean, Ralph; Payne, Gary A.

    2015-01-01

    Aflatoxin contamination of food and livestock feed results in significant annual crop losses internationally. Aspergillus flavus is the major fungus responsible for this loss. Additionally, A.?flavus is the second leading cause of aspergillosis in immunocompromised human patients. Here, we report the genome sequence of strain NRRL 3357.

  2. Use of aflatoxin-producing ability medium to distinguish aflatoxin-producing strains of Aspergillus flavus.

    OpenAIRE

    Wicklow, D T; Shotwell, O L; Adams, G L

    1981-01-01

    Aflatoxin-producing ability medium was tested for its ability to distinguish aflatoxin-positive from aflatoxin-negative strains of Aspergillus flavus in naturally occurring populations from corn at harvest. All of the aflatoxin-positive strains and some of the aflatoxin-negative strains produced aflatoxins when cultured on cracked corn. Although the data indicate that aflatoxin-producing ability medium is not entirely reliable in distinguishing potential aflatoxin-producing strains of A. flav...

  3. Anti - Aspergillus flavus Activity of Lactobacillus plantarum and Pediococcus acidilactici Isolated from Breast Milk

    Directory of Open Access Journals (Sweden)

    Sedighi-Khavidak Samaneh

    2016-12-01

    Full Text Available The breast milk is not only the best and optimal natural source of essential nutrients for babies, but also provides a broad range of bioactive compounds, as well as its own microbiota, therefore helps to protect body against many diseases too. Lactic acid bacteria (LAB are the major group of the breast milk microbiota and acts as biocontrol agent in milk. In this study LAB were isolated from the breast milk. Their antifungal activity against aflatoxin producing Aspergillus flavus was investigated with four methods: Study of the LAB isolates influence on biomass production of A. flavus in MRS medium, determination of their inhibitory activity against A. flavus on PDA medium, dual culture overlay assay and finally, effect of LAB cell-free supernatants (CFS against mycelia growth. The CFS also was analyzed by HPLC and titration experiments. The results indicated that seven isolated LAB had good inhibitory activity against A. flavus growth. Four isolates of LAB were identified as Pediococcus acidilactici and three of them were identified as Lactobacillus plantarum by 16s rDNA sequencing assay. The cell-free supernatants of L. plantarum RS2 expressed strong anti A. flavus activity. Analyzing of their CFS showed that, this strain had significant amounts of propionic acid and hydrogen peroxide in the CFS that might explain the high antifungal activity.

  4. RNA interference-based silencing of the alpha-amylase (amy1) gene in Aspergillus flavus decreases fungal growth and aflatoxin production in maize kernels.

    Science.gov (United States)

    Gilbert, Matthew K; Majumdar, Rajtilak; Rajasekaran, Kanniah; Chen, Zhi-Yuan; Wei, Qijian; Sickler, Christine M; Lebar, Matthew D; Cary, Jeffrey W; Frame, Bronwyn R; Wang, Kan

    2018-03-14

    Expressing an RNAi construct in maize kernels that targets the gene for alpha-amylase in Aspergillus flavus resulted in suppression of alpha-amylase (amy1) gene expression and decreased fungal growth during in situ infection resulting in decreased aflatoxin production. Aspergillus flavus is a saprophytic fungus and pathogen to several important food and feed crops, including maize. Once the fungus colonizes lipid-rich seed tissues, it has the potential to produce toxic secondary metabolites, the most dangerous of which is aflatoxin. The pre-harvest control of A. flavus contamination and aflatoxin production is an area of intense research, which includes breeding strategies, biological control, and the use of genetically-modified crops. Host-induced gene silencing, whereby the host crop produces siRNA molecules targeting crucial genes in the invading fungus and targeting the gene for degradation, has shown to be promising in its ability to inhibit fungal growth and decrease aflatoxin contamination. Here, we demonstrate that maize inbred B104 expressing an RNAi construct targeting the A. flavus alpha-amylase gene amy1 effectively reduces amy1 gene expression resulting in decreased fungal colonization and aflatoxin accumulation in kernels. This work contributes to the development of a promising technology for reducing the negative economic and health impacts of A. flavus growth and aflatoxin contamination in food and feed crops.

  5. 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.

  6. Volatile profiles and aflatoxin production by toxigenic and non-toxigenic isolates of Aspergillus flavus grown on sterile and non-sterile cracked corn.

    Science.gov (United States)

    De Lucca, Anthony J; Boue, Stephen M; Carter-Wientjes, Carol; Bhatnagar, Deepak

    2012-01-01

    Aspergillus flavus is a saprophytic fungus which can grow on corn and produce aflatoxins which render it unsafe for consumption as food and feed. In this study, aflatoxin and non-aflatoxin producing isolates of A. flavus were grown separately on wet (20% water added), sterile or non-sterile cracked corn. Wet and dry cracked corn controls were included as needed. Secondary metabolic volatiles were identified and aflatoxin concentrations determined over a 12-day period. Volatiles unique to the toxigenic A. flavus isolates were determined by comparison with volatiles produced by the respective corn controls and the non-toxigenic A. flavus isolate. The number and identity of the volatiles produced by these A. flavus isolates varied by isolate, whether sterile or non-sterile corn was the substrate, and the sampling day. Overall, most of the volatiles were produced before day 8 after inoculation. Aflatoxin production was 10-fold lower on the sterile corn, compared to the non-sterile corn. Volatiles unique to the aflatoxin producing isolates were identified on both substrates after comparison with those produced by the non-aflatoxin producing isolate, as well as the corn control samples. Results indicate that several factors (substrate, fungal isolate, culture age) affect volatile and aflatoxin production by A. flavus.

  7. 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

  8. 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

  9. [Irradiation effect of 60Co gamma ray on Aspergillus flavus spores in normal saline and maize].

    Science.gov (United States)

    Zhong, Kai; Gao, Xiang; Ji, Rong

    2011-05-01

    To observe irradiation effect of gamma ray on Aspergilllus flavus spores. Aspergillus flavus spores of different concentration were prepared on two media and were exposed to gamma ray. D10 values and theoretical minimal sterilizing doses were calculated by colony counting results. Actual minimal sterilizing doses were verified according to theoretical dose. D10 value and minimal sterilizing dose of high concentration spore in normal saline were 0.39 kGy and 2.5 kGy. Those of low concentration spore in normal saline were 0.47 kGy and 1.5 kGy. Dl0 value and minimal sterilizing dose of high concentration spore in maize were 0.67 kGy and 3.0 kGy. Those of low concentration spore in maize were 0.72 kGy and 2.0 kGy. 3.0 Gy may be suitable for grain processing to sterilize Aspergillus flavus.

  10. 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.

  11. Aflatoxins in Rice Artificially Contaminated with Aflatoxin-producing Aspergillus flavus under Natural Storage in Japan.

    Science.gov (United States)

    Sugihara, Satoshi; Doi, Hiroyuki; Kato, Masahiko; Mitoh, Yoshihiro; Tsuda, Toshihide; Ikeda, Satoru

    2016-06-01

    Aflatoxin (AFT) contamination is frequent in foods grown in tropical regions, including rice. Although AFTs are generally not found in temperate-region foods, global warming has affected typical temperate-region climates, potentially permitting the contamination of foods with AFT-producing Aspergillus flavus (A. flavus). Here we investigated the AFT production in rice during storage under natural climate conditions in Japan. We examined AFTs in brown rice and rough rice artificially contaminated with A. flavus for 1 year in Japan, and we subjected AFTs in white rice to the same treatment in airtight containers and examined the samples in warm and cold seasons, simulating the storage of white rice in general households. In the brown rice, AFTs increased after 2 months (March) and peaked after 9 months (October). The AFT contamination in the rough rice was minimal. After the polishing and cooking of the brown rice, AFTs were undetectable. In the white rice stored in airtight containers, AFTs increased after 1 month (August) and peaked after 2 months (September). Minimal AFTs were detected in the cold season. Thus, AFT contamination in rice may occur in temperate regions following A. flavus contamination. The storage of rice as rough rice could provide be useful for avoiding AFT contamination.

  12. 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.

  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. 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.

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

    International Nuclear Information System (INIS)

    Uddandarao, Priyanka; B, Raj Mohan

    2016-01-01

    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.

  16. Expression of Genes by Aflatoxigenic and Nonaflatoxigenic Strains of Aspergillus flavus Isolated from Brazil Nuts.

    Science.gov (United States)

    Baquião, Arianne Costa; Rodriges, Aline Guedes; Lopes, Evandro Luiz; Tralamazza, Sabina Moser; Zorzete, Patricia; Correa, Benedito

    2016-08-01

    The aims of the present study were to monitor the production of aflatoxin B1 (AFB1) and mycelial growth, and to evaluate the expression of genes directly and indirectly involved in the biosynthesis of aflatoxins by Aspergillus flavus isolated from Brazil nuts. Six previously identified A. flavus strains were grown on coconut agar at 25°C for up to 10 days. Mycotoxins were separated by high-performance liquid chromatography and fungal growth was measured daily using the diametric mycelial growth rate. Transcriptional analysis was performed by real-time polymerase chain reaction (PCR) after 2 and 7 d of incubation using specific primers (aflR, aflD, aflP, lipase, metalloprotease, and LaeA). Three (50%) of the six A. flavus isolates produced AFB1 (ICB-1, ICB-12, and ICB-54) and three (50%) were not aflatoxigenic (ICB-141, ICB-161, and ICB-198). Aflatoxin production was observed from d 2 of incubation (1.5 ng/g for ICB-54) and increased gradually with time of incubation until d 10 (15,803.6 ng/g for ICB-54). Almost all A. flavus isolates exhibited a similar gene expression pattern after 2 d of incubation (p > 0.10). After 7 d of incubation, the LaeA (p aflatoxin production in A. flavus and that overexpression of aflR could affect the transcriptional and aflatoxigenic pattern (ICB-54). Elucidation of the molecular mechanisms that regulate the secondary metabolism of toxigenic fungi may permit the rational silencing of the genes involved and consequently the programmed inhibition of aflatoxin production. Knowledge of the conditions, under which aflatoxin genes are expressed, should contribute to the development of innovative and more cost-effective strategies to reduce and prevent aflatoxin contamination in Brazil nuts.

  17. Cissus quadrangularis mediated ecofriendly synthesis of copper oxide nanoparticles and its antifungal studies against Aspergillus niger, Aspergillus flavus.

    Science.gov (United States)

    Devipriya, Duraipandi; Roopan, Selvaraj Mohana

    2017-11-01

    Recently, non-toxic source mediated synthesis of metal and a metal oxide nanoparticle attains more attention due to key applicational responsibilities. This present report stated that the eco-friendly synthesis of copper oxide nanoparticles (CuO NPs) using Cissus quadrangularis (C. quadrangularis) plant extract. Further the eco-friendly synthesized CuO NPs were characterized using a number of analytical techniques. The observed results stated that the synthesized CuO NPs were spherical in shape with 30±2nm. Then the eco-friendly synthesized CuO NPs were subjected for anti-fungal against two strains namely Aspergillus niger (A. niger) resulted in 83% at 500ppm, 86% of inhibition at 1000ppm and Aspergillus flavus (A. flavus) resulted in 81% at 500ppm, 85% of inhibition at 1000ppm respectively. Despite the fact that compared to standard Carbendazim, eco-friendly synthesized CuO NPs exhibits better results were discussed in this manuscript. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Partial retrotransposon-like DNA sequence in the genomic clone of Aspergillus flavus, pAF28.

    Science.gov (United States)

    Okubara, Patricia A; Tibbot, Brian K; Tarun, Alice S; McAlpin, Cesaria E; Hua, Sui-Sheng T

    2003-07-01

    A genomic clone of the aflatoxin-producing fungus Aspergillus flavus, designated pAF28, has been used as a probe for Southern blot fingerprinting of fungal strains. A large number of A. flavus strains isolated from corn fields and tree-nut orchards can be distinguished because the DNA fingerprint patterns are highly polymorphic. We have completed the sequencing of a 6355 bp insert in pAF28. The sequence features motifs and open reading frames characteristic of transposable elements of the gypsy class. We have named this new element AfRTL-1, for A. flavus retrotransposon-like DNA.

  19. 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)

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

    International Nuclear Information System (INIS)

    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.; Brasil, Davi S.B.

    2011-01-01

    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)

  1. Time course study of substrate utilization by Aspergillus flavus in medium simulating corn (Zea mays) kernels.

    Science.gov (United States)

    Mellon, Jay E; Dowd, Michael K; Cotty, Peter J

    2002-01-30

    Utilization of the three major corn reserve materials, starch, triglycerides (refined corn oil), and zein (storage protein), by Aspergillus flavus was monitored in vitro over a 7-day fermentation. Medium composition in which proportions of reserve materials initially approximated proportions in mature corn kernels changed little over the first 18 h. Subsequently, hydrolysis of both starch and triglycerides occurred simultaneously, with peak concentrations of glucose and free fatty acids on day 2 of the fermentation period. Fatty acid concentrations dropped relatively rapidly after day 2 but increased again after day 6. Aflatoxin B(1) production increased after 36 h, with a peak at day 4. Aflatoxin B(1) production paralleled fungal biomass production during the exponential growth phase. A. flavus did not appear to preferentially utilize any of the released fatty acids. A number of fungus-specific metabolites were detected, including arabitol, erythritol, mannitol, trehalose, and kojic acid. Mannitol exceeded the other metabolites in concentration, and the timing of mannitol production closely paralleled that of aflatoxin B(1). Kojic acid concentrations peaked at day 6. In contrast to previously described selective use of simple carbohydrates by A. flavus, less discrimination was displayed when faced with utilization of complex substrates such as starch or triglycerides.

  2. 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.

  3. Chemical properties of Aspergillus flavus-infected soybean seeds exposed to gamma-irradiation during storage

    International Nuclear Information System (INIS)

    Mahrous, S.R.

    2007-01-01

    The aim of the present study was to examine the chemical properties of Aspergillus flavus-infected soybean seeds exposed to different levels of gamma-irradiation; 0 1, 3 and 5 kGy, during storage. The results revealed that there was no effect of irradiation at different dose levels on moisture, protein, total lipids and amino acids content of the seeds for overall 60 days of storage under ambient temperature. At zero time, irradiation of A. flavus- infected-soybean seeds at 5.0 kGy caused a slight increase in peroxide value, no change in acid value, a slight decrease in saponification and iodine values in the crude oil extracted from the seeds. An increase in saturated fatty acids associated with a decrease in un-saturated fatty acids was also observed in the oil extracted from the seeds. Furthermore, at dose level 5 kGy the fungus growth was completely inhibited and there was no detection of aflatoxin B1 after 60 days of storage. It is concluded that gamma-irradiation of A. flavus-infected soybean seeds at dose level 5 kGY is sufficient to inhibit fungus growth and aflatoxin production over a storage period of 60 days without changes in major chemical properties of the seeds and the oil extracted from seeds

  4. 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.

  5. Influence of relative humidity on radiosensitivity of Aspergillus flavus Link. infecting cocoa beans

    International Nuclear Information System (INIS)

    Amoako-Atta, B.; Odamtten, G.T.; Appiah, V.

    1981-01-01

    The first part of this paper deals with the moisture sorption isotherms of dried cocoa beans under different relative humidities of 55, 65, 75, 85 or 95%. The second part evaluates the effects of relative humidity (RH), initial moisture content (m.c.) of cocoa beans, and different radiation exposure doses (0, 250, 350, 450, 500 or 550 krad) on Aspergillus flavus spore inoculated cocoa beans kept in fixed RH environmental chamber of 75 or 85% RH post-irradiation for forty days. The results discussed suggest that the m.c. of beans increased from an initial level of 6.4% to 7, 7.8 and 8.9% at 55, 65, and 75% respectively, after a storage period of 6-8 days. However, beans stored under 85% or 95% RH continued to absorb moisture from their respective environments indefinitely during the 64-day storage period. Furthermore, the ambient relative humidity to which the beans are subjected before or after irradiation significantly affect the radiosensitivity of toxigenic A. flavus; the differences in such radiosensitivity are influenced by either the available moisture or the initial m.c. of the beans to the inoculum. The authors conclude from their study that high environmental RH increased the radio-resistance of A. flavus spores making it difficult to establish a radiation decontamination level of practical value under a tropical environment with high ambient relative humidity. (author)

  6. The Pathogenesis-Related Maize Seed (PRms) Gene Plays a Role in Resistance toAspergillus flavusInfection 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.

  7. Morphological and molecular identification of filamentous Aspergillus flavus and Aspergillus parasiticus isolated from compound feeds in South Africa.

    Science.gov (United States)

    Iheanacho, Henry E; Njobeh, Patrick B; Dutton, Francis M; Steenkamp, Paul A; Steenkamp, Lucia; Mthombeni, Julian Q; Daru, Barnabas H; Makun, Anthony H

    2014-12-01

    Isolation of filamentous species of two Aspergillum genera from compound feeds produced in South Africa, and subsequent extraction of their individual DNA in this study, presents a simple but rapid molecular procedure for high through-put analysis of the individual morphological forms. DNA was successfully isolated from the Aspergillus spp. from agar cultures by use of a commercial kit. Agarose gel electrophoresis fractionation of the fungi DNA, showed distinct bands. The DNA extracted by this procedure appears to be relatively pure with a ratio absorbance at 260 and 280 nm. However, the overall morphological and molecular data indicated that 67.5 and 51.1% of feed samples were found to be contaminated with Aspergillus flavus and Aspergillus parasiticus, respectively, with poultry feed having the highest contamination mean level of 5.7 × 105 CFU/g when compared to cattle (mean: 4.0 × 106 CFU/g), pig (mean: 2.7 × 104 CFU/g) and horse (1.0 × 102 CFU) feed. This technique presents a readily achievable, easy to use method in the extraction of filamentous fungal DNA and it's identification. Hence serves as an important tool towards molecular study of these organisms for routine analysis check in monitoring and improving compound feed quality against fungal contamination. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Identification of two aflatrem biosynthesis gene loci in Aspergillus flavus and metabolic engineering of Penicillium paxilli to elucidate their function.

    Science.gov (United States)

    Nicholson, Matthew J; Koulman, Albert; Monahan, Brendon J; Pritchard, Beth L; Payne, Gary A; Scott, Barry

    2009-12-01

    Aflatrem is a potent tremorgenic toxin produced by the soil fungus Aspergillus flavus, and a member of a structurally diverse group of fungal secondary metabolites known as indole-diterpenes. Gene clusters for indole-diterpene biosynthesis have recently been described in several species of filamentous fungi. A search of Aspergillus complete genome sequence data identified putative aflatrem gene clusters in the genomes of A. flavus and Aspergillus oryzae. In both species the genes for aflatrem biosynthesis cluster at two discrete loci; the first, ATM1, is telomere proximal on chromosome 5 and contains a cluster of three genes, atmG, atmC, and atmM, and the second, ATM2, is telomere distal on chromosome 7 and contains five genes, atmD, atmQ, atmB, atmA, and atmP. Reverse transcriptase PCR in A. flavus demonstrated that aflatrem biosynthesis transcript levels increased with the onset of aflatrem production. Transfer of atmP and atmQ into Penicillium paxilli paxP and paxQ deletion mutants, known to accumulate paxilline intermediates paspaline and 13-desoxypaxilline, respectively, showed that AtmP is a functional homolog of PaxP and that AtmQ utilizes 13-desoxypaxilline as a substrate to synthesize aflatrem pathway-specific intermediates, paspalicine and paspalinine. We propose a scheme for aflatrem biosynthesis in A. flavus based on these reconstitution experiments in P. paxilli and identification of putative intermediates in wild-type cultures of A. flavus.

  9. 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.

  10. 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.

  11. 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 &...

  12. Spinal osteomyelitis due to Aspergillus flavus in a child: a rare complication after haematopoietic stem cell transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Beluffi, Giampiero [Fondazione IRCCS Policlinico ' S.Matteo' , Section of Paediatric Radiology, Department of Radiodiagnosis, Pavia PV (Italy); Bernardo, Maria E.; Locatelli, Franco [University of Pavia, Fondazione IRCCS Policlinico ' S.Matteo' , Department of Paediatric Haematology/Oncology, Pavia (Italy); Meloni, Giulia [University of Pavia, Fondazione IRCCS Policlinico ' S.Matteo' , Institute of Radiology, Pavia (Italy); Spinazzola, Angelo [Fondazione IRCCS Policlinico ' S.Matteo' , Section of Paediatric Radiology, Department of Radiodiagnosis, Pavia PV (Italy); Ospedale Maggiore, Crema CR (Italy)

    2008-06-15

    We report the case of a child affected by acute myeloid leukaemia who was treated with allogeneic haematopoietic stem cell transplantation and developed cervicothoracic spinal osteomyelitis due to Aspergillus flavus. The diagnosis was difficult on a clinical basis, but made possible by conventional radiography and MRI. (orig.)

  13. 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...

  14. Transcriptome of Aspergillus flavus aswA (AFLA_085170) deletion strain related to sclerotial development and production of secondary metabolites

    Science.gov (United States)

    Aspergillus flavus produces many secondary metabolites including aflatoxins. Besides conidia, the fungus uses sclerotia as another type of propagule. We obtained transcriptomes from four growth conditions of the aswA mutant, a strain impaired in sclerotial development and production of sclerotium-sp...

  15. 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...

  16. 77 FR 14287 - Aspergillus flavus AF36; Amendment to an Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2012-03-09

    ... (703) 305-5805. FOR FURTHER INFORMATION CONTACT: Jeannine Kausch, Biopesticides and Pollution... Biopesticides Registration Action Document (Dated July 3, 2003). Available from http://www.epa.gov/oppbppd1/biopesticides/ingredients/tech_docs/brad_006456.pdf . 2. U.S. EPA. 2011. Aspergillus flavus AF36 use on...

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

    Science.gov (United States)

    Zaccaria, Marco; Ludovici, Matteo; Sanzani, Simona Marianna; Ippolito, Antonio; Cigliano, Riccardo Aiese; Sanseverino, Walter; Scarpari, Marzia; Scala, Valeria; Fanelli, Corrado; Reverberi, Massimo

    2015-10-23

    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.

  18. 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.

  19. Larval Preference and Performance of Amyelois transitella (Navel Orangeworm, Lepidoptera: Pyralidae) in Relation to the Fungus Aspergillus flavus.

    Science.gov (United States)

    Ampt, Eline A; Bush, Daniel S; Siegel, Joel P; Berenbaum, May R

    2016-02-01

    The navel orangeworm, Amyelois transitella (Walker), is a polyphagous pest of California nut crops and is responsible for extensive losses in the United States. It directly damages crops by feeding and contaminating nuts with frass and webbing and vectors saprophytic fungi that infect crops. The navel orangeworm is commonly associated with Aspergillus species, including the toxigenic Aspergillus flavus, which causes crop loss by producing carcinogens, including aflatoxin B1. This lepidopteran-fungus association is the most economically serious pest complex in Central Valley orchards, and evidence indicates that this relationship is mutualistic. We assessed preference and performance of navel orangeworm larvae associated with A. flavus in behavioral bioassays in which neonates were allowed to orient within arenas to media with or without fungal tissue, and performance bioassays in which larvae were reared with and without A. flavus on potato dextrose agar (PDA) and a semidefined almond PDA diet to evaluate effects on development and pupal weight. Navel orangeworm larvae were attracted to A. flavus and developed faster in its presence, indicating a nutritional benefit to the caterpillars. Larvae reached pupation ∼33% faster on diet containing A. flavus, and pupal weights were ∼18% higher for males and ∼13% higher for females on this diet. Our findings indicate that A. flavus plays an important role in larval orientation and development on infected hosts. The preference-performance relationship between navel orangeworms and Aspergillus flavus is consistent with a facultative mutualism that has broad implications for pest management efforts and basic understanding of Lepidoptera-plant interactions. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. 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

  1. 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.

  2. 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.

  3. Effects of gamma radiation and electron beam on samples of the Brazil nuts artificially inoculated with Aspergillus flavus

    International Nuclear Information System (INIS)

    Coelho, Ednei Assuncao Antunes

    2012-01-01

    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

  4. 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

  5. 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.

  6. 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.

  7. 4-Hydroxy-7-methyl-3-phenylcoumarin Suppresses Aflatoxin Biosynthesis via Downregulation of aflK Expressing Versicolorin B Synthase in Aspergillus flavus.

    Science.gov (United States)

    Moon, Young-Sun; Kim, Leesun; Chun, Hyang Sook; Lee, Sung-Eun

    2017-04-29

    Naturally occurring coumarins possess antibacterial and antifungal properties. In this study, these natural and synthetic coumarins were used to evaluate their antifungal activities against Aspergillus flavus , which produces aflatoxins. In addition to control antifungal activities, antiaflatoxigenic properties were also determined using a high-performance liquid chromatography in conjunction with fluorescence detection. In this study, 38 compounds tested and 4-hydroxy-7-methyl-3-phenyl coumarin showed potent antifungal and antiaflatoxigenic activities against A. flavus . Inhibitory mode of antiaflatoxigenic action by 4-hydroxy-7-methyl-3-phenyl coumarin was based on the downregulation of aflD , aflK , aflQ , and aflR in aflatoxin biosynthesis. In the cases of coumarins, antifungal and aflatoxigenic activities are highly related to the lack of diene moieties in the structures. In structurally related compounds, 2,3-dihydrobenzofuran exhibited antifungal and antiaflatoxigenic activities against A. flavus . The inhibitory mode of antiaflatoxigenic action by 2,3-dihydrobenzofuran was based on the inhibition of the transcription factor ( aflS ) in the aflatoxin biosynthesis pathway. These potent inhibitions of 2,3-dihydrobenzofuran and 4-hydroxy-7-methyl-3-phenyl coumarin on the Aspergillus growth and production of aflatoxins contribute to the development of new controlling agents to mitigate aflatoxin contamination.

  8. Steroids and an oxylipin from an algicolous isolate of Aspergillus flavus.

    Science.gov (United States)

    Qiao, Ming-Feng; Ji, Nai-Yun; Miao, Feng-Ping; Yin, Xiu-Li

    2011-06-01

    A new oxylipin, (8E,12Z)-10,11-dihydroxyoctadeca-8,12-dienoic acid (1), a new steroid, 3β,4α-dihydroxy-26-methoxyergosta-7,24(28)-dien-6-one (2), and four known steroids, episterol (3), (22E,24R)-ergosta-7,22-dien-3β,5α,6α-triol (4), (22E,24R)-ergosta-5,22-dien-3β-ol (5), and (22E,24R)-ergosta-4,6,8(14),22-tetraen-3-one (6), were isolated from the cultures of Aspergillus flavus, an endophytic fungus isolated from the marine red alga Corallina officinalis. Their structures and relative stereochemistry were elucidated by 1D, 2D NMR and mass spectroscopic techniques. 1 and 2 exhibited low activity to inhibit acetylcholinesterase and no activity against plant pathogenic fungi Colletotrichum lagenarium and Fusarium oxysporum. Copyright © 2011 John Wiley & Sons, Ltd.

  9. Bioregulation of aflatoxin biosynthesis by unirradiated and irradiated conidia of Aspergillus flavus

    International Nuclear Information System (INIS)

    Aziz, N.H.; Abu-Shady, M.R.; El-Fouly, M.Z.; Moussa, L.A.

    1996-01-01

    A sequential technique involving the transfer of mycelia from peptone-based, aflatoxin-non-supporting medium to glucose based, aflatoxin-supporting medium was used to study the effect of γ-irradiation on the regulation of aflatoxin biosynthesis by Aspergillus flavus. Analysis indicated that irradiation at a dose of 1.00 kGy produced enhancement of aflatoxin biosynthesis in peptone-glucose mineral salt cultures with an increase of adenine nucleotide levels and fatty acid patterns of microsomes and mitochondria. The results suggest that aflatoxin synthesis is not regulated by the overall energy status of the fungal cell but that lipoperoxidation by γ-irradiation plays a role in aflatoxin biosynthesis

  10. Transcriptional profiles uncover Aspergillus flavus-induced resistance in maize kernels.

    Science.gov (United States)

    Luo, Meng; Brown, Robert L; Chen, Zhi-Yuan; Menkir, Abebe; Yu, Jiujiang; Bhatnagar, Deepak

    2011-07-01

    Aflatoxin contamination caused by the opportunistic pathogen A. flavus is a major concern in maize production prior to harvest and through storage. Previous studies have highlighted the constitutive production of proteins involved in maize kernel resistance against A. flavus' infection. However, little is known about induced resistance nor about defense gene expression and regulation in kernels. In this study, maize oligonucleotide arrays and a pair of closely-related maize lines varying in aflatoxin accumulation were used to reveal the gene expression network in imbibed mature kernels in response to A. flavus' challenge. Inoculated kernels were incubated 72 h via the laboratory-based Kernel Screening Assay (KSA), which highlights kernel responses to fungal challenge. Gene expression profiling detected 6955 genes in resistant and 6565 genes in susceptible controls; 214 genes induced in resistant and 2159 genes induced in susceptible inoculated kernels. Defense related and regulation related genes were identified in both treatments. Comparisons between the resistant and susceptible lines indicate differences in the gene expression network which may enhance our understanding of the maize-A. flavus interaction.

  11. 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.

  12. 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.

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

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    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.  

  14. Inactivation of Aspergillus flavus spores in a sealed package by cold plasma streamers

    Science.gov (United States)

    Sohbatzadeh, F.; Mirzanejhad, S.; Shokri, H.; Nikpour, M.

    2016-06-01

    The main objective of this study is to investigate the inactivation efficacy of cold streamers in a sealed package on pathogenic fungi Aspergillus flavus ( A. flavus) spores that artificially contaminated pistachio surface. To produce penetrating cold streamers, electric power supply was adapted to deposit adequate power into the package. The plasma streamers were generated by an alternating high voltage with carrier frequency of 12.5 kHz which was suppressed by a modulated pulsed signal at frequency of 110 Hz. The plasma exposition time was varied from 8 to 18 min to show the effect of the plasma treatment on fungal clearance while the electrode and sample remained at room temperature. This proved a positive effect of the cold streamers treatment on fungal clearance. Benefits of deactivation of fungal spores by streamers inside the package include no heating, short treatment time and adaptability to existing processes. Given its ability to ensure the safety and longevity of food products, this technology has great potential for utilization in food packaging and processing industry. In this study, moisture and pH changes of pistachio samples after plasma streamers treatment were also investigated.

  15. Molecular phylogeny and phenotypic variability of clinical and environmental strains of Aspergillus flavus.

    Science.gov (United States)

    Gonçalves, Sarah S; Cano, Josep F; Stchigel, Alberto M; Melo, Analy S; Godoy-Martinez, Patricio C; Correa, Benedito; Guarro, Josep

    2012-11-01

    Aspergillus flavus is the second most common cause of aspergillosis infection in immunocompromised patients and is responsible for the production of aflatoxins. Little is known about the population structure of A. flavus, although recent molecular and phenotypic data seem to demonstrate that different genetic lineages exist within this species. The aim of this study was to carry out a morphological, physiological, and molecular analysis of a set of clinical and environmental isolates to determine whether this variability is due to species divergence or intraspecific diversity, and to assess whether the clinical isolates form a separate group. The amdS and omtA genes were more phylogenetically informative than the other tested genes and their combined analysis inferred three main clades, with no clear distinction between clinical and environmental isolates. No important morphological and physiological differences were found between the members of the different clades, with the exception of the assimilation of d-glucosamine, which differentiates the members of the clade II from the others. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  16. Comparison of Two Inoculation Methods for Evaluating Maize for Resistance to Aspergillus flavus Infection and Aflatoxin Accumulation

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    W. Paul Williams

    2013-01-01

    Full Text Available Aflatoxin, the most potent carcinogen found in nature, is produced by the fungus Aspergillus flavus and occurs naturally in maize, Zea mays L. Growing maize hybrids with genetic resistance to aflatoxin contamination are generally considered a highly desirable way to reduce losses to aflatoxin. Developing resistant hybrids requires reliable inoculation methods for screening maize germplasm for resistance to A. flavus infection and aflatoxin accumulation. The side-needle technique is a widely used inoculation technique: an A. flavus conidial suspension is injected underneath the husks into the side of the ear. This wounds the ear and limits expression of resistance associated with husk coverage, pericarp thickness, and seed coat integrity. In this investigation, the side-needle technique was compared with a second inoculation method that involved dispensing wheat kernels infected with A. flavus into plant whorls at 35 and 49 days after planting. Results showed that although the side-needle technique produced higher levels of aflatoxin accumulation, differences in A. flavus biomass produced by the two inoculation techniques were not significant. Both inoculation techniques were effective in differentiating resistant and susceptible single cross hybrids irrespective of the use of A. flavus infection or aflatoxin accumulation as a basis to define resistance.

  17. Comparison of Expression of Secondary Metabolite Biosynthesis Cluster Genes in Aspergillus flavus, A. parasiticus, and A. oryzae

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    Kenneth C. Ehrlich

    2014-06-01

    Full Text Available 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.

  18. 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.

    2014-01-01

    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. PMID:24960201

  19. Intraspecific aflatoxin inhibition in Aspergillus flavus is thigmoregulated, independent of vegetative compatibility group and is strain dependent.

    Directory of Open Access Journals (Sweden)

    Changwei Huang

    Full Text Available Biological control of preharvest aflatoxin contamination by atoxigenic stains of Aspergillus flavus has been demonstrated in several crops. The assumption is that some form of competition suppresses the fungus's ability to infect or produce aflatoxin when challenged. Intraspecific aflatoxin inhibition was demonstrated by others. This work investigates the mechanistic basis of that phenomenon. A toxigenic and atoxigenic isolate of A. flavus which exhibited intraspecific aflatoxin inhibition when grown together in suspended disc culture were not inhibited when grown in a filter insert-plate well system separated by a .4 or 3 µm membrane. Toxigenic and atoxigenic conidial mixtures (50∶50 placed on both sides of these filters restored inhibition. There was ∼50% inhibition when a 12 µm pore size filter was used. Conidial and mycelial diameters were in the 3.5-7.0 µm range and could pass through the 12 µm filter. Larger pore sizes in the initially separated system restored aflatoxin inhibition. This suggests isolates must come into physical contact with one another. This negates a role for nutrient competition or for soluble diffusible signals or antibiotics in aflatoxin inhibition. The toxigenic isolate was maximally sensitive to inhibition during the first 24 hrs of growth while the atoxigenic isolate was always inhibition competent. The atoxigenic isolate when grown with a green fluorescent protein (GFP toxigenic isolate failed to inhibit aflatoxin indicating that there is specificity in the touch inhibiton. Several atoxigenic isolates were found which inhibited the GFP isolate. These results suggest that an unknown signaling pathway is initiated in the toxigenic isolate by physical interaction with an appropriate atoxigenic isolate in the first 24 hrs which prevents or down-regulates normal expression of aflatoxin after 3-5 days growth. We suspect thigmo-downregulation of aflatoxin synthesis is the mechanistic basis of intraspecific

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

    OpenAIRE

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

    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 infecti...

  1. 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.

  2. The Master Transcription Factor mtfA Governs Aflatoxin Production, Morphological Development and Pathogenicity in the Fungus Aspergillus flavus.

    Science.gov (United States)

    Zhuang, Zhenhong; Lohmar, Jessica M; Satterlee, Timothy; Cary, Jeffrey W; Calvo, Ana M

    2016-01-20

    Aspergillus flavus produces a variety of toxic secondary metabolites; among them, the aflatoxins (AFs) are the most well known. These compounds are highly mutagenic and carcinogenic, particularly AFB₁. A. flavus is capable of colonizing a number of economically-important crops, such as corn, cotton, peanut and tree nuts, and contaminating them with AFs. Molecular genetic studies in A. flavus could identify novel gene targets for use in strategies to reduce AF contamination and its adverse impact on food and feed supplies worldwide. In the current study, we investigated the role of the master transcription factor gene mtfA in A. flavus. Our results revealed that forced overexpression of mtfA results in a drastic decrease or elimination of several secondary metabolites, among them AFB₁. The reduction in AFB₁ was accompanied by a decrease in aflR expression. Furthermore, mtfA also regulates development; conidiation was influenced differently by this gene depending on the type of colonized substrate. In addition to its effect on conidiation, mtfA is necessary for the normal maturation of sclerotia. Importantly, mtfA positively affects the pathogenicity of A. flavus when colonizing peanut seeds. AF production in colonized seeds was decreased in the deletion mtfA strain and particularly in the overexpression strain, where only trace amounts were detected. Interestingly, a more rapid colonization of the seed tissue occurred when mtfA was overexpressed, coinciding with an increase in lipase activity and faster maceration of the oily part of the seed.

  3. Tissue-specific gene expression in maize seeds during colonization by Aspergillus flavus and Fusarium verticillioides.

    Science.gov (United States)

    Shu, Xiaomei; Livingston, David P; Franks, Robert G; Boston, Rebecca S; Woloshuk, Charles P; Payne, Gary A

    2015-09-01

    Aspergillus flavus and Fusarium verticillioides are fungal pathogens that colonize maize kernels and produce the harmful mycotoxins aflatoxin and fumonisin, respectively. Management practice based on potential host resistance to reduce contamination by these mycotoxins has proven difficult, resulting in the need for a better understanding of the infection process by these fungi and the response of maize seeds to infection. In this study, we followed the colonization of seeds by histological methods and the transcriptional changes of two maize defence-related genes in specific seed tissues by RNA in situ hybridization. Maize kernels were inoculated with either A. flavus or F. verticillioides 21-22 days after pollination, and harvested at 4, 12, 24, 48, 72, 96 and 120 h post-inoculation. The fungi colonized all tissues of maize seed, but differed in their interactions with aleurone and germ tissues. RNA in situ hybridization showed the induction of the maize pathogenesis-related protein, maize seed (PRms) gene in the aleurone and scutellum on infection by either fungus. Transcripts of the maize sucrose synthase-encoding gene, shrunken-1 (Sh1), were observed in the embryo of non-infected kernels, but were induced on infection by each fungus in the aleurone and scutellum. By comparing histological and RNA in situ hybridization results from adjacent serial sections, we found that the transcripts of these two genes accumulated in tissue prior to the arrival of the advancing pathogens in the seeds. A knowledge of the patterns of colonization and tissue-specific gene expression in response to these fungi will be helpful in the development of resistance. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  4. 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 B 1 (AFB 1 ) 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 AFB 1 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.

  5. Improving Peanut Productivity and Resistance to Aspergillus flavus L Through mutation Induction

    International Nuclear Information System (INIS)

    Ragab, A.I; Korani, W.A.A.; Rashed, M.A.; Salam, M.A

    2008-01-01

    The present study was conducted to improve peanut productivity and resistance to Aspergillus flavus that caused aflatoxin formation in peanut seeds . To achieve these goals , dry seeds of the two local varieties (Giza 4 and Giza5) were irradiated with gamma ray doses of 0 , 50 , 100 , 150 , 200 , 250 , 300 Gy. The irradiated seeds were sown to get the M1 and M2 generations. Six high yielding mutants were selected in M2 from irradiated populations of 150 Gy and 200 Gy for Giza 4 and Giza 5 respectively. These mutants were evaluated in M3 generation for yield and yield components , quality traits (protein and oil content) and the resistance to Aspergillus flavus infection. The obtained results revealed that analysis of variance for Giza 4 selected mutants showed significant differences between genotypes for different studied characters except for plant height and no. of branches /plant .However, for Giza5 selected mutants, significant differences between genotypes were only obtained for plant height , no of pods/plant, weight of pods/plant, weight of seeds/plant, and weight of 100 seeds. Different M3 mutants that selected from irradiated populations of both two peanut cultivars Giza4 and Giza5 shod marked improvement for yield and yield components, and quality traits in comparison with their mother varieties.The results of M3 progeny test indicated that most selected mutants retained the features of their M2 selectors, suggesting that they were considered true breeding materials. For Giza 4 selected mutants, aflatoxin concentrations ranged from 31.11 μg for mutant 1 to 188.46 μ g for mutant3 in comparison with 42.76 μg for the mother variety Giza 4. The lowest yielding progenies of mutant1 (1 ) showed the lowest aflatoxin concentrations as compared with the mother variety Giza 4 and other mutants, therefore the use of induced mutations for peanut improvement may be led to the development of improved varieties .However, for Giza 5 selected mutants aflatoxin

  6. The Aspergillus flavus Spermidine Synthase (spds Gene, Is Required for Normal Development, Aflatoxin Production, and Pathogenesis During Infection of Maize Kernels

    Directory of Open Access Journals (Sweden)

    Rajtilak Majumdar

    2018-03-01

    Full Text Available Aspergillus flavus is a soil-borne saprophyte and an opportunistic pathogen of both humans and plants. This fungus not only causes disease in important food and feed crops such as maize, peanut, cottonseed, and tree nuts but also produces the toxic and carcinogenic secondary metabolites (SMs known as aflatoxins. Polyamines (PAs are ubiquitous polycations that influence normal growth, development, and stress responses in living organisms and have been shown to play a significant role in fungal pathogenesis. Biosynthesis of spermidine (Spd is critical for cell growth as it is required for hypusination-mediated activation of eukaryotic translation initiation factor 5A (eIF5A, and other biochemical functions. The tri-amine Spd is synthesized from the diamine putrescine (Put by the enzyme spermidine synthase (Spds. Inactivation of spds resulted in a total loss of growth and sporulation in vitro which could be partially restored by addition of exogenous Spd. Complementation of the Δspds mutant with a wild type (WT A. flavus spds gene restored the WT phenotype. In WT A. flavus, exogenous supply of Spd (in vitro significantly increased the production of sclerotia and SMs. Infection of maize kernels with the Δspds mutant resulted in a significant reduction in fungal growth, sporulation, and aflatoxin production compared to controls. Quantitative PCR of Δspds mutant infected seeds showed down-regulation of aflatoxin biosynthetic genes in the mutant compared to WT A. flavus infected seeds. Expression analyses of PA metabolism/transport genes during A. flavus-maize interaction showed significant increase in the expression of arginine decarboxylase (Adc and S-adenosylmethionine decarboxylase (Samdc genes in the maize host and PA uptake transporters in the fungus. The results presented here demonstrate that Spd biosynthesis is critical for normal development and pathogenesis of A. flavus and pre-treatment of a Δspds mutant with Spd or Spd uptake from the

  7. Autoxidated linolenic acid inhibits aflatoxin biosynthesis in Aspergillus flavus via oxylipin species.

    Science.gov (United States)

    Yan, Shijuan; Liang, Yating; Zhang, Jindan; Chen, Zhuang; Liu, Chun-Ming

    2015-08-01

    Aflatoxins produced by Aspergillus species are among the most toxic and carcinogenic compounds in nature. Although it has been known for a long time that seeds with high oil content are more susceptible to aflatoxin contamination, the role of fatty acids in aflatoxin biosynthesis remains controversial. Here we demonstrate in A. flavus that both the saturated stearic acid (C18:0) and the polyunsaturated linolenic acid (C18:3) promoted aflatoxin production, while C18:3, but not C18:0, inhibited aflatoxin biosynthesis after exposure to air for several hours. Further experiments showed that autoxidated C18:3 promoted mycelial growth, sporulation, and kojic acid production, but inhibited the expression of genes in the AF biosynthetic gene cluster. Mass spectrometry analyses of autoxidated C18:3 fractions that were able to inhibit aflatoxin biosynthesis led to the identification of multiple oxylipin species. These results may help to clarify the role of fatty acids in aflatoxin biosynthesis, and may explain why controversial results have been obtained for fatty acids in the past. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Characterization and primary structure of elastase inhibitor, AFLEI, from Aspergillus flavus.

    Science.gov (United States)

    Okumura, Yoshiyuki; Ogawa, Kenji; Uchiya, Kei-ichi

    2007-01-01

    The amino acid sequence of elastase inhibitor, AFLEI, isolated from Aspergillus flavus was determined by the Edman sequencing procedure of peptides derived from digests utilizing clostripain. A molecular weight of 7,525.8 was observed by TOF-MS. AFLEI contained 68 amino acid residues and has a calculated molecular weight of 7,526.2. The search for amino acid homology with other proteins demonstrated that amino acid residues 1 to 51 of AFLEI are 100% identical to residues 20 to 70 of the hypothetical protein Afu3g14940. The Michaelis constant (Km) for succinyl L-alanyl- L-alanyl- L-alanyl p-nitroanilide (STANA), and inhibition constant (Ki), for elastase of AFLEI, were found to be 6.7 x 10(2) microM and 4.0 x 10(-2) microM, respectively. Inhibitory activity was compared with six protease inhibitors (ulinastatin, nafamostat mesilate, sivelestat sodium hydrate, gabexate mesilate, elastatinal and elafin). The other six protease inhibitors demonstrated very weak inhibitory activity by comparison with AFLEI.

  9. 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

  10. Modeling kinetics of aflatoxin production by Aspergillus flavus in maize-based medium and maize grain.

    Science.gov (United States)

    Garcia, Daiana; Ramos, Antonio J; Sanchis, Vicente; Marín, Sonia

    2013-03-15

    Predictive mycology has dealt mainly with germination, growth and inactivation of fungi while the issue of mycotoxin production remains relatively unexplored. Very few studies provide biomass dry weight/colony size data along with mycotoxin data for the same sample times, thus the ratio mycotoxin accumulation per fungal biomass dry weight/colony size has rarely been reported. For this reason, the objective of the present study was to model the kinetics of mycotoxin production under the assumption of existing both no-growth-associated and growth-associated production. Aspergillus flavus was chosen as a model mycotoxigenic microorganism, and it was grown in maize agar medium and maize grain at 0.90 and 0.99 aw at 25°C. A significant positive correlation (p<0.05) was observed among the biomass responses (colony radius and biomass dry weight) in agar medium and colony radius in maize at both aw levels assayed. The Luedeking-Piret model was used to model AFB1 production and reasonable percentages of variability were explained. Moreover, AFB1 production was in general slightly better predicted through colony area. As conclusion, aflatoxin production may follow a mixed-growth associated trend, confirming that toxin formation does not present a clear delay in relation to growth under certain conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. 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.

  12. 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.

  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. Effects of soil moisture and temperature on preharvest invasion of peanuts by the Aspergillus flavus group and subsequent aflatoxin development.

    Science.gov (United States)

    Hill, R A; Blankenship, P D; Cole, R J; Sanders, T H

    1983-02-01

    Four soil temperature and moisture treatment regimens were imposed on Florunner peanuts 94 days after planting in experimental plots in 1980. At harvest (145 days after planting), the incidence of the Aspergillus flavus group and the aflatoxin concentration were greatest in damaged kernels. Extensive colonization of sound mature kernels (SMK) by the A. flavus group occurred with the drought stress treatment (56% kernels colonized); colonization was less in the irrigated plot (7%) and the drought stress plot with cooled soil (11%) and was intermediate in the irrigated plot with heated soil (26%). Aflatoxin was virtually absent from SMK with the last three treatments, but it was found at an average concentration of 244 ppb (ng/g) in drought-stressed SMK. Colonization of SMK by the A. flavus group and aflatoxin production were greater with hot dry conditions. Neither elevated temperature alone nor drought stress alone caused aflatoxin contamination in SMK. When the ratio of SMK colonized by A. flavus compared with A. niger was greater than 19:1, there was aflatoxin contamination, but there was none if this ratio was less than 9:1. Irrigation caused a higher incidence of A. niger than drought did. This may have prevented the aflatoxin contamination of undamaged peanuts.

  15. A Simple Procedure to Evaluate Competitiveness of Toxigenic and Atoxigenic Isolates of Aspergillus flavus in Solid and Liquid Media

    Directory of Open Access Journals (Sweden)

    Mohammad Moradi

    2017-04-01

    Full Text Available Application of atoxigenic strains of Aspergillus flavus to reduce aflatoxin levels is the most successful strategy applied in some agricultural crops. The role of ammonium hydroxide for preliminary screening of the competitiveness of atoxigenic A. flavus isolates to interfere with aflatoxin production by highly toxigenic isolates were evaluated. Out of 270 A. flavus isolates, 17 were detected as true atoxigenic using cultural methods and confirmed by analytical assays from different pistachio agro-ecological zones during 2013. For assessment competitive ability among atoxigenic isolates of A. flavus with highly toxigenic one, rice flour, coconut agar and coconut broth medium substrates were inoculated with mixtures including combinations of toxigenic and atoxigenic isolates, simultaneously. The rice flour substrate was used to quantify the content of aflatoxin in either co-inoculations or toxigenic isolate alone on thin layer chromatography plates with a scanning densitometer. While the culture media were used to determine the intensity of color change on exposing to ammonium hydroxide vapor. The reduction rates of aflatoxin B1 in co-inoculations were varied and ranged from 2%-82%. Based on the intensity of colony color changes, the competitiveness of the isolates was classified into five groups. Atoxigenic isolates with high competitiveness have shown low color changes in culture media and high aflatoxin reduction in TLC assays with a ratio of higher than 78%. The method will facilitate preliminary screening of efficient atoxigenic isolates for mitigation of aflatoxins in food and feed as a cheap, simple and quick method.

  16. Identification of chemical components of corn kernel pericarp wax associated with resistance to Aspergillus flavus infection and aflatoxin production.

    Science.gov (United States)

    Gembeh, S V; Brown, R L; Grimm, C; Cleveland, T E

    2001-10-01

    Kernel pericarp wax of the corn breeding population GT-MAS:gk has been associated with resistance to Aspergillus flavus infection and aflatoxin production. GT-MAS:gk wax, previously compared to waxes of three susceptible genotypes, was presently compared to wax of a different, and more numerous, group of susceptible lines. Wax separation by TLC confirmed previous findings, demonstrating a unique GT-MAS:gk band and a unique "susceptible" band. Only GT-MAS:gk wax inhibited the growth of A. flavus; however, no association was established, as before, between kernel wax abundance and resistance. Gas chromatography-mass spectroscopy (GC-MS) analysis of kernel whole wax showed a higher percentage of phenol-like compounds in wax from GT-MAS:gk than in waxes from the susceptible lines. The GT-MAS:gk unique band contained phenol-like compounds and ethyl-hexadecanoate; butyl-hexadecanoate was preeminent in most of the "susceptible bands". Alkylresorcinol (phenolic compounds) content was dramatically higher in GT-MAS:gk wax than in the wax of susceptible lines. An alkylresorcinol, 5-methylresorcinol, also inhibited in vitro growth of A. flavus. These and other phenolic compounds may contribute to kernel wax inhibition of A. flavus infection/aflatoxin production. Further investigation is needed to confirm a role for them in GT-MAS:gk resistance.

  17. 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.

  18. Downregulation of transcription factor aflR in Aspergillus flavus confers reduction to aflatoxin accumulation in transgenic maize with alteration of host plant architecture.

    Science.gov (United States)

    Masanga, Joel Okoyo; Matheka, Jonathan Mutie; Omer, Rasha Adam; Ommeh, Sheila Cecily; Monda, Ethel Oranga; Alakonya, Amos Emitati

    2015-08-01

    We report success of host-induced gene silencing in downregulation of aflatoxin biosynthesis in Aspergillus flavus infecting maize transformed with a hairpin construct targeting transcription factor aflR. Infestation of crops by aflatoxin-producing fungi results in economic losses as well as negative human and animal health effects. Currently, the control strategies against aflatoxin accumulation are not effective to the small holder farming systems in Africa and this has led to widespread aflatoxin exposure especially in rural populations of sub-Saharan Africa that rely on maize as a staple food crop. A recent strategy called host-induced gene silencing holds great potential for developing aflatoxin-resistant plant germplasm for the African context where farmers are unable to make further investments other than access to the germplasm. We transformed maize with a hairpin construct targeting the aflatoxin biosynthesis transcription factor aflR. The developed transgenic maize were challenged with an aflatoxigenic Aspergillus flavus strain from Eastern Kenya, a region endemic to aflatoxin outbreaks. Our results indicated that aflR was downregulated in A. flavus colonizing transgenic maize. Further, maize kernels from transgenic plants accumulated significantly lower levels of aflatoxins (14-fold) than those from wild type plants. Interestingly, we observed that our silencing cassette caused stunting and reduced kernel placement in the transgenic maize. This could have been due to "off-target" silencing of unintended genes in transformed plants by aflR siRNAs. Overall, this work indicates that host-induced gene silencing has potential in developing aflatoxin-resistant germplasm.

  19. Transcriptional Profiles Uncover Aspergillus flavus-Induced Resistance in Maize Kernels

    Directory of Open Access Journals (Sweden)

    Zhi-Yuan Chen

    2011-06-01

    Full Text Available Aflatoxin contamination caused by the opportunistic pathogen A. flavus is a major concern in maize production prior to harvest and through storage. Previous studies have highlighted the constitutive production of proteins involved in maize kernel resistance against A. flavus’ infection. However, little is known about induced resistance nor about defense gene expression and regulation in kernels. In this study, maize oligonucleotide arrays and a pair of closely-related maize lines varying in aflatoxin accumulation were used to reveal the gene expression network in imbibed mature kernels in response to A. flavus’ challenge. Inoculated kernels were incubated 72 h via the laboratory-based Kernel Screening Assay (KSA, which highlights kernel responses to fungal challenge. Gene expression profiling detected 6955 genes in resistant and 6565 genes in susceptible controls; 214 genes induced in resistant and 2159 genes induced in susceptible inoculated kernels. Defense related and regulation related genes were identified in both treatments. Comparisons between the resistant and susceptible lines indicate differences in the gene expression network which may enhance our understanding of the maize-A. flavus interaction.

  20. Purification and characterization of a novel heparin degrading enzyme from Aspergillus flavus (MTCC-8654).

    Science.gov (United States)

    Banga, Jaspreet; Tripathi, C K M

    2010-02-01

    A heparinase-producing fungus was isolated, and the strain was taxonomically characterized as Aspergillus flavus by morphophysiological and 26S rRNA gene homology studies. The culture produced intracellular heparinase enzyme, which was purified 40.5-fold by DEAE-Sephadex A-50, CM-Sephadex C-50, and Sephadex G-100 column chromatography. Specific activity of the purified enzyme was found to be 44.6 IU/microg protein and the molecular weight of native as well as reduced heparinase was 24 kDa, showing a monomeric unit structure. Peptide mass spectrum showed poor homogeneity with the database in the peptide bank. The enzyme activity was maximum at 30 degrees C in the presence of 300 mM NaCl at pH 7.0. In the presence of Co2+, Mn2+ ions, and reducing agents (beta-mercaptoethanol, dithiothreitol), enzyme activity was enhanced and inhibited by iodoacetic acid. These observations suggested that free sulfohydryl groups of cysteine residues were necessary for catalytic activity of the enzyme. The enzyme was also inhibited by histidine modifier, DEPC, which suggests that along with cysteine, histidine may be present at its active site. The enzyme showed a high affinity for heparin as a substrate with K (m) and V (max) as 2.2 x 10(-5 )M and 30.8 mM min(-1), respectively. The affinity of the enzyme for different glycosaminoglycans studied varied, with high substrate specificity toward heparin and heparin-derived polysaccharides. Depolymerization of heparin and fractionation of the oligosaccharides yielded heparin disaccharides as main product.

  1. The Master Transcription Factor mtfA Governs Aflatoxin Production, Morphological Development and Pathogenicity in the Fungus Aspergillus flavus

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    Zhenhong Zhuang

    2016-01-01

    Full Text Available Aspergillus flavus produces a variety of toxic secondary metabolites; among them, the aflatoxins (AFs are the most well known. These compounds are highly mutagenic and carcinogenic, particularly AFB1. A. flavus is capable of colonizing a number of economically-important crops, such as corn, cotton, peanut and tree nuts, and contaminating them with AFs. Molecular genetic studies in A. flavus could identify novel gene targets for use in strategies to reduce AF contamination and its adverse impact on food and feed supplies worldwide. In the current study, we investigated the role of the master transcription factor gene mtfA in A. flavus. Our results revealed that forced overexpression of mtfA results in a drastic decrease or elimination of several secondary metabolites, among them AFB1. The reduction in AFB1 was accompanied by a decrease in aflR expression. Furthermore, mtfA also regulates development; conidiation was influenced differently by this gene depending on the type of colonized substrate. In addition to its effect on conidiation, mtfA is necessary for the normal maturation of sclerotia. Importantly, mtfA positively affects the pathogenicity of A. flavus when colonizing peanut seeds. AF production in colonized seeds was decreased in the deletion mtfA strain and particularly in the overexpression strain, where only trace amounts were detected. Interestingly, a more rapid colonization of the seed tissue occurred when mtfA was overexpressed, coinciding with an increase in lipase activity and faster maceration of the oily part of the seed.

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

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    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.

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

    Science.gov (United States)

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

    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. Wheat bran was the best carbon source for xylanase production by A. niger and A. flavus. The production of xylanase was 18 and 21% higher on wheat bran when we compare the xylanase production with xylan. At 50°C, the xylanase of A. niger retained over 85% activity with 2 h of incubation, and A. flavus had a half-life of more than 75 minutes. At 55°C, the xylanase produced by A. niger showed more stable than from A. flavus showing a half-life of more than 45 minutes. The xylanase activity of A. niger and A. flavus were somehow protected in the presence of glycerol 5% when compared to the control (without additives). On the biobleaching assay it was observed that the xylanase from A. flavus was more effective in comparison to A. niger. The kappa efficiency corresponded to 36.32 and 25.93, respectively. That is important to emphasize that the cellulase activity was either analyzed and significant levels were not detected, which explain why the viscosity was not significantly modified.

  4. La preservación multiobjetivo de alimentos: Efecto de factores tradicionales y emergentes en la respuesta de Aspergillus flavus

    OpenAIRE

    López-Malo Vigil, Aurelio

    2000-01-01

    El objetivo de esta tesis fue evaluar el efecto de la interacción de distintos factores de estrés (aw, pH, antimicrobianos sintetizados químicamente o antimicrobianos naturales y sus mezclas binarias) en la respuesta de crecimiento de Aspergillus flavus y determinar las condiciones de combinación inhibitorias sinérgicas o de cooperación de dichos factores, con miras a generar modelos predictivos para la conservación multiobjetivo de alimentos. Se determinó el efecto de distintas combinaciones...

  5. Genetic and Toxigenic Variability within Aspergillus flavus Population Isolated from Maize in Two Diverse Environments in Kenya

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    Sheila Okoth

    2018-01-01

    Full Text Available Aspergillus flavus is the main producer of carcinogenic aflatoxins in agricultural commodities such as maize. This fungus occurs naturally on crops, and produces aflatoxins when environmental conditions are favorable. The aim of this study is to analyse the genetic variability among 109 A. flavus isolates previously recovered from maize sampled from a known aflatoxin-hotspot (Eastern region, Kenya and the major maize-growing area in the Rift Valley (Kenya, and to determine their toxigenic potential. DNA analyses of internal transcribed spacer (ITS regions of ribosomal DNA, partial β-tubulin gene (benA and calmodulin gene (CaM sequences were used. The strains were further analyzed for the presence of four aflatoxin-biosynthesis genes in relation to their capability to produce aflatoxins and other metabolites, targeting the regulatory gene aflR and the structural genes aflP, aflD, and aflQ. In addition, the metabolic profile of the fungal strains was unraveled using state-of-the-art LC-MS/MS instrumentation. The three gene-sequence data grouped the isolates into two major clades, A. minisclerotigenes and A. flavus. A. minisclerotigenes was most prevalent in Eastern Kenya, while A. flavus was common in both regions. A. parasiticus was represented by a single isolate collected from Rift Valley. Diversity existed within the A. flavus population, which formed several subclades. An inconsistency in identification of some isolates using the three markers was observed. The calmodulin gene sequences showed wider variation of polymorphisms. The aflatoxin production pattern was not consistent with the presence of aflatoxigenic genes, suggesting an inability of the primers to always detect the genes or presence of genetic mutations. Significant variation was observed in toxin profiles of the isolates. This is the first time that a profound metabolic profiling of A. flavus isolates was done in Kenya. Positive associations were evident for some metabolites

  6. Genetic and Toxigenic Variability within Aspergillus flavus Population Isolated from Maize in Two Diverse Environments in Kenya.

    Science.gov (United States)

    Okoth, Sheila; De Boevre, Marthe; Vidal, Arnau; Diana Di Mavungu, José; Landschoot, Sofie; Kyallo, Martina; Njuguna, Joyce; Harvey, Jagger; De Saeger, Sarah

    2018-01-01

    Aspergillus flavus is the main producer of carcinogenic aflatoxins in agricultural commodities such as maize. This fungus occurs naturally on crops, and produces aflatoxins when environmental conditions are favorable. The aim of this study is to analyse the genetic variability among 109 A. flavus isolates previously recovered from maize sampled from a known aflatoxin-hotspot (Eastern region, Kenya) and the major maize-growing area in the Rift Valley (Kenya), and to determine their toxigenic potential. DNA analyses of internal transcribed spacer (ITS) regions of ribosomal DNA, partial β-tubulin gene (benA) and calmodulin gene (CaM) sequences were used. The strains were further analyzed for the presence of four aflatoxin-biosynthesis genes in relation to their capability to produce aflatoxins and other metabolites, targeting the regulatory gene aflR and the structural genes aflP, aflD, and aflQ. In addition, the metabolic profile of the fungal strains was unraveled using state-of-the-art LC-MS/MS instrumentation. The three gene-sequence data grouped the isolates into two major clades, A. minisclerotigenes and A. flavus . A. minisclerotigenes was most prevalent in Eastern Kenya, while A. flavus was common in both regions. A. parasiticus was represented by a single isolate collected from Rift Valley. Diversity existed within the A. flavus population, which formed several subclades. An inconsistency in identification of some isolates using the three markers was observed. The calmodulin gene sequences showed wider variation of polymorphisms. The aflatoxin production pattern was not consistent with the presence of aflatoxigenic genes, suggesting an inability of the primers to always detect the genes or presence of genetic mutations. Significant variation was observed in toxin profiles of the isolates. This is the first time that a profound metabolic profiling of A. flavus isolates was done in Kenya. Positive associations were evident for some metabolites, while for

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

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    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.

  8. 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.

  9. 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.

  10. Effect of gamma irradiation on growth and aflatoxin production by certain local aflatoxigenic isolates of aspergillus flavus

    International Nuclear Information System (INIS)

    Hammad, A.A.I.; Atalla, M.A.; El-Shayeb, N.M.A.; Ahmed, A.A.; Zeinat, Kamel

    1998-01-01

    The radiation D 1 0 values of two aflatoxigenic isolates of aspergillus flavus (No. 1 and No. 184) were determined. The D 1 0 -value of A. flavus isolate No.1 was found to be 0.43 and 0.50 kGy in physiological saline soulution and smoked herrings, while the D 1 0 - value of A. SFlavus isolateNo. 184 was 0.53 and -0.62 KGy in saline solution and raisins, respectively. The irradiated (0.05, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 KGy) and non-irradiated spores of two fungi were separately inoculated into rice-corn steep liquor and incubated at 28 degree C for 12 days. The fungal mycelial dry weight, as a function of growth, decreased with increasing gamma irradiation doses. Irradiation doses used gratly reduced aflatoxins formation. Smoked herrings and raisins were inoculated with spores of A. flavus isolated No.1 and No.184, respectively, then irradiated at 1.5, 3.0 and 4.5 KGy and stored for two months at room temperature. It was found that a gamma irradiation dose of 1.5 KGy greatly reduced the amount of aflatoxins produced, while 3.0 and 4.5 KGy completely prevented aflatoxin formation

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

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    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.

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

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    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.

  13. Effect of Various Compounds Blocking the Colony Pigmentation on the Aflatoxin B1 Production by Aspergillus flavus.

    Science.gov (United States)

    Dzhavakhiya, Vitaly G; Voinova, Tatiana M; Popletaeva, Sofya B; Statsyuk, Natalia V; Limantseva, Lyudmila A; Shcherbakova, Larisa A

    2016-10-28

    Aflatoxins and melanins are the products of a polyketide biosynthesis. In this study, the search of potential inhibitors of the aflatoxin B1 (AFB1) biosynthesis was performed among compounds blocking the pigmentation in fungi. Four compounds-three natural (thymol, 3-hydroxybenzaldehyde, compactin) and one synthetic (fluconazole)-were examined for their ability to block the pigmentation and AFB1 production in Aspergillus flavus . All compounds inhibited the mycelium pigmentation of a fungus growing on solid medium. At the same time, thymol, fluconazole, and 3-hydroxybenzaldehyde stimulated AFB1 accumulation in culture broth of A. flavus under submerged fermentation, whereas the addition of 2.5 μg/mL of compactin resulted in a 50× reduction in AFB1 production. Moreover, compactin also suppressed the sporulation of A. flavus on solid medium. In vivo treatment of corn and wheat grain with compactin (50 μg/g of grain) reduced the level of AFB1 accumulation 14 and 15 times, respectively. Further prospects of the compactin study as potential AFB1 inhibitor are discussed.

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

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    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.

  15. Differentiation between Aspergillus flavus and Aspergillus parasiticus from Pure Culture and Aflatoxin-Contaminated Grapes Using PCR-RFLP Analysis of aflR-aflJ Intergenic Spacer

    International Nuclear Information System (INIS)

    El Khoury, A.; Atoui, A.; Lebrihi, A.; Rizk, T.; Lteif, R.; Kallassy, M.

    2011-01-01

    Aflatoxins (AFs) represent the most important single mycotoxin-related food safety problem in developed and developing countries as they have adverse effects on human and animal health. They are produced mainly by Aspergillus flavus and A. parasiticus. Both species have different aflatoxinogenic profile. In order to distinguish between A. flavus and A. parasiticus, gene-specific primers were designed to target the intergenic spacer (IGS) for the AF biosynthesis genes, aflJ and aflR. Polymerase chain reaction (PCR) products were subjected to restriction endonuclease analysis using BglII to look for restriction fragment length polymorphisms (RFLPs). Our result showed that both species displayed different PCR-based RFLP (PCR-RFLP) profile. PCR products from A. flavus cleaved into 3 fragments of 362, 210, and 102 bp. However, there is only one restriction site for this enzyme in the sequence of A. parasiticus that produced only 2 fragments of 363 and 311 bp. The method was successfully applied to contaminated grapes samples. This approach of differentiating these 2 species would be simpler, less costly, and quicker than conventional sequencing of PCR products and/or morphological identification. (author)

  16. 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

  17. Cemaran Kapang pada Pakan Sapi dan Uji In Vitro Sirih terhadap Pertumbuhan Kapang Aspergillus flavus (MOLD CONTAMINATION IN CATTLE FEED AND IN VITRO ASSAY OF PIPER BETEL AGAINTS GROWTH OF MOLD CONTAMINANT ASPERGILLUS FLAVUS

    Directory of Open Access Journals (Sweden)

    Riza Zainuddin Ahmad

    2017-09-01

    Full Text Available Contamination of mold in feed and Ingridients of feed is important because pathogenic and toxigenic mold will contaminate and cause mycotic and mycotoxicosis on livestock especially cattle. Information regarding the data is required in an attempt to controll of mold contaminant. Base on the previous study piper betel leaf (Piper betle showed high activity as antimold. The aim of this study were to obtain data of mold contamination in cattle feed and ingredients of feed from the provinces of Banten, Lampung, Jakarta and West Java, and to test piper betel as an antimold herbal from traditional medicinal plants originated from Indonesia. Isolation and identification of fungi were conducted on the flour, glycerides, onggok, corn, peanut, coconut, coffee, concentrates, lamtoro, pineapple, rice, grass, palm, cassava, tofu lees, fish meal, bone meal from the provinces of Banten, Lampung, Jakarta and West Java. Isolation was done by plating the samples on agar medium, The mold have grown on media was identified. Feed that has been mixed with the extracts and powders plus mold inoculum was incubated. After 3=7 days incubation, colony forming unit (CFU of the mixtures were counted. The results showed that the majority of feed contaminated with mold, but still below the threshold. The mold contamination in wheat flour, corn, concentrates and tofu lees exceeds from the threshold. Aspergillus sp, A. amstelodami, A. clavatus, A. Candidus, A. flavus, A. fumigatus, A. glaucus, A. niger, Cladosporium sp., Curvularia sp., Fusarium sp., Hyphomycetes sp., Mycelia sterilata, Mucor sp., Paecilomyces sp., Penicillium sp., and Rhizopus sp. Penicillium sp were most commonly found in the feed as much as 2.56 x 107 CFU. At a concentration of 10%. in vitro test showed that the piper betel leaf in powder form is more effective than extract form to inhibit the growth of A.flavus The conclusion of this study was flour, corn, concentrates and tofu lees contaminated by molds

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

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    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

  19. Occurrence of aflatoxins in mahua (Madhuca indica Gmel.) seeds: synergistic effect of plant extracts on inhibition of Aspergillus flavus growth and aflatoxin production.

    Science.gov (United States)

    Sidhu, O P; Chandra, Harish; Behl, H M

    2009-04-01

    Occurrence of aflatoxin in Madhuca indica Gmel. seeds was determined by competitive ELISA. Eighty percent of mahua seed samples were found to be contaminated with aflatoxin. Total aflatoxin content ranged from 115.35 to 400.54ppb whereas the concentration of AFB(1) was in the range of 86.43 to 382.45ppb. Mahua oil was extracted by cold press expeller and analysed for contamination of aflatoxin in both the oil and cake samples. Total aflatoxin and aflatoxin B(1) were 220.66 and 201.57ppb in oil as compared to that in cake samples where it was 87.55 and 74.35ppb, respectively. Various individual and combined plant extracts were evaluated for their efficacy against growth of Aspergillus flavus and aflatoxin production in vitro. Combination of botanicals were found to be more effective in controlling fungal growth and aflatoxin production than individual extracts. Results of the present study suggests that synergistic effect of plant extracts can be used for control of fungal growth and aflatoxin production. These natural plant products may successfully replace synthetic chemicals and provide an alternative method to protect mahua as well as other agricultural commodities of nutritional significance from toxigenic fungi such as A. flavus and aflatoxin production.

  20. The Aspergillus flavus spermidine synthase (spds) gene, is required for normal development, aflatoxin production, and pathogenesis during infection of maize kernels

    Science.gov (United States)

    Aspergillus flavus is a soil-borne saprophyte and an opportunistic pathogen of both humans and plants. This fungus not only causes disease in several important food and feed crops such as maize, peanut, cottonseed and tree nuts but also produces the toxic and carcinogenic secondary metabolites (SMs)...

  1. 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 ...

  2. 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.

  3. Biological control of Verticillium dahliae by Talaromyces flavus

    OpenAIRE

    Nagtzaam, M.P.M.

    1998-01-01

    Verticillium dahliae causes vascular wilt in a wide range of host plants. Control of Verticillium wilt is by soil disinfestation and to a lesser extent by crop rotation or, for a few host plants, by growing resistant varieties. For environmental reasons, the development of alternatives to chemical soil disinfestation is being sought. Biocontrol by microbial agents is one of the options. The potential of Talaromyces flavus as a biocontrol agen...

  4. 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.

  5. Orientation of Navel Orangeworm (Lepidoptera: Pyralidae) Larvae and Adults Toward Volatiles Associated With Almond Hull Split and Aspergillus flavus.

    Science.gov (United States)

    Bush, Daniel S; Lawrance, Allen; Siegel, Joel P; Berenbaum, May R

    2017-06-01

    The navel orangeworm Amyelois transitella (Walker, 1863, Lepidoptera: Pyralidae), a pest of California tree nuts, is associated with the fungus Aspergillus flavus, and previous research suggests these species are facultative mutualists. Because navel orangeworm larvae exhibit improved performance on diets containing this fungus, orientation toward hostplants infected with A. flavus may be adaptive. We conducted behavioral assays to determine if larvae respond to chemical cues produced by almond hull split and fungal infection. In petri dish arenas, larvae showed a preference for 1-octen-3-ol and 2-phenylethanol, volatiles characteristic of damaged plants, as well as methanolic extracts of almond meal with 1-octen-3-ol and the fungal volatile conophthorin. In contrast, larvae displayed aversion to ethyl benzoate, an inhibitor of fungal growth. When we assessed oviposition behavior relative to substrates with and without A. flavus, females laid almost twice as many eggs near inoculated surfaces. Moreover, an average of 63% of eggs laid near inoculated substrates were fertilized, compared with 24% of eggs near uninoculated sites. We also tested the hypothesis that unfertilized eggs are laid on nutrient-poor substrates to provide supplemental nutrition for larvae in an assay comparing larval survivorship in the presence and absence of unfertilized eggs. Neonates given eggs survived 2.5 times longer on an average than unprovisioned neonates (208.8 h vs. 85.2 h), indicating that this species may compensate with cannibalism for oviposition on lower-quality food sources. We conclude that larvae orient to probable host plant and fungal volatiles associated with hull split and document a possible strategy for larvae to establish on low-quality hosts. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Zinc, nickel, and cobalt ions removal from aqueous solution and plating plant wastewater by modified Aspergillus flavus biomass: A dataset

    Directory of Open Access Journals (Sweden)

    Rauf Foroutan

    2017-06-01

    Full Text Available The biomass of Aspergillus flavus was modified by calcium chloride to achieve a bioadsorbent for treating nickel, cobalt, and zinc ions from aqueous solutions. The information of pH, bioadsorbent dose, contact time, and temperature effect on the removal efficiency are presented. The data of Freundlich and Langmuir isotherm and pseudo-first-order and pseudo-second-order kinetic models are also depicted. The data showed that the maximum bioadsorption capacity of nickel, cobalt, and zinc ions is 32.26, 31.06 and 27.86 mg/g, respectively. The suitability of the bioadsorbent in heavy metals removal at field condition was tested with a real wastewater sample collected from a plating plant in the final part of this dataset. Based on the findings, the bioadsorbent was shown to be an affordable alternative for the removal of metals in the wastewater.

  7. Survey of Candidate Genes for Maize Resistance to Infection by Aspergillus flavus and/or Aflatoxin Contamination

    Science.gov (United States)

    Hawkins, Leigh K.; Tang, Juliet D.; Tomashek, John; Alves Oliveira, Dafne; Ogunola, Oluwaseun F.; Smith, J. Spencer; Williams, W. Paul

    2018-01-01

    Many projects have identified candidate genes for resistance to aflatoxin accumulation or Aspergillus flavus infection and growth in maize using genetic mapping, genomics, transcriptomics and/or proteomics studies. However, only a small percentage of these candidates have been validated in field conditions, and their relative contribution to resistance, if any, is unknown. This study presents a consolidated list of candidate genes identified in past studies or in-house studies, with descriptive data including genetic location, gene annotation, known protein identifiers, and associated pathway information, if known. A candidate gene pipeline to test the phenotypic effect of any maize DNA sequence on aflatoxin accumulation resistance was used in this study to determine any measurable effect on polymorphisms within or linked to the candidate gene sequences, and the results are published here. PMID:29385107

  8. The Mode of Action of Cyclo(l-Ala-l-Pro) in Inhibiting Aflatoxin Production of Aspergillus flavus.

    Science.gov (United States)

    Iimura, Kurin; Furukawa, Tomohiro; Yamamoto, Toshiyoshi; Negishi, Lumi; Suzuki, Michio; Sakuda, Shohei

    2017-07-12

    Cyclo(l-Ala-l-Pro) inhibits aflatoxin production in aflatoxigenic fungi without affecting fungal growth. The mode of action of cyclo(l-Ala-l-Pro) in inhibiting aflatoxin production of Aspergillus flavus was investigated. A glutathione S -transferase (GST) of the fungus, designated AfGST, was identified as a binding protein of cyclo(l-Ala-l-Pro) in an experiment performed using cyclo(l-Ala-l-Pro)-immobilized Sepharose beads. Cyclo(l-Ala-l-Pro) specifically bound to recombinant AfGST and inhibited its GST activity. Ethacrynic acid, a known GST inhibitor, inhibited the GST activity of recombinant AfGST and aflatoxin production of the fungus. Ethacrynic acid reduced the expression level of AflR, a key regulatory protein for aflatoxin production, similar to cyclo(l-Ala-l-Pro). These results suggest that cyclo(l-Ala-l-Pro) inhibits aflatoxin production by affecting GST function in A. flavus , and that AfGST inhibitors are possible candidates as selective aflatoxin production inhibitors.

  9. 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.

  10. 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.

  11. 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

  12. A Network Approach of Gene Co-expression in theZea mays/Aspergillus flavusPathosystem 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 .

  13. 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

  14. Identification of Two Aflatrem Biosynthesis Gene Loci in Aspergillus flavus and Metabolic Engineering of Penicillium paxilli To Elucidate Their Function ▿

    Science.gov (United States)

    Nicholson, Matthew J.; Koulman, Albert; Monahan, Brendon J.; Pritchard, Beth L.; Payne, Gary A.; Scott, Barry

    2009-01-01

    Aflatrem is a potent tremorgenic toxin produced by the soil fungus Aspergillus flavus, and a member of a structurally diverse group of fungal secondary metabolites known as indole-diterpenes. Gene clusters for indole-diterpene biosynthesis have recently been described in several species of filamentous fungi. A search of Aspergillus complete genome sequence data identified putative aflatrem gene clusters in the genomes of A. flavus and Aspergillus oryzae. In both species the genes for aflatrem biosynthesis cluster at two discrete loci; the first, ATM1, is telomere proximal on chromosome 5 and contains a cluster of three genes, atmG, atmC, and atmM, and the second, ATM2, is telomere distal on chromosome 7 and contains five genes, atmD, atmQ, atmB, atmA, and atmP. Reverse transcriptase PCR in A. flavus demonstrated that aflatrem biosynthesis transcript levels increased with the onset of aflatrem production. Transfer of atmP and atmQ into Penicillium paxilli paxP and paxQ deletion mutants, known to accumulate paxilline intermediates paspaline and 13-desoxypaxilline, respectively, showed that AtmP is a functional homolog of PaxP and that AtmQ utilizes 13-desoxypaxilline as a substrate to synthesize aflatrem pathway-specific intermediates, paspalicine and paspalinine. We propose a scheme for aflatrem biosynthesis in A. flavus based on these reconstitution experiments in P. paxilli and identification of putative intermediates in wild-type cultures of A. flavus. PMID:19801473

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

    OpenAIRE

    Z. Jurjevic; G.C. Rains; D.M. Wilson; W.J. Lewis

    2009-01-01

    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 ...

  16. 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

  17. Behaviour of Aspergillus flavus and Fusarium graminearum on rice as affected by degree of milling, temperature, and relative humidity during storage.

    Science.gov (United States)

    Choi, Seonyeong; Jun, Hyejung; Bang, Jihyun; Chung, Soo-Hyun; Kim, Yoonsook; Kim, Byeong-Sam; Kim, Hoikyung; Beuchat, Larry R; Ryu, Jee-Hoon

    2015-04-01

    We investigated the survival and growth patterns of Aspergillus flavus and Fusarium graminearum, as well as mycotoxin production, on Korean rice as affected by the degree of milling (rough, brown, and white rice) and storage conditions (21 °C/85% relative humidity [RH], 21 °C/97% RH, and 30 °C/85% RH). When rice was stored at 21 °C/85% RH, the population of A. flavus remained constant and aflatoxin was not produced, regardless of the degree of milling. At 21 °C/97% RH and 30 °C/85% RH, the populations of A. flavus increased significantly (P ≤ 0.05) and aflatoxins were produced. The highest population of A. flavus and highest amount of aflatoxin B1 were observed on brown rice stored at 21 °C/97% RH. For F. graminearum, when stored at 85% RH, the populations were reduced to less than a detectable level (5 CFU/g of rice) within 120 days and no deoxynivalenol (DON) was produced, regardless of the degree of milling and storage temperature. However, at 21 °C/97% RH, the population of F. graminearum increased significantly (P ≤ 0.05) and DON was produced on all types of rice. Findings from this study provide insights concerning storage conditions necessary to prevent growth and mycotoxin production by A. flavus and F. graminearum on Korean rice with different degrees of milling. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. 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

    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...

  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. The Breeding of a Pigment Mutant Strain of Steroid Hydroxylation Aspergillus Flavus by Low Energy Ion Implantation

    International Nuclear Information System (INIS)

    Ye Hui; Ma Jingming; Feng Chun; Cheng Ying; Zhu Suwen; Cheng Beijiu

    2009-01-01

    In the process of the fermentation of steroid C 11 α-hydroxylgenation strain Aspergillus flavus AF-ANo208, a red pigment is derived, which will affect the isolation and purification of the target product. Low energy ion beam implantation is a new tool for breeding excellent mutant strains. In this study, the ion beam implantation experiments were performed by infusing two different ions: argon ion (Ar + ) and nitrogen ion (N + ). The results showed that the optimal ion implantation was N + with an optimum dose of 2.08 x 10 15 ions/cm 2 , with which the mutant strain AF-ANm16 that produced no red pigment was obtained. The strain had high genetic stability and kept the strong capacity of C11α-hydroxylgenation, which could be utilized in industrial fermentation. The differences between the original strain and the mutant strain at a molecular level were analyzed by randomly amplified polymorphic DNA (RAPD). The results indicated that the frequency of variation was 7.00%, which would establish the basis of application investigation into the breeding of pigment mutant strains by low energy ion implantation. (ion beam bioengineering)

  1. 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.

  2. Dynamics of mycotoxin and Aspergillus flavus levels in aging Bt and non-Bt corn residues under Mississippi no-till conditions.

    Science.gov (United States)

    Abbas, Hamed K; Accinelli, Cesare; Zablotowicz, Robert M; Abel, Craig A; Bruns, H Arnold; Dong, Yanhong; Shier, W Thomas

    2008-08-27

    Mycotoxin and Aspergillus flavus levels in soil-surface corn debris left by no-till agriculture methods (stover, cobs, and cobs with grain) were determined during the December-March fallow period for near-isogenic Bt and non-Bt hybrid corn. By December, average mycotoxin levels in non-Bt corn were many times higher in cobs with grain than in grain harvested in September (total aflatoxins, 774 vs 211 ng/g; total fumonisins, 216 vs 3.5 microg/g; cyclopiazonic acid, 4102 vs 72.2 microg/g; zearalenone, 0.2 vs corn debris fractions decreased during winter but began to rise in March. Levels of all mycotoxins and A. flavus propagules were lower in harvested grain and debris from Bt than non-Bt corn, but differences were significant (p < 0.05) only for aflatoxins.

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

    African Journals Online (AJOL)

    Sorghum grains suffer from severe infection and colonization by several toxigenic fungi and subsequent production of mycotoxins, posing a threat to human and animal health. Among all the mycotoxins, aflatoxins represent one of the most important toxicants considered as important constraint of grain quality and sorghum ...

  4. 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.

  5. The 14-3-3 Protein Homolog ArtA Regulates Development and Secondary Metabolism in the Opportunistic Plant Pathogen Aspergillus flavus.

    Science.gov (United States)

    Ibarra, Beatriz A; Lohmar, Jessica M; Satterlee, Timothy; McDonald, Taylor; Cary, Jeffrey W; Calvo, Ana M

    2018-03-01

    The opportunistic plant-pathogenic fungus Aspergillus flavus produces carcinogenic mycotoxins termed aflatoxins (AF). Aflatoxin contamination of agriculturally important crops, such as maize, peanut, sorghum, and tree nuts, is responsible for serious adverse health and economic impacts worldwide. In order to identify possible genetic targets to reduce AF contamination, we have characterized the artA gene, encoding a putative 14-3-3 homolog in A. flavus The artA deletion mutant presents a slight decrease in vegetative growth and alterations in morphological development and secondary metabolism. Specifically, artA affects conidiation, and this effect is influenced by the type of substrate and culture condition. In addition, normal levels of artA are required for sclerotial development. Importantly, artA negatively regulates AF production as well as the concomitant expression of genes in the AF gene cluster. An increase in AF is also observed in seeds infected with the A. flavus strain lacking artA Furthermore, the expression of other secondary metabolite genes is also artA dependent, including genes in the cyclopiazonic acid (CPA) and ustiloxin gene clusters, in this agriculturally important fungus. IMPORTANCE In the current study, artA , which encodes a 14-3-3 homolog, was characterized in the agriculturally and medically important fungus Aspergillus flavus , specifically, its possible role governing sporulation, formation of resistant structures, and secondary metabolism. The highly conserved artA is necessary for normal fungal morphogenesis in an environment-dependent manner, affecting the balance between production of conidiophores and the formation of resistant structures that are necessary for the dissemination and survival of this opportunistic pathogen. This study reports a 14-3-3 protein affecting secondary metabolism in filamentous fungi. Importantly, artA regulates the biosynthesis of the potent carcinogenic compound aflatoxin B1 (AFB1) as well as the

  6. Prediction of the three-dimensional structure of aflatoxin of Aspergillus flavus by homology modelling.

    Science.gov (United States)

    Kasoju, Aruna; Narasu, M Lakshmi; Muvva, Charuvaka; Subbarao, Bathula Vv

    2012-01-01

    Aflatoxins are polyketide-derived secondary metabolites produced by Aspergillus spp. The toxic effects of aflatoxins have adverse consequences for human health and agricultural economics. The aflR gene, a regulatory gene for aflatoxin biosynthesis, encodes a protein containing a zinc-finger DNA-binding motif. AFLR-Protein three-dimensional model was generated using Robetta server. The modeled AFLR-Protein was further optimization and validation using Rampage. In the simulations, we monitored the backbone atoms and the C-α-helix of the modeled protein. The low RMSD and the simulation time indicate that, as expected, the 3D structural model of AFLR-protein represents a stable folding conformation. This study paves the way for generating computer molecular models for proteins whose crystal structures are not available and which would aid in detailed molecular mechanism of inhibition of aflatoxin.

  7. Improvement of Aspergillus flavus saponin hydrolase thermal stability and productivity via immobilization on a novel carrier based on sugarcane bagasse

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    Hala A. Amin

    2018-03-01

    Full Text Available Soyasapogenol B (SB is known to have many biological activities such as hepatoprotective, anti-inflammatory, anti-mutagenic, antiviral and anticancer activities. Enzymatic conversion of soyasaponins to SB was carried out using saponin hydrolase (SH extracted from Aspergillus flavus. The partially purified enzyme was immobilized on different carriers by physical adsorption, covalent binding or entrapment. Among the investigated carriers, Eupergit C and sugarcane bagasse (SCB activated by DIC and NHS were the most suitable two carriers for immobilization (the immobilized forms recovered 46.5 and 37.1% of the loaded enzyme activity, respectively. Under optimized immobilization conditions, immobilized SH on Eupergit C and on activated SBC recovered 87.7 and 83.3% of its original activity, respectively. Compared to free SH, immobilized SH on Eupergit C and on activated SCB showed higher optimum pH, activation energy, half-lives and lower deactivation constant rate. Also, their SB productivities were improved by 2.3- and 2.2-folds compared to free SH (87.7 and 83.3 vs. 37.5%, respectively. Hence, being SCB more sustainable and an inexpensive material, it can be considered a good alternative to Eupergit C as a support for SH immobilization. SH immobilization on industrially applicable and inexpensive carrier is necessary to improve SB yield and reduce its production cost. The chemical structure of SCB and the resulting cellulose derivatives were studied by ATR-IR spectroscopy. The thermal analysis technique was used to study the chemical treatment of SCB and coupling with the enzyme. This technique confirmed the removal of lignin and hemicellulose by chemical treatment of SCB.

  8. Recombinant production of Aspergillus Flavus uricase and investigation of its thermal stability in the presence of raffinose and lactose.

    Science.gov (United States)

    Imani, Mehdi; Shahmohamadnejad, Serveh

    2017-07-01

    Aspergillus flavus uricase (Rasburicase) with a molecular mass of 135 kDa is currently used for the treatment of gout and hyperuricemia occurring in tumor lysis syndrome. To characterize the effects of raffinose and lactose osmolytes on the uricase structure, its coding sequence was cloned, expressed in E. coli BL21, and purified by Ni-NTA agarose affinity chromatography. Thermal inactivation studies at 40 °C showed that nearly 15% of UOX activity was preserved, while the presence of raffinose and lactose reduced its activity to 35 and 45% of its original activity, respectively. Investigation of UOX thermal stability at 40 °C in the course of time showed that the enzyme relatively lost almost 60% of its original activity after 40 min, whereas more than 50% of UOX activity is preserved in the presence of lactose. Estimation of thermal inactivation rate constant, k in , showed that the UOX k in and UOX k in in the presence of raffinose was unchanged (0.018 min -1 ), whereas for the presence of lactose, it was 0.015 min -1 . Half-life and T m analysis showed that UOX half-life is almost 38 min and addition of raffinose did not change the half-life, whereas the presence of lactose had remarkable impact on UOX half-life (46 min). The presence of raffinose increased UOX T m to a lesser extent, whereas lactose notably enhanced the T m from 27 to 37 °C. Overall, our findings show that lactose has protective effects on UOX stability, while for raffinose, it is relatively compromised.

  9. A study on trypsin, Aspergillus flavus and Bacillus sp. protease inhibitory activity in Cassia tora (L. syn Senna tora (L. Roxb. seed extract

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    Garg Satyendra K

    2011-07-01

    Full Text Available Abstract Background Proteases play an important role in virulence of many human, plant and insect pathogens. The proteinaceous protease inhibitors of plant origin have been reported widely from many plant species. The inhibitors may potentially be used for multiple therapeutic applications in viral, bacterial, fungal diseases and physiological disorders. In traditional Indian medicine system, Cassia tora (Senna tora is reportedly effective in treatment of skin and gastrointestinal disorders. The present study explores the protease inhibitory activity of the above plant seeds against trypsin, Aspergillus flavus and Bacillus sp. proteases. Methods The crushed seeds of Cassia tora were washed thoroughly with acetone and hexane for depigmentation and defatting. The proteins were fractionated by ammonium sulphate (0-30, 30-60, 60-90% followed by dialysis and size exclusion chromatography (SEC. The inhibitory potential of crude seed extract and most active dialyzed fraction against trypsin and proteases was established by spot test using unprocessed x-ray film and casein digestion methods, respectively. Electrophoretic analysis of most active fraction (30-60% and SEC elutes were carried employing Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE and Gelatin SDS-PAGE. Inhibition of fungal spore germination was studied in the presence of dialyzed active inhibitor fraction. Standard deviation (SD and ANOVA were employed as statistical tools. Results The crude seeds' extract displayed strong antitryptic, bacterial and fungal protease inhibitory activity on x-ray film. The seed protein fraction 30-60% was found most active for trypsin inhibition in caseinolytic assay (P Aspergillus flavus and Bacillus sp. proteases remained only 4, 7 and 3.1%, respectively when proteases were incubated with 3 mg ml-1 seed protein extract for 60 min. The inhibitory activity was evident in gelatin SDS-PAGE where a major band (~17-19 kD of protease

  10. 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)

  11. An attempt to model the probability of growth and aflatoxin B1 production of Aspergillus flavus under non-isothermal conditions in pistachio nuts.

    Science.gov (United States)

    Aldars-García, Laila; Ramos, Antonio J; Sanchis, Vicente; Marín, Sonia

    2015-10-01

    Human exposure to aflatoxins in foods is of great concern. The aim of this work was to use predictive mycology as a strategy to mitigate the aflatoxin burden in pistachio nuts postharvest. The probability of growth and aflatoxin B1 (AFB1) production of aflatoxigenic Aspergillus flavus, isolated from pistachio nuts, under static and non-isothermal conditions was studied. Four theoretical temperature scenarios, including temperature levels observed in pistachio nuts during shipping and storage, were used. Two types of inoculum were included: a cocktail of 25 A. flavus isolates and a single isolate inoculum. Initial water activity was adjusted to 0.87. Logistic models, with temperature and time as explanatory variables, were fitted to the probability of growth and AFB1 production under a constant temperature. Subsequently, they were used to predict probabilities under non-isothermal scenarios, with levels of concordance from 90 to 100% in most of the cases. Furthermore, the presence of AFB1 in pistachio nuts could be correctly predicted in 70-81 % of the cases from a growth model developed in pistachio nuts, and in 67-81% of the cases from an AFB1 model developed in pistachio agar. The information obtained in the present work could be used by producers and processors to predict the time for AFB1 production by A. flavus on pistachio nuts during transport and storage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. 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.

  13. Efficacy of Mentha spicata essential oil in suppression of Aspergillus flavus and aflatoxin contamination in chickpea with particular emphasis to mode of antifungal action.

    Science.gov (United States)

    Kedia, Akash; Dwivedy, Abhishek Kumar; Jha, Dhruva Kumar; Dubey, Nawal Kishore

    2016-05-01

    The present study reports in vivo antifungal and antiaflatoxigenic efficacy of Mentha spicata essential oil (EO) against toxigenic Aspergillus flavus strain LHP(C)-D6 in chickpea food system up to 12 months of storage. In addition, the mode of antifungal action of EO was also determined to understand the mechanism of fungal growth inhibition. The in vivo study with different concentrations of M. spicata EO showed dose-dependent decrease in fungal colony count as well as aflatoxin B1 concentration. The EO caused >50% protection in inoculated sets and >70% protection in uninoculated sets of chickpea food system against A. flavus at 1.0 μL mL(-1) air concentration. However, at the same concentration, EO caused 100% inhibition to aflatoxin B1 production in both sets when analyzed through high-performance liquid chromatography (HPLC). The antifungal target of EO in fumigated cells of A. flavus was found to be the plasma membrane when analyzed through electron microscopic observations and ions leakage test. The EO fumigated chickpea seeds showed 100% seed germination and seedling growth after 12 months of storage. Based on these observations, M. spicata EO can be recommended as plant-based preservative for safe protection of food commodities during storage conditions against fungal and most importantly mycotoxin contaminations.

  14. Identification of genetic defects in the atoxigenic biocontrol strain Aspergillus flavus K49 reveals the presence of a competitive recombinant group in field populations.

    Science.gov (United States)

    Chang, Perng-Kuang; Abbas, Hamed K; Weaver, Mark A; Ehrlich, Kenneth C; Scharfenstein, Leslie L; Cotty, Peter J

    2012-03-15

    Contamination of corn, cotton, peanuts and tree nuts by aflatoxins is a severe economic burden for growers. A current biocontrol strategy is to use non-aflatoxigenic Aspergillus flavus strains to competitively exclude field toxigenic Aspergillus species. A. flavus K49 does not produce aflatoxins and cyclopiazonic acid (CPA) and is currently being tested in corn-growing fields in Mississippi. We found that its lack of production of aflatoxins and CPA resulted from single nucleotide mutations in the polyketide synthase gene and hybrid polyketide-nonribosomal peptide synthase gene, respectively. Furthermore, based on single nucleotide polymorphisms of the aflatoxin biosynthesis omtA gene and the CPA biosynthesis dmaT gene, we conclude that K49, AF36 and previously characterized TX9-8 form a biocontrol group. These isolates appear to be derived from recombinants of typical large and small sclerotial morphotype strains. This finding provides an easy way to select future biocontrol strains from the reservoir of non-aflatoxigenic populations in agricultural fields. Published by Elsevier B.V.

  15. 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...

  16. Inorganic composition determination and evaluation of the biological activity of Peperomia pellucida in the Aspergillus flavus growth

    International Nuclear Information System (INIS)

    Sussa, Fabio Vitorio

    2011-01-01

    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 50 values against the pathogen on Petri plates assays. Also, the essential oil chemical composition was determined by GC-MS. (author)

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

    African Journals Online (AJOL)

    The addition of 5% glycerol, mannitol or xylitol protected the xylanase from thermal inactivation at 50°C. The protective effect by glycerol, xylitol and mannitol resulted in increases of 162, 262.5 and 150% when compared with the control at 120 min, approximately. Increasing the polyols concentration up to 20% (w/v) further ...

  18. 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.

  19. Contaminação por Aspergillus flavus e A. fumigatus em sementes de girassol (Helianthus annuus utilizados na alimentação de psitacídeos

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    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.

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

    OpenAIRE

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

    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. Wheat bran was the best carbon source for xylanase production by A. niger and A. flavus. The production of xylanase was 18 and 21% higher on wheat bran when we compare the xylanase production with xylan. At 50°C, the xylanase of A. niger retained over 85% activity with 2 h of ...

  1. 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.

  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. A study on trypsin, Aspergillus flavus and Bacillus sp. protease inhibitory activity in Cassia tora (L.) syn Senna tora (L.) Roxb. seed extract.

    Science.gov (United States)

    Tripathi, Vinayak R; Kumar, Shailendra; Garg, Satyendra K

    2011-07-12

    Proteases play an important role in virulence of many human, plant and insect pathogens. The proteinaceous protease inhibitors of plant origin have been reported widely from many plant species. The inhibitors may potentially be used for multiple therapeutic applications in viral, bacterial, fungal diseases and physiological disorders. In traditional Indian medicine system, Cassia tora (Senna tora) is reportedly effective in treatment of skin and gastrointestinal disorders. The present study explores the protease inhibitory activity of the above plant seeds against trypsin, Aspergillus flavus and Bacillus sp. proteases. The crushed seeds of Cassia tora were washed thoroughly with acetone and hexane for depigmentation and defatting. The proteins were fractionated by ammonium sulphate (0-30, 30-60, 60-90%) followed by dialysis and size exclusion chromatography (SEC). The inhibitory potential of crude seed extract and most active dialyzed fraction against trypsin and proteases was established by spot test using unprocessed x-ray film and casein digestion methods, respectively. Electrophoretic analysis of most active fraction (30-60%) and SEC elutes were carried employing Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and Gelatin SDS-PAGE. Inhibition of fungal spore germination was studied in the presence of dialyzed active inhibitor fraction. Standard deviation (SD) and ANOVA were employed as statistical tools. The crude seeds' extract displayed strong antitryptic, bacterial and fungal protease inhibitory activity on x-ray film. The seed protein fraction 30-60% was found most active for trypsin inhibition in caseinolytic assay (P Cassia tora seed extract has strong protease inhibitory activity against trypsin, Aspergillus flavus and Bacillus sp. proteases. The inhibitor in Cassia tora may attenuate microbial proteases and also might be used as phytoprotecting agent. © 2011 Tripathi et al; licensee BioMed Central Ltd.

  4. 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.

  5. Application of loop-mediated isothermal amplification assays for direct identification of pure cultures of Aspergillus flavus, A. nomius, and A. caelatus and for their rapid detection in shelled Brazil nuts.

    Science.gov (United States)

    Luo, Jie; Taniwaki, Marta H; Iamanaka, Beatriz T; Vogel, Rudi F; Niessen, Ludwig

    2014-02-17

    Brazil nuts have a high nutritional content and are a very important trade commodity for some Latin American countries. Aflatoxins are carcinogenic fungal secondary metabolites. In Brazil nuts they are produced predominantly by Aspergillus (A.) nomius and A. flavus. In the present study we applied and evaluated two sets of primers previously published for the specific detection of the two species using loop-mediated isothermal amplification (LAMP) technology. Moreover, a primer set specific for A. caelatus as a frequently occurring non-aflatoxigenic member of Aspergillus section Flavi in Brazil nuts was newly developed. LAMP assays were combined with a simplified DNA release method and used for rapid identification of pure cultures and rapid detection of A. nomius and A. flavus from samples of shelled Brazil nuts. An analysis of pure cultures of 68 isolates representing the major Aspergillus species occurring on Brazil nuts showed that the three LAMP assays had individual accuracies of 61.5%, 84.4%, and 93.3% for A. flavus, A. nomius, and A. caelatus, respectively when morphological identification was used as a reference. The detection limits for conidia added directly to the individual LAMP reactions were found to be 10⁵ conidia per reaction with the primer set ID9 for A. nomius and 10⁴ conidia per reaction with the primer set ID58 for A. flavus. Sensitivity was increased to 10¹ and 10² conidia per reaction for A. nomius and A. flavus, respectively, when sample preparation included a spore disruption step. The results of LAMP assays obtained during the analysis of 32 Brazil nut samples from different regions of Brazil and from different steps in the production process of the commodity were compared with results obtained from mycological analysis and aflatoxin analysis of corresponding samples. Compared with mycological analysis of the samples, the Negative Predictive Values of LAMP assays were 42.1% and 12.5% while the Positive Predictive Values were 61

  6. 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

  7. 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)

  8. 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

  9. Abiotic factors and their interactions influence on the co-production of aflatoxin B(1) and cyclopiazonic acid by Aspergillus flavus isolated from corn.

    Science.gov (United States)

    Astoreca, Andrea; Vaamonde, Graciela; Dalcero, Ana; Marin, Sonia; Ramos, Antonio

    2014-04-01

    The objectives of this study were i) to determine the effects of the interactions of water activity, temperature and incubation time on the co-production of AFB1 and CPA by isolates of Aspergillus flavus with different profile of mycotoxin production and ii) to identify the aW and temperature limiting conditions for the production of both mycotoxins. Fungi used in this study were selected because they belonged to different chemotypes: chemotype I (AFB1+/CPA+), III (AFB1+/CPA-) and IV (AFB1-/CPA+), respectively. Two culture media were used; Czapek yeast agar (CYA) and corn extract agar (CEM), at different incubated temperatures (10-40 °C) and aW levels (0.80-0.98). AFB1 and CPA production were analyzed after 7, 14, 21 and 28 days of incubation. Significant differences were observed with respect to mycotoxin production depending on the media evaluated. The AFB1 production occurred more favorably on CYA while the highest CPA concentrations were recorded on CEM. Within the range of aW evaluated in this study, 0.83 was the limiting level for both toxins production. The optimum conditions for AFB1 production occurred at 0.96 aW and 30 °C after 21 days of incubation, regardless of the media and isolate. Although different amounts of toxins were produced in each medium, the limiting and optimum conditions for their production were similar in both. No differences in the response of the three isolates to the abiotic factors discussed were observed despite belonging to different chemotypes. The determination of the thresholds of mycotoxins co-production, especially in the case of data obtained with the corn extract medium can be useful to avoid the conditions conducive to co-occurrence of these mycotoxins in corn. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  10. Biological control of Verticillium dahliae by Talaromyces flavus

    NARCIS (Netherlands)

    Nagtzaam, M.P.M.

    1998-01-01

    Verticillium dahliae causes vascular wilt in a wide range of host plants. Control of Verticillium wilt is by soil disinfestation and to a lesser extent by crop rotation or, for a few host plants, by growing resistant varieties. For environmental reasons, the development

  11. 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...

  12. 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

  13. Effect of geocarposphere temperature on pre-harvest colonization of drought-stressed peanuts by Aspergillus flavus and subsequent aflatoxin contamination.

    Science.gov (United States)

    Blankenship, P D; Cole, R J; Sanders, T H; Hill, R A

    1984-03-15

    Florunner peanuts grown in research plots were subjected to 5 soil temperature and moisture treatment regimes resulting in A. flavus infestation and subsequent aflatoxin contamination in drought-stressed peanuts. Treatments imposed beginning 85 days after planting were drought, drought with heated soil and 3 drought treatments with cooled soil. The incidence of A. flavus in drought-stressed, unshelled , sound mature kernels ( SMK ) decreased with decreases in the mean 5 cm deep soil temperature. The incidence of A. flavus was greater in inedible categories and in damaged kernels than in SMK . The mean, threshold, geocarposphere temperature required for aflatoxin development during the latter part of the peanut growth cycle was found to be between 25.7 degrees C and 27 degrees C.

  14. 76 FR 16297 - Aspergillus flavus

    Science.gov (United States)

    2011-03-23

    ... exposure to drinking water or runoff may be mitigated by, among other things, percolation through soil.... Other types of entities not listed in this unit could also be affected. The North American Industrial....'' This includes exposure through drinking water and in residential settings but does not include...

  15. Detection of Aspergillus flavus and A. fumigatus in Bronchoalveolar Lavage Specimens of Hematopoietic Stem Cell Transplants and Hematological Malignancies Patients by Real-Time Polymerase Chain Reaction, Nested PCR and Mycological Assays

    Science.gov (United States)

    Zarrinfar, Hossein; Mirhendi, Hossein; Fata, Abdolmajid; Khodadadi, Hossein; Kordbacheh, Parivash

    2015-01-01

    Background: Pulmonary aspergillosis (PA) is one of the most serious complications in immunocompromised patients, in particular among hematopoietic stem cell transplants (HSCT) and patients with hematological malignancies. Objectives: The current study aimed to evaluate the incidence of PA and utility of molecular methods in HSCT and patients with hematological malignancies, four methods including direct examination, culture, nested polymerase chain reaction (PCR) and real-time PCR were performed on bronchoalveolar lavage (BAL) specimens in Tehran, Iran. Patients and Methods: During 16 months, 46 BAL specimens were obtained from individuals with allogeneic HSCT (n = 18) and patients with hematological malignancies (n = 28). Direct wet mounts with 20% potassium hydroxide (KOH) and culture on mycological media were performed. The molecular detection of Aspergillus fumigatus and A. flavus was done by amplifying the conserved sequences of internal transcribed spacer 1 (ITS1) ribosomal DNA by nested-PCR and the β-tubulin gene by TaqMan real-time PCR. Results: Seven (15.2%) out of 46 specimens were positive in direct examination and showed branched septate hyphae; 11 (23.9%) had positive culture including eight (72.7%) A. flavus and three (27.3%) A. fumigatus; 22 (47.8%) had positive nested-PCR and eight (17.4%) had positive real-time PCR. The incidence of invasive pulmonary aspergillosis (IPA) in these patients included proven IPA in 1 (2.2%), probable IPA in 10 (21.7%), possible IPA in 19 (41.3%) and not IPA in 16 cases (34.8%). Conclusions: The incidence of IPA in allogeneic HSCT and patients with hematological malignancies was relatively high and A. flavus was the most common cause of PA. As molecular methods had higher sensitivity, it may be useful as screening methods in HSCT and patients with hematological malignancies, or to determine when empirical antifungal therapy can be withheld. PMID:25763133

  16. 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

    International Nuclear Information System (INIS)

    Aquino, Simone

    2003-01-01

    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 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 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)

  17. Metabolic control analysis of xylose catabolism in Aspergillus

    DEFF Research Database (Denmark)

    Prathumpai, Wai; Gabelgaard, J.B.; Wanchanthuek, P.

    2003-01-01

    A kinetic model for xylose catabolism in Aspergillus is proposed. From a thermodynamic analysis it was found that the intermediate xylitol will accumulate during xylose catabolism. Use of the kinetic model allowed metabolic control analysis (MCA) of the xylose catabolic pathway to be carried out......, and flux control was shown to be dependent on the metabolite levels. Due to thermodynamic constraints, flux control may reside at the first step in the pathway, i.e., at the xylose reductase, even when the intracellular xylitol concentration is high. On the basis of the kinetic analysis, the general dogma...... specifying that flux control often resides at the step following an intermediate present at high concentrations was, therefore, shown not to hold. The intracellular xylitol concentration was measured in batch cultivations of two different strains of Aspergillus niger and two different strains of Aspergillus...

  18. Metabolic control analysis of xylose catabolism in Aspergillus

    DEFF Research Database (Denmark)

    Prathumpai, Wai; Gabelgaard, J.B.; Wanchanthuek, P.

    2003-01-01

    A kinetic model for xylose catabolism in Aspergillus is proposed. From a thermodynamic analysis it was found that the intermediate xylitol will accumulate during xylose catabolism. Use of the kinetic model allowed metabolic control analysis (MCA) of the xylose catabolic pathway to be carried out...... specifying that flux control often resides at the step following an intermediate present at high concentrations was, therefore, shown not to hold. The intracellular xylitol concentration was measured in batch cultivations of two different strains of Aspergillus niger and two different strains of Aspergillus...... nidulans grown on media containing xylose, and a concentration up to 30 mM was found. Applying MCA showed that the first polyol dehydrogenase (XDH) in the catabolic pathway of xylose exerted the main flux control in the two strains of A. nidulans and A. niger NW324, but the flux control was exerted mainly...

  19. Metabolic control analysis of xylose catabolism in Aspergillus

    NARCIS (Netherlands)

    Prathumpai, W.; Gabelgaard, J.B.; Wanchanthuek, P.; Vondervoort, van de P.J.I.; Groot, de M.J.L.; McIntyre, M.; Nielsen, J.

    2003-01-01

    A kinetic model for xylose catabolism in Aspergillus is proposed. From a thermodynamic analysis it was found that the intermediate xylitol will accumulate during xylose catabolism. Use of the kinetic model allowed metabolic control analysis (MCA) of the xylose catabolic pathway to be carried out,

  20. Efficacy of Some Essential Oils Against Aspergillus flavus with Special Reference to Lippia alba Oil an Inhibitor of Fungal Proliferation and Aflatoxin B1 Production in Green Gram Seeds during Storage.

    Science.gov (United States)

    Pandey, Abhay K; Sonker, Nivedita; Singh, Pooja

    2016-04-01

    During mycofloral analysis of green gram (Vigna radiata (L.) R. Wilczek) seed samples taken from different grocery stores by agar and standard blotter paper methods, 5 fungal species were identified, of which Aspergillus flavus exhibited higher relative frequency (75.20% to 80.60%) and was found to produce aflatoxin B1 . On screening of 11 plant essential oils against this mycotoxigenic fungi, Lippia alba essential oil was found to be most effective and showed absolute inhibition of mycelia growth at 0.28 μL/mL. The oil of L. alba was fungistatic and fungicidal at 0.14 and 0.28 μL/mL, respectively. Oil had broad range of fungitoxicity at its MIC value and was absolutely inhibited the AFB1 production level at 2.0 μL/mL. Chemical analysis of this oil revealed geranial (36.9%) and neral (29.3%) as major components followed by myrcene (18.6%). Application of a dose of 80 μL/0.25 L air of Lippia oil in the storage system significantly inhibited the fungal proliferation and aflatoxin production without affecting the seed germination rate. By the virtue of fungicidal, antiaflatoxigenic nature and potent efficacy in storage food system, L. alba oil can be commercialized as botanical fungicide for the protection of green gram seeds during storage. © 2016 Institute of Food Technologists®

  1. On the Permeation by Dioxygen of Urate Oxidase from Aspergillus flavus in Complex with Xanthine Anion: Dioxygen Pathways and a Portrait of the Enzyme Cavities from Molecular Dynamics Simulations in Water Solution.

    Science.gov (United States)

    Pietra, Francesco

    2016-06-01

    This work describes molecular dynamics (MD) simulations in aqueous media for the complex of the homotetrameric urate oxidase (UOX) from Aspergillus flavus with xanthine anion (5) in the presence of dioxygen (O2 ). After 196.6 ns of trajectory from unrestrained MD, a O2 molecule was observed leaving the bulk solvent to penetrate the enzyme between two subunits, A/C. From here, the same O2 molecule was observed migrating, across subunit C, to the hydrophobic cavity that shares residue V227 with the active site. The latter was finally attained, after 378.3 ns of trajectory, with O2 at a bonding distance from 5. The reverse same O2 pathway, from 5 to the bulk solvent, was observed as preferred pathway under random acceleration MD (RAMD), where an external, randomly oriented force was acting on O2 . Both MD and RAMD simulations revealed several cavities populated by O2 during its migration from the bulk solvent to the active site or backwards. Paying attention to the last hydrophobic cavity that apparently serves as O2 reservoir for the active site, it was noticed that its volume undergoes ample fluctuations during the MD simulation, as expected from the thermal motion of a flexible protein, independently from the particular subunit and no matter whether the cavity is filled or not by O2 . © 2016 Verlag Helvetica Chimica Acta AG, Zürich.

  2. 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.

  3. Metabolic control analysis of Aspergillus niger L-arabinose catabolism

    DEFF Research Database (Denmark)

    de Groot, M.J.L.; Prathumpai, Wai; Visser, J.

    2005-01-01

    A mathematical model of the L-arabinose/D-xylose catabolic pathway of Aspergillus niger was constructed based on the kinetic properties of the enzymes. For this purpose L-arabinose reductase, L-arabitol dehydrogenase and D-xylose reductase were purified using dye-affinity chromatography, and thei......A mathematical model of the L-arabinose/D-xylose catabolic pathway of Aspergillus niger was constructed based on the kinetic properties of the enzymes. For this purpose L-arabinose reductase, L-arabitol dehydrogenase and D-xylose reductase were purified using dye-affinity chromatography......-arabinose, a level that resulted in realistic intermediate concentrations in the model, flux control coefficients for L-arabinose reductase, L-arabitol dehydrogenase and L-xylulose reductase were 0.68, 0.17 and 0.14, respectively. The analysis can be used as a guide to identify targets for metabolic engineering...

  4. Metabolic control analysis of Aspergillus niger L-arabinose catabolism

    DEFF Research Database (Denmark)

    de Groot, M.J.L.; Prathumpai, Wai; Visser, J.

    2005-01-01

    A mathematical model of the L-arabinose/D-xylose catabolic pathway of Aspergillus niger was constructed based on the kinetic properties of the enzymes. For this purpose L-arabinose reductase, L-arabitol dehydrogenase and D-xylose reductase were purified using dye-affinity chromatography, and thei......A mathematical model of the L-arabinose/D-xylose catabolic pathway of Aspergillus niger was constructed based on the kinetic properties of the enzymes. For this purpose L-arabinose reductase, L-arabitol dehydrogenase and D-xylose reductase were purified using dye-affinity chromatography...... at the enzyme following the intermediate with the highest concentration, L-arabitol, but is distributed over the first three steps in the pathway, preceding and following L-arabitol. Flux control appeared to be strongly dependent on the intracellular L-arabinose concentration. At 5 mM intracellular L...

  5. Biodiversity of Aspergillus section Flavi in Europe in relation to the management of aflatoxin risk.

    Science.gov (United States)

    Perrone, Giancarlo; Gallo, Antonia; Logrieco, Antonio F

    2014-01-01

    Aflatoxins and the producing fungi Aspergillus section Flavi are widely known as the most serious and dangerous mycotoxin issue in agricultural products. In Europe, before the outbreak of aflatoxins on maize (2003-2004) due to new climatic conditions, their contamination was confined to imported foods. Little information is available on molecular biodiversity and population structure of Aspergillus section Flavi in Europe. Preliminary reports evidenced the massive presence of Aspergillus flavus L -morphotype as the predominant species in maize field, no evidence of the highly toxigenic S-morphotype and of other aflatoxigenic species are reported. The risk of a shift in traditional occurrence areas for aflatoxins is expected in the world and in particular in South East of Europe due to the increasing average temperatures. Biological control of aflatoxin risk in the field by atoxigenic strains of A. flavus starts to be widely used in Africa and USA. Studies are necessary on the variation of aflatoxin production in populations of A. flavus to characterize stable atoxigenic A. flavus strains. The aim of present article is to give an overview on biodiversity and genetic variation of Aspergillus section Flavi in Europe in relation to the management of aflatoxins risk in the field.

  6. 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

  7. 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 ...

  8. Biodiversity of Aspergillus Section Flavi in Europe in relation to the management of aflatoxin risk

    Directory of Open Access Journals (Sweden)

    Giancarlo ePerrone

    2014-07-01

    Full Text Available Aflatoxins and the producing fungi Aspergillus Section Flavi are widely known as the most serious and dangerous mycotoxin issue in agricultural products. In Europe, before the outbreak of aflatoxins on maize (2003-2004 due to new climatic conditions, their contamination was confined to imported foods. Little information is available on molecular biodiversity and population structure of Aspergillus Section Flavi in Europe. Preliminary reports evidenced the massive presence of A. flavus L-morphotype as the predominant species in maize field, no evidence of the highly toxigenic S-morphotype and of other aflatoxigenic species are reported. The risk of a shift in traditional occurrence areas for aflatoxins is expected in the world and in particular in South East of Europe due to the increasing average temperatures. Biological control of aflatoxin risk in the field by atoxigenic strains of A. flavus starts to be widely used in Africa and USA. Studies are necessary on the variation of aflatoxin production in populations of A. flavus to characterize stable atoxigenic A. flavus strains. The aim of present article is to give an overview on biodiversity and genetic variation of Aspergillus Sect. Flavi in Europe in relation to the management of aflatoxins risk in the field.

  9. Density and molecular epidemiology of Aspergillus in air and relationship to outbreaks of Aspergillus infection

    NARCIS (Netherlands)

    A.C.A.P. Leenders (Alexander); A.F. van Belkum (Alex); M.D. Behrendt (Myra); A. Luijendijk (Ad); H.A. Verbrugh (Henri)

    1999-01-01

    textabstractAfter 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

  10. 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...

  11. Characterization of Aspergillus species on Brazil nut from the Brazilian Amazonian region and development of a PCR assay for identification at the genus level.

    Science.gov (United States)

    Midorikawa, Glaucia E O; de Sousa, Maria de Lourdes M; Freitas Silva, Otniel; Dias, Jurema do Socorro A; Kanzaki, Luis I B; Hanada, Rogerio E; Mesquita, Renata M L C; Gonçalves, Rivadalve C; Alvares, Virginia S; Bittencourt, Daniela M C; Miller, Robert N G

    2014-05-30

    Brazil nut is a protein-rich extractivist tree crop in the Amazon region. Fungal contamination of shells and kernel material frequently includes the presence of aflatoxigenic Aspergillus species from the section Flavi. Aflatoxins are polyketide secondary metabolites, which are hepatotoxic carcinogens in mammals. The objectives of this study were to identify Aspergillus species occurring on Brazil nut grown in different states in the Brazilian Amazon region and develop a specific PCR method for collective identification of member species of the genus Aspergillus. Polyphasic identification of 137 Aspergillus strains isolated from Brazil nut shell material from cooperatives across the Brazilian Amazon states of Acre, Amapá and Amazonas revealed five species, with Aspergillus section Flavi species A. nomius and A. flavus the most abundant. PCR primers ASP_GEN_MTSSU_F1 and ASP_GEN_MTSSU_R1 were designed for the genus Aspergillus, targeting a portion of the mitochondrial small subunit ribosomal RNA gene. Primer specificity was validated through both electronic PCR against target gene sequences at Genbank and in PCR reactions against DNA from Aspergillus species and other fungal genera common on Brazil nut. Collective differentiation of the observed section Flavi species A. flavus, A. nomius and A. tamarii from other Aspergillus species was possible on the basis of RFLP polymorphism. Given the abundance of Aspergillus section Flavi species A. nomius and A. flavus observed on Brazil nut, and associated risk of mycotoxin accumulation, simple identification methods for such mycotoxigenic species are of importance for Hazard Analysis Critical Control Point system implementation. The assay for the genus Aspergillus represents progress towards specific PCR identification and detection of mycotoxigenic species.

  12. Determination of Aspergillus pathogens in agricultural products by a specific nanobody-polyclonal antibody sandwich ELISA.

    Science.gov (United States)

    Wang, Ting; Li, Peiwu; Zhang, Qi; Zhang, Wen; Zhang, Zhaowei; Wang, Tong; He, Ting

    2017-06-28

    Aspergillus and its poisonous mycotoxins are distributed worldwide throughout the environment and are of particular interest in agriculture and food safety. In order to develop a specific method for rapid detection of Aspergillus flavus to forecast diseases and control aflatoxins, a nanobody, PO8-VHH, highly reactive to A. flavus was isolated from an immunized alpaca nanobody library by phage display. The nanobody was verified to bind to the components of extracellular and intracellular antigen from both A. flavus and A. parasiticus. To construct a sandwich format immunoassay, polyclonal antibodies against Aspergillus were raised with rabbits. Finally, a highly selective nanobody-polyclonal antibody sandwich enzyme-linked immunosorbent assay was optimized and developed. The results revealed that the detection limits of the two fungi were as low as 1 μg mL -1 , and that it is able to detect fungal concentrations below to 2 μg mg -1 of peanut and maize grains in both artificially and naturally contaminated samples. Therefore, we here provided a rapid and simple method for monitoring Aspergillus spp. contamination in agricultural products.

  13. [Aspergillus species in hospital environments with pediatric patients in critical condition].

    Science.gov (United States)

    Fernández, Mariana; Cattana, María; Rojas, Florencia; Sosa, María de Los Ángeles; Aguirre, Clarisa; Vergara, Marta; Giusiano, Gustavo

    2014-01-01

    Aspergillus is a group of opportunistic fungi that cause infections, with high morbimortality in immunosuppressed patients. Aspergillus fumigatus is the most frequent species in these infections, although the incidence of other species has increased in the last few years. To evaluate the air fungal load and the diversity of Aspergillus species in hospitals with pediatric patients in critical condition. The Intensive Care Unit and Burns Unit of a pediatric hospital were sampled every 15 days during the autumn and spring seasons. The air samples were collected with SAS Super 100(®) and the surface samples were collected by swab method. The UFC/m(3) counts found exceeded the acceptable levels. The UFC/m(3) and the diversity of Aspergillus species found in the Intensive Care Unit were higher than those found in the Burns Unit. The fungal load and the diversity of species within the units were higher than those in control environments. The use of both methods -SAS and swab- allowed the detection of a higher diversity of species, with 96 strains of Aspergillus being isolated and 12 species identified. The outstanding findings were Aspergillus sydowii, Aspergillus niger, Aspergillus flavus, Aspergillus terreus and Aspergillus parasiticus, due to their high frequency. Aspergillus fumigatus, considered unacceptable in indoor environments, was isolated in both units. Aspergillus was present with high frequency in these units. Several species are of interest in public health for being potential pathogenic agents. Air control and monitoring are essential in the prevention of these infections. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

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

    OpenAIRE

    F Kalantary

    2014-01-01

    Background: Nutrition transition, that is, increase in consumption of high energy-dense foods, with low consumption of fruits and vegetables, has been implicated as the major factors responsible for the increase in prevalence of diet-related diseases such as diabetes and cardiovascular diseases worldwide. Evidence has shown that consumption of plant-based foods prevents the risk of these chronic diseases, hence, the present study formulated and evaluated nutrient compositions and antidiabetic...

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

    OpenAIRE

    Arias, Ren?e S.; Dang, Phat M.; Sobolev, Victor S.

    2015-01-01

    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 pean...

  16. In vitro Antagonistic Mechanisms of Trichoderma spp. and Talaromyces flavus to Control Gaeumannomyces graminis var. tritici the Causal Agent of Wheat Take-all Disease

    Directory of Open Access Journals (Sweden)

    Seddighe Mohammadi

    2015-07-01

    Full Text Available Wheat take-all disease caused by Gaeumannomyces graminis var. tritici has recently been detected in different regions of Iran. With respect to biocontrol effect of Trichoderma spp. on many pathogenic fungi, seven isolates of Trichoderma and four isolates of Talaromyces were in vitro evaluated in terms of their biological control against the disease causal agent. In dual culture test the five isolates showed efficient competition for colonization against pathogenic fungus and the highest percentages of inhibition belonging to Talaromyces flavus 60 and Talaromyces flavus 136 were 59.52 and 57.61%, respectively. Microscopic investigations showed that in regions where antagonistic isolates and Gaeumannomyces graminis var. tritici coincide, hyphal contact, penetration and fragmentation of Gaeumannomyces graminis var. tritici were observed. Investigating the effect of volatile and non-volatile compounds at 10 ml concentration showed that the highest inhibition percentage on mycelium growth of the pathogen caused by T. harzianum (44.76% and T. longibrachiatum (52.38% respectively.

  17. Verification of radio frequency pasteurization treatment for controlling Aspergillus parasiticus on corn grains.

    Science.gov (United States)

    Zheng, Ajuan; Zhang, Lihui; Wang, Shaojin

    2017-05-16

    Radio frequency (RF) heating has been proposed and tested to achieve a required anti-fungal efficacy on various food samples due to its advantage of deeper penetration depth and better heating uniformity. The purpose of this study was to validate applications of RF treatments for controlling Aspergillus parasiticus in corn while maintaining product quality. A pilot-scale, 27.12MHz, 6kW RF heating system together with hot air heating was used to rapidly pasteurize 3.0kg corn samples. Results showed that the pasteurizing effect of RF heating on Aspergillus parasiticus increased with increasing heating temperature and holding time, and RF heating at 70°C holding in hot air for at least 12min resulted in 5-6 log reduction of Aspergillus parasiticus in corn samples with the moisture content of 15.0% w.b. Furthermore, thermal resistance of Aspergillus parasiticus decreased with increasing moisture content (MC) of corn samples. Quality (MC, water activity - a w , protein, starch, ash, fat, fatty acid, color, electrical conductivity and germination rate) of RF treated corn met the required quality standard used in cereal industry. Therefore, RF treatments can provide an effective and rapid heating method to control Aspergillus parasiticus and maintain acceptable corn quality. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Novel synthetic peptides control mycotoxigenic fungi

    Science.gov (United States)

    The fungus Aspergillus flavus infects cottonseed, peanut, corn and tree nuts and produces aflatoxin, a highly toxic and carcinogenic secondary metabolite. Measures to control preharvest aflatoxin contamination in these crops through breeding for resistance has had limited success. There is no natur...

  19. Production of aflatoxin byAspergillus parasiticus and its control.

    Science.gov (United States)

    Emara, H A

    1997-03-01

    The aim of the present work was to investigate the production of aflatoxin byAspergillus parasiticus and to find out the possible ways to control it. Of 40 food samples collected from Abha region, Saudi Arabia, only 25% were contaminated with aflatoxins. Oil-rich commodities had the highly contaminated commodities by fungi and aflatoxins while spices were free from aflatoxins.Bacillus megatertum andB cereus were suitable for microbiological assay of aflatoxins. Czapek's-Dox medium was found a suitable medium for isolation of fungi from food samples. The optimal pH for the growth ofA. parasiticus and its productivity of aflatoxin B1 was found at 6.0, while the best incubation conditions were found at 30°C for 10 days. D-glucose was the best carbon source for fungal growth, as well as aflatoxin production. Corn steep liquor, yeast extract and peptone were the best nitrogen sources for both fungal growth and toxin production (NH4)2HPO4 (1.55 gL(-1)) and NaNO2 (1.6 gL(-1)) reduced fungal growth and toxin production with 37.7% and 85%, respectively. Of ten amino acids tested, asparagine was the best for aflatoxin B1 production. Zn(2+) and Co(2+) supported significantly both fungal growth, as well as, aflatoxin B1 production at the different tested concentrations. Zn(2+) was effective when added toA. parasiticus growth medium at the first two days of the culture age. The other tested metal ions expressed variable effects depending on the type of ion and its concentration. Water activity (aw) was an important factor controlling the growth ofA. parasiticus and toxin production. The minimum aw for the fungal growth was 0.8 on both coffee beans and rice grains, while aw of 0.70 caused complete inhibition for the growth and aflatoxin B1 production. H2O2 is a potent inhibitor for growth ofA. parasiticus and its productivity of toxins. NaHCO3 and C6H5COONa converted aflatoxin B1 to water-soluble form which returned to aflatoxin B1 by acidity. Black pepper, ciliated heath

  20. Characterization of Aspergillus section Flavi isolated from organic Brazil nuts using a polyphasic approach.

    Science.gov (United States)

    Reis, T A; Baquião, A C; Atayde, D D; Grabarz, F; Corrêa, B

    2014-09-01

    Brazil nut (Bertholletia excelsa), an important non-timber forest product from Amazonia, is commercialized in worldwide markets. The main importers of this nut are North America and European countries, where the demand for organic products has grown to meet consumers concerned about food safety. Thus, the precise identification of toxigenic fungi is important because the Brazil nut is susceptible to colonization by these microorganisms. The present study aimed to characterize by polyphasic approach strains of Aspergillus section Flavi from organic Brazil nuts. The results showed Aspergillus flavus as the main species found (74.4%), followed by Aspergillus nomius (12.7%). The potential mycotoxigenic revealed that 80.0% of A. flavus were toxin producers, 14.3% of which produced only aflatoxin B (AFB), 22.85% of which produced only cyclopiazonic acid (CPA), and 42.85% produced both them. All strains of A. nomius were AFB and AFG producers and did not produce CPA. There is no consensus about what Aspergillus species predominates on Brazil nuts. Apparently, the origin, processing, transport and storage conditions of this commodity influence the species that are found. The understanding about population of fungi is essential for the development of viable strategies to control aflatoxins in organic Brazil nuts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. The Effectiveness of Antifungal Controlling Aspergillus Niger Growth on Plasterboard

    Directory of Open Access Journals (Sweden)

    Parjo Umi Kalthsom

    2017-01-01

    Full Text Available Good indoor environmental quality is desired for a healthy indoor environment. The microbial growth under indoor environments contribute to the poor indoor environmental quality that can cause various of health problems. In this study, the applications of three types of antifungals to prevent microbial migration, subsequent growth and bio-deterioration of the substrates. The aim of this research was to evaluate the coating-bio resistance in remediation of indoor fungal using three types of antifungals with different types of wall finishing materials. The treatment was exposed to optimum temperature and relative humidity at 30°C and 90% respectively. The potassium sorbate, zinc salicylate and calcium benzoate are tested against Aspergillus niger which is collected from indoor rooms. This study has revealed the growth of A. niger are more affected by the potassium sorbate on thick wallpaper, which is the percentage growth are 47%.

  2. Control of Tribolium confusum J. du val by diatomaceous earth ...

    African Journals Online (AJOL)

    Environmental and human health problems associated with the use of synthetic pesticides have prompted the demand for non-polluting, biologically specific insecticides. The current study assessed the losses caused by Tribolium confusum and its control by diatomaceous earth and the effect on Aspergillus flavus spore ...

  3. 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 ...

  4. 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 ...

  5. 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

  6. The Use of Trichoderma spp. for Controlling the Growth and Aflatoxin Production of Aspergillus parasiticus in Agricultural Products

    International Nuclear Information System (INIS)

    Thanaboripat, Dusanee; Piadiang, Nattaya; Qian, Yang

    2006-09-01

    Various strains of Trichoderma spp. were screened from soils and irradiated by gamma ray. After the irradiation all strains were tested for an ability to inhibit the growth of aflatoxin producing fungi (A. parasiticus IMI 105266 and A. flavus IMI 24268). The results indicate that Trichoderma virde S84-1 480526 I08(1) was the most effective strain in controlling the growth of these two fungi on PDA.

  7. 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...

  8. Polyphasic approach to the identification of Aspergillus section Flavi isolated from Brazil nuts.

    Science.gov (United States)

    Baquião, Arianne Costa; de Oliveira, Maitê Martins Melo; Reis, Tatiana Alves; Zorzete, Patricia; Diniz Atayde, Danielle; Correa, Benedito

    2013-08-15

    The aim of this study was to use a polyphasic approach to identify Aspergillus section Flavi isolated from Brazil nuts collected in the Amazon forest: investigation of macro- and microscopic morphology, production of extrolites, heat-resistance fungi, and sequencing of DNA regions. The following Aspergillus section Flavi species were identified: Aspergillus flavus (75.5%), Aspergillus nomius (22.3%), and Aspergillus parasiticus (2.2%). All A. nomius and A. parasiticus isolates produced aflatoxins B and G, but not cyclopiazonic acid (CPA). A. flavus isolates were more diversified and a high frequency of mycotoxigenic strains was observed. The polyphasic approach permitted the reliable identification of section Flavi species. The rate of mycotoxigenic strains was high (92.7%) and mainly included A. flavus strains producing elevated levels of aflatoxins and CPA. These results highlight the possibility of co-occurrence of both toxins, increasing their potential toxic effect in this commodity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Study of the genetic diversity of the aflatoxin biosynthesis cluster in Aspergillus section Flavi using insertion/deletion markers in peanut seeds from Georgia, USA.

    Science.gov (United States)

    Faustinelli, Paola C; Palencia, Edwin R; Sobolev, Victor S; Horn, Bruce W; Sheppard, Hank T; Lamb, Marshall C; Wang, Xinye M; Scheffler, Brian E; Martinez Castillo, Jaime; Arias, Renée S

    2017-01-01

    Aflatoxins are among the most powerful carcinogens in nature. The major aflatoxin-producing fungi are Aspergillus flavus and A. parasiticus. Numerous crops, including peanut, are susceptible to aflatoxin contamination by these fungi. There has been an increased use of RNA interference (RNAi) technology to control phytopathogenic fungi in recent years. In order to develop molecular tools targeting specific genes of these fungi for the control of aflatoxins, it is necessary to obtain their genome sequences. Although high-throughput sequencing is readily available, it is still impractical to sequence the genome of every isolate. Thus, in this work, the authors proposed a workflow that allowed prescreening of 238 Aspergillus section Flavi isolates from peanut seeds from Georgia, USA. The aflatoxin biosynthesis cluster (ABC) of the isolates was fingerprinted at 25 InDel (insertion/deletion) loci using capillary electrophoresis. All isolates were tested for aflatoxins using ultra-high-performance liquid chromatography. The neighbor-joining, three-dimension (3D) principal coordinate, and Structure analyses revealed that the Aspergillus isolates sampled consisted of three main groups determined by their capability to produce aflatoxins. Group I comprised 10 non-aflatoxigenic A. flavus; Group II included A. parasiticus; and Group III included mostly aflatoxigenic A. flavus and the three non-aflatoxigenic A. caelatus. Whole genomes of 10 representative isolates from different groups were sequenced. Although InDels in Aspergillus have been used by other research groups, this is the first time that the cluster analysis resulting from fingerprinting was followed by whole-genome sequencing of representative isolates. In our study, cluster analysis of ABC sequences validated the results obtained with fingerprinting. This shows that InDels used here can predict similarities at the genome level. Our results also revealed a relationship between groups and their capability to produce

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    (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...... aflatoxins G(1) and G(2), aflavarins, aflatrem, aflavinines, parasiticolides and paspaline. This species also includes several isolates previously assigned to A. flavus group II and three Australian soil isolates. A. arachidicola produces aflatoxins B-1, B-2, G(1) and G(2), kojic acid, chrysogine...

  11. Biological control of post harvest disease caused by Aspergillus ...

    African Journals Online (AJOL)

    The highest control was obtained by the cell suspension of Pantoea agglomerans RK-153. 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 disease ...

  12. 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.

  13. Suppression of Aflatoxin Production in Aspergillus Species by Selected Peanut (Arachis hypogaea) Stilbenoids.

    Science.gov (United States)

    Sobolev, Victor; Arias, Renee; Goodman, Kerestin; Walk, Travis; Orner, Valerie; Faustinelli, Paola; Massa, Alicia

    2018-01-10

    Aspergillus flavus is a soil fungus that commonly invades peanut seeds and often produces carcinogenic aflatoxins. Under favorable conditions, the fungus-challenged peanut plant produces and accumulates resveratrol and its prenylated derivatives in response to such an invasion. These prenylated stilbenoids are considered peanut antifungal phytoalexins. However, the mechanism of peanut-fungus interaction has not been sufficiently studied. We used pure peanut stilbenoids arachidin-1, arachidin-3, and chiricanine A to study their effects on the viability of and metabolite production by several important toxigenic Aspergillus species. Significant reduction or virtually complete suppression of aflatoxin production was revealed in feeding experiments in A. flavus, Aspergillus parasiticus, and Aspergillus nomius. Changes in morphology, spore germination, and growth rate were observed in A. flavus exposed to the selected peanut stilbenoids. Elucidation of the mechanism of aflatoxin suppression by peanut stilbenoids could provide strategies for preventing plant invasion by the fungi that produce aflatoxins.

  14. Isolation of culturable mycobiota from agricultural soils and determination of tolerance to glyphosate of nontoxigenic Aspergillus section Flavi strains.

    Science.gov (United States)

    Carranza, Cecilia S; Barberis, Carla L; Chiacchiera, Stella M; Dalcero, Ana María; Magnoli, Carina E

    2016-01-01

    Glyphosate-based herbicides are extensively used in Argentina's agricultural system to control undesirable weeds. This study was conducted to evaluate the culturable mycobiota [colony forming units (CFU) g(-1) and frequency of fungal genera or species] from an agricultural field exposed to pesticides. In addition, we evaluated the tolerance of A. oryzae and nontoxigenic A. flavus strains to high concentrations (100 to 500 mM - 17,000 to 84,500 ppm) of a glyphosate commercial formulation. The analysis of the mycobiota showed that the frequency of the main fungal genera varied according to the analyzed sampling period. Aspergillus spp. or Aspergillus section Flavi strains were isolated from 20 to 100% of the soil samples. Sterilia spp. were also observed throughout the sampling (50 to 100%). Aspergillus section Flavi tolerance assays showed that all of the tested strains were able to develop at the highest glyphosate concentration tested regardless of the water availability conditions. In general, significant reductions in growth rates were observed with increasing concentrations of the herbicide. However, a complete inhibition of fungal growth was not observed with the concentrations assayed. This study contributes to the knowledge of culturable mycobiota from agricultural soils exposed to pesticides and provides evidence on the effective growth ability of A. oryzae and nontoxigenic A. flavus strains exposed to high glyphosate concentrations in vitro.

  15. 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 ...

  16. ASPERGILLUS NIGER ASPERGILLUS NIGER

    African Journals Online (AJOL)

    User

    CITRIC ACID PRODUCTION FROM DILUTE ACID HYDROLYSED CORN STARCH USING ASPERGILLUS NIGER. , N. A. Amenaghawon ..... “The effect of the sugar source on citric acid production by. Aspergillusniger”. Applied. Microbiology and Biotechnology, Vol. 19, Number 6,. 1984, pp. 393-397. [25]. Xu, D.B., Madrid ...

  17. Method for measuring postantifungal effect in Aspergillus species.

    NARCIS (Netherlands)

    Vitale, R.G.; Mouton, J.W.; Afeltra, J.; Meis, J.F.G.M.; Verweij, P.E.

    2002-01-01

    An in vitro method for determination of postantifungal effect (PAFE) in molds was developed by using three isolates each of Aspergillus fumigatus, A. flavus, A. terreus, A. nidulans, and A. ustus. MICs of amphotericin B and itraconazole were determined by using National Committee for Clinical

  18. Detection of Aspergillus spp . and determination of the levels of ...

    African Journals Online (AJOL)

    Aflatoxins (B1, B2, G1 and G2) are hepatotoxic metabolites produced by Aspergillus flavus on a number of agricultural commodities. Their levels were studied in rice samples imported to Iran through a southern port in Bushehr. Aflatoxins analysis was performed by solvent extraction, immunoaffinity clean-up and ...

  19. Different control mechanisms regulate glucoamylase and protease gene transcription in Aspergillus oryzae in solid-state and submerged fermentation

    NARCIS (Netherlands)

    Biesebeke, te R.; Biezen, de N.; Vos, de W.M.; Hondel, van den C.A.M.J.J.; Punt, P.J.

    2005-01-01

    Solid-state fermentation (SSF) with Aspergillus oryzae results in high levels of secreted protein. However, control mechanisms of gene expression in SSF have been only poorly studied. In this study we show that both glucoamylase (glaB) and protease (alpA, nptB) genes are highly expressed during

  20. Biological control of aflatoxin production in corn using non-aflatoxigenic Aspergillus flavus administered as a bioplastic-based seed coating

    Science.gov (United States)

    Since its first introduction in the early 1990s, tremendous progress has been made in the application of biocontrol techniques for reducing aflatoxin contamination in corn. In almost three decades, the basic concept has remained centered on massive application of propagules of non-aflatoxigenic A. f...

  1. 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.

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

    African Journals Online (AJOL)

    ajl2

    2012-08-14

    Aug 14, 2012 ... al., 2009). They have been detected in many food and oilseed commodities from many parts of the world and are presently considered as one of the most dangerous contaminants of food and feed. ..... Teniola OD, Addo PA, Brost IM, Farber P, Jany KD, Alberts JF (2005). Degradation of aflatoxin B1 by ...

  3. aflatoxigenic Aspergillus flavus in groundnut seeds across India

    African Journals Online (AJOL)

    user

    2013-05-08

    May 8, 2013 ... including decaying plant and animal debris under field conditions. The mycotoxins produced by ... groundnut growing regions of India and 38 seed samples were collected from National and State seed ... Aflatoxin from 100 g of seed samples was extracted following the procedure explained by Kumar et al.

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

    African Journals Online (AJOL)

    Chemist

    2012-04-26

    Apr 26, 2012 ... mm mesh sieve. Both maize and soil samples were packed in sealed plastic bags and stored at 4°C for subsequent fungal enumeration analysis. All the research work pertaining to this project was carried out in the Toxicology Laboratory of the. Department of Agricultural Chemistry, Khyber Pakhtunkhwa.

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

    African Journals Online (AJOL)

    The enzyme retained 80% of its original activity in the presence of non ionic and ionic surfactants and 100% with 10% H2O2 after 1 h of incubation at 30°C. In addition, the enzyme showed excellent compatibility with some commercial powder detergents. The compatibility of our protease with several detergents, oxidants ...

  6. [Preliminary study on citral impaires the Aspergillus flavus membrane].

    Science.gov (United States)

    Luo, M; Jiang, L; Wu, Z

    2001-12-01

    Compared with the normally growing A. flauas, the content as below was determined: the utilization ratio to protein and reducing sugar of hyphostroma poisened by citral, the activity of [Na+, K+]-ATPase capable of decomposition ATP, and the seepagevity ratio of electrolyte. In addition, the shape change in spore was observed via the scanning electron microscope (SEM) and the fast multi-channel micro-spectrophotomer (FMCM). The result above all suggested facts as following after it's poised by the citral in MIC. The surface of hyphostroma and spore turned into be porous and rough. The pass trace on spore shriveled and closed. The rate of conduct electricity increased by 52.8%. The utilization ratio to protein and reducing sugar respectively decreased 61.5% and 44.3%. The rate of spore's sprout dropped to 61.4%. The molecular structure of membrane was so distinctly changed that it lost the selective permeability. There was inhibition on hyphostroma growth and spore sprout.

  7. Combinatorial control of gene expression in Aspergillus niger grown on sugar beet pectin.

    Science.gov (United States)

    Kowalczyk, Joanna E; Lubbers, Ronnie J M; Peng, Mao; Battaglia, Evy; Visser, Jaap; de Vries, Ronald P

    2017-09-27

    Aspergillus niger produces an arsenal of extracellular enzymes that allow synergistic degradation of plant biomass found in its environment. Pectin is a heteropolymer abundantly present in the primary cell wall of plants. The complex structure of pectin requires multiple enzymes to act together. Production of pectinolytic enzymes in A. niger is highly regulated, which allows flexible and efficient capture of nutrients. So far, three transcriptional activators have been linked to regulation of pectin degradation in A. niger. The L-rhamnose-responsive regulator RhaR controls the production of enzymes that degrade rhamnogalacturonan-I. The L-arabinose-responsive regulator AraR controls the production of enzymes that decompose the arabinan and arabinogalactan side chains of rhamnogalacturonan-II. The D-galacturonic acid-responsive regulator GaaR controls the production of enzymes that act on the polygalacturonic acid backbone of pectin. This project aims to better understand how RhaR, AraR and GaaR co-regulate pectin degradation. For that reason, we constructed single, double and triple disruptant strains of these regulators and analyzed their growth phenotype and pectinolytic gene expression in A. niger grown on sugar beet pectin.

  8. Control of Aspergillus niger with garlic, onion and leek extracts | Irkin ...

    African Journals Online (AJOL)

    Allium cepa L.) and leek (Allium porrum L.) were investigated against Aspergillus niger. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of aqueous, ethyl alcohol and acetone extracts were determined by ...

  9. Environmental dimensionality controls the interaction of phagocytes with the pathogenic fungi Aspergillus fumigatus and Candida albicans.

    Science.gov (United States)

    Behnsen, Judith; Narang, Priyanka; Hasenberg, Mike; Gunzer, Frank; Bilitewski, Ursula; Klippel, Nina; Rohde, Manfred; Brock, Matthias; Brakhage, Axel A; Gunzer, Matthias

    2007-02-01

    The fungal pathogens Aspergillus fumigatus and Candida albicans are major health threats for immune-compromised patients. Normally, macrophages and neutrophil granulocytes phagocytose inhaled Aspergillus conidia in the two-dimensional (2-D) environment of the alveolar lumen or Candida growing in tissue microabscesses, which are composed of a three-dimensional (3-D) extracellular matrix. However, neither the cellular dynamics, the per-cell efficiency, the outcome of this interaction, nor the environmental impact on this process are known. Live imaging shows that the interaction of phagocytes with Aspergillus or Candida in 2-D liquid cultures or 3-D collagen environments is a dynamic process that includes phagocytosis, dragging, or the mere touching of fungal elements. Neutrophils and alveolar macrophages efficiently phagocytosed or dragged Aspergillus conidia in 2-D, while in 3-D their function was severely impaired. The reverse was found for phagocytosis of Candida. The phagocytosis rate was very low in 2-D, while in 3-D most neutrophils internalized multiple yeasts. In competitive assays, neutrophils primarily incorporated Aspergillus conidia in 2-D and Candida yeasts in 3-D despite frequent touching of the other pathogen. Thus, phagocytes show activity best in the environment where a pathogen is naturally encountered. This could explain why "delocalized" Aspergillus infections such as hematogeneous spread are almost uncontrollable diseases, even in immunocompetent individuals.

  10. Environmental dimensionality controls the interaction of phagocytes with the pathogenic fungi Aspergillus fumigatus and Candida albicans.

    Directory of Open Access Journals (Sweden)

    Judith Behnsen

    2007-02-01

    Full Text Available The fungal pathogens Aspergillus fumigatus and Candida albicans are major health threats for immune-compromised patients. Normally, macrophages and neutrophil granulocytes phagocytose inhaled Aspergillus conidia in the two-dimensional (2-D environment of the alveolar lumen or Candida growing in tissue microabscesses, which are composed of a three-dimensional (3-D extracellular matrix. However, neither the cellular dynamics, the per-cell efficiency, the outcome of this interaction, nor the environmental impact on this process are known. Live imaging shows that the interaction of phagocytes with Aspergillus or Candida in 2-D liquid cultures or 3-D collagen environments is a dynamic process that includes phagocytosis, dragging, or the mere touching of fungal elements. Neutrophils and alveolar macrophages efficiently phagocytosed or dragged Aspergillus conidia in 2-D, while in 3-D their function was severely impaired. The reverse was found for phagocytosis of Candida. The phagocytosis rate was very low in 2-D, while in 3-D most neutrophils internalized multiple yeasts. In competitive assays, neutrophils primarily incorporated Aspergillus conidia in 2-D and Candida yeasts in 3-D despite frequent touching of the other pathogen. Thus, phagocytes show activity best in the environment where a pathogen is naturally encountered. This could explain why "delocalized" Aspergillus infections such as hematogeneous spread are almost uncontrollable diseases, even in immunocompetent individuals.

  11. Aspergillus alliaceus, a new potential biological control of the root parasitic weed Orobanche.

    Science.gov (United States)

    Aybeke, Mehmet; Sen, Burhan; Okten, Suzan

    2014-07-01

    During extensive surveys in fields heavily infested by broomrape in the Trakya Region-Turkey, a different new fungus, Aspergillus alliaceus, was isolated from the infected broomrape. It is aimed to investigate whether or not it is really a pathogen for Orobanche. The fungi was exposed to a greenhouse environment in order to assess its pathogenicity and virulence against Orobanche cernua. In addition, infection tests on Orobanche seeds were also performed under laboratory conditions. The fungus was subjected using two different methods, exposure to a liquid culture with conidial solution and a sclerotial solid culture with fungal mycelia. Cytological studies were carried out at light, TEM and SEM levels. The results show that the sclerotial solid culture with fungal mycelia quickly caused necrosis and was more effective than the other type. It also greatly diminished attachments, tubercles, and caused the emergence of shoots and an increase in the total shoot number of Orobanche. In addition, both when the fungi was exposed to both soil and used to contaminate sunflower seeds, its pathogenicity was more effective. Consequently, it was determined that A. alliaceus was an effective potential biological control of broomrape throughout its life cycle from dormant seed to mature plant. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Potential of Chitinolytic Serratia marcescens Strain JPP1 for Biological Control of Aspergillus parasiticus and Aflatoxin

    Directory of Open Access Journals (Sweden)

    Kai Wang

    2013-01-01

    Full Text Available Serratia marcescens strain JPP1 was isolated from peanut hulls in Huai'an city, Jiangsu Province, China. Its potential to inhibit the mycelial growth of Aspergillus parasiticus and the subsequent aflatoxin production was evaluated. The strain JPP1 could produce chitinase to degrade fungal cell walls, which was the main mechanism of strain JPP1 for biocontrol. Scanning electron microscopy of fungi treated with the crude chitinase revealed abnormal morphological changes. While the strain was grown in the peanut hulls-based medium, the chitinase activity reached 7.39 units. RT-PCR analysis showed that the crude chitinase repressed the transcription of genes involved in the aflatoxin gene cluster, such as aflR, aflC (pksL1, and aflO (dmtA genes. By visual agar plate assay and tip culture method, the strain JPP1 exhibited remarkable inhibitory effect on mycelia growth (antifungal ratio >95% and subsequent aflatoxin production (antiaflatoxigenic ratio >98%. An in vitro assay with seed coating agent of bacterial suspension showed that strain JPP1 effectively reduced fungal growth and subsequent aflatoxin production on peanut seeds, and its antagonistic effect was superior to the common agricultural fungicide of carbendazim. These characteristics suggest that S. marcescens JPP1 strain could potentially be utilized for the biological control of phytopathogenic fungi and aflatoxin in Chinese peanut main producing areas.

  13. Potential of chitinolytic Serratia marcescens strain JPP1 for biological control of Aspergillus parasiticus and aflatoxin.

    Science.gov (United States)

    Wang, Kai; Yan, Pei-Sheng; Cao, Li-Xin; Ding, Qing-Long; Shao, Chi; Zhao, Teng-Fei

    2013-01-01

    Serratia marcescens strain JPP1 was isolated from peanut hulls in Huai'an city, Jiangsu Province, China. Its potential to inhibit the mycelial growth of Aspergillus parasiticus and the subsequent aflatoxin production was evaluated. The strain JPP1 could produce chitinase to degrade fungal cell walls, which was the main mechanism of strain JPP1 for biocontrol. Scanning electron microscopy of fungi treated with the crude chitinase revealed abnormal morphological changes. While the strain was grown in the peanut hulls-based medium, the chitinase activity reached 7.39 units. RT-PCR analysis showed that the crude chitinase repressed the transcription of genes involved in the aflatoxin gene cluster, such as aflR, aflC (pksL1), and aflO (dmtA) genes. By visual agar plate assay and tip culture method, the strain JPP1 exhibited remarkable inhibitory effect on mycelia growth (antifungal ratio >95%) and subsequent aflatoxin production (antiaflatoxigenic ratio >98%). An in vitro assay with seed coating agent of bacterial suspension showed that strain JPP1 effectively reduced fungal growth and subsequent aflatoxin production on peanut seeds, and its antagonistic effect was superior to the common agricultural fungicide of carbendazim. These characteristics suggest that S. marcescens JPP1 strain could potentially be utilized for the biological control of phytopathogenic fungi and aflatoxin in Chinese peanut main producing areas.

  14. Biological Control of Meloidogyne incognita by Aspergillus niger F22 Producing Oxalic Acid.

    Science.gov (United States)

    Jang, Ja Yeong; Choi, Yong Ho; Shin, Teak Soo; Kim, Tae Hoon; Shin, Kee-Sun; Park, Hae Woong; Kim, Young Ho; Kim, Hun; Choi, Gyung Ja; Jang, Kyoung Soo; Cha, Byeongjin; Kim, In Seon; Myung, Eul Jae; Kim, Jin-Cheol

    2016-01-01

    Restricted usage of chemical nematicides has led to development of environmentally safe alternatives. A culture filtrate of Aspergillus niger F22 was highly active against Meloidogyne incognita with marked mortality of second-stage juveniles (J2s) and inhibition of egg hatching. The nematicidal component was identified as oxalic acid by organic acid analysis and gas chromatography-mass spectroscopy (GC-MS). Exposure to 2 mmol/L oxalic acid resulted in 100% juvenile mortality at 1 day after treatment and suppressed egg hatching by 95.6% at 7 days after treatment. Oxalic acid showed similar nematicidal activity against M. hapla, but was not highly toxic to Bursaphelenchus xylophilus. The fungus was incubated on solid medium and dried culture was used for preparation of a wettable powder-type (WP) formulation as an active ingredient. Two WP formulations, F22-WP10 (ai 10%) and oxalic acid-WP8 (ai 8%), were prepared using F22 solid culture and oxalic acid. In a field naturally infested with M. incognita, application of a mixture of F22-WP10 + oxalic acid-WP8 at 1,000- and 500-fold dilutions significantly reduced gall formation on the roots of watermelon plants by 58.8 and 70.7%, respectively, compared to the non-treated control. The disease control efficacy of the mixture of F22-WP10 + oxalic acid-WP8 was significantly higher than that of a chemical nematicide, Sunchungtan (ai 30% fosthiazate). These results suggest that A. niger F22 can be used as a microbial nematicide for the control of root-knot nematode disease.

  15. Biological Control of Meloidogyne incognita by Aspergillus niger F22 Producing Oxalic Acid.

    Directory of Open Access Journals (Sweden)

    Ja Yeong Jang

    Full Text Available Restricted usage of chemical nematicides has led to development of environmentally safe alternatives. A culture filtrate of Aspergillus niger F22 was highly active against Meloidogyne incognita with marked mortality of second-stage juveniles (J2s and inhibition of egg hatching. The nematicidal component was identified as oxalic acid by organic acid analysis and gas chromatography-mass spectroscopy (GC-MS. Exposure to 2 mmol/L oxalic acid resulted in 100% juvenile mortality at 1 day after treatment and suppressed egg hatching by 95.6% at 7 days after treatment. Oxalic acid showed similar nematicidal activity against M. hapla, but was not highly toxic to Bursaphelenchus xylophilus. The fungus was incubated on solid medium and dried culture was used for preparation of a wettable powder-type (WP formulation as an active ingredient. Two WP formulations, F22-WP10 (ai 10% and oxalic acid-WP8 (ai 8%, were prepared using F22 solid culture and oxalic acid. In a field naturally infested with M. incognita, application of a mixture of F22-WP10 + oxalic acid-WP8 at 1,000- and 500-fold dilutions significantly reduced gall formation on the roots of watermelon plants by 58.8 and 70.7%, respectively, compared to the non-treated control. The disease control efficacy of the mixture of F22-WP10 + oxalic acid-WP8 was significantly higher than that of a chemical nematicide, Sunchungtan (ai 30% fosthiazate. These results suggest that A. niger F22 can be used as a microbial nematicide for the control of root-knot nematode disease.

  16. The potential hazards of Aspergillus sp. in foods and feeds, and the role of biological treatment: a review.

    Science.gov (United States)

    Sheikh-Ali, Sheikh Imranudin; Ahmad, Akil; Mohd-Setapar, Siti-Hamidah; Zakaria, Zainul Akmal; Abdul-Talib, Norfahana; Khamis, Aidee Kamal; Hoque, Md Enamul

    2014-10-01

    The contamination of food and feed by Aspergillus has become a global issue with a significant worldwide economic impact. The growth of Aspergillus is unfavourable to the development of food and feed industries, where the problems happen mostly due to the presence of mycotoxins, which is a toxic metabolite secreted by most Aspergillus groups. Moreover, fungi can produce spores that cause diseases, such as allergies and asthma, especially to human beings. High temperature, high moisture, retarded crops, and poor food storage conditions encourage the growth of mold, as well as the development of mycotoxins. A variety of chemical, biological, and physical strategies have been developed to control the production of mycotoxins. A biological approach, using a mixed culture comprised of Saccharomyces cerevisiae and Lactobacillus rhamnosus resulted in the inhibition of the growth of fungi when inoculated into fermented food. The results reveal that the mixed culture has a higher potential (37.08%) to inhibit the growth of Aspergillus flavus (producer of Aflatoxin) compared to either single culture, L. rhamnosus NRRL B-442 and S. cerevisiae, which inhibit the growth by 63.07% and 64.24%, respectively.

  17. Suppression of Aspergillus by Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib

    Objectives: Cystic fibrosis patients are commonly infected by Pseudomonas aeruginosa, but Aspergilli are also frequently isolated. Our aim was to examine the possible interaction between P. aeruginosa and different Aspergillus. Methods: A suspension of 106 fungal spores/ml was streaked onto WATM......, here among 2-heptyl-3-hydroxy-4-quinolone (PQS). An unidentified green pseudomonas compound was also observed. Interestingly the P. aeruginosa mutant rpoN was unable to suppress A. fumigatus, but suppressed A. flavus, A. oryzae and A. niger. However several other P. aeruginosa mutants suppressed A....... fumigatus including flif, pilA, lasR, PVDA, PQSC and rhlA mutants indicating that phenazines may be involved in the suppressed growth of A. fumigatus. All pseudomonas mutants suppressed A. oryzae, A. niger and A. flavus. Conclusions: An increase in phenazine production by P. aeruginosa may contribute...

  18. Regulation and control of L-arabinose catabolism in Aspergillus niger

    NARCIS (Netherlands)

    Groot, de M.J.L.

    2005-01-01

    This thesis describes studies on the biochemical properties and regulation of L-arabinose metabolism and arabinan degrading enzymes of Aspergillus niger. We focused on the investigation of the catabolic pathway, firstly by isolating pathway specific regulatory mutants using a newly developed

  19. Identification of a Transcription Factor Controlling pH-Dependent Organic Acid Response in Aspergillus niger

    DEFF Research Database (Denmark)

    Poulsen, Lars; Andersen, Mikael Rørdam; Lantz, Anna Eliasson

    2012-01-01

    Acid formation in Aspergillus niger is known to be subjected to tight regulation, and the acid production profiles are fine-tuned to respond to the ambient pH. Based on transcriptome data, putative trans-acting pH responding transcription factors were listed and through knock out studies, mutants...

  20. Use of Epidemiological Cutoff Values To Examine 9-Year Trends in Susceptibility of Aspergillus Species to the Triazoles▿

    Science.gov (United States)

    Pfaller, M.; Boyken, L.; Hollis, R.; Kroeger, J.; Messer, S.; Tendolkar, S.; Diekema, D.

    2011-01-01

    In the absence of clinical breakpoints, epidemiological cutoff values (ECVs) have been established to distinguish wild-type (WT) isolates of Aspergillus spp. from those that may harbor resistance mutations. Recently, the CLSI has developed ECVs for triazoles (itraconazole, posaconazole, and voriconazole) and common Aspergillus species. We applied the triazole ECVs to 1,789 Aspergillus isolates collected from 63 centers worldwide from 2001 to 2009 to determine the frequency of non-WT strains of each species. Temporal trends were evaluated for Aspergillus fumigatus and Aspergillus flavus over the 9-year period for each drug. The collection included 1,312 isolates of A. fumigatus, 235 of A. flavus, 162 of Aspergillus niger, 64 of Aspergillus terreus, and 15 of Aspergillus versicolor. Using the ECVs, the percentages of non-WT isolates for itraconazole, posaconazole, and voriconazole, respectively, were as follows: A. fumigatus (2.0%, 3.5%, and 1.4%), A. flavus (0.8%, 5.1%, and 1.7%), A. niger (17.3%, 3.7%, and 0.6%), A. terreus (0.0%, 1.6%, and 3.2%), and A. versicolor (6.3%, 0.0%, and 0.0%). Among 49 Aspergillus isolates for which itraconazole MICs were >2 μg/ml, the posaconazole and voriconazole MICs were greater than the ECVs for 14 and 12 isolates, respectively. The percentages of isolates for which MICs were greater than the ECVs ranged from 1.1 to 5.7% for posaconazole, 0.0 to 1.6% for voriconazole, and 0.7 to 4.0% for itraconazole. There was no consistent trend toward decreased susceptibility for any triazole and A. fumigatus or A. flavus over time. Decreased susceptibility among Aspergillus spp. was observed for each of the extended-spectrum triazoles and varied by species over the 9-year study period. PMID:21123534

  1. Inhibition of citric acid accumulation by manganese ions in Aspergillus niger mutants with reduced citrate control of phosphofructokinase

    Energy Technology Data Exchange (ETDEWEB)

    Schreferl, G.; Kubicek, C.P.; Roehr, M.

    1986-03-01

    Mutant strains of Aspergillus niger with reduced citrate control of carbohydrate catabolism (cic mutants) grow faster than the parent strain on media containing 5% (wt/vol) citrate. The mutants tolerated a higher intracellular citrate concentration than the parent strain. One mutant (cic-7/3) contained phosphofructokinase activity significantly less sensitive towards citrate than the enzyme from the parent strain. When this mutant was grown under citrate accumulating conditions, acidogenesis was far less sensitive to inhibition by Mn/sup 2 +/ than in the parent strain. Some of the cic mutants also showed altered citrate inhibition of NADP-specific isocitrate dehydrogenase.

  2. A possible mechanism to control the spread and growth of facultative marine fungus Aspergillus niger using magnetic fluid

    Science.gov (United States)

    Vala, A. K.; Desai, R.; Upadhyay, R. V.; Mehta, R. V.

    2008-12-01

    Interaction of facultative marine fungus Aspergillus niger with a Mn-Zn ferrite magnetic fluid (MF) has been studied. The fungus exhibited a luxuriant growth in the presence of magnetic fluid at test concentrations. Though the biomass accumulation was found to be almost similar, mycelial spread was found to be rapid in the presence of MF if compared to the control one. The MF also exhibited a positive effect on the biomass accumulation during prolonged incubation. These preliminary observations provide a baseline information for possible exploitation of the magnetic fluid-facultative marine fungal interaction for bioremediation purposes. Figs 5, Refs 13.

  3. Transcriptomic and proteomic analyses of the Aspergillus fumigatus hypoxia response using an oxygen-controlled fermenter

    Directory of Open Access Journals (Sweden)

    Barker Bridget M

    2012-02-01

    Full Text Available Abstract Background Aspergillus fumigatus is a mold responsible for the majority of cases of aspergillosis in humans. To survive in the human body, A. fumigatus must adapt to microenvironments that are often characterized by low nutrient and oxygen availability. Recent research suggests that the ability of A. fumigatus and other pathogenic fungi to adapt to hypoxia contributes to their virulence. However, molecular mechanisms of A. fumigatus hypoxia adaptation are poorly understood. Thus, to better understand how A. fumigatus adapts to hypoxic microenvironments found in vivo during human fungal pathogenesis, the dynamic changes of the fungal transcriptome and proteome in hypoxia were investigated over a period of 24 hours utilizing an oxygen-controlled fermenter system. Results Significant increases in transcripts associated with iron and sterol metabolism, the cell wall, the GABA shunt, and transcriptional regulators were observed in response to hypoxia. A concomitant reduction in transcripts was observed with ribosome and terpenoid backbone biosynthesis, TCA cycle, amino acid metabolism and RNA degradation. Analysis of changes in transcription factor mRNA abundance shows that hypoxia induces significant positive and negative changes that may be important for regulating the hypoxia response in this pathogenic mold. Growth in hypoxia resulted in changes in the protein levels of several glycolytic enzymes, but these changes were not always reflected by the corresponding transcriptional profiling data. However, a good correlation overall (R2 = 0.2, p A. fumigatus. Conclusions Taken together, our data suggest a robust cellular response that is likely regulated both at the transcriptional and post-transcriptional level in response to hypoxia by the human pathogenic mold A. fumigatus. As with other pathogenic fungi, the induction of glycolysis and transcriptional down-regulation of the TCA cycle and oxidative phosphorylation appear to major

  4. Biosynthesis and Characterization of Silver Nanoparticles by Aspergillus Species

    OpenAIRE

    Zomorodian, Kamiar; Pourshahid, Seyedmohammad; Sadatsharifi, Arman; Mehryar, Pouyan; Pakshir, Keyvan; Rahimi, Mohammad Javad; Arabi Monfared, Ali

    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 ...

  5. Aspergillus vegetative endocarditis and complete heart block in a patient with acute leukemia.

    Science.gov (United States)

    Mikulski, S M; Love, L J; Bergquist, E J; Hargadon, M T; Applefeld, M M; Mergner, W

    1979-10-01

    Aspergillus flavus vegetative endocarditis together with myocardial abscesses and pneumonitis developed in a patient with acute lymphocytic leukemia. The initial diagnosis was not suspected until 67gallium imaging revealed a radiographically undetectable thoracic abnormality. Despite apparently "early" diagnosis, antifungal therapy was inadequate to prevent disruption of the bundle of His, complete heart block and death.

  6. Effects of biological control of rice weevil by Anisopteromalus calandrae with a population of two Aspergillus spp.

    Science.gov (United States)

    Yoon, Eun Young; Nam, Youngwoo; Ryoo, Mun Il

    2009-02-01

    In this study, we assessed the interaction occurring between the rice weevil and two storage molds (Aspergillus candidus Link and Aspergillus niger Van Tiegem) that prefer different moisture regimens under rice storage conditions. Rice weevil induced rapid population growth in both of the storage molds. The colony forming units (CFUs) of A. candidus and A. niger peaked at 10(9.00 +/- 0.02) and 10(7.72 +/- 0.03)/g, respectively. All of the rice grains were infested with the molds and eventually deteriorated; in the jars infested with A. candidus, no living weevils were found after 135 d. Suppression of the rice weevil by its larval parasitoid, Anisopteromalus calandrae (Howard), significantly retarded the growth of A. candidus but completely halted the growth of A. niger, which was replaced by xerophyllic molds including Aspergillus penicilloides Spegazzini and Wallemia sebi (Fries). Regression analyses showed that the total number of weevils was a significant factor explaining grain moisture content, which was in turn a significant factor in the growth of both mold species. The growth of A. niger was dependent on the grain moisture content (r2 = 0.52), thereby suggesting that the growth of A. niger was caused primarily by activity of the rice weevil and the resulting increased grain moisture content. However, 27% of the growth of A. candidus was explained by grain moisture contents, suggesting that a factor other than the grain moisture content may also affect its growth. Suppression of rice weevil by A. calandrae could induce an A. candidus-dominant molds community, which would be a factor for consideration in biological control program.

  7. Aspergillus triggers phenazine production in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib

    Objectives: Pseudomonas aeruginosa is an opportunistic human pathogen, commonly infecting cystic fibrosis (CF) patients. Aspergilli, especially Aspergillus fumigatus, are also frequently isolated from CF patients. Our aim was to examine the possible interaction between P. aeruginosa and different...... in the contact area of A. niger, A. flavus, A. oryzae, but not A. fumigatus. In addition, other metabolites with UV chromophores similar to the phenazines were only found in the contact zone between Aspergillus and Pseudomonas. No change in secondary metabolite profiles were seen for the Aspergilli, when...... comparing with or without the presence of Pseudomonas. Conclusion: All Aspergilli tested, with the exception of A. fumigatus, triggered the upregulation of phenazine-1-carboxamide and phenazine-1-carboxylic acid production by P. aeruginosa. Surprisingly no changes in secondary metabolite profiles were...

  8. Control of reactive oxygen species (ROS production through histidine kinases in Aspergillus nidulans under different growth conditions

    Directory of Open Access Journals (Sweden)

    Saki Hayashi

    2014-01-01

    Full Text Available Sensor histidine kinases (HKs are important factors that control cellular growth in response to environmental conditions. The expression of 15 HKs from Aspergillus nidulans was analyzed by quantitative real-time PCR under vegetative, asexual, and sexual growth conditions. Most HKs were highly expressed during asexual growth. All HK gene-disrupted strains produced reactive oxygen species (ROS. Three HKs are involved in the control of ROS: HysA was the most abundant under the restricted oxygen condition, NikA is involved in fungicide sensing, and FphA inhibits sexual development in response to red light. Phosphotransfer signal transduction via HysA is essential for ROS production control.

  9. DOSES DE EXTRATO DE PRÓPOLIS NO CONTROLE DO FUNGO Aspergillus sp E NO TRATAMENTO DE SEMENTES DE PEPINO / EXTRACT OF PROPOLIS IN THE TREATMENT OF CUCUMBER SEEDS AND CONTROL OF Aspergillus sp

    Directory of Open Access Journals (Sweden)

    E.P. de Souza

    2017-12-01

    Full Text Available The alternative control has as characteristics the absence of contamination and social and environmental toxicity, and an alternative is the extract of propolis, which objectified with this work verify the effect of solutions of propolis extract in vitro control of the fungus Aspergillus sp, and the physiological quality of the cucumber seeds after treatment with the same solutions. Isolate from the fungus was inoculated in BDA medium with concentrations of 0; 8; 12; 18 and 25% of aqueous Propamax® extract, totaling five treatments. For the seed treatment, were used the same concentrations of propolis extract. The design was completely randomized with six replicates. It was verified that with the linear increase of the dose of the propolis extract, there was interference in the fungus development reaching maximum with 25%. Cucumber seeds treated with propolis solutions do not affect the physiological quality, resulting in a possible alternative seed treatment.

  10. Effect of Essential Oils of Syzygium aromaticum and Melaleuca alternifolia on Isolates of Aspergillus sp.

    Directory of Open Access Journals (Sweden)

    A. Lima

    2014-03-01

    Full Text Available Essential  oils  have  antimicrobial  substances,  lower  cost  and  the  lower  resistance  of microorganism. This study aimed to evaluate the inhibition of mycelial growth of Aspergillus flavus and  A.  niger  with  essential  oils  of  Syzygium  aromaticum  and  Melaleuca  alternifolia.  For  this, aliquots  (0.5,  5,  10  and  15μL  of  essential  oils  from  S.  aromaticum  and  M.  alternifolia   were distributed on the surface of the culture medium Potato Dextrose Agar (PDA with Drigaslsky. In the control treatment were used only plates containing PDA plus chloramphenicol (1%. After 2 hours, a disc (8mm diameter of the isolated mycelium, with 10 days of age on PDA, was peaked to the center of the plates, these plates were sealed and incubated at 282°C, in the dark. The essential  oil  of  S.  aromaticum  inhibited  the  mycelial  growth  of  A.  flavus  and  A.  niger,  in  all aliquots. When using the essential oil of M. alternifolia decreased the mycelial growth of A. flavus in all aliquots, however, showed a low efficiency in control of A. niger. It was concluded that the essential  oil  S.  aromaticum  is  effective  against  A.  flavus  and  A.  niger,  which  can  be  used  in control against these microorganisms, and M. alternifolia not show satisfactory results in relation to reducing the growth of pathogens evaluated.

  11. 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.

  12. Metabolomics Analysis Reveals Specific Novel Tetrapeptide and Potential Anti-Inflammatory Metabolites in Pathogenic Aspergillus species

    Directory of Open Access Journals (Sweden)

    Kim-Chung Lee

    2015-06-01

    Full Text Available Infections related to Aspergillus species have emerged to become an important focus in infectious diseases, as a result of the increasing use of immunosuppressive agents and high fatality associated with invasive aspergillosis. However, laboratory diagnosis of Aspergillus infections remains difficult. In this study, by comparing the metabolomic profiles of the culture supernatants of 30 strains of six pathogenic Aspergillus species (A. fumigatus, A. flavus, A. niger, A. terreus, A. nomius and A. tamarii and 31 strains of 10 non-Aspergillus fungi, eight compounds present in all strains of the six Aspergillus species but not in any strain of the non-Aspergillus fungi were observed. One of the eight compounds, Leu–Glu–Leu–Glu, is a novel tetrapeptide and represents the first linear tetrapeptide observed in Aspergillus species, which we propose to be named aspergitide. Two other closely related Aspergillus-specific compounds, hydroxy-(sulfooxybenzoic acid and (sulfooxybenzoic acid, may possess anti-inflammatory properties, as 2-(sulfooxybenzoic acid possesses a structure similar to those of aspirin [2-(acetoxybenzoic acid] and salicylic acid (2-hydroxybenzoic acid. Further studies to examine the potentials of these Aspergillus-specific compounds for laboratory diagnosis of aspergillosis are warranted and further experiments will reveal whether Leu–Glu–Leu–Glu, hydroxy-(sulfooxybenzoic acid and (sulfooxybenzoic acid are virulent factors of the pathogenic Aspergillus species.

  13. Isolation of Aspergillus species from Nasal Cavity and Bedroom of Healthy Volunteers and Patients with Allergic Rhinitis in Mashhad, Iran

    Directory of Open Access Journals (Sweden)

    Samaneh Eidi

    2014-12-01

    Full Text Available Background: The purpose of this study was to investigate the presence, frequency and comparison of Aspergillus spp. in nasal cavity and bedroom of healthy volunteers and patients with allergic rhinitis. Materials and Methods: In this cross-sectional study, a group of patients with allergic rhinitis (N=50 were selected based on positive skin prick test. Healthy volunteers were chosen to be in the comparison group by matching in age, gender, and no history of respiratory system disease. Samples from nasal cavity and different parts of bedroom were collected and cultured. Cultured Aspergillus spp. was identified by standard mycological techniques. Results: The most common species isolated from all samples of healthy volunteers was A. flavus (88%, followed by A. niger (76% and A. fumigatus (74%. A. flavus (56% was the predominant species isolated from all samples of patients, followed by A. niger (34% and A. fumigatus (6%. Conclusion: A. flavus was the most prevalent species of Aspergillus both healthy volunteers and patients. The presence of Aspergillus in homes does not necessarily imply a cause and effect relationship with illness, but we speculate that A. flavus may be a major source of aeroallergens along with A. niger and A. fumigatus; and should alert physicians and healthcare professionals to do more vigorous environmental testing.

  14. Comparison of different inoculating methods to evaluate the pathogenicity and virulence of Aspergillus niger on two maize hybrids

    Science.gov (United States)

    A two-year field study was conducted to determine the effects of inoculation techniques on the aggressiveness of Aspergillus niger kernel infection in A. flavus resistant and susceptible maize hybrids. Ears were inoculated with the silk-channel, side-needle, and spray techniques 7 days after midsilk...

  15. Chicken single-chain antibody fused to alkaline phosphatase detects Aspergillus pathogens and their presence in natural samples by direct sandwich enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Xue, Sheng; Li, He-Ping; Zhang, Jing-Bo; Liu, Jin-Long; Hu, Zu-Quan; Gong, An-Dong; Huang, Tao; Liao, Yu-Cai

    2013-11-19

    A sensitive and specific analytical method to detect ubiquitous aflatoxigenic Aspergillus pathogens is essential for monitoring and controlling aflatoxins. Four highly reactive chicken single-chain variable fragments (scFvs) against soluble cell wall proteins (SCWPs) from Aspergillus flavus were isolated by phage display. The scFv antibody AfSA4 displayed the highest activity toward both A. flavus and A. parasiticus and specifically recognized a surface target of their cell walls as revealed by immunofluorescence localization. Molecular modeling revealed a unique compact motif on the antibody surface mainly involving L-CDR2 and H-CDR3. As measured by surface plasmon resonance, AfSA4 fused to alkaline phosphatase had a higher binding capability and 6-fold higher affinity compared with AfSA4 alone. Immunoblot analyses showed that the fusion had good binding capacity to SCWP components from the two fungal species. Direct sandwich enzyme-linked immunosorbent assays with mouse antiaspergillus monoclonal antibody mAb2A8 generated in parallel as a capture antibody revealed that the detection limit of the two fungi was as low as 10(-3) μg/mL, 1000-fold more sensitive than that reported previously (1 μg/mL). The fusion protein was able to detect fungal concentrations below 1 μg/g of maize and peanut grains in both artificially and naturally contaminated samples, with at least 10-fold more sensitivity than that reported (10 μg/g) thus far. Thus, the fusion can be applied in rapid, simple, and specific diagnosis of Aspergillus contamination in field and stored food/feed commodities.

  16. Aflatoxin-producing Aspergillus spp. and aflatoxin levels in stored cassava chips as affected by processing practices

    DEFF Research Database (Denmark)

    Essono, G.; Ayodele, M.; Akoa, A.

    2009-01-01

    two months and contaminated by a wide array of harmful microbes. In order to assess persistence of toxigenic fungi in cassava chips, aflatoxin-producing fungi (Aspergillus flavus, Aspergillus nomius, and Aspergillus parasiticus) and aflatoxins were contrasted at regular intervals in home....... The levels of aflatoxin ranged between 5.2 and 14.5 ppb. The distribution of aflatoxin in positive samples depended on 8 parameters including pH, moisture content, storage duration, types of chips, level of contamination by aflatoxin-producing fungi, processing practices and storage facilities. From analysis...... significantly (p practices, storage facilities, and storage duration of the chips....

  17. Control of Acid Phosphatases Expression from Aspergillus niger by Soil Characteristics

    Directory of Open Access Journals (Sweden)

    Ely Nahas

    2015-10-01

    Full Text Available ABSTRACTThis work studied the acid phosphatase (APase activity from culture medium (extracellular, eAPase and mycelial extract (intracellular, iAPase ofAspergillus niger F111. The influence of fungus growth and phosphate concentration of the media on the synthesis and secretion of phosphatase was demonstrated. The effects of pH, substrate concentration and inorganic and organic compounds added to the reaction mixture on APase activity were also studied. Both enzymes were repressed by high concentrations of phosphate. Overexpression of iAPase in relation to eAPase was detected; iAPase activity was 46.1 times higher than eAPase. The maximal activity of eAPase was after 24h of fungus growth and for iAPase was after 96h. Optimal pH and substrate concentrations were 4.5 and 8.0 mM, respectively. Michaelis-Menten constant (Km for the hydrolysis of p-nitrophenyl phosphate was 0.57 mM with Vmax = 14,285.71 U mg-1 mycelium for the iAPase and 0.31 mM with V max = 147.06 U mg-1 mycelium for eAPase. Organic substances had little effect on acid phosphatases when compared with the salts. Both the APases were inhibited by 10 mM KH 2PO4 and 5 mM (NH42MoO4; eAPase was also inhibited by 1 mM CoCl2.

  18. Identification of a transcription factor controlling pH-dependent organic acid response in Aspergillus niger.

    Directory of Open Access Journals (Sweden)

    Lars Poulsen

    Full Text Available Acid formation in Aspergillus niger is known to be subjected to tight regulation, and the acid production profiles are fine-tuned to respond to the ambient pH. Based on transcriptome data, putative trans-acting pH responding transcription factors were listed and through knock out studies, mutants exhibiting an oxalate overproducing phenotype were identified. The yield of oxalate was increased up to 158% compared to the wild type and the corresponding transcription factor was therefore entitled Oxalic Acid repression Factor, OafA. Detailed physiological characterization of one of the ΔoafA mutants, compared to the wild type, showed that both strains produced substantial amounts of gluconic acid, but the mutant strain was more efficient in re-uptake of gluconic acid and converting it to oxalic acid, particularly at high pH (pH 5.0. Transcriptional profiles showed that 241 genes were differentially expressed due to the deletion of oafA and this supported the argument of OafA being a trans-acting transcription factor. Furthermore, expression of two phosphoketolases was down-regulated in the ΔoafA mutant, one of which has not previously been described in fungi. It was argued that the observed oxalate overproducing phenotype was a consequence of the efficient re-uptake of gluconic acid and thereby a higher flux through glycolysis. This results in a lower flux through the pentose phosphate pathway, demonstrated by the down-regulation of the phosphoketolases. Finally, the physiological data, in terms of the specific oxygen consumption, indicated a connection between the oxidative phosphorylation and oxalate production and this was further substantiated through transcription analysis.

  19. Aspergillus on tree nuts: incidence and associations.

    Science.gov (United States)

    Bayman, Paul; Baker, James L; Mahoney, Noreen E

    2002-01-01

    California exports tree nuts to countries where they face stringent standards for aflatoxin contamination. Trade concerns have stimulated efforts to eliminate aflatoxins and Aspergillus flavus from almonds, pistachios and walnuts. Incidence of fungi on tree nuts and associations among fungi on tree nuts were studied. Eleven hundred pistachios, almonds, walnuts and brazil nuts without visible insect damage were plated on salt agar and observed for growth of fungi. Samples came both from California nut orchards and from supermarkets. To distinguish internal fungal colonization of nuts from superficial colonization, half the nuts were surface-sterilized before plating. The most common genera found were Aspergillus, Rhizopus and Penicillium. Each species of nut had a distinct mycoflora. Populations of most fungi were reduced by surface sterilization in all except brazil nuts, suggesting that they were present as superficial inoculum on (rather than in) the nuts. In general, strongly positive associations were observed among species of Aspergillus; nuts infected by one species were likely to be colonized by other species as well. Presence of Penicillium was negatively associated with A. niger and Rhizopus in some cases. Results suggest that harvest or postharvest handling has a major influence on nut mycoflora, and that nuts with fungi are usually colonized by several fungi rather than by single species.

  20. Controlled Synthesis of Gold Nanoparticles Using Aspergillus terreus IF0 and Its Antibacterial Potential against Gram Negative Pathogenic Bacteria

    International Nuclear Information System (INIS)

    Priyadarshini, E.; Pradhan, N.; Sukla, L.B.; Panda, P.K.; Pradhan, N.

    2014-01-01

    Biosynthesis of monodispersed nanoparticles, along with determination of potential responsible biomolecules, is the major bottleneck in the area of bio nano technology research. The present study focuses on an eco friendly, ambient temperature protocol for size controlled synthesis of gold nanoparticles, using the fungus Aspergillus terreus IF0. Gold nanoparticles were formed immediately, with the addition of chloroauric acid to the aqueous fungal extract. Synthesized nanoparticles were characterized by UV-Vis spectroscopy, TEM-EDX, and XRD analysis. Particle diameter and dispersity of nanoparticles were controlled by varying the ph of the fungal extract. At ph 10, the average size of the synthesized particles was in the range of 10–19 nm. Dialysis to obtain high and low molecular weight fraction followed by FTIR analysis revealed that biomolecules larger than 12 kDa and having –CH, –NH, and –SH functional groups were responsible for bioreduction and stabilization. In addition, the synthesized gold nanoparticles were found to be selectively bactericidal against the pathogenic gram negative bacteria, Escherichia coli.

  1. In vitro activity of disinfectants against Aspergillus spp

    Directory of Open Access Journals (Sweden)

    A.S. Mattei

    2013-01-01

    Full Text Available Fungi of the Aspergillus genus are widespread and contaminate the environment. Thousands of conidia are released from each phialide and dispersed in the air every day. These fungi are considered important mycose-causing agents in hospitals. Due to this, research to determine prevalent fungi from the Aspergillus genus in hospital environments, and an adequate disinfection program in these areas is are needed. This study evaluated the susceptibility of Aspergillus spp. isolated from a veterinary environment against four disinfectants. Successive dilutions of disinfectants (log2 were used according to CLSI M38-A2 microdilution technique adapted to chemical agents against 18 isolates of this genus. After 72 hours of incubation, the Minimum Inhibiting Concentration and Minimum Fungicidal Concentration capable of inhibiting 50% and 90% of the isolates were determined. Chlorexidine-cetrimine, benzalconium chloride and a chlorophenol derivative proved to be effective against all isolates with a lower MIC than that suggested by the manufacturer, except for the A. flavus strain. Sodium hypochlorite was ineffective against three A. fumigatus, three A. flavus and one A. niger isolate. These results demonstrated that all studied disinfectants were effective against environmental isolates, with the exception of sodium hypochlorite, which showed lower effectiveness.

  2. Biosynthesis and Characterization of Silver Nanoparticles by Aspergillus Species

    Directory of Open Access Journals (Sweden)

    Kamiar Zomorodian

    2016-01-01

    Full Text Available 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 the biosynthesis of silver nanoparticles. The formation of silver nanoparticles in the cell filtrates was confirmed by the passage of laser light, change in the color of cell filtrates, absorption peak at 430 nm in UV-Vis spectra, and atomic force microscopy (AFM. There was a logical relationship between the efficiencies of studied Aspergillus species in the production of silver nanoparticles and their nitrate reductase activity. A. fumigatus as the most efficient species showed the highest nitrate reductase activity among the studied species while A. flavus exhibited the lowest capacity in the biosynthesis of silver nanoparticles which was in accord with its low nitrate reductase activity. The present study showed that Aspergillus species had potential for the biosynthesis of silver nanoparticles depending on their nitrate reductase activity.

  3. Biosynthesis and Characterization of Silver Nanoparticles by Aspergillus Species

    Science.gov (United States)

    Pourshahid, Seyedmohammad; Mehryar, Pouyan; Pakshir, Keyvan; Rahimi, Mohammad Javad; Arabi Monfared, Ali

    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 the biosynthesis of silver nanoparticles. The formation of silver nanoparticles in the cell filtrates was confirmed by the passage of laser light, change in the color of cell filtrates, absorption peak at 430 nm in UV-Vis spectra, and atomic force microscopy (AFM). There was a logical relationship between the efficiencies of studied Aspergillus species in the production of silver nanoparticles and their nitrate reductase activity. A. fumigatus as the most efficient species showed the highest nitrate reductase activity among the studied species while A. flavus exhibited the lowest capacity in the biosynthesis of silver nanoparticles which was in accord with its low nitrate reductase activity. The present study showed that Aspergillus species had potential for the biosynthesis of silver nanoparticles depending on their nitrate reductase activity. PMID:27652264

  4. Biosynthesis and Characterization of Silver Nanoparticles by Aspergillus Species.

    Science.gov (United States)

    Zomorodian, Kamiar; Pourshahid, Seyedmohammad; Sadatsharifi, Arman; Mehryar, Pouyan; Pakshir, Keyvan; Rahimi, Mohammad Javad; Arabi Monfared, Ali

    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 the biosynthesis of silver nanoparticles. The formation of silver nanoparticles in the cell filtrates was confirmed by the passage of laser light, change in the color of cell filtrates, absorption peak at 430 nm in UV-Vis spectra, and atomic force microscopy (AFM). There was a logical relationship between the efficiencies of studied Aspergillus species in the production of silver nanoparticles and their nitrate reductase activity. A. fumigatus as the most efficient species showed the highest nitrate reductase activity among the studied species while A. flavus exhibited the lowest capacity in the biosynthesis of silver nanoparticles which was in accord with its low nitrate reductase activity. The present study showed that Aspergillus species had potential for the biosynthesis of silver nanoparticles depending on their nitrate reductase activity.

  5. X-ray based irradiation of navel orangeworm for sterile insect control

    Science.gov (United States)

    The navel orangeworm (NOW) is a pest of California tree nuts, including almonds, pistachios, and walnuts. NOW damage is also correlated with infection by Aspergillus flavus and subsequent mycotoxin contamination, primarily aflatoxins. These potential carcinogens / animal toxins are strictly regulate...

  6. Aspergillus niger: an unusual cause of invasive pulmonary aspergillosis

    Science.gov (United States)

    Person, A. K.; Chudgar, S. M.; Norton, B. L.; Tong, B. C.; Stout, J. E.

    2010-01-01

    Infections due to Aspergillus species cause significant morbidity and mortality. Most are attributed to Aspergillus fumigatus, followed by Aspergillus flavus and Aspergillus terreus. Aspergillus niger is a mould that is rarely reported as a cause of pneumonia. A 72-year-old female with chronic obstructive pulmonary disease and temporal arteritis being treated with steroids long term presented with haemoptysis and pleuritic chest pain. Chest radiography revealed areas of heterogeneous consolidation with cavitation in the right upper lobe of the lung. Induced bacterial sputum cultures, and acid-fast smears and cultures were negative. Fungal sputum cultures grew A. niger. The patient clinically improved on a combination therapy of empiric antibacterials and voriconazole, followed by voriconazole monotherapy. After 4 weeks of voriconazole therapy, however, repeat chest computed tomography scanning showed a significant progression of the infection and near-complete necrosis of the right upper lobe of the lung. Serum voriconazole levels were low–normal (1.0 μg ml−1, normal range for the assay 0.5–6.0 μg ml−1). A. niger was again recovered from bronchoalveolar lavage specimens. A right upper lobectomy was performed, and lung tissue cultures grew A. niger. Furthermore, the lung histopathology showed acute and organizing pneumonia, fungal hyphae and oxalate crystallosis, confirming the diagnosis of invasive A. niger infection. A. niger, unlike A. fumigatus and A. flavus, is less commonly considered a cause of invasive aspergillosis (IA). The finding of calcium oxalate crystals in histopathology specimens is classic for A. niger infection and can be helpful in making a diagnosis even in the absence of conidia. Therapeutic drug monitoring may be useful in optimizing the treatment of IA given the wide variations in the oral bioavailability of voriconazole. PMID:20299503

  7. Genetic control of chromosome instability in Aspergillus nidulans as a means for gene amplification in eukaryotic microorganisms

    International Nuclear Information System (INIS)

    Parag, Y.; Roper, J.A.

    1975-01-01

    A haploid strain of Aspergillus nidulans carrying I-II duplication homozygous for the leaky mutation adE20 shows improved growth on minimal medium. The duplication, though more stable than disomics, still shows instability. Several methods were used for detecting genetic control of improved stability. a) visual selection, using a duplicated strain which is very unstable due to UV sensitivity, (adE20, biAl/dp yA2; uvsB). One stable strain showed a deletion (or a lethal mutation) distal to biA on the segment at the original position (on chromosome I). This deletion reduces crossing-over frequency detween the two homologous segments. As the deletion of the non-translated segment (yellow sectors) must be preceded by crossing-over, the above reduces the frequency of yellow sectors. A deletion of the translocated segment (green sectors) results in non-viability due to the deletion, and such sectors do not appear. The net result is a stable duplication involving only 12 C.O. units carrying the gene in concern. b) Suppressors of UV sensitivity (su-uvsB) were attempted using the above uvs duplicated strain. Phenotypic revertants were easily obtained, but all were back mutations at the uvsB locus. c) Mutations for UV resistance higher than that of the wild type were not obtained, in spite of the strong selective pressure inserted. d) Recombination deficient mutations (rec), six altogether, all uvs + , did not have any effect on stability. (orig.) [de

  8. Molecular identification and amphotericin B susceptibility testing of clinical isolates of Aspergillus from 11 hospitals in Korea.

    Science.gov (United States)

    Heo, Min Seok; Shin, Jong Hee; Choi, Min Ji; Park, Yeon Joon; Lee, Hye Soo; Koo, Sun Hoe; Lee, Won Gil; Kim, Soo Hyun; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook

    2015-11-01

    We investigated the species distribution and amphotericin B (AMB) susceptibility of Korean clinical Aspergillus isolates by using two Etests and the CLSI broth microdilution method. A total of 136 Aspergillus isolates obtained from 11 university hospitals were identified by sequencing the internal transcribed spacer (ITS) and β-tubulin genomic regions. Minimal inhibitory concentrations (MICs) of AMB were determined in Etests using Mueller-Hinton agar (Etest-MH) and RPMI agar (Etest-RPG), and categorical agreement with the CLSI method was assessed by using epidemiological cutoff values. ITS sequencing identified the following six Aspergillus species complexes: Aspergillus fumigatus (42.6% of the isolates), A. niger (23.5%), A. flavus (17.6%), A. terreus (11.0%), A. versicolor (4.4%), and A. ustus (0.7%). Cryptic species identifiable by β-tubulin sequencing accounted for 25.7% (35/136) of the isolates. Of all 136 isolates, 36 (26.5%) had AMB MICs of ≥2 μg/mL by the CLSI method. The categorical agreement of Etest-RPG with the CLSI method was 98% for the A. fumigatus, A. niger, and A. versicolor complexes, 87% for the A. terreus complex, and 37.5% for the A. flavus complex. That of Etest-MH was ≤75% for the A. niger, A. flavus, A. terreus, and A. versicolor complexes but was higher for the A. fumigatus complex (98.3%). Aspergillus species other than A. fumigatus constitute about 60% of clinical Aspergillus isolates, and reduced AMB susceptibility is common among clinical isolates of Aspergillus in Korea. Molecular identification and AMB susceptibility testing by Etest-RPG may be useful for characterizing Aspergillus isolates of clinical relevance.

  9. In vivo and in vitro control activity of plant essential oils against three strains of Aspergillus niger.

    Science.gov (United States)

    Kumar, Peeyush; Mishra, Sapna; Kumar, Atul; Kumar, Sanjeev; Prasad, Chandra Shekhar

    2017-09-01

    Contamination of environment and food from the prevalent spores and mycotoxins of Aspergillus niger has led to several diseases in humans and other animals. The present study investigated the control activity of plant essential oils against three strains of A. niger. In the elaborate assays done through microdilution plate assay and agar disk diffusion assay in the lab condition and in vivo assay on the stored wheat grains, the essential oil of Thymus vulgaris depicted overall superior efficacy. In microdilution plate assay, the oil of Anethum graveolens showed best fungistatic activity, while best fungicidal activity was depicted by Syzygium aromaticum oil. The oil of T. vulgaris showed moderate control efficacy against A. niger strains with its antifungal activity resulting mainly due to killing of microorganism rather than growth inhibition. In agar disk diffusion assay, T. vulgaris oil with a zone of inhibition (ZOI) of 23.3-61.1% was the most effective fungicide. The in vivo assay to evaluate the protection efficacy of oils for stored wheat grains against A. niger (AN1) revealed T. vulgaris (90.5-100%) to be the best control agent, followed by the oil of S. aromaticum (61.9-100%). The GC-MS analysis of T. vulgaris oil indicated the presence of thymol (39.11%), γ-terpinene (19.73%), o-cymene (17.21%), and β-pinene (5.38%) as major oil components. Phytotoxic effects of the oils on wheat seeds showed no significant phytotoxic effect of oils in terms of seed germination or seedling growth. The results of the study demonstrated control potentiality of essential oils for the protection of stored wheat against A. niger with prospect for development of eco-friendly antifungal products.

  10. Multilocus sequence analysis of Aspergillus Sect. Nigri in dried vine fruits of worldwide origin.

    Science.gov (United States)

    Susca, Antonia; Perrone, Giancarlo; Cozzi, Giuseppe; Stea, Gaetano; Logrieco, Antonio F; Mulè, Giuseppina

    2013-07-15

    Dried vine fruits may be heavily colonized by Aspergillus species. The molecular biodiversity of an Aspergillus population (234 strains) isolated from dried vine fruit samples of worldwide origin were analyzed by investigating four housekeeping gene loci (calmodulin, β-tubulin, elongation factor 1-α, RPB2). Aspergillus Sect. Nigri was dominant and the strains were identified as A. tubingensis (138), A. awamori (38), A. carbonarius (27), A. uvarum (16) and A. niger (11). Four Aspergillus flavus strains were also identified from Chilean raisins. Two clusters closely related to the A. tubingensis species with a significant bootstrap (60% and 99%) were identified as distinct populations. Among the four loci, RPB2 showed the highest genetic variability. This is the first complete study on the worldwide distribution of black Aspergilli occurring on dried vine fruits identified by a molecular approach. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Biodiversity of Aspergillus species in some important agricultural products

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Susca, A.,; Cozzi, G.

    2007-01-01

    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...... occurring in agricultural fields. Altogether nine different black Aspergillus species can be found on grapes which are often difficult to identify with classical methods. The polyphasic approach used in our studies led to the identification of three new species occurring on grapes: A. brasiliensis, A...

  12. Identification of toxigenic Aspergillus species from diet dairy goat using a polyphasic approach

    OpenAIRE

    Silva, Janaina Lara da; Aparecido, Christiane Ceriani; Hansen, Daiane; Pereira, Tacila Alves Muniz; Felicio, Joana D'arc; Gonçalez, Edlayne

    2015-01-01

    Some species of filamentous fungi that infest agricultural commodities are able to produce mycotoxins, contaminating feed and animal products. The aim of this research was to identify the mycoflora present in the feed and forage for dairy goat and to isolate and characterize the Aspergillus flavus and A. parasiticus strains based on a morphological and molecular characterization and mycotoxigenic ability. The goat dairy diets were collected monthly from 11 goat milk farms, totaling 129 and 10...

  13. Lignocellulosic enzymes from Flavodon flavus , a fungus isolated ...

    African Journals Online (AJOL)

    The LiP of F. flavus, purified by ion exchange chromatography, revealed that it has a molecular weight of 46 kDa and isoelectric point (pI) of 3.8. The study confirmed extracellular enzymes from F. flavus to be potential degraders of organic pollutants and showed that facultative marine fungi that live under harsh seawater ...

  14. Lignocellulosic enzymes from Flavodon flavus, a fungus isolated ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-03

    Sep 3, 2008 ... flavus, purified by ion exchange chromatography, revealed that it has a molecular weight of 46 kDa and isoelectric point (pI) of 3.8. The study confirmed extracellular enzymes ... This study investigated the production and application of lignocellolosic enzymes from marine F. flavus isolated from decayed sea ...

  15. What can comparative genomics tell us about species concepts in the genus Aspergillus?

    Energy Technology Data Exchange (ETDEWEB)

    Rokas, Antonis; payne, gary; Federova, Natalie D.; Baker, Scott E.; Machida, Masa; yu, Jiujiang; georgianna, D. R.; Dean, Ralph A.; Bhatnagar, Deepak; Cleveland, T. E.; Wortman, Jennifer R.; Maiti, R.; Joardar, V.; Amedeo, Paolo; Denning, David W.; Nierman, William C.

    2007-12-15

    Understanding the nature of species" boundaries is a fundamental question in evolutionary biology. The availability of genomes from several species of the genus Aspergillus allows us for the first time to examine the demarcation of fungal species at the whole-genome level. Here, we examine four case studies, two of which involve intraspecific comparisons, whereas the other two deal with interspecific genomic comparisons between closely related species. These four comparisons reveal significant variation in the nature of species boundaries across Aspergillus. For example, comparisons between A. fumigatus and Neosartorya fischeri (the teleomorph of A. fischerianus) and between A. oryzae and A. flavus suggest that measures of sequence similarity and species-specific genes are significantly higher for the A. fumigatus - N. fischeri pair. Importantly, the values obtained from the comparison between A. oryzae and A. flavus are remarkably similar to those obtained from an intra-specific comparison of A. fumigatus strains, giving support to the proposal that A. oryzae represents a distinct ecotype of A. flavus and not a distinct species. We argue that genomic data can aid Aspergillus taxonomy by serving as a source of novel and unprecedented amounts of comparative data, as a resource for the development of additional diagnostic tools, and finally as a knowledge database about the biological differences between strains and species.

  16. Aflatoxin control in maize by Trametes versicolor.

    Science.gov (United States)

    Scarpari, Marzia; Bello, Cristiano; Pietricola, Chiara; Zaccaria, Marco; Bertocchi, Luigi; Angelucci, Alessandra; Ricciardi, Maria Rosaria; Scala, Valeria; Parroni, Alessia; Fabbri, Anna A; Reverberi, Massimo; Zjalic, Slaven; Fanelli, Corrado

    2014-12-17

    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.

  17. 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.

  18. F-box protein RcyA controls turnover of the kinesin-7 motor KipA in Aspergillus nidulans.

    Science.gov (United States)

    Herrero, Saturnino; Takeshita, Norio; Fischer, Reinhard

    2014-08-01

    Fungal filamentous growth depends on continuous membrane insertion at the tip, the delivery of membrane-bound positional markers, and the secretion of enzymes for cell wall biosynthesis. This is achieved through exocytosis. At the same time, polarized growth requires membrane and protein recycling through endocytosis. Endocytic vesicles are thought to enter the protein degradation pathway or recycle their content to the cell surface. In Saccharomyces cerevisiae, the Rcy1 F-box protein is involved in the recycling process of a v-SNARE protein. We identified a Rcy1 orthologue, RcyA, in the filamentous fungus Aspergillus nidulans as a protein interacting with the KipA kinesin-7 motor protein in a yeast two-hybrid screen. The interaction was confirmed through bimolecular fluorescence complementation. RcyA possesses an F-box domain at the N terminus and a prenylation (CaaX) motif at the C terminus. RcyA shows also similarity to Sec10, a component of the exocyst complex. The RcyA protein localized to the hyphal tip and forming septa, likely through transportation on secretory vesicles and partially on early endosomes, but independently of KipA. Deletion of rcyA did not cause severe morphological changes but caused partial defects in the recycling of the SynA v-SNARE protein and the positioning of the cell end markers TeaA and TeaR. In addition, deletion of rcyA led to increased concentrations of the KipA protein, whereas the transcript concentration was unaffected. These results suggest that RcyA probably labels KipA for degradation and thereby controls the protein amount of KipA. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  19. 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. AFG 1 and AFG 2 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.

  20. Pterocarpenes elicited by Aspergillus caelatus in peanut (Arachis hypogaea) seeds.

    Science.gov (United States)

    Sobolev, Victor S; Neff, Scott A; Gloer, James B; Khan, Shabana I; Tabanca, Nurhayat; De Lucca, Anthony J; Wedge, David E

    2010-12-01

    The substituted pterocarpenes named aracarpene-1 (1) and aracarpene-2 (2) were isolated from wounded peanut seeds challenged by a strain of Aspergillus caelatus. The structures of these putative phytoalexins were determined by interpretation of NMR and MS data. The aracarpenes were investigated for their antifungal and antibacterial activities as well as antioxidant, anti-inflammatory, and cytotoxic activities in mammalian cells. Aracarpene-2 demonstrated high antibacterial properties against tested gram-positive and gram-negative bacteria, whereas aracarpene-1 displayed low antibacterial properties against the same bacteria. Both compounds had no antifungal activity against Aspergillus flavus. Together with peanut stilbenoids that are also produced in the challenged seeds, these compounds may represent a class of low-molecular weight peanut metabolites with a defensive role(s) against pathogenic microorganisms. Published by Elsevier Ltd.

  1. Standardization of a two-step real-time polymerase chain reaction based method for species-specific detection of medically important Aspergillus species

    Directory of Open Access Journals (Sweden)

    P Das

    2017-01-01

    Full Text Available Purpose: Standardization of Aspergillus polymerase chain reaction (PCR poses two technical challenges (a standardization of DNA extraction, (b optimization of PCR against various medically important Aspergillus species. Many cases of aspergillosis go undiagnosed because of relative insensitivity of conventional diagnostic methods such as microscopy, culture or antigen detection. The present study is an attempt to standardize real-time PCR assay for rapid sensitive and specific detection of Aspergillus DNA in EDTA whole blood. Materials and Methods: Three nucleic acid extraction protocols were compared and a two-step real-time PCR assay was developed and validated following the recommendations of the European Aspergillus PCR Initiative in our setup. In the first PCR step (pan-Aspergillus PCR, the target was 28S rDNA gene, whereas in the second step, species specific PCR the targets were beta-tubulin (for Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, gene and calmodulin gene (for Aspergillus niger. Results: Species specific identification of four medically important Aspergillus species, namely, A. fumigatus, A. flavus, A. niger and A. terreus were achieved by this PCR. Specificity of the PCR was tested against 34 different DNA source including bacteria, virus, yeast, other Aspergillus sp., other fungal species and for human DNA and had no false-positive reactions. The analytical sensitivity of the PCR was found to be 102 CFU/ml. Conclusion: The present protocol of two-step real-time PCR assays for genus- and species-specific identification for commonly isolated species in whole blood for diagnosis of invasive Aspergillus infections offers a rapid, sensitive and specific assay option and requires clinical validation at multiple centers.

  2. Standardization of a two-step real-time polymerase chain reaction based method for species-specific detection of medically important Aspergillus species.

    Science.gov (United States)

    Das, P; Pandey, P; Harishankar, A; Chandy, M; Bhattacharya, S; Chakrabarti, A

    2017-01-01

    Standardization of Aspergillus polymerase chain reaction (PCR) poses two technical challenges (a) standardization of DNA extraction, (b) optimization of PCR against various medically important Aspergillus species. Many cases of aspergillosis go undiagnosed because of relative insensitivity of conventional diagnostic methods such as microscopy, culture or antigen detection. The present study is an attempt to standardize real-time PCR assay for rapid sensitive and specific detection of Aspergillus DNA in EDTA whole blood. Three nucleic acid extraction protocols were compared and a two-step real-time PCR assay was developed and validated following the recommendations of the European Aspergillus PCR Initiative in our setup. In the first PCR step (pan-Aspergillus PCR), the target was 28S rDNA gene, whereas in the second step, species specific PCR the targets were beta-tubulin (for Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus), gene and calmodulin gene (for Aspergillus niger). Species specific identification of four medically important Aspergillus species, namely, A. fumigatus, A. flavus, A. niger and A. terreus were achieved by this PCR. Specificity of the PCR was tested against 34 different DNA source including bacteria, virus, yeast, other Aspergillus sp., other fungal species and for human DNA and had no false-positive reactions. The analytical sensitivity of the PCR was found to be 102 CFU/ml. The present protocol of two-step real-time PCR assays for genus- and species-specific identification for commonly isolated species in whole blood for diagnosis of invasive Aspergillus infections offers a rapid, sensitive and specific assay option and requires clinical validation at multiple centers.

  3. The global regulator LaeA controls production of citric acid and endoglucanases in Aspergillus carbonarius

    DEFF Research Database (Denmark)

    Linde, Tore; Zoglowek, Marta; Lübeck, Mette

    2016-01-01

    The global regulatory protein LaeA is known for regulating the production of many kinds of secondary metabolites in Aspergillus species, as well as sexual and asexual reproduction, and morphology. In Aspergillus carbonarius, it has been shown that LaeA regulates production of ochratoxin. We have...... investigated the regulatory effect of LaeA on production of citric acid and cellulolytic enzymes in A. carbonarius. Two types of A. carbonarius strains, having laeA knocked out or overexpressed, were constructed and tested in fermentation. The knockout of laeA significantly decreased the production of citric...... acid and endoglucanases, but did not reduce the production of beta-glucosidases or xylanases. The citric acid accumulation was reduced with 74–96 % compared to the wild type. The endoglucanase activity was reduced with 51–78 %. Overexpression of LaeA seemed not to have an effect on citric acid...

  4. Interaction of Wild Strains of Aspergilla with Aspergillus parasiticus ATCC15517 on Aflatoxins Production

    Directory of Open Access Journals (Sweden)

    Fernando Bernardo

    2008-03-01

    Full Text Available Aflatoxins are secondary metabolites produced by some competent mould strains of Aspergillus flavus, A. parasiticus and A. nomius. These compounds have been extensively studied concerning its toxicity for animals and humans; they are able to induce liver cancer and caused a large range of adverse effects on 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. Moulds growth is conditioned by many ecological factors, including biotic one’s. Hazard characterization models for Aflatoxins in crops must take in consideration the biotic interaction that moulds establish between them on their 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 laboratorial model concerns to a natural matrix (humidified cracked corn, in which each wild strain challenged the producer strain for Aflatoxins production. Cultures were incubated at 28ºC for 12 days and sampled at 8th and 12th. Aflatoxins 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 antagonist effects on the Aflatoxin biosynthesis. Productivity increases were particularly evident at 8th day of incubation with wild strains of A. flavipes (+ 70.4 % , A. versicolor (+ 54.9 % and A. flavus 3 (+ 62.6 %. Antagonist effects were found with A. niger (- 69.5% , A. fumigatus (- 47.6 % and A. terreus (- 47.6 % at 12th day. The increasable effects were more evident at 8th of incubation and the decrease was more patent at the 12th day. Results show that the development of Aspergilla strains

  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. Microbiological and physicochemical factors affecting Aspergillus section Flavi incidence in Cavendish banana (Musa cavendishii) chips production in Southern Philippines.

    Science.gov (United States)

    Sales, A C; Azanza, P V; Yoshizawa, T

    2005-01-01

    Microbiological and physicochemical factors affecting the incidence of Aspergillus section Flavi in dried Cavendish banana (Musa cavendishii) chips production in Southern Philippines were examined. The average counts of Aspergillus section Flavi (AFC) in fresh and dried Cavendish bananas from 10 production batches of the Philippine Agro-Industrial Development Cooperative in Davao del Norte, Southern Philippines were 1.2 x 10(2) and 1.6 x 10(2) cfu/g, respectively. Isolates from both samples were identified to be Aspergillus flavus based on spore type and conidial structure of isolates. An increasing trend in the AFC of Cavendish bananas was observed during dried banana chips processing. Variability in the AFC between production batches was attributed to differences in aerobic and fungal populations and physicochemical characteristics of the fruits, peel damage of the raw materials, concentration of AFC in the air and food-contact surfaces of the production area, and temperature and relative humidity (RH) conditions of the environment during production and storage. Physicochemical characteristics of Cavendish bananas from the receipt of raw materials up to the first day of drying were within the reported range of values allowing growth and toxin production by aflatoxigenic fungi. Air-borne AFC varied depending on the section of the production area examined. The close proximity of the waste disposal area from the production operation to the preparation, drying and storage areas suggests that cross-contamination, probably air-borne or insect-borne was a likely occurrence. The hands of workers were also identified as AFC sources. Results of this study highlight the need for the development of strategies to control aflatoxigenic fungi and aflatoxin contamination in Philippine dried Cavendish bananas.

  7. Aspergillus section Flavi community structure in Zambia influences aflatoxin contamination of maize and groundnut.

    Science.gov (United States)

    Kachapulula, Paul W; Akello, Juliet; Bandyopadhyay, Ranajit; Cotty, Peter J

    2017-11-16

    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 populations associated with aflatoxin contamination in Zambia have not been adequately detailed. Most of Zambia's arable land is non-cultivated and Aspergillus communities in crops may originate in non-cultivated soil. However, relationships between Aspergillus populations on crops and those resident in non-cultivated soils have not been explored. Because characterization of similar fungal populations outside of Zambia have resulted in strategies to prevent aflatoxins, the current study sought to improve understanding of fungal communities in cultivated and non-cultivated soils and in crops. Crops (n=412) and soils from cultivated (n=160) and non-cultivated land (n=60) were assayed for Aspergillus section Flavi from 2012 to 2016. The L-strain morphotype of Aspergillus flavus and A. parasiticus were dominant on maize and groundnut (60% and 42% of Aspergillus section Flavi, respectively). Incidences of A. flavus L-morphotype were negatively correlated with aflatoxin in groundnut (log y=2.4990935-0.09966x, R 2 =0.79, P=0.001) but not in maize. Incidences of A. parasiticus partially explained groundnut aflatoxin concentrations in all agroecologies and maize aflatoxin in agroecology III (log y=0.1956034+0.510379x, R 2 =0.57, Paflatoxin contamination in Zambia. Communities in both non-cultivated and cultivated soils were dominated by A. parasiticus (69% and 58%, respectively). Aspergillus parasiticus from cultivated and non-cultivated land produced statistically similar concentrations of aflatoxins. Aflatoxin-producers causing contamination of crops in Zambia may be native and, originate from non-cultivated areas, and not be introduced with non-native crops such as maize and

  8. High fungal spore burden with predominance of Aspergillus in hospital air of a tertiary care hospital in Chandigarh

    Directory of Open Access Journals (Sweden)

    S M Rudramurthy

    2016-01-01

    Full Text Available The prevalence of fungal spores in the hospital air is essential to understand the hospital-acquired fungal infections. Air conditioners (ACs used in hospitals may either reduce spores in air or be colonised by fungi and aid in its dissemination. The present study was conducted to assess the fungal spore burden in AC and non-AC areas. We found a high fungal spore count in air irrespective of whether the area was AC or non-AC. The most predominant species isolated were Aspergillus flavus and Aspergillus fumigatus. Such high concentrations of pathogenic fungi in air may predispose individuals to develop disease.

  9. Computational study of β-N-acetylhexosaminidase from Talaromyces flavus, a glycosidase with high substrate flexibility.

    Science.gov (United States)

    Kulik, Natallia; Slámová, Kristýna; Ettrich, Rüdiger; Křen, Vladimír

    2015-01-28

    β-N-Acetylhexosaminidase (GH20) from the filamentous fungus Talaromyces flavus, previously identified as a prominent enzyme in the biosynthesis of modified glycosides, lacks a high resolution three-dimensional structure so far. Despite of high sequence identity to previously reported Aspergillus oryzae and Penicilluim oxalicum β-N-acetylhexosaminidases, this enzyme tolerates significantly better substrate modification. Understanding of key structural features, prediction of effective mutants and potential substrate characteristics prior to their synthesis are of general interest. Computational methods including homology modeling and molecular dynamics simulations were applied to shad light on the structure-activity relationship in the enzyme. Primary sequence analysis revealed some variable regions able to influence difference in substrate affinity of hexosaminidases. Moreover, docking in combination with consequent molecular dynamics simulations of C-6 modified glycosides enabled us to identify the structural features required for accommodation and processing of these bulky substrates in the active site of hexosaminidase from T. flavus. To access the reliability of predictions on basis of the reported model, all results were confronted with available experimental data that demonstrated the principal correctness of the predictions as well as the model. The main variable regions in β-N-acetylhexosaminidases determining difference in modified substrate affinity are located close to the active site entrance and engage two loops. Differences in primary sequence and the spatial arrangement of these loops and their interplay with active site amino acids, reflected by interaction energies and dynamics, account for the different catalytic activity and substrate specificity of the various fungal and bacterial β-N-acetylhexosaminidases.

  10. Transcriptional profiling of Aspergillus niger

    OpenAIRE

    Veen, van der, D.

    2009-01-01

    The industrially important fungus Aspergillus niger feeds naturally on decomposing plant material, of which a significant proportion is lipid. Examination of the A. niger genome sequence suggested that all proteins required for metabolic conversion of lipids are present, including 63 predicted lipases. In contrast to polysaccharide-degrading enzyme networks, not much is known about the signaling and regulatory processes that control lipase expression and activity in fungi. This project was ai...

  11. Pemanfaatan Fungi Aspergillus Flavus, Aspergillus Tereus, Dan Trichoderma Harzianum Untuk Meningkatkan Pertumbuhan Bibit Bruguiera Cylindrica Di Desa Nelayan Indah

    OpenAIRE

    Saputri, Ade Khana; Yunasfi, Yunasfi; Basyuni, Mohammad

    2015-01-01

    Mangrove forest is one of coastal ecosystems that have high productivity. Recently, mangrove damaged either directly or indirectly. Direct damage for example logging, timber harvesting, settlement construction and ponds manufacturing, ports and roads construction, and arrest biota in mangrove ecosystems. Furthermore, indrectly threat maybe caused by coastal dredging, disposal of waste and industrial waste in the sea and the coast, coastal and marine mining, and deforestation. As a result abov...

  12. Pgas, a Low-pH-Induced Promoter, as a Tool for Dynamic Control of Gene Expression for Metabolic Engineering of Aspergillus niger.

    Science.gov (United States)

    Yin, Xian; Shin, Hyun-Dong; Li, Jianghua; Du, Guocheng; Liu, Long; Chen, Jian

    2017-03-15

    The dynamic control of gene expression is important for adjusting fluxes in order to obtain desired products and achieve appropriate cell growth, particularly when the synthesis of a desired product drains metabolites required for cell growth. For dynamic gene expression, a promoter responsive to a particular environmental stressor is vital. Here, we report a low-pH-inducible promoter, P gas , which promotes minimal gene expression at pH values above 5.0 but functions efficiently at low pHs, such as pH 2.0. First, we performed a transcriptional analysis of Aspergillus niger , an excellent platform for the production of organic acids, and we found that the promoter P gas may act efficiently at low pH. Then, a gene for synthetic green fluorescent protein ( sGFP ) was successfully expressed by P gas at pH 2.0, verifying the results of the transcriptional analysis. Next, P gas was used to express the cis -aconitate decarboxylase ( cad ) gene of Aspergillus terreus in A. niger , allowing the production of itaconic acid at a titer of 4.92 g/liter. Finally, we found that P gas strength was independent of acid type and acid ion concentration, showing dependence on pH only. IMPORTANCE The promoter P gas can be used for the dynamic control of gene expression in A. niger for metabolic engineering to produce organic acids. This promoter may also be a candidate tool for genetic engineering. Copyright © 2017 American Society for Microbiology.

  13. 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

    , the potential for aflatoxin production by the isolates was tested using the agar plug technique and the presence of aflatoxins in peanuts was assessed using an immunoaffinity column followed by quantification using HPLC with reverse phase column and fluorescence detection. The limit of detection...... and quantification were 0.05 and 0.17 mu g/kg for total aflatoxins, respectively. Four species of Aspergillus section Flavi were isolated: A. caelatus (11), A. flavus (515), A. parasiticus (17) and A. tamarii (13). All isolates of A. parasiticus were able to produce aflatoxin B and G whereas aflatoxin B was produced...... by 50% of A. flavus isolates. Aflatoxins were found in 12 samples at concentrations ranging from 0.3 to 100 mu g/kg. The data reported in this study add information on the occurrence and biodiversity of fungi in peanuts at several stages of the production chain. The occurrence of aflatoxins is also...

  14. Molecular analysis of Aspergillus section Flavi isolated from Brazil nuts.

    Science.gov (United States)

    Gonçalves, Juliana Soares; Ferracin, Lara Munique; Carneiro Vieira, Maria Lucia; Iamanaka, Beatriz Thie; Taniwaki, Marta Hiromi; Pelegrinelli Fungaro, Maria Helena

    2012-04-01

    Brazil nuts are an important export market in its main producing countries, including Brazil, Bolivia, and Peru. Approximately 30,000 tons of Brazil nuts are harvested each year. However, substantial nut contamination by Aspergillus section Flavi occurs with subsequent production of aflatoxins. In our study, Aspergillus section Flavi were isolated from Brazil nuts (Bertholletia excelsa), and identified by morphological and molecular means. We obtained 241 isolates from nut samples, 41% positive for aflatoxin production. Eighty-one isolates were selected for molecular investigation. Pairwise genetic distances among isolates and phylogenetic relationships were assessed. The following Aspergillus species were identified: A. flavus, A. caelatus, A. nomius, A. tamarii, A. bombycis, and A. arachidicola. Additionally, molecular profiles indicated a high level of nucleotide variation within β-tubulin and calmodulin gene sequences associated with high genetic divergence from RAPD data. Among the 81 isolates analyzed by molecular means, three of them were phylogenetically distinct from all other isolates representing the six species of section Flavi. A putative novel species was identified based on molecular profiles.

  15. [Rabies in Potos flavus identified in Madre de Dios, Peru].

    Science.gov (United States)

    Vargas-Linares, Elena; Romaní-Romaní, Franco; López-Ingunza, Ricardo; Arrasco-Alegre, Juan; Yagui-Moscoso, Martín

    2014-01-01

    The Potos flavus is a nocturnal mammal that lives in neotropical forests from Central America to South America. A study of four cases of rabies in Potos flavus was conducted; these occurred in April 2012 in the Madre de Dios region in Peru and were collected as part of epidemiological surveillance. The analysis performed in the regional reference laboratory of Madre de Dios determined the presence of the rabies virus antigen in three of the brain tissue samples. Results were verified in the Laboratory of Viral Zoonoses of the Peruvian National Institute of Health by direct immunofluorescence. The typification did not identify any of the known variants in bats or dogs. The occurrence of four cases of rabies in Potos flavus adds evidence of the emergence of a new reservoir of the rabies virus previously reported in the same region in 2007.

  16. 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...

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

    DEFF Research Database (Denmark)

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

    capable of producing aflatoxin. These species can be perceived as ecotypes. We have analyzed A. oryzae RIB40 and found that the chemical potential could be enhanced significantly under certain conditions. Delicate analysis of their metabolic profiles allow for chemical insight on the transcription level...

  18. Visualization of aflatoxigenic Aspergillus flavus contamination of coconut (Cocos nucifera) nutmeat (Copra) using ammonia treatment

    Science.gov (United States)

    For many crops government regulations define mycotoxin contamination levels that reflect the primary determinants of quality, value and possible uses of crops. Quality can be raised by lowering the mycotoxin level through a remediation process. In the case of copra, the dried nutmeat of the coconu...

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

    African Journals Online (AJOL)

    Nelciele

    2Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Department of Biology, University of São Paulo, Av do. Café s/n°,14040-901 Ribeirão Preto, SP, Brazil. Received 25 August, 2015; Accepted 18 November, 2015. The production of xylanase without cellulase is required for prebleaching of pulp in pulp and paper.

  20. Effects of hydrogen peroxide on different toxigenic and atoxigenic isolates of Aspergillus flavus

    Science.gov (United States)

    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, t...

  1. Biocontrol of Aspergillus species on peanut kernels by antifungal diketopiperazine producing Bacillus cereus associated with entomopathogenic nematode.

    Directory of Open Access Journals (Sweden)

    Sasidharan Nishanth Kumar

    Full Text Available The rhabditid entomopathogenic nematode associated Bacillus cereus and the antifungal compounds produced by this bacterium were evaluated for their activity in reducing postharvest decay of peanut kernels caused by Aspergillus species in in vitro and in vivo tests. The results showed that B. cereus had a significant effect on biocontrol effectiveness in in vitro and in vivo conditions. The antifungal compounds produced by the B. cereus were purified using silica gel column chromatography and their structure was elucidated using extensive spectral analyses. The compounds were identified as diketopiperazines (DKPs [cyclo-(L-Pro-Gly, cyclo(L-Tyr-L-Tyr, cyclo-(L-Phe-Gly and cyclo(4-hydroxy-L-Pro-L-Trp]. The antifungal activities of diketopiperazines were studied against five Aspergillus species and best MIC of 2 µg/ml was recorded against A. flavus by cyclo(4-hydroxy-L-Pro-L-Trp. To investigate the potential application of cyclo(4-hydroxy-L-Pro-L-Trp to eliminate fungal spoilage in food and feed, peanut kernels was used as a food model system. White mycelia and dark/pale green spores of Aspergillus species were observed in the control peanut kernels after 2 days incubation. However the fungal growth was not observed in peanut kernels treated with cyclo(4-hydroxy-L-Pro-L-Trp. The cyclo(4-hydroxy-L-Pro-L-Trp was nontoxic to two normal cell lines [fore skin (FS normal fibroblast and African green monkey kidney (VERO] up to 200 µg/ml in MTT assay. Thus the cyclo(4-hydroxy-L-Pro-L-Trp identified in this study may be a promising alternative to chemical preservatives as a potential biopreservative agent which prevent fungal growth in food and feed. To the best of our knowledge, this is the first report demonstrating that the entomopathogenic nematode associated B. cereus and cyclo(4-hydroxy-L-Pro-L-Trp could be used as a biocontrol agents against postharvest fungal disease caused by Aspergillus species.

  2. A controlled study to determine the efficacy of Loxostylis alata (Anacardiaceae in the treatment of aspergillus in a chicken (Gallus domesticus model in comparison to ketoconazole

    Directory of Open Access Journals (Sweden)

    Suleiman Mohammed M

    2012-10-01

    Full Text Available Abstract Background The poultry industry due to intensive methods of farming is burdened with losses from numerous infectious agents, of which one is the fungus Aspergillus fumigatus. In a preliminary study, the extracts of Loxostylis alata A. Spreng, ex Rchb. showed good activity in vitro against A. fumigatus with a minimum inhibitory concentration of 0.07 mg/ml. For this study crude, a crude acetone extract of L. alata leaves was evaluated for its acute toxicity in a healthy chicken model and for efficacy in an infectious model of aspergillosis (A. fumigatus. Results At a dose of 300 mg/kg, the extract induced some toxicity characterised by decreased feed intake and weight loss. Consequently, 100 and 200 mg/kg were used to ascertain efficacy in the infectious model. The plant extract significantly reduced clinical disease in comparison to the control in a dose dependant manner. The extract was as effective as the positive control ketoconazole dosed at 60 mg/kg. Conclusions The results indicate that a crude extract of L. alata leaves has potential as an antifungal agent to protect poultry against avian aspergillosis.

  3. [Genetic control of the sensitivity of Aspergillus nidulans to mutagenic factors. VII. Inheritance of cross-sensitivity to different mutagenic factors by uvs-mutants].

    Science.gov (United States)

    Evseeva, G V; Kameneva, S V

    1977-01-01

    To study the inheritance of the sensitivity to UV, X-rays, methylmethanesulphonate (MMS), nitrosoguanidine (NG) and nitrous acid (NA) in five uvs mutants of Aspergillus nidulans, having multiple sensitivity to these factors, the sensitivity of recombinants obtained from crossing uvs mutants with uvs+ strain, resistant to all the factors analysed, and uvs leads to uvs+ revertants is investigated. Four uvs mutants (15, 17, 19 and 26) are found to have a nomogenic control of sensitivity to different mutagens. In one mutant (uvs11) the sensitivity to five factors is controlled by two non-linked mutations, one of them determining the sensitivity to UV, NG, NA, and the other--to X-rays and MMC. Phenotypic manifestations of uvs mutations is modified by cell genotype, both chromosomal and cytoplasmic factors being responsible for the modification. Phenotypic modification of uvs mutation results in the change to some (but not to all) mutagenic factors. It suggests, that not the product of uvs gene, but some other components of the reparation complex are modified. Otherwise, reparation of different DNA damages can be carried out by a single enzyme acting in different reparation complexes.

  4. Antígenos nativos de Aspergillus fumigatus con utilidad para el inmunodiagnóstico de aspergiloma

    Directory of Open Access Journals (Sweden)

    José Casquero

    2009-04-01

    Full Text Available Con el objetivo de evaluar la utilidad de los antígenos nativos de cepas autóctonas de Aspergillus fumigatus para el inmunodiagnóstico de aspergiloma, se desarrolló un estudio empleando dos cepas de ese hongo, aisladas de pacientes con diagnóstico de aspergiloma (533 y 554, los cuales fueron confrontados con sueros controles comerciales de A. fumigatus, A. flavus, A. niger, Candida, Coccidioides, Histoplasma y Paracoccidioides mediante la prueba de inmunodifusión, asimismo, se evaluaron frente a 28 sueros de pacientes con sospecha de aspergiloma. Además, se realizó la caracterización de los componentes proteicos de los antígenos nativos con la técnica de SDS-PAGE y se confrontaron con diez sueros de pacientes con aspergiloma, paracoccidioidomicosis, histoplasmosis, proteína C reactiva e hidatidosis y suero de persona sana por inmunoblot. Se encontró una buena concordancia (kappa 0,92 entre los antígenos 533 y 554, y algo menor de éstos con el antígeno comercial para A. fumigatus (kappa 0,73 y 0,81 para el 553 y 554; respectivamente. La banda de 97 kDa reaccionó sólo con sueros de pacientes con aspergiloma siendo inmunodominante.

  5. 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...

  6. 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

    In order to facilitate easy and rapid identification of aflatoxin-producing Aspergillus species, the phenotypic traits of Aspergillus section Flavi isolates were examined on neutral red desiccated coconut agar (NRDCA). Phenotype variations in colony morphology and the relationship between colour...... supported morphological differentiation of the four species based on colony features, conidia type and colour. In particular, the two very closely related minisclerotial species, A. minisclerotigenes and A. parvisclerotigenus, were clearly differentiated by their colony colour on NRDCA. All toxigenic...... 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...

  7. mutant of Aspergillus niger

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-19

    Jan 19, 2009 ... enzyme glucose oxidase production from mutagenization of A. niger, resistant to a range of ... strain, forward from Department of Microbiology, was used and maintained on potato dextrose agar (PDA) slants, .... (1993). Induction of glucose oxidase, catalase and lactonase in. Aspergillus niger. Curr. Genet.

  8. The Phosducin-Like Protein PhnA Is Required for Gβγ-Mediated Signaling for Vegetative Growth, Developmental Control, and Toxin Biosynthesis in Aspergillus nidulans

    Science.gov (United States)

    Seo, Jeong-Ah; Yu, Jae-Hyuk

    2006-01-01

    Phosducin or phosducin-like protein (PhLP) is a positive regulator of Gβγ activity. The Gβ (SfaD) and Gγ (GpgA) subunits function in vegetative growth and developmental control in the model filamentous fungus Aspergillus nidulans. To better understand the nature of Gβγ-mediated signaling, phnA, encoding an A. nidulans PhLP, has been studied. Deletion of phnA resulted in phenotypes almost identical to those caused by deletion of sfaD, i.e., reduced biomass, asexual sporulation in liquid submerged culture, and defective fruiting body formation, suggesting that PhnA is necessary for Gβ function. The requirement for the RGS protein FlbA in asexual sporulation could be bypassed by the ΔphnA mutation, indicating that PhnA functions in FlbA-controlled vegetative growth signaling, primarily mediated by the heterotrimeric G protein composed of FadA (Gα), SfaD, and GpgA. However, whereas deletion of fadA restored both asexual sporulation and the production of sterigmatocystin (ST), deletion of sfaD, gpgA, or phnA failed to restore ST production in the ΔflbA mutant. Further studies revealed that SfaD, GpgA, and PhnA are necessary for the expression of aflR, encoding the transcriptional activator for the ST biosynthetic genes, and subsequent ST biosynthesis. Overexpression of aflR bypassed the need for SfaD in ST production, indicating that the results of SfaD-mediated signaling may include transcriptional activation of aflR. Potential differential roles of FadA, Gβγ, and FlbA in controlling ST biosynthesis are further discussed. PMID:16467480

  9. Molecular detection and species-specific identification of medically important Aspergillus species by real-time PCR in experimental invasive pulmonary aspergillosis.

    Science.gov (United States)

    Walsh, Thomas J; Wissel, Mark C; Grantham, Kevin J; Petraitiene, Ruta; Petraitis, Vidmantas; Kasai, Miki; Francesconi, Andrea; Cotton, Margaret P; Hughes, Johanna E; Greene, Lora; Bacher, John D; Manna, Pradip; Salomoni, Martin; Kleiboeker, Steven B; Reddy, Sushruth K

    2011-12-01

    Diagnosis of invasive pulmonary aspergillosis (IPA) remains a major challenge to clinical microbiology laboratories. We developed rapid and sensitive quantitative PCR (qPCR) assays for genus- and species-specific identification of Aspergillus infections by use of TaqMan technology. In order to validate these assays and understand their potential diagnostic utility, we then performed a blinded study of bronchoalveolar lavage (BAL) fluid specimens from well-characterized models of IPA with the four medically important species. A set of real-time qPCR primers and probes was developed by utilizing unique ITS1 regions for genus- and species-specific detection of the four most common medically important Aspergillus species (Aspergillus fumigatus, A. flavus, A. niger, and A. terreus). Pan-Aspergillus and species-specific qPCRs with BAL fluid were more sensitive than culture for detection of IPA caused by A. fumigatus in untreated (P < 0.0007) and treated (P ≤ 0.008) animals, respectively. For infections caused by A. terreus and A. niger, culture and PCR amplification from BAL fluid yielded similar sensitivities for untreated and treated animals. Pan-Aspergillus PCR was more sensitive than culture for detection of A. flavus in treated animals (P = 0.002). BAL fluid pan-Aspergillus and species-specific PCRs were comparable in sensitivity to BAL fluid galactomannan (GM) assay. The copy numbers from the qPCR assays correlated with quantitative cultures to determine the pulmonary residual fungal burdens in lung tissue. Pan-Aspergillus and species-specific qPCR assays may improve the rapid and accurate identification of IPA in immunocompromised patients.

  10. Aspergillus Oxylipin Signaling and Quorum Sensing Pathways Depend on G Protein-Coupled Receptors

    Directory of Open Access Journals (Sweden)

    Katharyn J. Affeldt

    2012-09-01

    Full Text Available Oxylipins regulate Aspergillus development and mycotoxin production and are also involved in Aspergillus quorum sensing mechanisms. Despite extensive knowledge of how these oxylipins are synthesized and what processes they regulate, nothing is known about how these signals are detected and transmitted by the fungus. G protein-coupled receptors (GPCR have been speculated to be involved as they are known oxylipin receptors in mammals, and many putative GPCRs have been identified in the Aspergilli. Here, we present evidence that oxylipins stimulate a burst in cAMP in A. nidulans, and that loss of an A. nidulans GPCR, gprD, prevents this cAMP accumulation. A. flavus undergoes an oxylipin-mediated developmental shift when grown at different densities, and this regulates spore, sclerotial and aflatoxin production. A. flavus encodes two putative GprD homologs, GprC and GprD, and we demonstrate here that they are required to transition to a high-density development state, as well as to respond to spent medium of a high-density culture. The finding of GPCRs that regulate production of survival structures (sclerotia, inoculum (spores and aflatoxin holds promise for future development of anti-fungal therapeutics.

  11. Aspergillus oxylipin signaling and quorum sensing pathways depend on g protein-coupled receptors.

    Science.gov (United States)

    Affeldt, Katharyn J; Brodhagen, Marion; Keller, Nancy P

    2012-09-01

    Oxylipins regulate Aspergillus development and mycotoxin production and are also involved in Aspergillus quorum sensing mechanisms. Despite extensive knowledge of how these oxylipins are synthesized and what processes they regulate, nothing is known about how these signals are detected and transmitted by the fungus. G protein-coupled receptors (GPCR) have been speculated to be involved as they are known oxylipin receptors in mammals, and many putative GPCRs have been identified in the Aspergilli. Here, we present evidence that oxylipins stimulate a burst in cAMP in A. nidulans, and that loss of an A. nidulans GPCR, gprD, prevents this cAMP accumulation. A. flavus undergoes an oxylipin-mediated developmental shift when grown at different densities, and this regulates spore, sclerotial and aflatoxin production. A. flavus encodes two putative GprD homologs, GprC and GprD, and we demonstrate here that they are required to transition to a high-density development state, as well as to respond to spent medium of a high-density culture. The finding of GPCRs that regulate production of survival structures (sclerotia), inoculum (spores) and aflatoxin holds promise for future development of anti-fungal therapeutics.

  12. Fumigant antifungal activity of Myrtaceae essential oils and constituents from Leptospermum petersonii against three Aspergillus species.

    Science.gov (United States)

    Kim, Eunae; Park, Il-Kwon

    2012-09-03

    Commercial plant essential oils obtained from 11 Myrtaceae plant species were tested for their fumigant antifungal activity against Aspergillus ochraceus, A. flavus, and A. niger. Essential oils extracted from Leptospermum petersonii at air concentrations of 56 × 10(-3) mg/mL and 28 × 10(-3) mg/mL completely inhibited the growth of the three Aspergillus species. However, at an air concentration of 14 × 10(-3) mg/mL, inhibition rates of L. petersonii essential oils were reduced to 20.2% and 18.8% in the case of A. flavus and A. niger, respectively. The other Myrtaceae essential oils (56 × 10(-3) mg/mL) only weakly inhibited the fungi or had no detectable affect. Gas chromatography-mass spectrometry analysis identified 16 compounds in L. petersonii essential oil. The antifungal activity of the identified compounds was tested individually by using standard or synthesized compounds. Of these, neral and geranial inhibited growth by 100%, at an air concentration of 56 × 10(-3) mg/mL, whereas the activity of citronellol was somewhat lover (80%). The other compounds exhibited only moderate or weak antifungal activity. The antifungal activities of blends of constituents identified in L. petersonii oil indicated that neral and geranial were the major contributors to the fumigant and antifungal activities.

  13. 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.

  14. 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.

  15. Chemical composition and antifungal activity of Hyptis suaveolens (L. poit leaves essential oil against Aspergillus species

    Directory of Open Access Journals (Sweden)

    Ana Carolina Pessoa Moreira

    2010-03-01

    Full Text Available This study aimed to identify the constituents of the essential oil from Hyptis suaveolens (L. leaves using a Gas Chromatograph -Mass Spectrometer and assess its inhibitory effect on some potentially pathogenic Aspergilli (A. flavus, A. parasiticus, A. ochraceus, A. fumigatus and A. niger. Eucaliptol (47.64 % was the most abundant component in the oil, followed for gama-ellemene (8.15 %, beta-pynene (6.55 %, (+3-carene (5.16 %, trans-beta-cariophyllene (4.69 % and germacrene (4.86 %. The essential oil revealed an interesting anti-Aspergillus property characterized by a Minimum Inhibitory Concentration and Minimum Fungicidal Concentration of 40 and 80 µL/mL, respectively. The oil at 80 and 40 µL/mL strongly inhibited the mycelial growth of A. fumigatus and A. parasiticus along 14 days. In addition, at 10 and 20 µL/mL the oil was able to cause morphological changes in A. flavus as decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure suggesting fungal wall degeneration. These findings showed the interesting anti-Aspergillus property of H. suaveolens leaves essential oil supporting its possible rational use as alternative source of new antifungal compounds to be applied in the aspergillosis treatment.

  16. The Pan-AC assay: a single-reaction real-time PCR test for quantitative detection of a broad range of Aspergillus and Candida species.

    Science.gov (United States)

    Basková, Lenka; Landlinger, Christine; Preuner, Sandra; Lion, Thomas

    2007-09-01

    In view of the growing incidence and the high mortality of invasive aspergillosis and candidiasis, adequate diagnostic techniques permitting timely onset of treatment are of paramount importance. More than 90 % of all invasive fungal infections in immunocompromised individuals can be attributed to Candida and Aspergillus species. To date, standardized techniques permitting rapid, sensitive and, no less importantly, economic screening for the clinically most relevant fungi are lacking. In the present report, a real-time quantitative PCR assay, developed for the detection of the most common pathogenic Candida and Aspergillus species, is described. The single-reaction PCR assay targets a judiciously selected region of the 28S subunit of the fungal rDNA gene. The unique design of the universal primer/probe system, including a pan-Aspergillus and pan-Candida (Pan-AC) hydrolysis probe, facilitates the detection of numerous Aspergillus species (e.g. Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus terreus, Aspergillus versicolor and Aspergillus nidulans) and Candida species (e.g. Candida albicans, Candida glabrata, Candida krusei, Candida tropicalis, Candida parapsilosis, Candida kefyr, Candida guilliermondii, Candida lusitaniae and Candida dubliniensis). The assay permits highly reproducible detection of 10 fg fungal DNA, which corresponds to a fraction of a fungal genome, and facilitates accurate quantification of fungal load across a range of at least five logs. Upon standardization of the technique using cultured fungal strains, the applicability in the clinical setting was assessed by investigating a series of clinical specimens from patients with documented fungal infections (n=17). The Pan-AC assay provides an attractive and economic approach to the screening and monitoring of invasive aspergillosis and candidiasis, which is readily applicable to routine clinical diagnosis.

  17. A combination of acid lactase from Aspergillus oryzae and yogurt bacteria improves lactose digestion in lactose maldigesters synergistically: A randomized, controlled, double-blind cross-over trial.

    Science.gov (United States)

    de Vrese, Michael; Laue, Christiane; Offick, Birte; Soeth, Edlyn; Repenning, Frauke; Thoß, Angelika; Schrezenmeir, Jürgen

    2015-06-01

    Lactose digestion can be improved in subjects with impaired or completely absent intestinal lactase activity by administration of lactase preparations and particularly of acid lactase, which is active in the stomach, or by yogurt containing live lactic acid bacteria. It is the question, if lactose digestion can be further enhanced by combining these two approaches. We investigated in a randomised, placebo-controlled, double-blind, 5-arm crossover study on 24 lactose malabsorbers with variable degrees of lactase deficiency if different lactase preparations and freeze-dried yogurt culture affect gastrointestinal lactose digestion after consuming moderate amounts of lactose (12.5 g) by assessing hydrogen exhalation over 6 h. Furthermore, symptoms of lactose intolerance (excess gas production, abdominal pain, diarrhoea or nausea) were assessed using validated questionnaires. All preparations increased lactose digestion and reduced peak hydrogen exhalation by -27% (yogurt), -29/-33% (3300/9000 FCC(1) ((1) One FCC hydrolyses about 5 or 1.7-2.5 mg lactose in aquous solution or in (artificial) chyme, respectively, according to the FCC-III method of the Committee on Codex Specifications, Food and Nutrition Board, National Research Council. Food Chemicals Codex, 3rd edition. Washington, DC, National Academy Press, 1981 It cannot precisely be defined how much lactose can be hydrolysed in vivo by the consumption of a certain number of FCC units.) units acid lactase from Aspergillus oryzae) or -46%, respectively (3300 FCC units lactase plus yogurt culture combined), as compared with placebo (p lactose digestion more than either freeze-dried yogurt cultures or acid lactase alone, and more lactose malabsorbers benefited from this effect. Copyright © 2014. Published by Elsevier Ltd.

  18. Efficacy of the application of a coating composed of chitosan and Origanum vulgare L. essential oil to control Rhizopus stolonifer and Aspergillus niger in grapes (Vitis labrusca L.).

    Science.gov (United States)

    dos Santos, Nereide Serafim Timóteo; Athayde Aguiar, Ana Júlia Alves; de Oliveira, Carlos Eduardo Vasconcelos; Veríssimo de Sales, Camila; de Melo E Silva, Silvanda; Sousa da Silva, Rosana; Stamford, Thayza Christina Montenegro; de Souza, Evandro Leite

    2012-12-01

    This study evaluated the efficacy of the combined application of chitosan (CHI) and Origanum vulgare L. essential oil (OV) in the inhibition of Rhizopus stolonifer URM 3728 and Aspergillus niger URM 5842 on laboratory media and on grapes (Vitis labrusca L.) and its influence on the physical, physicochemical and sensory characteristics of the fruits during storage (25 °C, 12 days and 12 °C, 24 days). The application of mixtures of different CHI and OV concentrations (Minimum Inhibitory Concentration - MIC, 1/2 MIC and 1/4 MIC) inhibited the mycelial growth of the test fungi. The application of CHI and OV at sub-inhibitory concentrations (CHI 1/2 MIC + OV 1/4 MIC; CHI 1/2 MIC + OV 1/2 MIC) inhibited spore germination and caused morphological changes in fungal spores and mycelia, in addition to inhibiting the growth of the assayed fungi strains in artificially infected grapes as well as the autochthonous mycoflora of grapes stored at both room and cold temperature. In general, the application of a coating composed of CHI and OV at sub-inhibitory concentrations preserved the quality of grapes as measured by their physical and physicochemical attributes, while some of their sensory attributes improved throughout the assessed storage time. These results demonstrate the potential of the combination of CHI and OV at sub-inhibitory concentrations to control post-harvest pathogenic fungi in fruits, in particular, R. stolonifer and A. niger in grapes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. (+)-Geodin from Aspergillus terreus

    DEFF Research Database (Denmark)

    Rønnest, Mads Holger; Nielsen, Morten Thrane; Leber, Blanka

    2011-01-01

    The fungal metabolite (+)-geodin [systematic name: (2R)-methyl 5,7-dichloro-4-hydroxy-6'-methoxy-6-methyl-3,4'-dioxospiro[benzofuran-2,1'-cyclohexa-2',5'-diene]-2'-carboxylate], C(17)H(12)Cl(2)O(7), was isolated from Aspergillus terreus. The crystal structure contains two independent molecules in...... molecules. The structurally related (+)-griseofulvin has an S configuration at the spiro centre, a difference of potential biological and biosynthetic relevance....

  20. Chemodiversity in the genus Aspergillus

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Larsen, Thomas Ostenfeld

    2015-01-01

    to be characterized. The genus Aspergillus is cladistically holophyletic but phenotypically polythetic and very diverse and is associated to quite different sexual states. Following the one fungus one name system, the genus Aspergillus is restricted to a holophyletic clade that include the morphologically different...... biosynthetic family isoextrolites. However, it appears that secondary metabolites from one Aspergillus section have analogous metabolites in other sections (here also called heteroisoextrolites). In this review, we give a genus-wide overview of secondary metabolite production in Aspergillus species. Extrolites...

  1. Effect of essential oils on Aspergillus spore germination, growth and mycotoxin production: a potential source of botanical food preservative.

    Science.gov (United States)

    Gemeda, Negero; Woldeamanuel, Yimtubezinash; Asrat, Daniel; Debella, Asfaw

    2014-05-01

    To investigate effect of essential oils on Aspergillus spore germination, growth and mycotoxin production. In vitro antifungal and antiaflatoxigenic activity of essential oils was carried out using poisoned food techniques, spore germination assay, agar dilution assay, and aflatoxin arresting assay on toxigenic strains of Aspergillus species. Cymbopogon martinii, Foeniculum vulgare and Trachyspermum ammi (T. ammi) essential oils were tested against toxicogenic isolates of Aspergillus species. T. ammi oil showed highest antifungal activity. Absolute mycelial inhibition was recorded at 1 µl/mL by essential oils of T. ammi. The oil also showed, complete inhibition of spore germination at a concentration of 2 µl/mL. In addition, T. ammi oil showed significant antiaflatoxigenic potency by totally inhibiting aflatoxin production from Aspergillus niger and Aspergillus flavus at 0.5 and 0.75 µl/mL, respectively. Cymbopogon martinii, Foeniculum vulgare and T. ammi oils as antifungal were found superior over synthetic preservative. Moreover, a concentration of 5 336.297 µl/kg body weight was recorded for LC50 on mice indicating the low mammalian toxicity and strengthening its traditional reputations. In conclusion, the essential oils from T. ammi can be a potential source of safe natural food preservative for food commodities contamination by storage fungi.

  2. Comparative studies on pectinases obtained from Aspergillus ...

    African Journals Online (AJOL)

    Comparative studies on pectinases obtained from Aspergillus fumigatus and Aspergillus niger in submerged fermentation system using pectin extracted from mango, orange and pineapple peels as carbon sources.

  3. Determining the analytical specificity of PCR-based assays for the diagnosis of IA: What is Aspergillus?

    Science.gov (United States)

    Morton, C Oliver; White, P Lewis; Barnes, Rosemary A; Klingspor, Lena; Cuenca-Estrella, Manuel; Lagrou, Katrien; Bretagne, Stéphane; Melchers, Willem; Mengoli, Carlo; Caliendo, Angela M; Cogliati, Massimo; Debets-Ossenkopp, Yvette; Gorton, Rebecca; Hagen, Ferry; Halliday, Catriona; Hamal, Petr; Harvey-Wood, Kathleen; Jaton, Katia; Johnson, Gemma; Kidd, Sarah; Lengerova, Martina; Lass-Florl, Cornelia; Linton, Chris; Millon, Laurence; Morrissey, C Orla; Paholcsek, Melinda; Talento, Alida Fe; Ruhnke, Markus; Willinger, Birgit; Donnelly, J Peter; Loeffler, Juergen

    2017-06-01

    A wide array of PCR tests has been developed to aid the diagnosis of invasive aspergillosis (IA), providing technical diversity but limiting standardisation and acceptance. Methodological recommendations for testing blood samples using PCR exist, based on achieving optimal assay sensitivity to help exclude IA. Conversely, when testing more invasive samples (BAL, biopsy, CSF) emphasis is placed on confirming disease, so analytical specificity is paramount. This multicenter study examined the analytical specificity of PCR methods for detecting IA by blind testing a panel of DNA extracted from a various fungal species to explore the range of Aspergillus species that could be detected, but also potential cross reactivity with other fungal species. Positivity rates were calculated and regression analysis was performed to determine any associations between technical specifications and performance. The accuracy of Aspergillus genus specific assays was 71.8%, significantly greater (P < .0001) than assays specific for individual Aspergillus species (47.2%). For genus specific assays the most often missed species were A. lentulus (25.0%), A. versicolor (24.1%), A. terreus (16.1%), A. flavus (15.2%), A. niger (13.4%), and A. fumigatus (6.2%). There was a significant positive association between accuracy and using an Aspergillus genus PCR assay targeting the rRNA genes (P = .0011). Conversely, there was a significant association between rRNA PCR targets and false positivity (P = .0032). To conclude current Aspergillus PCR assays are better suited for detecting A. fumigatus, with inferior detection of most other Aspergillus species. The use of an Aspergillus genus specific PCR assay targeting the rRNA genes is preferential. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Pharmacokinetic/pharmacodynamic analysis of voriconazole against Candida spp. and Aspergillus spp. in children, adolescents and adults by Monte Carlo simulation.

    Science.gov (United States)

    Xu, Gaoqi; Zhu, Liqin; Ge, Tingyue; Liao, Shasha; Li, Na; Qi, Fang

    2016-06-01

    The objective of this study was to investigate the cumulative fraction of response of various voriconazole dosing regimens against six Candida and six Aspergillus spp. in immunocompromised children, immunocompromised adolescents, and adults. Using pharmacokinetic parameters and pharmacodynamic data, 5000-subject Monte Carlo simulations (MCSs) were conducted to evaluate the ability of simulated dosing strategies in terms of fAUC/MIC targets of voriconazole. According to the results of the MCSs, current voriconazole dosage regimens were all effective for children, adolescents and adults against Candida albicans, Candida parapsilosis and Candida orthopsilosis. For adults, dosing regimens of 4 mg/kg intravenous every 12 h (q12h) and 300 mg orally q12h were sufficient to treat fungal infections by six Candida spp. (C. albicans, C. parapsilosis, Candida tropicalis, Candida glabrata, Candida krusei and C. orthopsilosis) and five Aspergillus spp. (Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Aspergillus niger and Aspergillus nidulans). However, high doses should be recommended for children and adolescents in order to achieve better clinical efficacy against A. fumigatus and A. nidulans. The current voriconazole dosage regimens were all ineffective against A. niger for children and adolescents. All voriconazole dosage regimens were not optimal against Aspergillus versicolor. This is the first study to evaluate clinical therapy of various voriconazole dosing regimens against Candida and Aspergillus spp. infections in children, adolescents and adults using MCS. The pharmacokinetic/pharmacodynamic-based dosing strategy provided a theoretical rationale for identifying optimal voriconazole dosage regimens in children, adolescents and adults in order to maximise clinical response and minimise the probability of exposure-related toxicity. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  5. The biodiversity of Aspergillus section Flavi in brazil nuts: from rainforest to consumer.

    Science.gov (United States)

    Calderari, Thaiane O; Iamanaka, Beatriz T; Frisvad, Jens C; Pitt, John I; Sartori, Daniele; Pereira, Jose Luiz; Fungaro, Maria Helena P; Taniwaki, Marta H

    2013-01-01

    A total of 288 brazil nut samples (173 kernel and 115 shell) from the Amazon rainforest region and São Paulo State, Brazil were collected at different stages of brazil nut production. Samples were analysed for: percentages of aflatoxigenic fungal species and potential for aflatoxin production and presence of aflatoxins. Aspergillus nomius was the most common species found (1235 isolates) which amounted to 30% of the total species with potential to produce aflatoxins. This species is of concern since 100% of all isolates produced aflatoxins B(1), B(2), G(1) and G(2). Aspergillus flavus was almost equally common (1212 isolates) although only 46% produced aflatoxins under laboratory conditions, and only aflatoxins B(1) and B(2). Low number of other species with the potential to produce aflatoxins was isolated: Aspergillus arachidicola and Aspergillus bombycis produced B and G aflatoxins whilst Aspergillus pseudotamarii produced only aflatoxin B(1). The total aflatoxin levels found in samples taken from the rainforests was 0.7 μg/kg, from processing plants before and after sorting 8.0 and 0.1 μg/kg respectively, from street markets in the Amazon region 6.3 μg/kg and from supermarkets in São Paulo State 0.2 μg/kg. Processing, which included manual or mechanical sorting and drying at 60°C for 30 to 36 h, eliminated on average more than 98% of total aflatoxins. These results showed that sorting is a very effective way to decrease aflatoxin content in brazil nuts. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Aspergillus arthritis: analysis of clinical manifestations, diagnosis, and treatment of 31 reported cases.

    Science.gov (United States)

    Gamaletsou, Maria N; Rammaert, Blandine; Bueno, Marimelle A; Sipsas, Nikolaos V; Moriyama, Brad; Kontoyiannis, Dimitrios P; Roilides, Emmanuel; Zeller, Valerie; Taj-Aldeen, Saad J; Henry, Michael; Petraitis, Vidmantas; Denning, David W; Lortholary, Olivier; Walsh, Thomas J

    2017-04-01

    Aspergillus arthritis is a debilitating form of invasive aspergillosis. Little is known about its epidemiology, clinical manifestations, laboratory features, treatment, and prognosis. Cases of Aspergillus arthritis were reviewed in the English literature from 1967 through 2015 for variables of arthritis with Aspergillus spp. recovered from joint and/or adjacent bone, underlying conditions, symptoms, signs, inflammatory biomarkers, diagnostic imaging, management, and outcome. Among 31 evaluable cases, 87% were males and 13% pediatric. Median age was 50 y (range 1-83 y). Seventeen (55%) patients were immunosuppressed with such conditions as hematological malignancies (26%), corticosteroids (39%), and/or transplantation (26%). Approximately one-half (52%) of patients had hematogenous seeding of the joint, and more than 80% had de novo infection with no prior antifungal therapy. Oligoarticular infection (2-3 joints) occurred in 45% and contiguous osteomyelitis was present in 61%. Clinical manifestations included pain (87%), edema (26%), and limited function (23%), with knees (35%), intervertebral discs (26%), and hips (16%) being most commonly infected. Aspergillus fumigatus constituted 77% of cases followed by Aspergillus flavus in 13%, Aspergillus niger in 3%, and not specified in 7%. Median ESR was 90 mm/hr and median CRP was 3.6 mg/dl. Median synovial fluid WBC was 17,200/μL (7,300-128,000) with 72% PMNs (range 61-92). Osteolysis occurred in 35%, and soft-tissue extension 47%. Nineteen patients (61%) were managed with combined medical and surgical therapy, 10 (32%) with medical therapy only, and 2 (6%) surgery only. Amphotericin B and itraconazole were the most frequently used agents with median duration of therapy of 219 days (range 30-545). Surgical interventions included debridement in 61%, drainage 19%, and amputation 6%. Complete or partial response was achieved in 71% and relapse occurred in 16%. Medical therapy was reinstituted with successful outcome in

  7. Aspergillus and aflatoxin in groundnut (Arachis hypogaea L.) and groundnut cake in Eastern Ethiopia.

    Science.gov (United States)

    Mohammed, Abdi; Chala, Alemayehu; Dejene, Mashilla; Fininsa, Chemeda; Hoisington, David A; Sobolev, Victor S; Arias, Renee S

    2016-12-01

    This study was conducted to assess major Aspergillus species and aflatoxins associated with groundnut seeds and cake in Eastern Ethiopia and evaluate growers' management practices. A total of 160 groundnut seed samples from farmers' stores and 50 groundnut cake samples from cafe and restaurants were collected. Fungal isolation was done from groundnut seed samples. Aspergillus flavus was the dominant species followed by Aspergillus parasiticus. Aflatoxin analyses of groundnut seed samples were performed using ultra performance liquid chromatography; 22.5% and 41.3% of samples were positive, with total aflatoxin concentrations of 786 and 3135 ng g -1 from 2013/2014 and 2014/2015 samples, respectively. The level of specific aflatoxin concentration varied between 0.1 and 2526 ng g -1 for B 2 and B 1 , respectively. Among contaminated samples of groundnut cake, 68% exhibited aflatoxin concentration below 20 ng g -1 , while as high as 158 ng g -1 aflatoxin B 1 was recorded. The study confirms high contamination of groundnut products in East Ethiopia.

  8. Coinfection by Aspergillus and Zygomycetes Species in a Case of Acute Rhinosinusitis

    Directory of Open Access Journals (Sweden)

    Dhara Vaidya

    2011-01-01

    Full Text Available Invasive mycotic infections can be effectively treated if rapid identification of fungus is obtained. We reported a case of coinfection by Aspergillus and Rhizopus sp. involving nose, paranasal sinuses, orbit, and brain in a 68-year-old known hypertensive male. He was presented to ENT OPD with history of fever and intermittent headache since fifteen days along with history of right-sided nasal obstruction and proptosis since seven days. CT scan of brain and paranasal sinuses showed findings of pansinusitis with cellulitic changes in right orbit. MRI confirmed the same along with features of intracranial extension with focal meningitis in right frontotemporal region. Laboratory parameters did not conclude much except for leucocytosis and hyponatremia. Patient was taken for endoscopic debridement from nose and paranasal sinuses, and tissue was sent for microbiological and histopathological examination. Minced tissue was processed, and after 48 hrs of incubation two types of growth were identified, one was yellowish, granular, and powdery consistent with Aspergillus sp., and another was cottony and woolly consistent with Rhizopus sp. LCB mount confirmed presence of Aspergillus flavus and Rhizopus arrhizus. Patient responded to therapy with IV amphotericin B and surgical debridement. On discharge patient's condition was good.

  9. Monochrome LightCycler PCR assay for detection and quantification of five common species of Candida and Aspergillus.

    Science.gov (United States)

    Bu, Rong; Sathiapalan, Rajeev K; Ibrahim, Muna M; Al-Mohsen, Ibrahim; Almodavar, Edna; Gutierrez, Marina I; Bhatia, Kishor

    2005-03-01

    Invasive fungal pathogens, especially in immunocompromised hosts, can result in life-threatening infections. Current laboratory/radiological methods for fungal identification are time-consuming and lack sensitivity and specificity. A monochrome, multiplex, real-time PCR assay for the identification and quantification of Candida albicans, Candida krusei, Candida tropicalis, Aspergillus flavus and Aspergillus fumigatus is described here. Detection of each of these fungi was specific and demonstrated 100 % concordance with biochemical/culture identification in all 60 isolates tested. Samples from 16 febrile neutropenic patients with haematological malignancies were also analysed and the utility of the assay in clinical samples was reconfirmed without false-negative results. The sensitivity of this assay was 0.1 pg fungal genomic DNA, corresponding to three cells, for C. albicans, C. krusei, C. tropicalis and A. flavus, and 0.01 pg fungal genomic DNA, i.e. less than one cell, for A. fumigatus. The analysis allows a low-cost, simple, rapid and sensitive alternative for clinical identification and quantification of these five common fungal species.

  10. Clinical implications of globally emerging azole resistance in Aspergillus fumigatus.

    Science.gov (United States)

    Meis, Jacques F; Chowdhary, Anuradha; Rhodes, Johanna L; Fisher, Matthew C; Verweij, Paul E

    2016-12-05

    Aspergillus fungi are the cause of an array of diseases affecting humans, animals and plants. The triazole antifungal agents itraconazole, voriconazole, isavuconazole and posaconazole are treatment options against diseases caused by Aspergillus However, resistance to azoles has recently emerged as a new therapeutic challenge in six continents. Although de novo azole resistance occurs occasionally in patients during azole therapy, the main burden is the aquisition of resistance through the environment. In this setting, the evolution of resistance is attributed to the widespread use of azole-based fungicides. Although ubiquitously distributed, A. fumigatus is not a phytopathogen. However, agricultural fungicides deployed against plant pathogenic moulds such as Fusarium, Mycospaerella and A. flavus also show activity against A. fumigatus in the environment and exposure of non-target fungi is inevitable. Further, similarity in molecule structure between azole fungicides and antifungal drugs results in cross-resistance of A. fumigatus to medical azoles. Clinical studies have shown that two-thirds of patients with azole-resistant infections had no previous history of azole therapy and high mortality rates between 50% and 100% are reported in azole-resistant invasive aspergillosis. The resistance phenotype is associated with key mutations in the cyp51A gene, including TR 34 /L98H, TR 53 and TR 46 /Y121F/T289A resistance mechanisms. Early detection of resistance is of paramount importance and if demonstrated, either with susceptibility testing or through molecular analysis, azole monotherapy should be avoided. Liposomal amphotericin B or a combination of voriconazole and an echinocandin are recomended for azole-resistant aspergillosis.This article is part of the themed issue 'Tackling emerging fungal threats to animal health, food security and ecosystem resilience'. © 2016 The Author(s).

  11. Aspergillus-Related Lung Disease

    Directory of Open Access Journals (Sweden)

    Alia Al-Alawi

    2005-01-01

    Full Text Available Aspergillus is a ubiquitous dimorphic fungus that causes a variety of human diseases ranging in severity from trivial to life-threatening, depending on the host response. An intact host defence is important to prevent disease, but individuals with pre-existing structural lung disease, atopy, occupational exposure or impaired immunity are susceptible. Three distinctive patterns of aspergillus-related lung disease are recognized: saprophytic infestation of airways, cavities and necrotic tissue; allergic disease including extrinsic allergic alveolitis, asthma, allergic bronchopulmonary aspergillosis, bronchocentric granulomatosis and chronic eosinophilic pneumonia; and airway and tissue invasive disease -- pseudomembranous tracheobronchitis, acute bronchopneumonia, angioinvasive aspergillosis, chronic necrotizing aspergillosis and invasive pleural disease. A broad knowledge of these clinical presentations and a high index of suspicion are required to ensure timely diagnosis and treatment of the potentially lethal manifestations of aspergillus-related pulmonary disease. In the present report, the clinical, radiographic and pathological aspects of the various aspergillus-related lung diseases are briefly reviewed.

  12. The use of ionising radiation from 60CO gamma source in controlling mouldiness in dried cocoa beans

    International Nuclear Information System (INIS)

    Appiah, Victoria

    2001-01-01

    Mouldiness in stored cocoa beans in Ghana and the production of aflatoxin have been studied. Based on actual weight of discarded beans, mouldy beans have been estimated to constitute 0.13 % and 0.00002 % of marketable beans at the farmers' level and the buying agents' depots respectively in the Tafo District. This is contrasted with an estimated value of 0.16 % obtained in a questionnaire type study involving farmers. Estimated mouldy beans at the Tema port was 0.69 % per year (based on the cut test) representing a financial loss of $1,688,637.19 per year at $989/T should the mouldy beans be discarded. Fifty-eight (58) internally- and externally- borne fungal species were isolated from dried cocoa beans. Of these, forty-eight (48) were internally- borne and ten (10) were superficial. Twenty-nine (29) of the internally occurring fungi have been recorded for the first time on cocoa beans in Ghana. Twenty-six (26) of the fungi isolated belong to Aspergillus group. They included A. parasiticus and A. flavus, which can produce aflatoxins. Five (5) belong to Penicillium, eight (8) to Fusarium and nineteen (19) to other species. Ionising radiation effectively controlled fungi associated with mouldiness in cocoa beans in a dose - dependent manner. A radiation dose of 6 kGy completely inactivated the moulds. A. flavus and A. tamarii were the most radiation - resistant moulds encountered. The moisture content of the beans before, during and after irradiation influenced the effect of radiation. The relative humidity during storage and the type of packaging also influenced the radiation effect. Conidia of A. flavus subjected to moist heat at temperatures 20 0 C to 60 0 C for 2.5, 5 and 10 min respectively were not significantly affected by heating up to 50 0 C. Heating an aqueous conidial suspension at 60 0 C for at least 2.5 min reduced the number of fungal colonies by at least 5 log cycles when the suspension was assayed on agar plate media. Heating at 59 0 C for 10 min

  13. Modulation of antimicrobial metabolites production by the fungus Aspergillus parasiticus.

    Science.gov (United States)

    Bracarense, Adriana A P; Takahashi, Jacqueline A

    2014-01-01

    Biosynthesis of active secondary metabolites by fungi occurs as a specific response to the different growing environments. Changes in this environment alter the chemical and biological profiles leading to metabolites diversification and consequently to novel pharmacological applications. In this work, it was studied the influence of three parameters (fermentation length, medium composition and aeration) in the biosyntheses of antimicrobial metabolites by the fungus Aspergillus parasiticus in 10 distinct fermentation periods. Metabolism modulation in two culturing media, CYA and YES was evaluated by a 2(2) full factorial planning (ANOVA) and on a 2(3) factorial planning, role of aeration, medium composition and carbohydrate concentration were also evaluated. In overall, 120 different extracts were prepared, their HPLC profiles were obtained and the antimicrobial activity against A. flavus, C. albicans, E. coli and S. aureus of all extracts was evaluated by microdilution bioassay. Yield of kojic acid, a fine chemical produced by the fungus A. parasiticus was determined in all extracts. Statistical analyses pointed thirteen conditions able to modulate the production of bioactive metabolites by A. parasiticus. Effect of carbon source in metabolites diversification was significant as shown by the changes in the HPLC profiles of the extracts. Most of the extracts presented inhibition rates higher than that of kojic acid as for the extract obtained after 6 days of fermentation in YES medium under stirring. Kojic acid was not the only metabolite responsible for the activity since some highly active extracts showed to possess low amounts of this compound, as determined by HPLC.

  14. Tolerancia a endosulfan de Aspergillus flavus aislados de suelos agrícolas destinados al cultivo de oleaginosas

    OpenAIRE

    Barberis, Carla; Asurmendi, Paula; Carranza, Cecilia Soledad; Dalcero, Ana Maria; Magnoli, Carina Elizabeth

    2015-01-01

    En nuestro país, pesticidas tales como endosulfan, son de importancia durante el desarrollo del cultivo de soja y maní. La Agencia de Protección Ambiental (EPA, USA,), clasifica a este como alta y agudamente tóxico. Debido a las preocupaciones asociadas con la acumulación de plaguicidas en alimentos y agua, en la actualidad existe una gran necesidad de desarrollar métodos seguros, convenientes y económicamente viables para la degradación de éstas sustancias. La acción de los microorganismos d...

  15. Retting of Flax by Aspergillus niger.

    Science.gov (United States)

    De França, F P; Rosemberg, J A; De Jesus, A M

    1969-01-01

    In this study, retting was carried out by Aspergillus niger. The pH, galacturonic acid (GA), and total reducing sugar were determined; the end point was identified by the classic empirical processes and by the maximal GA content of the retting water. The process gave clear and resistent fibers, and the retting time was similar to that of current industrial processes with bacterial enzymes. Control of total acidity was not required, since the pH remained close to neutrality throughout the entire process.

  16. Retting of Flax by Aspergillus niger

    Science.gov (United States)

    De França, F. P.; Rosemberg, J. A.; De Jesus, A. M.

    1969-01-01

    In this study, retting was carried out by Aspergillus niger. The pH, galacturonic acid (GA), and total reducing sugar were determined; the end point was identified by the classic empirical processes and by the maximal GA content of the retting water. The process gave clear and resistent fibers, and the retting time was similar to that of current industrial processes with bacterial enzymes. Control of total acidity was not required, since the pH remained close to neutrality throughout the entire process. PMID:16349835

  17. 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.

  18. Obstructive cholelithiasis and cholecystitis in a kinkajou (Potos flavus).

    Science.gov (United States)

    Potier, Romain; Reineau, Olivier

    2015-03-01

    A 14.5-yr-old female kinkajou (Potos flavus) was diagnosed with cholelithiasis after an episode of vomiting; diagnostics included biochemical analysis and abdominal ultrasound exam. Despite antimicrobial treatment, cholelithiasis led to cholecystitis. A cholecystotomy was performed to remove choleliths and inspissated bile. Morphological and spectroscopic properties of the choleliths were similar to those of gallstones from the brown pigment family and Streptococcus sp. and Escherichia coli were isolated from the bile. Biliary tract infection is directly related to pathogenesis of brown pigment gallstones. Serial ultrasound exams revealed that cholecystitis developed secondary to the presence of gallstones in the biliary tree. Despite full recovery postsurgery, the patient died 15 mo later from gallbladder necrosis. Based on the progression of this case, a cholecystectomy would be preferred over a cholecystotomy in similar cases, and the efficacy of long-acting antibiotics may not be adequate in nontarget species. Gallstones and biliary tract infection are rarely described in small domestic carnivores, and this is the first reported case in a kinkajou.

  19. Efficient production of Arthromyces ramosus peroxidase by Aspergillus awamori

    NARCIS (Netherlands)

    Lokman, B.C.; Joosten, V.; Hovenkamp, J.; Gouka, R.J.; Verrips, C.T.; Hondel, C.A.M.J.J. van den

    2003-01-01

    The heterologous production of Arthromyces ramosus peroxidase (ARP) was analysed in the filamentous fungus Aspergillus awamori under control of the inducible endoxylanase promoter. Secretion of active ARP was achieved up to 800 mg l-1 in shake flask cultures. Western blot analysis showed that an

  20. Effects Of Solid State Fermentation By Aspergillus niger and ...

    African Journals Online (AJOL)

    fermentation and incubated for O (control), 4,8 and 10 days to evaluate the changes in crude protein (CP), crude fibre (CF), neutral detergent fibre (NDF), acid detergent fibre (ADF) and hemicellulose (HEMI). Ten days after inoculation of Cassava peel meal (CPM) with Aspergillus niger, the crude protein increased from ...

  1. Expression of human lymphotoxin alpha in Aspergillus niger

    NARCIS (Netherlands)

    Krasevec, N.; Hondel, C.A.M.J.J. van de; Komel, R.

    2000-01-01

    A gene-fusion expression strategy was applied for heterologous expression of human lymphotoxin alpha (LTα) in the Aspergillus niger AB1.13 protease-deficient strain. The LTα gene was fused with the A. niger glucoamylase GII-form as a carrier-gene, behind its transcription control and secretion

  2. In Vitro Pharmacokinetic/Pharmacodynamic Modeling of Voriconazole Activity against Aspergillus Species in a New In Vitro Dynamic Model

    Science.gov (United States)

    Al-Saigh, R.; Elefanti, A.; Velegraki, A.; Zerva, L.

    2012-01-01

    The pharmacodynamics (PD) of voriconazole activity against Aspergillus spp. were studied using a new in vitro dynamic model simulating voriconazole human pharmacokinetics (PK), and the PK-PD data were bridged with human drug exposure to assess the percent target (near-maximum activity) attainment of different voriconazole dosages. Three Aspergillus clinical isolates (1 A. fumigatus, 1 A. flavus, and 1 A. terreus isolate) with CLSI MICs of 0.5 mg/liter were tested in an in vitro model simulating voriconazole PK in human plasma with Cmax values of 7, 3.5, and 1.75 mg/liter and a t1/2 of 6 h. The area under the galactomannan index-time curve (AUCGI) was used as the PD parameter. In vitro PK-PD data were bridged with population human PK of voriconazole exposure, and the percent target attainment was calculated. The in vitro PK-PD relationship of fAUC0-24-AUCGI followed a sigmoid pattern (global R2 = 0.97), with near-maximum activities (10% fungal growth) observed at an fAUC0-24 (95% confidence interval [CI]) of 18.9 (14.4 to 23.1) mg · h/liter against A. fumigatus, 26.6 (21.1 to 32.9) mg · h/liter against A. flavus, and 36.2 (27.8 to 45.7) mg · h/liter against A. terreus (F test; P voriconazole dosages was 24% (11 to 45%), 80% (32 to 97%), and 93% (86 to 97%) for A. fumigatus, 12% (5 to 26%), 63% (17 to 93%), and 86% (73 to 94%) for A. flavus, and 4% (2 to 11%), 36% (6 to 83%), and 68% (47 to 83%) for A. terreus. Based on the in vitro exposure-effect relationships, a standard dosage of voriconazole may be adequate for most patients with A. fumigatus but not A. flavus and A. terreus infections, for which a higher drug exposure may be required. This could be achieved using a higher voriconazole dosage, thus highlighting the usefulness of therapeutic drug monitoring in patients receiving a standard dosage. PMID:22869563

  3. Microbiological quality of cold smoked sardine, Sardinella ...

    African Journals Online (AJOL)

    ... Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus wentii, Fusarium sp., Mucor sp, Penicillium sp, Rhizopus stolonifer, Saccharomyces sp. and Trichoderma sp. were found in the samples. The lowest mean for bacterial count was 0.350x106 cfu/g for smoked fish from the control in October (wet season) ...

  4. Selection arena in Aspergillus nidulans

    NARCIS (Netherlands)

    Bruggeman, J.; Debets, A.J.M.; Hoekstra, R.F.

    2004-01-01

    The selection arena hypothesis states that overproduction of zygotes-a widespread phenomenon in animals and plants-can be explained as a mechanism of progeny choice. As a similar mechanism, the ascomycetous fungus Aspergillus nidulans may overproduce dikaryotic fruit initials, hereafter called

  5. The Aspergillus Mine - publishing bioinformatics

    DEFF Research Database (Denmark)

    Vesth, Tammi Camilla; Rasmussen, Jane Lind Nybo; Theobald, Sebastian

    with the Joint Genome Institute. The Aspergillus Mine is not intended as a genomic data sharing service but instead focuses on creating an environment where the results of bioinformatic analysis is made available for inspection. The data and code is public upon request and figures can be obtained directly from...

  6. Nitrile biotransformation by Aspergillus niger

    Czech Academy of Sciences Publication Activity Database

    Šnajdrová, Radka; Kristová, Veronika; Crestia, D.; Nikolaou, K.; Kuzma, Marek; Lemaire, M.; Gallienne, E.; Bolte, J.; Bezouška, K.; Křen, Vladimír; Martínková, Ludmila

    2004-01-01

    Roč. 29, - (2004), s. 227-232 ISSN 1381-1177 R&D Projects: GA MŠk OC D25.002; GA AV ČR IAA4020213 Institutional research plan: CEZ:AV0Z5020903 Keywords : aspergillus niger * nitrile-converting enzymes * nitrile hydratase Subject RIV: EE - Microbiology, Virology Impact factor: 1.547, year: 2004

  7. 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.

  8. Determination of unique microbial volatile organic compounds produced by five Aspergillus species commonly found in problem buildings.

    Science.gov (United States)

    Gao, Pengfei; Korley, Frederick; Martin, Jennifer; Chen, Bean T

    2002-01-01

    This study identified unique microbial volatile organic compounds (UMVOCs) produced by five Aspergillus species (A. fumigatus, A. versicolor, A. sydowi, A. flavus, and A. niger) cultivated on malt extract agar and gypsum board. The hypothesis was that UMVOCs can be used to predict the presence of Aspergillus species. During the cultivation humidified air was continually supplied and evenly distributed through each of the culture flasks. Volatile metabolites were collected using Tenax TA tubes on Days 8, 16, and 30 after inoculation. The volatile metabolites were determined by gas chromatography/mass spectroscopy after thermal desorption. Nine compounds recognized as UMVOCs--3-methyl-1-butanol; 2-methyl-1-propanol; terpineol; 2-heptanone; 1-octen-3-ol; dimethyl disulfide; 2-hexanone; 3-octanone; and 2-pentylfuran--were found on the cultures in detectable amounts. The first two compounds were detected at the highest frequency when combining both media. The first four compounds were found to be the dominant UMVOCs on gypsum board, which could be used as chemical markers of the common Aspergillus species grown indoors.

  9. Retraction of colonies and structures of Aspergillus Spp. as a possible high dose sensor

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Valeria B., E-mail: valeriabborges@hotmail.com [Coordenacao dos Programas de Pos-Graduacao em Processos Quimicos e Bioquimicos (EQ/UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica; Vital, Helio C., E-mail: vital@ctex.eb.br [Centro Tecnologico do Exercito (DDQBN/CTEx), Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear. Secao de Defesa Nuclear; Moraes, Aurea M.L., E-mail: ltbbf@ioc.fiocruz.br [Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Departamento de Micologia

    2013-07-01

    Changes in the length of macro-and microscopic structures of irradiated Aspergillus spp. colonies were investigated in this work in search for correlations with radiation dose. Effects related to growth and morphology produced by exposure to radiation doses ranging from 0.0 up to 8.0 kGy on strains of A. flavus (CMT 00079), A. parasiticus (CMT 00064) and A ochraceus (CMT 00145) were analyzed. Fungal colonies were inoculated on fresh peanut seeds and incubated for 5 days at 25°C. On the sixth day the samples were irradiated and moved to Petri dishes containing PDA culture medium where they remained incubated for 7 days at 25°C Post irradiation growth was periodically monitored by visual inspections and measurements of mycelial diameters. In addition, microscopic analyses were performed to determine the length of the major structures of the colonies. It has been found that irradiation causes a decrease in the diameter of colonies as well as in the length of microscopic structures of the fungus. The amount of retraction has been found to be strongly correlated to radiation dose. Such findings hint at the possibility of using in situ Aspergillus spp. colonies as high-dose living dosimeters in the event of massive radiation exposures. (author)

  10. 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.

  11. Pre-termination in aflR of Aspergillus sojae inhibits aflatoxin biosynthesis.

    Science.gov (United States)

    Matsushima, K; Chang, P K; Yu, J; Abe, K; Bhatnagar, D; Cleveland, T E

    2001-05-01

    The aflR gene product is the main transcriptional regulator of aflatoxin biosynthesis in Aspergillus parasiticus and Aspergillus flavus. Although A. sojae strains do not produce aflatoxins, they do have an aflR homologue. When compared with the aflR of A. parasiticus, the A. sojae gene contains two mutations: an HAHA motif and a premature stop codon. To investigate the functionality of the A. sojae aflR gene product, we used a GAL4 one-hybrid system in yeast. The transcription-activating activity of AflR from A. sojae was 15% of that from A. parasiticus. The introduction of an additional aflR from A. sojae into an A. parasiticus strain did not affect aflatoxin productivity. A hybrid aflR comprising the amino-terminal region of A. sojae aflR and the carboxy-terminal region of A. parasiticus aflR suppressed the effect associated with pre-termination of the A. sojae AflR. We conclude that the premature stop codon of the A. sojae aflR is the key to its functionality and leads to prevention of aflatoxin biosynthesis through loss of the transcription of aflatoxin biosynthesis-related genes.

  12. Biochemical properties and primary structure of elastase inhibitor AFUEI from Aspergillus fumigatus.

    Science.gov (United States)

    Okumura, Yoshiyuki; Matsui, Takeshi; Ogawa, Kenji; Uchiya, Kei-ichi; Nikai, Toshiaki

    2008-07-01

    An elastase inhibitor from Aspergillus fumigatus (AFUEI) was isolated, and its biochemical properties and primary structure examined. The inhibitor was purified by column chromatography using DE52 cellulose and Sephadex G-75, and was found to be homogeneous as indicated by a single band following discontinuous PAGE and SDS-PAGE. A molecular mass of 7525.1 Da was observed by matrix-assisted desorption/ionization time-of-flight mass spectroscopy. The elastolytic activity of elastases from A. fumigatus, Aspergillus flavus and human leukocytes was inhibited by AFUEI. However, the elastolytic activity of porcine pancreas elastase, Pseudomonas aeruginosa elastase and elastase from snake venom was not affected by AFUEI. No inhibitory effect of DTT or 2-mercaptoethanol on the elastase inhibitory activity of AFUEI was observed. The amino acid sequence of AFUEI peptides derived from digests utilizing clostripain was determined by Edman sequencing. AFUEI was composed of 68 aa and had a calculated molecular mass of 7526.2 Da. The search for amino acid homology with other proteins demonstrated that aa 1-68 of AFUEI are 100 % identical to aa 20-87 of the hypothetical protein AFUA 3G14940 of A. fumigatus.

  13. Retraction of colonies and structures of Aspergillus Spp. as a possible high dose sensor

    International Nuclear Information System (INIS)

    Borges, Valeria B.; Vital, Helio C.; Moraes, Aurea M.L.

    2013-01-01

    Changes in the length of macro-and microscopic structures of irradiated Aspergillus spp. colonies were investigated in this work in search for correlations with radiation dose. Effects related to growth and morphology produced by exposure to radiation doses ranging from 0.0 up to 8.0 kGy on strains of A. flavus (CMT 00079), A. parasiticus (CMT 00064) and A ochraceus (CMT 00145) were analyzed. Fungal colonies were inoculated on fresh peanut seeds and incubated for 5 days at 25°C. On the sixth day the samples were irradiated and moved to Petri dishes containing PDA culture medium where they remained incubated for 7 days at 25°C Post irradiation growth was periodically monitored by visual inspections and measurements of mycelial diameters. In addition, microscopic analyses were performed to determine the length of the major structures of the colonies. It has been found that irradiation causes a decrease in the diameter of colonies as well as in the length of microscopic structures of the fungus. The amount of retraction has been found to be strongly correlated to radiation dose. Such findings hint at the possibility of using in situ Aspergillus spp. colonies as high-dose living dosimeters in the event of massive radiation exposures. (author)

  14. Development of novel real-time PCR assays for detection and differentiation of eleven medically important Aspergillus and Candida species in clinical specimens.

    Science.gov (United States)

    Schabereiter-Gurtner, Claudia; Selitsch, Brigitte; Rotter, Manfred L; Hirschl, Alexander M; Willinger, Birgit

    2007-03-01

    In the present study, novel real-time PCR assays targeting the fungal ITS2 region were developed for the detection and differentiation of medically important Aspergillus species (Aspergillus fumigatus, Aspergillus flavus, Aspergillus nidulans, Aspergillus niger, and Aspergillus terreus) and Candida species (Candida albicans, Candida dubliniensis, Candida glabrata, Candida krusei, Candida parapsilosis, and Candida tropicalis) using a LightCycler instrument. The combination of a group-specific and a universal primer with five Aspergillus or six Candida species-specific biprobes in one reaction mixture facilitated rapid screening and species differentiation by the characteristic peak melting temperatures of the biprobes. Both assays can be performed either as single assays or simultaneously in the same LightCycler run. The analytical sensitivity using pure cultures and EDTA-anticoagulated blood, cerebrospinal fluid (CSF), and tissue samples spiked with A. fumigatus and C. albicans cell suspensions was shown to be at least 1 CFU per PCR, corresponding to 5 to 10 CFU/ml blood and 10 CFU/200 microl CSF or 0.02 g tissue. To assess the clinical applicability, 26 respiratory samples, 4 tissue samples from the maxillary sinus, and 1 blood sample were retrospectively tested and real-time PCR results were compared with results from culture, histology, or a galactomannan enzyme-linked immunosorbent assay (ELISA). Twenty samples (64.5%) were both culture positive and positive by real-time PCR. Six samples (19.4%) showed no growth of fungi but were positive by real-time PCR. However, all of the tissue samples were positive by both PCR and histology. The blood sample showed no growth of Aspergillus, but aspergillosis was confirmed by positive galactomannan ELISA, histology, and PCR results. The remaining samples (16.1%) were culture and PCR negative; also, no other signs indicating fungal infection were observed. Our data suggest that the Aspergillus and Candida assays may be

  15. Involvement of the opportunistic pathogen Aspergillus tubingensis in osteomyelitis of the maxillary bone: A case report

    NARCIS (Netherlands)

    Bathoorn, E.; Escobar Salazar, N.; Sepehrkhouy, S.; Meijer, M.; de Cock, H.; Haas, P.J.

    2013-01-01

    Background: Aspergillus tubingensis is a black Aspergillus belonging to the Aspergillus section Nigri, which includes species that morphologically resemble Aspergillus niger. Recent developments in species determination have resulted in clinical isolates presumed to be Aspergillus niger being

  16. Hyphal heterogeneity in Aspergillus niger

    OpenAIRE

    de Bekker, A.M.

    2011-01-01

    Mycelial fungi use hyphae to colonize substrates. These hyphae secrete enzymes that convert complex polymers into breakdown products that can be taken up to serve as nutrients. Using GFP as a reporter it has been shown that exploring hyphae of Aspergillus niger are heterogenic with respect to expression of the glucoamylase gene glaA; some hyphae strongly express the glucoamylase gene glaA, while others express it lowly. This was a surprising finding considering the fact that all hyphae were e...

  17. Germination of Aspergillus niger conidia

    OpenAIRE

    Hayer, Kimran

    2014-01-01

    Aspergillus niger is a black-spored filamentous fungus that forms asexual spores called conidospores (‘conidia’). Germination of conidia, leading to the formation of hyphae, is initiated by conidial swelling and mobilisation of endogenous carbon and energy stores, followed by polarisation and emergence of a hyphal germ tube. These morphological and biochemical changes which define the model of germination have been studied with the aim of understanding how conidia sense and utilise different...

  18. Regulatory processes in Aspergillus niger

    OpenAIRE

    Poulsen, Lars; Thykær, Jette; Eliasson Lantz, Anna

    2012-01-01

    Filamentous fungi are extensively used in the fermentation industry for synthesis of numerous products. One of the most important, is the fungus Aspergillus niger, used industrially for production of organic acids, and homologous as well as heterologous enzymes. This fungus has numerous of advantages, including tolerance for low pH, which is important for acid production. Furthermore, it has the capability of metabolizing a wide variety of carbon sources, possesses an exceptional efficient pr...

  19. Fatal invasive aspergillosis caused by Aspergillus niger after bilateral lung transplantation

    Directory of Open Access Journals (Sweden)

    Enora Atchade

    2017-09-01

    Full Text Available Aspergillus niger is usually considered to be a low virulence fungus, not commonly reported to cause invasive infections. Invasive pulmonary aspergillosis due to Aspergillus niger was diagnosed in a 43-year-old woman following bilateral lung transplantation. Intravenous voriconazole failed to control progression of the disease. Despite salvage therapy with a combination of voriconazole and caspofungin for 23 days, the patient developed massive hemoptysis leading to death. The authors report the clinical features and treatment of this case.

  20. A p53-like transcription factor similar to Ndt80 controls the response to nutrient stress in the filamentous fungus, Aspergillus nidulans [v1; ref status: indexed, http://f1000r.es/y2

    Directory of Open Access Journals (Sweden)

    Margaret E Katz

    2013-03-01

    Full Text Available The Aspergillus nidulans xprG gene encodes a putative transcriptional activator that is a member of the Ndt80 family in the p53-like superfamily of proteins. Previous studies have shown that XprG controls the production of extracellular proteases in response to starvation. We undertook transcriptional profiling to investigate whether XprG has a wider role as a global regulator of the carbon nutrient stress response. Our microarray data showed that the expression of a large number of genes, including genes involved in secondary metabolism, development, high-affinity glucose uptake and autolysis, were altered in an xprGΔ null mutant. Many of these genes are known to be regulated in response to carbon starvation. We confirmed that sterigmatocystin and penicillin production is reduced in xprG- mutants. The loss of fungal mass and secretion of pigments that accompanies fungal autolysis in response to nutrient depletion was accelerated in an xprG1 gain-of-function mutant and decreased or absent in an xprG- mutant. The results support the hypothesis that XprG plays a major role in the response to carbon limitation and that nutrient sensing may represent one of the ancestral roles for the p53-like superfamily. Disruption of the AN6015 gene, which encodes a second Ndt80-like protein, showed that it is required for sexual reproduction in A. nidulans.

  1. Xanthobacter flavus employs a single triosephosphate isomerase for heterotrophic and autotrophic metabolism

    NARCIS (Netherlands)

    Meijer, WG; deBoer, P; vanKeulen, G

    The expression of the cbb and gap-pgk operons of Xanthobacter flavus encoding enzymes of the Calvin cycle is regulated by the transcriptional regulator CbbR. In order to identify other genes involved in the regulation of these operons, a mutant was isolated with a lowered activity of a fusion

  2. Identification and organization of carbon dioxide fixation genes in Xanthobacter flavus H4-14

    NARCIS (Netherlands)

    Meijer, Wim G.; Arnberg, Annika; Enequist, Hans G.; Terpstra, Peter; Lidstrom, Mary E.; Dijkhuizen, Lubbert

    The genes encoding the large (cfxL) and small (cfxS) subunits of ribulose-1,5-bisphosphate carboxylase (RuBisC/O) from Xanthobacter flavus H4-14 were identified and characterized. The RuBisC/O genes are separated by 11 bp and cotranscribed in Escherichia coli from the lac promoter in the order

  3. Mycobiota of Slovak wine grapes with emphasis on Aspergillus and Penicillium species in the small carpathian area

    Directory of Open Access Journals (Sweden)

    Soňa Felšöciová

    2015-12-01

    Full Text Available The Slovak wine-growing region is divided into six viticulture areas. The largest in size and the most important over the centuries has been the Small Carpathian area (around 5800 ha of vineyards spreads in the western of Slovakia. The objectives of this study were: to gain more knowledge about mycobiota on grapes originating from Slovakia, with a focus on genera Aspergillus and Penicillium and their ability to produce mycotoxins in in vitro conditions by thin layer chromatography method. From the twelve vineyards were collected 14 samples of wine grapes (white 6, blue 8 during harvesting 2011, 2012 and 2013. Fifty wine grapes per bunch (approximately 7-8 berries per plate that showed no symptoms were randomly selected on Dichloran Rose Bengal Chloramphenicol agar medium. The plates were then incubated aerobically at 25 ±1 °C for 5 to 7 days in the dark. Of these samples were identified 22 genera. Ninety-three percent of samples were colonies by the genus Penicillium and 79% by the genus Aspergillus. During the survey, 251 isolates belonging to 14 Penicillium species (P. aurantiogriseum, P. citrinum, P. coprophylum, P. crustosum, P. expansum, P. funiculosum, P. glabrum, P. griseofulvum, P. chrysogenum, P. oxalicum, P. polonicum, P. purpurogenum, P. roqueforti and P. thomii and 37 isolates belonging to 7 Aspergillus species (A. clavatus, A. flavus, A. section Nigri, A. ostianus, A. parasiticus, A. versicolor and A. westerdijkiae were isolated and identified from exogenous contamination. The main occurring penicillium species of the samples were P. chrysogenum (36% Fr, followed P. crustosum (29% Fr, P. griseofulvum (21% Fr and P. expansum (21% Fr. The main occurring aspergillus species of the samples were A. section Nigri (64%. Thirteen potentially toxigenic species were tested for their toxigenic ability. It was confirmed the production of various mycotoxins such as aflatoxin B1, G1, citrinin, griseofulvin, patulin, cyclopiazonic acid, penitrem

  4. Effect of simulated microgravity on Aspergillus niger

    Science.gov (United States)

    Pratap, Jeffrey J.

    2005-08-01

    A rotating bioreactor was developed to simulate microgravity and its influence was studied on fungal growth. The reactor was designed to simulate microgravity using 'free fall' principle, which creates an apparent weightlessness for a brief period of time. In this experiment, a sealed vertically rotating tube is the reactor in which the cells are grown. For the first time vertically rotating tubes were used to obtain 'free fall' thereby simulating microgravity. Simulated microgravity served significant in the alteration of growth and productivity of Aspergillus niger, a common soil fungi. Two other sets of similar cultures were maintained as still and shake control cultures to compare with the growth and productivity of cells in rotating culture. It was found increased growth and productivity occurred in simulated microgravity. Since this experiment involves growth of cells in a liquid medium, the fluidic effects must also be studied which is a limitation.

  5. 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®

  6. Evaluation of aflatoxicosis in hens fed with commercial poultry feed

    OpenAIRE

    DHANASEKARAN, Dharumadurai; PANNEERSELVAM, Annamalai; THAJUDDIN, Noorudin

    2014-01-01

    The effect of aflatoxin in the growth of hens was histopathologically analyzed. Mycotoxigenic fungi were isolated and characterized as Aspergillus flavus and Aspergillus niger. The aflatoxin was extracted from Aspergillus flavus and their impact on the growth pattern of hens was evaluated. The histopathological analysis reveals that more lesions were found in the vital organs of hens in comparison with the control chick group. In the present study, it is concluded that the quality of poultry ...

  7. Liver injury in invasive aspergillus. Echographic findings

    International Nuclear Information System (INIS)

    Otero Fernandez, R.; Garcia Revillo, J.; Paez Moreno, J.; Zurera Tendero, L.J.

    1994-01-01

    Aspergillus is the second most common mycoses in immuno compromised patients. The invasive form is associated with a mortality of approximately 100%. We present a case of invasive aspergillus in a heart transplant recipient in whom ultrasound disclosed the presence of liver injury which was later confirmed by necropsy. We review the available literature. (Author) 15 refs

  8. Infectious keratitis caused by Aspergillus tubingensis

    NARCIS (Netherlands)

    Kredics, L.; Varga, J.; Kocsube, S.; Rajaraman, R.; Raghavan, A.; Doczi, I.; Bhaskar, M.; Nemeth, T.M.; Antal, Z.; Venkatapathy, N.; Vagvolgyi, C.; Samson, R.A.; Chockaiya, M.; Palanisamy, M.

    2009-01-01

    PURPOSE: To report 2 cases of keratomycosis caused by Aspergillus tubingensis. METHODS: The therapeutic courses were recorded for 2 male patients, 52 and 78 years old, with fungal keratitis caused by black Aspergillus strains. Morphological examination of the isolates was carried out on malt extract

  9. Sporulation inhibited secretion in Aspergillus niger

    NARCIS (Netherlands)

    Krijgsheld, P.

    2013-01-01

    Aspergillus niger is abundantly found in nature. It degrades dead material of plants and animals but can also be a pathogen of these organisms. Aspergillus niger is also important for mankind because it is one of the main organisms used for the industrial production of enzymes. These enzymes are

  10. Aspergillus infections of the lung

    International Nuclear Information System (INIS)

    Nicolas, V.; Hottenrott, K.; Hossfeld, D.K.

    1989-01-01

    In this article the three different manifestations of pulmonary aspergillosis are compared with each other: Bronchopulmonary aspergillosis, aspergilloma and invasive pulmonary aspergillosis, and their different clinical and radiological manifestations. In particular, invasive pulmonary aspergillosis - being a severe complication in immuno-suppressed patients whose defenses are weak - often presents diagnostic problems due to its initially mostly unspecific clinical and radiological signs. The late signs of a pulmonary aspergillus infection, such as formation of a cavern or the manifestation of the 'air crescent' sign, however, are seen only when the patient is just beginning to convalesce. (orig.) [de

  11. Lysine aminopeptidase of Aspergillus niger

    OpenAIRE

    Basten, D.E.J.W.; Visser, J.; Schaap, P.J.

    2001-01-01

    Conserved regions within the M1 family of metallo-aminopeptidases have been used to clone a zinc aminopeptidase from the industrially used fungus Aspergillus niger. The derived amino acid sequence of ApsA is highly similar to two yeast zinc aminopeptidases, LAPI and AAPI (53.3 and 50.9␘verall similarity, respectively), two members of the M1 family of metallo-aminopeptidases. The encoding gene was successfully overexpressed in A. niger and the overexpressed product was purified and characteriz...

  12. Heterologous expression of Gaeumannomyces graminis lipoxygenase in Aspergillus nidulans

    NARCIS (Netherlands)

    Heshof, R.; Schayck, van J.P.; Tamayo Ramos, J.A.; Graaff, de L.H.

    2014-01-01

    Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain

  13. Decolorization of molasses spent wash by the white-rot fungus Flavodon flavus, isolated from a marine habitat

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Rivonkar, G.

    Flavodon flavus (Klotzsch) Ryvarden, a basidiomycete (NIOCC strain 312) isolated from decomposing leaves of a sea grass, decolorized pigments in molasses spent wash (MSW) by 80% after 8 days of incubation, when used at concentrations of 10% and 50...

  14. Aspergillus niger contains the cryptic phylogenetic species A. awamori

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Stea, Gaetano; Epifani, Filomena

    2011-01-01

    Aspergillus section Nigri is an important group of species for food and medical mycology, and biotechnology. The Aspergillus niger ‘aggregate’ represents its most complicated taxonomic subgroup containing eight morphologically indistinguishable taxa: A. niger, Aspergillus tubingensis, Aspergillus...... acidus, Aspergillus brasiliensis, Aspergillus costaricaensis, Aspergillus lacticoffeatus, Aspergillus piperis, and Aspergillus vadensis. Aspergillus awamori, first described by Nakazawa, has been compared taxonomically with other black aspergilli and recently it has been treated as a synonym of A. niger....... Phylogenetic analyses of sequences generated from portions of three genes coding for the proteins β-tubulin (benA), calmodulin (CaM), and the translation elongation factor-1 alpha (TEF-1α) of a population of A. niger strains isolated from grapes in Europe revealed the presence of a cryptic phylogenetic species...

  15. Ribonuclease Production by Aspergillus species

    Directory of Open Access Journals (Sweden)

    Gomes Eleni

    1998-01-01

    Full Text Available Ribonuclease production by Aspergillus flavipes, A. sulphureus and A. fischeri in semi-synthetic medium, after 24-144 hours at 30ºC under shaking, was studied. After cultivation, the medium was separated from micelia by filtration and the resultant solution was used as enzymatic extract. The highest amount of biomass and RNase was obtained after 96 hours of cultivation. The enzymes produced by three species presented similar characteristics, with optimum temperature at 55ºC and two peaks of activity at pH 4.5 and 7.0. A. flavipes RNases were more sensitive to temperature: 50% of the initial activity was lost after 1 hour at 70ºC. After this heat treatment, RNase of A. sulphureus lost 30% of this activity and that of A. fischeri only 16%. The nucleotides released by enzimatic hydrolysis of RNA were separated by ion exchange chromatography in a AG-1X8-formiate column and identified by paper chromatography. This procedure indicated that the raw enzymatic extract of Aspergillus flavipes is able to hydrolyze RNA, releasing 3'-nucleotides monophosphate at pH 4.5 and 3' and 5'-nucleotides monophosphate at pH 7.0 and 8.5. This result suggests that this strain produces two different types of RNase, one acidic and other alcaline, with different specificities.

  16. Role of relative humidity in controlling rate of aflatoxin contamination in certain medicinal herbs under prolonged storage

    International Nuclear Information System (INIS)

    Elbazza, Z.E.; Mahmoud, M.I.; Roushdy, H.M.; Farrag, H.A.; Tablawy, S.Y.E.I.

    1995-01-01

    The effect of water activity on growth of aspergillus flavus test strain and aflatoxin production was studied in sabouraoud's yeast broth regulated with glycerol. Aflatoxin production increased with increasing the a w . The minimal a w was 0.92 for fungal growth and aflatoxins production. Growth of A.flavus test strain and aflatoxin production at 26+- I o and two relative humidities of 85% and 92.9% along four months incubation period on caraway, khlla, shih balady and wild chamomile samples were investigated. At 92.9% Rh, growth of A.flavus on caraway and khella samples was noticed after 20 days of incubation and increased with time incubation and increased with time. Aflatoxin production was detected after 30 days and decreased with prolonged incubation. Fungal growth and aflatoxin production were not observed on shih balady and wild chamomile samples at 92.9% Rh, and on the for studied herbs at 85%, Rh. 3 tabs

  17. The influence of gamma radiation on the aflatoxigenic fungi, phenolics content and antioxidant activity of the green tea; Irradiacao do cha verde para controle de fungos Aspergillus sp.

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, S.G.; Silva, E.B.; Costa, L.F., E-mail: sloana.lemos@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear. Centro de Tecnologia e Geociencias; Nascimento, M.S. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Centro de Ciencias Biologicas. Departamento de Antibioticos; Oliveira, I.S. [Universidade Federal de Pernambuco (CAV/UFPE), Vitoria de Santo Antao, PE (Brazil). Centro Academico de Vitoria

    2013-08-15

    The use of raw plants, including the green tea (Camelia sinensis), has been increasing in Brazil. Along with this increasing tea consumption, there are risks due to its unsuitable handling and storage, which points to the need of controlling possible contaminations. This could be achieved with the use of ionizing radiation. In this context, the present study aimed to evaluate the effect of gamma irradiation over the total phenolics amount, antioxidants and fungic activities of the green tea aqueous extract aiming its processing. Aliquots of the bulk samples have been analyzed before and after gamma irradiation (dosages of 0; 5; 7,5 and 10 kGy). The total phenolics content of the aqueous extracts was determined by using the Folin-Ciocalteu reagent having the catechin as the standard. Those same extracts were used to evaluate its ability of scavenging the free radical DPPH. The microbiological analysis were performed through irradiated samples and control. The results have allowed to check that different dosages of radiation (5; 7,5 e 10 kGy) did not induce significant differences on the content of total phenols and on the antioxidant capacity of the analyzed samples when compared to control. Also, it was also observed that the radiation may have had a catalytic effect on the oxidation of the DPPH and was effective on the microbiological control, even though it was not possible to kill the aflatoxigenic fungus. (author)

  18. Induction and characterization of an unusual Alfa-D-galactosidase from Talaromyces flavus

    Czech Academy of Sciences Publication Activity Database

    Simerská, Pavla; Monti, D.; Čechová, Ivana; Pelantová, Helena; Macková, M.; Bezouška, Karel; Riva, S.; Křen, Vladimír

    2007-01-01

    Roč. 128, - (2007), s. 61-71 ISSN 0168-1656 R&D Projects: GA ČR GA203/05/0172; GA MŠk OC D25.002; GA MŠk LC06010 Institutional research plan: CEZ:AV0Z50200510 Keywords : talaromyces flavus * α-d-galactosidase * 6-deoxy-d-glucose Subject RIV: EE - Microbiology, Virology Impact factor: 2.565, year: 2007

  19. Aspergillus uvarum sp. nov., an uniseriate black Aspergillus species isolated from grapes in Europe

    DEFF Research Database (Denmark)

    Perrone, Giancarlo; Varga, János; Susca, Antonia

    2008-01-01

    A novel species, Aspergillus uvarum sp. nov., is described within Aspergillus section Nigri. This species can be distinguished from other black aspergilli based on internal transcribed spacers (ITS), beta-tubulin and calmodulin gene sequences, by AFLP analysis and by extrolite profiles. Aspergill...... atypical strains of Aspergillus aculeatus, CBS 114.80 and CBS 620.78, and was isolated from grape berries in Portugal, Italy, France, Israel, Greece and Spain. The type strain of Aspergillus uvarum sp. nov. is IMI 388523(T)=CBS 127591(T)= ITEM 4834(T)= IBT26606(T)....

  20. Rabia en Potos flavus identificados en el departamento de madre de dios, Perú

    Directory of Open Access Journals (Sweden)

    Elena Vargas-Linares

    Full Text Available El Potos flavus es un mamífero nocturno que habita en bosques neotropicales desde Centroamérica hasta Sudamérica. Se realizó un estudio de cuatro casos de rabia en Potos flavus ocurridos desde abril de 2012 en el departamento de Madre de Dios en Perú, captados como parte de la vigilancia epidemiológica. Los análisis realizados en el laboratorio de referencia regional de Madre de Dios determinaron presencia de antígeno del virus de la rabia en tres de las muestras de tejido encefálico, dichos resultados fueron corroborados en el Laboratorio de Zoonosis Virales del Instituto Nacional de Salud del Perú mediante inmunofluorescencia directa, la tipificación no identificó ninguna de las variantes conocidas en murciélagos o en perros. La ocurrencia de cuatro casos de rabia en Potos flavus suma evidencias de la emergencia de un nuevo reservorio del virus de la rabia y que ha sido reportada previamente en el mismo departamento el año 2007

  1. Conidial Dihydroxynaphthalene Melanin of the Human Pathogenic Fungus Aspergillus fumigatus Interferes with the Host Endocytosis Pathway.

    Science.gov (United States)

    Thywißen, Andreas; Heinekamp, Thorsten; Dahse, Hans-Martin; Schmaler-Ripcke, Jeannette; Nietzsche, Sandor; Zipfel, Peter F; Brakhage, Axel A

    2011-01-01

    Aspergillus fumigatus is the most important air-borne fungal pathogen of humans. The interaction of the pathogen with the host's immune system represents a key process to understand pathogenicity. For elimination of invading microorganisms, they need to be efficiently phagocytosed and located in acidified phagolysosomes. However, as shown previously, A. fumigatus is able to manipulate the formation of functional phagolysosomes. Here, we demonstrate that in contrast to pigmentless pksP mutant conidia of A. fumigatus, the gray-green wild-type conidia inhibit the acidification of phagolysosomes of alveolar macrophages, monocyte-derived macrophages, and human neutrophil granulocytes. Therefore, this inhibition is independent of the cell type and applies to the major immune effector cells required for defense against A. fumigatus. Studies with melanin ghosts indicate that the inhibitory effect of wild-type conidia is due to their dihydroxynaphthalene (DHN)-melanin covering the conidia, whereas the hydrophobin RodA rodlet layer plays no role in this process. This is also supported by the observation that pksP conidia still exhibit the RodA hydrophobin layer, as shown by scanning electron microscopy. Mutants defective in different steps of the DHN-melanin biosynthesis showed stronger inhibition than pksP mutant conidia but lower inhibition than wild-type conidia. Moreover, A. fumigatus and A. flavus led to a stronger inhibition of phagolysosomal acidification than A. nidulans and A. terreus. These data indicate that a certain type of DHN-melanin that is different in the various Aspergillus species, is required for maximal inhibition of phagolysosomal acidification. Finally, we identified the vacuolar ATPase (vATPase) as potential target for A. fumigatus based on the finding that addition of bafilomycin which inhibits vATPase, led to complete inhibition of the acidification whereas the fusion of phagosomes containing wild-type conidia and lysosomes was not affected.

  2. Molecular analysis of an inactive aflatoxin biosynthesis gene cluster in Aspergillus oryzae RIB strains.

    Science.gov (United States)

    Tominaga, Mihoko; Lee, Yun-Hae; Hayashi, Risa; Suzuki, Yuji; Yamada, Osamu; Sakamoto, Kazutoshi; Gotoh, Kuniyasu; Akita, Osamu

    2006-01-01

    To help assess the potential for aflatoxin production by Aspergillus oryzae, the structure of an aflatoxin biosynthesis gene homolog cluster in A. oryzae RIB 40 was analyzed. Although most genes in the corresponding cluster exhibited from 97 to 99% similarity to those of Aspergillus flavus, three genes shared 93% similarity or less. A 257-bp deletion in the aflT region, a frameshift mutation in norA, and a base pair substitution in verA were found in A. oryzae RIB 40. In the aflR promoter, two substitutions were found in one of the three putative AreA binding sites and in the FacB binding site. PCR primers were designed to amplify homologs of aflT, nor-1, aflR, norA, avnA, verB, and vbs and were used to detect these genes in 210 A. oryzae strains. Based on the PCR results, the A. oryzae RIB strains were classified into three groups, although most of them fell into two of the groups. Group 1, in which amplification of all seven genes was confirmed, contained 122 RIB strains (58.1% of examined strains), including RIB 40. Seventy-seven strains (36.7%) belonged to group 2, characterized by having only vbs, verB, and avnA in half of the cluster. Although slight expression of aflR was detected by reverse transcription-PCR in some group 1 strains, including RIB 40, other genes (avnA, vbs, verB, and omtA) related to aflatoxin production were not detected. aflR was not detected in group 2 strains by Southern analysis.

  3. New species in Aspergillus section Terrei

    DEFF Research Database (Denmark)

    Samson, R. A.; Peterson, S. W.; Frisvad, Jens Christian

    2011-01-01

    . clade including the type isolate of A. niveus (CBS 115.27) constitutes a lineage closely related to A. carneus. Fennellia nivea, the hypothesized teleomorph is not related to this clade. Aspergillus allahabadii, A. niveus var. indicus, and two species originally placed in section Versicolores, A......Section Terrei of Aspergillus was studied using a polyphasic approach including sequence analysis of parts of the beta-tubulin and calmodulin genes and the ITS region, macro- and micromorphological analyses and examination of extrolite profiles to describe three new species in this section. Based....... floccosus, A. terreus var. africanus, A. terreus var. aureus, while Aspergillus hortai is recognised at species level. Aspergillus terreus NRRL 4017 is described as the new species A. pseudoterreus. Also included in section Terrei are some species formerly placed in sections Flavipedes and Versicolores. A...

  4. A prospective international Aspergillus terreus survey

    DEFF Research Database (Denmark)

    Risslegger, B; Zoran, T; Lackner, M

    2017-01-01

    OBJECTIVES: A prospective international multicentre surveillance study was conducted to investigate the prevalence and amphotericin B susceptibility of Aspergillus terreus species complex infections. METHODS: A total of 370 cases from 21 countries were evaluated. RESULTS: The overall prevalence o...

  5. Three new species of Aspergillus section Flavi isolated from almonds and maize in Portugal

    Science.gov (United States)

    Three new aflatoxin-producing species belonging to Aspergillus section Flavi are described, Aspergillus mottae, Aspergillus sergii and Aspergillus transmontanensis. These species were isolated from Portuguese almonds and maize. An investigation examining morphology, extrolites and molecular data was...

  6. Nonfunctionality of Aspergillus sojae aflR in a strain of Aspergillus parasiticus with a disrupted aflR gene.

    Science.gov (United States)

    Takahashi, Tadashi; Chang, Perng-Kuang; Matsushima, Kenichiro; Yu, Jiujiang; Abe, Keietsu; Bhatnagar, Deepak; Cleveland, Thomas E; Koyama, Yasuji

    2002-08-01

    Aspergillus sojae belongs to the Aspergillus section Flavi but does not produce aflatoxins. The functionality of the A. sojae aflR gene (aflRs) was examined by transforming it into an DeltaaflR strain of A. parasiticus, derived from a nitrate-nonutilizing, versicolorin A (VERA)-accumulating strain. The A. parasiticus aflR gene (aflRp) transformants produced VERA, but the aflRs transformants did not. Even when aflRs was placed under the control of the amylase gene (amyB) promoter of Aspergillus oryzae, the amy(p)::aflRs transformants did not produce VERA. A chimeric construct containing the aflRs promoter plus the aflRs N- and aflRp C-terminal coding regions could restore VERA production, but a construct containing the aflRp promoter plus the aflRp N- and aflRs C-terminal coding regions could not. These results show that the A. sojae aflR promoter is functional in A. parasiticus and that the HAHA motif does not affect the function of the resulting hybrid AflR. We conclude that the lack of aflatoxin production by A. sojae can be attributed, at least partially, to the premature termination defect in aflRs, which deletes the C-terminal transcription activation domain that is critical for the expression of aflatoxin biosynthetic genes.

  7. Overexpression of Aspergillus tubingensis faeA in protease-deficient Aspergillus niger enables ferulic acid production from plant material.

    Science.gov (United States)

    Zwane, Eunice N; Rose, Shaunita H; van Zyl, Willem H; Rumbold, Karl; Viljoen-Bloom, Marinda

    2014-06-01

    The production of ferulic acid esterase involved in the release of ferulic acid side groups from xylan was investigated in strains of Aspergillus tubingensis, Aspergillus carneus, Aspergillus niger and Rhizopus oryzae. The highest activity on triticale bran as sole carbon source was observed with the A. tubingensis T8.4 strain, which produced a type A ferulic acid esterase active against methyl p-coumarate, methyl ferulate and methyl sinapate. The activity of the A. tubingensis ferulic acid esterase (AtFAEA) was inhibited twofold by glucose and induced twofold in the presence of maize bran. An initial accumulation of endoglucanase was followed by the production of endoxylanase, suggesting a combined action with ferulic acid esterase on maize bran. A genomic copy of the A. tubingensis faeA gene was cloned and expressed in A. niger D15#26 under the control of the A. niger gpd promoter. The recombinant strain has reduced protease activity and does not acidify the media, therefore promoting high-level expression of recombinant enzymes. It produced 13.5 U/ml FAEA after 5 days on autoclaved maize bran as sole carbon source, which was threefold higher than for the A. tubingensis donor strain. The recombinant AtFAEA was able to extract 50 % of the available ferulic acid from non-pretreated maize bran, making this enzyme suitable for the biological production of ferulic acid from lignocellulosic plant material.

  8. Post-genomic insights into the plant polysaccharide degradation potential of Aspergillus nidulans and comparison to Aspergillus niger and Aspergillus oryzae

    NARCIS (Netherlands)

    Coutinho, Pedro M; Andersen, Mikael R; Kolenova, Katarina; vanKuyk, Patricia A; Benoit, Isabelle; Gruben, Birgit S; Trejo-Aguilar, Blanca; Visser, Hans; van Solingen, Piet; Pakula, Tiina; Seiboth, Bernard; Battaglia, Evy; Aguilar-Osorio, Guillermo; de Jong, Jan F; Ohm, Robin A; Aguilar, Mariana; Henrissat, Bernard; Nielsen, Jens; Stålbrand, Henrik; de Vries, Ronald P

    The plant polysaccharide degradative potential of Aspergillus nidulans was analysed in detail and compared to that of Aspergillus niger and Aspergillus oryzae using a combination of bioinformatics, physiology and transcriptomics. Manual verification indicated that 28.4% of the A. nidulans ORFs

  9. Caracterización cultural y morfológica e identificación de especies deAspergillus asociadas a semillas de Leucaena leucocephala cv. Perú

    Directory of Open Access Journals (Sweden)

    J. C Lezcano

    Full Text Available Se evaluaron, desde el punto de vista cultural y morfológico, diez aislamientos puros de Aspergillus, obtenidos de semillas previamente desinfectadas de Leucaena leucocephala cv. Perú, con el objetivo de identificar a qué especie(s pertenecían. La siembra de los hongos se realizó a partir de discos miceliales de 7 mm de diámetro, procedentes de cultivos de 10-15 días de edad, que fueron colocados en el centro de placas Petri de cristal de 9 cm de diámetro y se incubaron durante 10 días a 25 °C, con alternancia de 8 h luz por 6 h oscuridad. El diseño experimental fue completamente aleatorizado, y para cada aislamiento se utilizaron como réplicas tres placas. Los aspectos culturales medidos fueron: el color de la colonia en el anverso y el reverso, el diámetro, la textura, el crecimiento lineal (cm/día, el crecimiento aéreo y la pigmentación del sustrato; y los morfológicos: el tamaño, la forma y el color de las estructuras con valor taxonómico para la determinación de las especies de Aspergillus. Los aislamientos No. 2, No. 3, No. 4 y No. 5 se correspondieron con la especie Aspergillus flavus Link; el No. 19, conAspergillus wentii Wehmer; y los tratamientos No. 7, No. 20 y No. 21, con Aspergillus niger van Tieghem. Se concluye que tres especies deAspergillus se asociaron a las simientes de leucaena almacenadas. Se recomienda continuar los estudios para lograr la identificación de los aislamientos No. 6 y No. 22 hasta el nivel de especie.

  10. Effect of Cymbopogon martinii, Foeniculum vulgare, and Trachyspermum ammi Essential Oils on the Growth and Mycotoxins Production by Aspergillus Species.

    Science.gov (United States)

    Gemeda, Negero; Woldeamanuel, Yimtubezinash; Asrat, Daniel; Debella, Asfaw

    2014-01-01

    This study was performed to investigate effect of essential oils on Aspergillus spore germination, growth, and mycotoxin production. In vitro antifungal and antiaflatoxigenic activities of Cymbopogon martinii, Foeniculum vulgare, and Trachyspermum ammi essential oils were carried out on toxigenic strains of Aspergillus species. Plant materials were hydrodistilled for 4-5 h in Clevenger apparatus. 0.25 μL/mL, 0.5 μL/mL, 1 μL/mL, 2 μL/mL, and 4 μL/mL concentrations of each essential oil were prepared in 0.1% Tween 80 (V/V). T. ammi oil showed highest antifungal activity. Absolute mycelial inhibition was recorded at 1 μL/mL by essential oils of T. ammi. The oil also showed complete inhibition of spore germination at a concentration of 2 μL/mL. In addition, T. ammi oil showed significant antiaflatoxigenic potency by totally inhibiting toxin production from A. niger and A. flavus at 0.5 and 0.75 μL/mL, respectively. C. martinii, F. vulgare, and T. ammi oils as antifungals were found superior over synthetic preservative. Moreover, a concentration of 5336.297 μL/kg body weight was recorded for LC50 on mice indicating the low mammalian toxicity. In conclusion, the essential oils from T. ammi can be a potential source of safe natural food preservative for food commodities contamination by Aspergillus species.

  11. Effect of Cymbopogon martinii, Foeniculum vulgare, and Trachyspermum ammi Essential Oils on the Growth and Mycotoxins Production by Aspergillus Species

    Directory of Open Access Journals (Sweden)

    Negero Gemeda

    2014-01-01

    Full Text Available This study was performed to investigate effect of essential oils on Aspergillus spore germination, growth, and mycotoxin production. In vitro antifungal and antiaflatoxigenic activities of Cymbopogon martinii, Foeniculum vulgare, and Trachyspermum ammi essential oils were carried out on toxigenic strains of Aspergillus species. Plant materials were hydrodistilled for 4-5 h in Clevenger apparatus. 0.25 μL/mL, 0.5 μL/mL, 1 μL/mL, 2 μL/mL, and 4 μL/mL concentrations of each essential oil were prepared in 0.1% Tween 80 (V/V. T. ammi oil showed highest antifungal activity. Absolute mycelial inhibition was recorded at 1 μL/mL by essential oils of T. ammi. The oil also showed complete inhibition of spore germination at a concentration of 2 μL/mL. In addition, T. ammi oil showed significant antiaflatoxigenic potency by totally inhibiting toxin production from A. niger and A. flavus at 0.5 and 0.75 μL/mL, respectively. C. martinii, F. vulgare, and T. ammi oils as antifungals were found superior over synthetic preservative. Moreover, a concentration of 5336.297 μL/kg body weight was recorded for LC50 on mice indicating the low mammalian toxicity. In conclusion, the essential oils from T. ammi can be a potential source of safe natural food preservative for food commodities contamination by Aspergillus species.

  12. Identification and toxigenic potential of the industrially important fungi, Aspergillus oryzae and Aspergillus sojae

    DEFF Research Database (Denmark)

    Jørgensen, Thomas R

    2007-01-01

    Mold strains belonging to the species Aspergillus oryzae and Aspergillus sojae are highly valued as koji molds in the traditional preparation of fermented foods, such as miso, sake, and shoyu, and as protein production hosts in modern industrial processes. A. oryzae and A. sojae are relatives...

  13. Variability in Galactomannan detection by platelia Aspergillus EIA™ according to the Aspergillus species

    Directory of Open Access Journals (Sweden)

    Melissa Orzechowski Xavier

    2013-06-01

    Full Text Available Here we investigate the extent to which different Aspergillus species release galactomannan (GM in vitro. Marked variability was observed in GM reactivity between and within Aspergillus species, with A. terreus strains showing the highest GM indexes. The in vivo significance of these findings remains to be determined.

  14. The Cell Factory Aspergillus Enters the Big Data Era: Opportunities and Challenges for Optimising Product Formation.

    Science.gov (United States)

    Meyer, Vera; Fiedler, Markus; Nitsche, Benjamin; King, Rudibert

    2015-01-01

    Living with limits. Getting more from less. Producing commodities and high-value products from renewable resources including waste. What is the driving force and quintessence of bioeconomy outlines the lifestyle and product portfolio of Aspergillus, a saprophytic genus, to which some of the top-performing microbial cell factories belong: Aspergillus niger, Aspergillus oryzae and Aspergillus terreus. What makes them so interesting for exploitation in biotechnology and how can they help us to address key challenges of the twenty-first century? How can these strains become trimmed for better growth on second-generation feedstocks and how can we enlarge their product portfolio by genetic and metabolic engineering to get more from less? On the other hand, what makes it so challenging to deduce biological meaning from the wealth of Aspergillus -omics data? And which hurdles hinder us to model and engineer industrial strains for higher productivity and better rheological performance under industrial cultivation conditions? In this review, we will address these issues by highlighting most recent findings from the Aspergillus research with a focus on fungal growth, physiology, morphology and product formation. Indeed, the last years brought us many surprising insights into model and industrial strains. They clearly told us that similar is not the same: there are different ways to make a hypha, there are more protein secretion routes than anticipated and there are different molecular and physical mechanisms which control polar growth and the development of hyphal networks. We will discuss new conceptual frameworks derived from these insights and the future scientific advances necessary to create value from Aspergillus Big Data.

  15. Evaluation of the Aspergillus Western blot IgG kit for diagnosis of chronic aspergillosis.

    Science.gov (United States)

    Oliva, A; Flori, P; Hennequin, C; Dubus, J-C; Reynaud-Gaubert, M; Charpin, D; Vergnon, J M; Gay, P; Colly, A; Piarroux, R; Pelloux, H; Ranque, S

    2015-01-01

    Immunoprecipitin detection (IPD) is the current reference confirmatory technique for anti-Aspergillus antibody detection; however, the lack of standardization is a critical drawback of this assay. In this study, we evaluated the performance of the Aspergillus Western blot (Asp-WB) IgG kit (LDBio Diagnostics, Lyon, France), a recently commercialized immunoblot assay for the diagnosis of various clinical presentations of chronic aspergillosis. Three hundred eight serum samples from 158 patients with aspergillosis sensu lato (s.l.) were analyzed. More specifically, 267 serum samples were derived from patients with Aspergillus disease, including 89 cases of chronic pulmonary aspergillosis, 10 of aspergilloma, and 32 of allergic bronchopulmonary aspergillosis, while 41 samples were from patients with Aspergillus colonization, including 15 cystic fibrosis (CF) and 12 non-CF patients. For blood donor controls, the Asp-WB specificity was 94%, while the kit displayed a sensitivity for the aspergillosis s.l. diagnosis of 88.6%, with a diagnostic odds ratio (DOR) of 119 (95% confidence interval [CI], 57 to 251). The DOR values were 185.22 (95% CI,78.79 to 435.45) and 43.74 (95% CI, 15.65 to 122.20) for the diagnosis of Aspergillus disease and Aspergillus colonization, respectively. Among the patients, the sensitivities of the Asp-WB in the diagnosis of Aspergillus colonization were 100% and 41.7% in CF and non-CF patients, respectively. The Asp-WB yielded fewer false-negative results than did IPD. In conclusion, the Asp-WB kit performed well for the diagnosis of various clinical presentations of aspergillosis in nonimmunocompromised patients, with an enhanced standardization and a higher sensitivity than with IPD, which is the current reference method. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Purification and characterization of RNA allied extracellular tyrosinase from Aspergillus species.

    Science.gov (United States)

    Inamdar, Shrirang; Joshi, Swati; Bapat, Vishwas; Jadhav, Jyoti

    2014-02-01

    Production of L-DOPA, an anti-Parkinson's drug, using biological sources is widely studied in which tyrosinase is known to play a vital role. Tyrosinase is an omnipresent type 3 copper enzyme participating in many essential biological functions. Understanding properties of tyrosinase is essential for developing useful tyrosinase-based applications. Hence, extracellular tyrosinase from Aspergillus flavus UWFP 570 was purified using ammonium sulphate precipitation and DEAE ion exchange chromatography up to 8.3-fold. Purified protein was a riboprotein in nature containing significant amount of RNA which was confirmed colorimetrically and by electrophoresis. Removal of RNA reduced the activity and altered the conformation of tyrosinase as suggested by spectroflurometric results. Optimum pH and temperature of this 140 kDa protein were 7 and 40 °C, respectively. Copper sulphate and magnesium chloride enhanced the activity whereas in contrast FeCl₃ inhibited the activity completely. Purified tyrosinase transformed L-tyrosine (5 mM) to L-DOPA within 5 h.

  17. The use of a-methyl-D-glucoside, a synthetic analogue of maltose, as inducer of amylase by Aspergillus sp in solid-state and submerged fermentations

    Directory of Open Access Journals (Sweden)

    Moreira Fabiana G.

    2001-01-01

    Full Text Available The use of a methyl-D-glucoside (alphaMG, a synthetic analogue of maltose, as carbon source and inducer of amylase synthesis to several species of Aspergillus was studied in submerged and solid-state fermentations. Among a group of ten species, A. tamarii, A. fumigatus and A. flavus were able to produce biomass and high specific amylolytic activity in submerged cultures containing alphaMG as the only carbon source. In solid state fermentation, the enrichment of basal wheat bran or corn cob medium with alphaMG increased up to 3 times the production of amylases. In both submerged and solid state fermentations, alphaMG was more effective inducer of amylases than maltose and starch.

  18. The use of alpha-methyl-D-glucoside, a synthetic analogue of maltose, as inducer of amylase by Aspergillus sp in solid-state and submerged fermentations

    Directory of Open Access Journals (Sweden)

    Fabiana G. Moreira

    2001-03-01

    Full Text Available The use of a methyl-D-glucoside (alphaMG, a synthetic analogue of maltose, as carbon source and inducer of amylase synthesis to several species of Aspergillus was studied in submerged and solid-state fermentations. Among a group of ten species, A. tamarii, A. fumigatus and A. flavus were able to produce biomass and high specific amylolytic activity in submerged cultures containing alphaMG as the only carbon source. In solid state fermentation, the enrichment of basal wheat bran or corn cob medium with alphaMG increased up to 3 times the production of amylases. In both submerged and solid state fermentations, alphaMG was more effective inducer of amylases than maltose and starch.

  19. Methionine and glucose transport by isolated intestinal brush border membrane vesicles from pigs and lambs fed an Aspergillus product

    OpenAIRE

    Jang, Insurk

    1993-01-01

    This study was designed to determine whether feeding an Aspergillus product would influence growth or feed utilization and intestinal mucosal cell function as indicated by uptake of methionine and glucose by isolated intestinal brush border membrane vesicles (BBMV). In Experiment 1, 24 weanling pigs were paired by sex, BW, and litter and were allotted, within pairs, to either an 18% CP corn-soy diet (control) or the same diet supplemented (.15%) with an Aspergillus product. There were no diff...

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

    Science.gov (United States)

    Korani, Walid Ahmed; Chu, Ye; Holbrook, Corley; Clevenger, Josh; Ozias-Akins, Peggy

    2017-07-12

    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.

  1. 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.

  2. Fumigant Antifungal Activity of Myrtaceae Essential Oils and Constituents from Leptospermum petersonii against Three Aspergillus Species

    Directory of Open Access Journals (Sweden)

    Il-Kwon Park

    2012-09-01

    Full Text Available Commercial plant essential oils obtained from 11 Myrtaceae plant species were tested for their fumigant antifungal activity against Aspergillus ochraceus, A. flavus, and A. niger. Essential oils extracted from Leptospermum petersonii at air concentrations of 56 × 10−3 mg/mL and 28 × 10−3 mg/mL completely inhibited the growth of the three Aspergillus species. However, at an air concentration of 14 × 10−3 mg/mL, inhibition rates of L. petersonii essential oils were reduced to 20.2% and 18.8% in the case of A. flavus and A. niger, respectively. The other Myrtaceae essential oils (56 × 10−3 mg/mL only weakly inhibited the fungi or had no detectable affect. Gas chromatography-mass spectrometry analysis identified 16 compounds in L. petersonii essential oil. The antifungal activity of the identified compounds was tested individually by using standard or synthesized compounds. Of these, neral and geranial inhibited growth by 100%, at an air concentration of 56 × 10−3 mg/mL, whereas the activity of citronellol was somewhat lover (80%. The other compounds exhibited only moderate or weak antifungal activity. The antifungal activities of blends of constituents identified in L. petersonii oil indicated that neral and geranial were the major contributors to the fumigant and antifungal activities.

  3. Human platelets attenuate Aspergillus species via granule-dependent mechanisms.

    NARCIS (Netherlands)

    Perkhofer, S.; Kehrel, B.E.; Dierich, M.P.; Donnelly, J.P.; Nussbaumer, W.; Hofmann, J.; Eiff, C. von; Lass-Florl, C.

    2008-01-01

    Using laser scanning microscopy, we investigated whether platelets are capable of internalizing Aspergillus conidia and examined Aspergillus-platelet adherence. The influence of platelets on fungal growth was evaluated by assessing galactomannan (GM) release, hyphal elongation, and colony size. A

  4. Prevalence and mechanism of triazole resistance in Aspergillus fumigatus in a referral chest hospital in Delhi, India and an update of the situation in Asia

    Directory of Open Access Journals (Sweden)

    Anuradha eChowdhary

    2015-05-01

    Full Text Available Aspergillus fumigatus causes varied clinical syndromes ranging from colonization to deep infections. The mainstay of therapy of Aspergillus diseases is triazoles but several studies globally highlighted variable prevalence of triazole resistance, which hampers the management of aspergillosis. We studied the prevalence of resistance in clinical A. fumigatus isolates during 4 years in a referral Chest Hospital in Delhi, India and reviewed the scenario in Asia and the Middle East. Aspergillus species (n=2117 were screened with selective plates for azole resistance. The isolates included 45.4% A. flavus, followed by 32.4% A. fumigatus, 15.6% Aspergillus species and 6.6% A. terreus. Azole resistance was found in only 12 (1.7% A. fumigatus isolates.These triazole resistant A. fumigatus (TRAF isolates were subjected to (a calmodulin and β tubulin gene sequencing (b in vitro antifungal susceptibility testing against triazoles using CLSI M38-A2 (c sequencing of cyp51A gene and real-time PCR assay for detection of mutations and (d microsatellite typing of the resistant isolates. TRAF harbored TR34/L98H mutation in 10 (83.3% isolates with a pan-azole resistant phenotype. Among the remaining 2 TRAF isolates, one had G54E and the other had three non-synonymous point mutations. The majority of patients were diagnosed as invasive aspergillosis followed by allergic bronchopulmonary aspergillosis and chronic pulmonary aspergillosis. The Indian TR34/L98H isolates had a unique genotype and were distinct from the Chinese, Middle East and European TR34/L98H strains. This resistance mechanism has been linked to the use of fungicide azoles in agricultural practices in Europe as it has been mainly reported from azole naïve patients. Reports published from Asia demonstrate the same environmental resistance mechanism in A. fumigatus isolates from two highly populated countries in Asia i.e., China and India and also from the neighboring Middle East.

  5. Rhizomucor miehei triglyceride lipase is processed and secreted from transformed Aspergillus oryzae.

    Science.gov (United States)

    Huge-Jensen, B; Andreasen, F; Christensen, T; Christensen, M; Thim, L; Boel, E

    1989-09-01

    The cDNA encoding the precursor of the Rhizomucor miehei triglyceride lipase was inserted in an Aspergillus oryzae expression vector. In this vector the expression of the lipase cDNA is under control of the Aspergillus oryzae alpha-amylase gene promoter and the Aspergillus niger glucoamylase gene terminator. The recombinant plasmid was introduced into Aspergillus oryzae, and transformed colonies were selected and screened for lipase expression. Lipase-positive transformants were grown in a small fermentor, and recombinant triglyceride lipase was purified from the culture broth. The purified enzymatically active recombinant lipase (rRML) secreted from A. oryzae was shown to have the same characteristics with respect to mobility on reducing SDS-gels and amino acid composition as the native enzyme. N-terminal amino acid sequencing indicated that approximately 70% of the secreted rRML had the same N-terminal sequence as the native Rhizomucor miehei enzyme, whereas 30% of the secreted rRML was one amino acid residue shorter in the N-terminal. The recombinant lipase precursor, which has a 70 amino acid propeptide, is thus processed in and secreted from Aspergillus oryzae. We have hereby demonstrated the utility of this organism as a host for the production of recombinant triglyceride lipases.

  6. The volatome of Aspergillus fumigatus.

    Science.gov (United States)

    Heddergott, C; Calvo, A M; Latgé, J P

    2014-08-01

    Early detection of invasive aspergillosis is absolutely required for efficient therapy of this fungal infection. The identification of fungal volatiles in patient breath can be an alternative for the detection of Aspergillus fumigatus that still remains problematic. In this work, we investigated the production of volatile organic compounds (VOCs) by A. fumigatus in vitro, and we show that volatile production depends on the nutritional environment. A. fumigatus produces a multiplicity of VOCs, predominantly terpenes and related compounds. The production of sesquiterpenoid compounds was found to be strongly induced by increased iron concentrations and certain drugs, i.e., pravastatin. Terpenes that were always detectable in large amounts were α-pinene, camphene, and limonene, as well as sesquiterpenes, identified as α-bergamotene and β-trans-bergamotene. Other substance classes that were found to be present in the volatome, such as 1-octen-3-ol, 3-octanone, and pyrazines, were found only under specific growth conditions. Drugs that interfere with the terpene biosynthesis pathway influenced the composition of the fungal volatome, and most notably, a block of sesquiterpene biosynthesis by the bisphosphonate alendronate fundamentally changed the VOC composition. Using deletion mutants, we also show that a terpene cyclase and a putative kaurene synthase are essential for the synthesis of volatile terpenes by A. fumigatus. The present analysis of in vitro volatile production by A. fumigatus suggests that VOCs may be used in the diagnosis of infections caused by this fungus. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  7. 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

  8. Induction and characterization of an unusual Alfa-D-galactosidase from Talaromyces flavus

    Czech Academy of Sciences Publication Activity Database

    Simerská, Pavla; Monti, D.; Čechová, Ivana; Pelantová, Helena; Macková, M.; Bezouška, Karel; Riva, S.; Křen, Vladimír

    2007-01-01

    Roč. 128, č. 1 (2007), s. 61-71 ISSN 0168-1656 R&D Projects: GA ČR GA203/05/0172; GA MŠk OC D25.002; GA MŠk LC06010; GA MŠk OC D25.001 Grant - others:US(US) NATO LST.CLG.980125 Institutional research plan: CEZ:AV0Z50200510 Source of funding: N - neverejné zdroje Keywords : alfa-d-galactosidase * talaromyces flavus * enzyme purification Subject RIV: EE - Microbiology, Virology Impact factor: 2.565, year: 2007

  9. Evaluation of the detection techniques of toxigenic Aspergillus isolates

    African Journals Online (AJOL)

    However, our results showed that use of these techniques were not sufficiently sensitive for all Aspergillus species and suggested a simple thin layer chromatography (TLC) as a sensitive and reliable technique for detection of aflatoxins and OTA produced by Aspergillus and Eurotium species. Key words: Aspergillus ...

  10. Effective Control of Molds Using a Combination of Nanoparticles.

    Directory of Open Access Journals (Sweden)

    Ariana Auyeung

    Full Text Available Molds are filamentous fungi able to grow on a variety of surfaces, including constructed surfaces, food, rotten organic matter, and humid places. Mold growth is characterized by having an unpleasant odor in enclosed or non-ventilated places and a non-aesthetic appearance. They represent a health concern because of their ability to produce and release mycotoxins, compounds that are toxic to animals and humans. The aim of this study was to evaluate commercial nanoparticles (NPs that can be used as an additive in coatings and paints to effectively control the growth of harmful molds. Four different NPs were screened for their antifungal activities against the mycotoxin producing mold strains Aspergillus flavus and A. fumigatus. The minimal inhibitory concentrations of the NPs were determined in broth media, whereas an agar diffusion test was used to assess the antimold activity on acrylic- and water-based paints. The cytotoxic activity and the inflammatory response of the NPs were also evaluated using the established human derived macrophage cell line THP-1. Results showed that a combination of mix metallic- and ZnO-NPs (50:10 μg/mL effectively inhibited the fungal growth when exposed to fluorescent light. Neither cytotoxic effect nor inflammatory responses were recorded, suggesting that this combination can be safely used in humid or non-ventilated environments without any health concerns.

  11. First case report of isolated aspergillus dacryoadenitis

    Directory of Open Access Journals (Sweden)

    Ishan Acharya

    2016-01-01

    Full Text Available We report a case of isolated Aspergillus dacryoadenitis. A 23-year-old male presented with dull ache, diffuse swelling in superolateral quadrant of the right orbit and proptosis for 4 months. Ocular examination showed conjunctival congestion, discharge in the fornix and palpable lacrimal gland (LG mass. Routine hematological investigations followed by computed tomography scan of orbits were done. He did not respond to a course of systemic and topical antibiotics. Lateral orbitotomy with extended lid crease incision was performed with excision biopsy of LG. Abundant blackish material was found in the LG intraoperatively. The specimen was sent for histopathological examination (HPE. HPE report showed Aspergillus. Thorough ENT and systemic evaluation ruled out any other site with the fungus. To the best of our knowledge, this is the first case report of Aspergillus infection in LG.

  12. A rare case of bilateral aspergillus endophthalmitis

    Directory of Open Access Journals (Sweden)

    Saurabh Gupta

    2015-12-01

    Full Text Available Aspergillus endophthalmitis is a devastating inflammatory condition of the intraocular cavities that may result in irreparable loss of vision and rapid destruction of the eye. Almost all cases in the literature have shown an identified source causing aspergillus endophthalmitis as a result of direct extension of disease. We present a rare case of bilateral aspergillus endophthalmitis. A 72-year-old woman with a history of diabetes mellitus, congenital Hirschsprung disease, and recent culture-positive candida pyelonephritis with hydronephrosis status post-surgical stent placement presented with difficulty opening her eyes. She complained of decreased vision (20/200 with pain and redness in both eyes – right worse then left. Examination demonstrated multiple white fungal balls in both retinas consistent with bilateral fungal endophthalmitis. Bilateral vitreous taps for cultures and staining were performed. Patient was given intravitreal injections of amphotericin B, vancomycin, ceftazidime, and started on oral fluconazole. Patient was scheduled for vitrectomy to decrease organism burden and to remove loculated areas of infection that would not respond to systemic antifungal agents. Four weeks after initial presentation, the fungal cultures revealed mold growth consistent with aspergillus. Patient was subsequently started on voriconazole and fluconazole was discontinued due to poor efficacy against aspergillus. Further workup was conducted to evaluate for the source of infection and seeding. Transthoracic cardiogram was unremarkable for any vegetation or valvular abnormalities. MRI of the orbits and sinuses did not reveal any mass lesions or bony destruction. CT of the chest was unremarkable for infection. Aspergillus endophthalmitis may occur because of one of these several mechanisms: hematogenous dissemination, direct inoculation by trauma, and contamination during surgery. Our patient's cause of bilateral endophthalmitis was through an

  13. Genomic Diversity in the Genus of Aspergillus

    DEFF Research Database (Denmark)

    Rasmussen, Jane Lind Nybo

    Aspergillus is a highly important genus of saprotrophic filamentous fungi. It is a very diverse genus that is inextricably intertwined with human a↵airs on a daily basis, holding species relevant to plant and human pathology, enzyme and bulk chemistry production, food and beverage biotechnology......, and scientific model organisms. The phenotypic diversity in this genus is extraordinary and identifying the genetic basis for this diversity has great potential for academia and industry. When the genomic era began for Aspergillus in 2005 with the genome sequences of A. nidulans, A. oryzae and A. fumigatus...

  14. Study of the glucoamylase promoter in Aspergillus niger using green fluorescent protein

    NARCIS (Netherlands)

    Santerre Henriksen, A.L.; Even, S.; Müller, C.; Punt, P.J.; Hondel, C.A.M.J.J. van den; Nielsen, J.

    1999-01-01

    An Aspergillus niger strain expressing a red-shifted green fluorescent protein (GFP) in the cytoplasm under the control of the glucoamylase promoter (PglaA) was characterized with respect to its physiology and morphology. Although xylose acted as a repressor carbon source during batch cultivations,

  15. Effects of Aspergillus niger treated Shea butter cake based diets on ...

    African Journals Online (AJOL)

    Effects of feed intake, weight gain and digestibility when growing Red Sokoto goats consuming Aspergillus niger treated and untreated shea-butter cake (SBC) were determined. Twenty five Red Sokoto goats in a completely randomized design model with 56 d periods consumed diet A (control, without SBC), B (15% ...

  16. 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:...

  17. [Survival Strategies of Aspergillus in the Human Body].

    Science.gov (United States)

    Tashiro, Masato; Izumikawa, Koichi

    2017-01-01

     The human body is a hostile environment for Aspergillus species, which originally live outside the human body. There are lots of elimination mechanisms against Aspergillus inhaled into the human body, such as high body temperature, soluble lung components, mucociliary clearance mechanism, or responses of phagocytes. Aspergillus fumigatus, which is the primary causative agent of human infections among the human pathogenic species of Aspergillus, defend itself from the hostile human body environment by various mechanisms, such as thermotolerance, mycotoxin production, and characteristic morphological features. Here we review mechanisms of defense in Aspergillus against elimination from the human body.

  18. Muscodor albus Volatiles Control Toxigenic Fungi under Controlled Atmosphere (CA Storage Conditions

    Directory of Open Access Journals (Sweden)

    Gordon Braun

    2012-11-01

    Full Text Available Muscodor albus, a biofumigant fungus, has the potential to control post-harvest pathogens in storage. It has been shown to produce over 20 volatile compounds with fungicidal, bactericidal and insecticidal properties. However, M. albus is a warm climate endophyte, and its biofumigant activity is significantly inhibited at temperatures below 5 °C. Conidia of seven mycotoxin producing fungi, Aspergillus carbonarius, A. flavus, A. niger, A. ochraceus, Penicillium verrucosum, Fusarium culmorum and F. graminearum, were killed or prevented from germinating by exposure to volatiles from 2 g M. albus-colonized rye grain per L of headspace in sealed glass jars for 24 h at 20 °C. Two major volatiles of M. albus, isobutyric acid (IBA and 2-methyl-1-butanol (2MB at 50 µL/L and 100 µL/L, respectively, gave differential control of the seven fungi when applied individually at 20 °C. When the fungi were exposed to both IBA and 2MB together, an average of 94% of the conidia were killed or suppressed. In a factorial experiment with controlled atmosphere storage (CA at 3 °C and 72 h exposure to four concentrations of IBA and 2MB combinations, 50 µL/L IBA plus 100 µL/L 2MB killed or suppressed germination of the conidia of all seven fungi. Controlled atmosphere had no significant effect on conidial viability or volatile efficacy. Major volatiles of M. albus may have significant potential to control plant pathogens in either ambient air or CA storage at temperatures below 5 °C. However, combinations of volatiles may be required to provide a broader spectrum of control than individual volatiles.

  19. Aspergillus pragensis sp nov discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi

    Czech Academy of Sciences Publication Activity Database

    Hubka, Vít; Lysková, P.; Frisvad, J.C.; Peterson, S.W.; Skořepová, M.; Kolařík, Miroslav

    2014-01-01

    Roč. 52, č. 6 (2014), s. 565-576 ISSN 1369-3786 R&D Projects: GA MŠk(CZ) EE2.3.20.0055; GA MŠk(CZ) EE2.3.30.0003 Institutional support: RVO:61388971 Keywords : Aspergillus candidus * Aspergillus tritici * antifungal susceptibility testing Subject RIV: EE - Microbiology, Virology Impact factor: 2.335, year: 2014

  20. Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs

    Directory of Open Access Journals (Sweden)

    Mariana Greco

    2015-09-01

    Full Text Available Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods and animal feeds. These fungi can synthesize a variety of secondary metabolites, many of which show animal toxicity, creating a health risk for food production animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60% were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%. These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds.