Characterization of metabolites from a strain of Aspergillus flavus accumulating aflatoxin B2

International Nuclear Information System (INIS)

Dutton, M.F.

1985-01-01

A number of aflatoxins and anthraquinone pigments were isolated from a strain of Aspergillus flavus, several of which were fully characterized. The major metabolites isolated were aflatoxin B 2 and versicolorin C, which are normally only found as minor products from species of the genus Aspergillus. The identification of these products supports the proposal that aflatoxin B 2 can arise independently of aflatoxin B 1 and that, in this case, the branch in the pathway occurs at the versicolorins. Other metabolites charaterized were aflatoxin M 2 , norsolorinic acid, and averufin

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

DEFF Research Database (Denmark)

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

2014-01-01

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

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

Science.gov (United States)

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

2014-06-01

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

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

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Eduardo Afonso da Silva-Junior

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

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

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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.

Aspergillus flavus secondary metabolites: more than just aflatoxins

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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...

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

Science.gov (United States)

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

2018-02-02

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

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...

Effect of Gamma-irradiation on aflatoxin B1 produced by aspergillus parasiticus in barley containing antimicrobial food additives

International Nuclear Information System (INIS)

Aziz, N.H.; Abd El-Rehim, L.M.; El-Far, M.A.

1999-01-01

Influence of gamma irradiation on, growth and aflatoxin B 1 produced by aspergillus parasiticus in ba supplemented with sodium chloride, potassium sorbate and sodium benzoate was investigated. Total viable population of A. Parasiticus and aflatoxin B 1 production decreased significantly by increasing gamma irradiation doses. No growth or aflatoxin B 1 production occurred at 4.0 KGy. Increasing the concentration of NaCl reduced the total viable population A. Parasiticus as well as the accumulation of aflatoxin B 1 . No growth and aflatoxin B 1 production occurred in barley treated with 2.0 KGy and 6% NaCl. Potassium sorbate and sodium benzoate at concentration 500 ppm reduced the population of A. Parasiticus and the levels of aflatoxin B 1 over 100 days. At 2.0 KGy, a sharp drop in aflatoxin B 1 level occurred in barley by 2% NaCl and 500 ppm potassium sorbate and sodium benzoate. At 2.0 KGy, 2% NaCl and 1000 ppm potassium sorbate and sodium benzoate completely inhibited growth and aflatoxin B 1 production by A. parasiticus for 100 days of incubation

Biodiversity of Aspergillus species in some important agricultural products

DEFF Research Database (Denmark)

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

2007-01-01

The genus Aspergillus is one of the most important filamentous fungal genera. Aspergillus species are used in the fermentation industry, but they are also responsible of various plant and food secondary rot, with the consequence of possible accumulation of mycotoxins. The aflatoxin producing A....... flavus and A. parasiticus, and ochratoxinogenic A. niger, A. ochraceus and A. carbonarius species are frequently encountered in agricultural products. Studies on the biodiversity of toxigenic Aspergillus species is useful to clarify molecular, ecological and biochemical characteristics of the different...... 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...

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.

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

Science.gov (United States)

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

2014-01-01

Aflatoxins are a metabolite of Aspergillus molds and are widespread in the natural environment. Workers who handle food grains are at increased risk of exposure to aflatoxins and subsequently certain respiratory conditions. In India, more than half of the employed population is engaged in some type of agricultural work, yet little known about the respiratory problems as a result of exposure to aflatoxins among workers who handle food grains in India. The aim of this study was to determine the risk of occupational exposure to aflatoxins in food-grain workers compared to workers who are not occupationally exposed to food grains. Bronchoalveolar lavage (BAL) and serum samples from 46 food-grain workers and 44 non-food-grain workers were analyzed for the presence of aflatoxins. Microscopy and culture of BAL samples were performed to detect Aspergillus species. Aflatoxins were detected in 32·6% of the food-grain workers and 9·1% of non food grain workers (Pworkers and 11·4% of non-food-grain workers had chronic respiratory symptoms. Occupational exposure to aflatoxins in food-grain workers was found to be associated with the increased presence of respiratory symptoms.

Aspergillus: introduction

Science.gov (United States)

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

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...

Aspergillus Species and Their Associated Mycotoxins.

Science.gov (United States)

Perrone, Giancarlo; Gallo, Antonia

2017-01-01

The genus Aspergillus is among the most abundant and widely distributed organism on earth, and at the moment comprises 339 known species. It is one of the most important economically fungal genus and the biotechnological use of Aspergillus species is related to production of soy sauce, of different hydrolytic enzymes (amylases, lipases) and organic acid (citric acid, gluconic acid), as well as biologically active metabolites such as lovastatin. Although they are not considered to be major cause of plant diseases, Aspergillus species are responsible for several disorders in various plants and plant products, especially as opportunistic storage moulds. The notable consequence of their presence is contamination of foods and feeds by mycotoxins, among which the most important are aflatoxins, ochratoxin A, and, at a less extent, fumonisins. Aflatoxins B 1 , B 2 , G 1 , G 2 are the most toxic and carcinogenic mycotoxins, due to their extreme hepatocarcinogenicity; ochratoxin A is a potent nephrotoxin, it is also carcinogenic, teratogenic, and immunotoxic in rats and possibly in humans; fumonisins are hepatotoxic and nephrotoxic with potential carcinogenic effects on rat and mice. In this chapter we summarize the main aspects of morphology, ecology, epidemiology, and toxigenicity of Aspergillus foodborne pathogens which belong to sections Flavi, Circumdati, and Nigri, occurring in several agricultural products and responsible of aflatoxin, ochratoxin A, and fumonisins contamination of food and feed.

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

Radiation degradation of biological residues (Aflatoxins) produced in food laboratory

International Nuclear Information System (INIS)

Rogovschi, Vladimir D.; Aquino, Simone; Nunes, Thaise C.F.; Trindade, Reginaldo A.; Villavicencio, Anna L.C.H.; Zorzete, Patricia; Correa, Benedito

2007-01-01

Some molds have the capacity to produce substances that are toxic and generally cancer-causing agents, such as aflatoxins, that stand between the most important carcinogenic substances (class one of the agents which are certainly carcinogenous for human people according to the International Agency for Research on Cancer). Aspergillus spp. is present in world-wide distribution, with predominance in tropical and subtropical regions growing in any substratum. The aim of this work is establish a minimum dose of radiation that degrades aflatoxins produced by fungi Aspergillus spp. The Aspergillus spp. colonies will be cultivated in coconut agar medium and the samples will be conditioned in appropriate bags for irradiation treatment of contaminated material and processed in the Gammacell 220 with dose of 20 kGy. (author)

Radiation degradation of biological residues (Aflatoxins) produced in food laboratory

Energy Technology Data Exchange (ETDEWEB)

Rogovschi, Vladimir D.; Aquino, Simone; Nunes, Thaise C.F.; Trindade, Reginaldo A.; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (brazil)]. E-mails: vladrogo@yahoo.com.br; villavic@ipen.br; Zorzete, Patricia; Correa, Benedito [Universidade de Sao Paulo, SP (Brazil). Inst. de Ciencias Biomedicas]. E-mail: correabe@usp.br

2007-07-01

Some molds have the capacity to produce substances that are toxic and generally cancer-causing agents, such as aflatoxins, that stand between the most important carcinogenic substances (class one of the agents which are certainly carcinogenous for human people according to the International Agency for Research on Cancer). Aspergillus spp. is present in world-wide distribution, with predominance in tropical and subtropical regions growing in any substratum. The aim of this work is establish a minimum dose of radiation that degrades aflatoxins produced by fungi Aspergillus spp. The Aspergillus spp. colonies will be cultivated in coconut agar medium and the samples will be conditioned in appropriate bags for irradiation treatment of contaminated material and processed in the Gammacell 220 with dose of 20 kGy. (author)

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.

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

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

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

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.

A study on the possibility of production of aflatoxin B1 in saffron

Directory of Open Access Journals (Sweden)

Abbas Mohammadi

2017-06-01

Full Text Available Saffron is the most important medicinal plants in the Khorasan Razavi and South Khorasan provinces, Iran. Aspergillus species can infect saffron tissues during harvesting, storage and transportation. Aflatoxin B1 is one of the important carcinogenic mycotoxin which is produced by Aspergillus species in saffron tissues. This study was carried out in order to investigate the production of aflatoxin B1 in saffron tissues from farm to food by TLC chromatography during the year 2015. Wet and dry saffron tissues and rice grains (with and without saffron extract were inoculated with Aspergillus flavus spore suspensions. Production of Aflatoxin B1 in inoculated tissues was investigated by the TLC chromatography method. The results showed that the wet leaves and rice grains were infected with Aspergillus species very quickly. However, this process was very slow in dry tissues. Aflatoxin B1 was detected in all of the tested samples. The amounts of Aflatoxin B1 in the wet saffron tissues and rice grains were more than those found in dry tissues and saffron rice, respectively. The amount of Aflatoxin B1 had a direct correlation with moisture in the environment and the tissues. The contamination of the tissues and production of AflatoxinB1 were increased with increasing the amount of moisture. The results showed that the packaging of saffron before complete drying of its tissue or storing it in conditions with high humidity can increase the risk of infection with the Aspergillus species and production of Aflatoxin B1 in them. Based on our data, saffron can reduce Aspergillus infection and aflatoxin B1 production but not inhibit it. Saffron extract reduces Aspergillus infection and Aflatoxin B1 production in food and grains.

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

Science.gov (United States)

Jørgensen, Thomas R

2007-12-01

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 of the wild molds Aspergillus flavus and Aspergillus parasiticus. All four species are classified to the A. flavus group. Strains of the A. flavus group are characterized by a high degree of morphological similarity. Koji mold species are generally perceived of as being nontoxigenic, whereas wild molds are associated with the carcinogenic aflatoxins. Thus, reliable identification of individual strains is very important for application purposes. This review considers the pheno- and genotypic markers used in the classification of A. flavus group strains and specifically in the identification of A. oryzae and A. sojae strains. Separation of A. oryzae and A. sojae from A. flavus and A. parasiticus, respectively, is inconsistent, and both morphologic and molecular evidence support conspecificity. The high degree of identity is reflected by the divergent identification of reference cultures maintained in culture collections. As close relatives of aflatoxin-producing wild molds, koji molds possess an aflatoxin gene homolog cluster. Some strains identified as A. oryzae and A. sojae have been implicated in aflatoxin production. Identification of a strain as A. oryzae or A. sojae is no guarantee of its inability to produce aflatoxins or other toxic metabolites. Toxigenic potential must be determined specifically for individual strains. The species taxa, A. oryzae and A. sojae, are currently conserved by societal issues.

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

. 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......), followed by A. nomius (58 isolates in 15 samples), whereas A. parasiticus was rarest. A direct competitive Enzyme-linked immunosorbent assay (ELISA)-based method was implemented to quantify the content in aflatoxins. Eighteen of the samples contained some aflatoxins at detectable levels whereas 54 did not...... of variance results, only pH (p levels were...

[Morphological characteristics and physiological properties of aflatoxin B1 producing and non-producing Aspergillus flavus strains].

Science.gov (United States)

Kogbo, W; Lemarinier, S; Boutibonnes, P

1985-09-01

Comparison between about 80 strains of Aspergillus flavus, belonging to the series flavus and oryzae, obtained from international collections but also isolated from French or African substrates revealed the following observations: 1. Cultural and morphological characteristics of toxicogenic and atoxicogenic strains of A. flavus are similar. However, the former produce a diffusible yellow pigment in 83% of isolates. 2. The two groups of conidiospores have the same resistance to UV irradiation (254 nm, 5 and 10 min). All the strains are equally sensitive to 4 antifungal antibiotics: nystatine, ketoconazole, clotrimazole and amphotericine. 3. A difference was seen in the capacity to produce enzymes as alpha-galactosidase, beta-galactosidase and beta-glucosidase, implicated in the glucid metabolism. The specific hydrolytic activity has been confirmed by the characterization of a large amount of beta-galactosidase and by a diauxic growth on glucose medium supplemented by lactose. Possible relationship between these characters and aflatoxin B1 production by A. flavus strains is discussed.

Distribution and mycotoxigenic potential of Aspergillus section Nigri species in naturally-contaminated almonds

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In a previous study, inedible almond pick-out samples were assayed for aflatoxin and aflatoxigenic Aspergillus species. These samples were observed to contain high populations of black-spored Aspergillus section Nigri species. To investigate whether these species may contribute to the total potent...

Aspergillus flavus: human pathogen, allergen and mycotoxin producer.

Science.gov (United States)

Hedayati, M T; Pasqualotto, A C; Warn, P A; Bowyer, P; Denning, D W

2007-06-01

Aspergillus infections have grown in importance in the last years. However, most of the studies have focused on Aspergillus fumigatus, the most prevalent species in the genus. In certain locales and hospitals, Aspergillus flavus is more common in air than A. fumigatus, for unclear reasons. After A. fumigatus, A. flavus is the second leading cause of invasive aspergillosis and it is the most common cause of superficial infection. Experimental invasive infections in mice show A. flavus to be 100-fold more virulent than A. fumigatus in terms of inoculum required. Particularly common clinical syndromes associated with A. flavus include chronic granulomatous sinusitis, keratitis, cutaneous aspergillosis, wound infections and osteomyelitis following trauma and inoculation. Outbreaks associated with A. flavus appear to be associated with single or closely related strains, in contrast to those associated with A. fumigatus. In addition, A. flavus produces aflatoxins, the most toxic and potent hepatocarcinogenic natural compounds ever characterized. Accurate species identification within Aspergillus flavus complex remains difficult due to overlapping morphological and biochemical characteristics, and much taxonomic and population genetics work is necessary to better understand the species and related species. The flavus complex currently includes 23 species or varieties, including two sexual species, Petromyces alliaceus and P. albertensis. The genome of the highly related Aspergillus oryzae is completed and available; that of A. flavus in the final stages of annotation. Our understanding of A. flavus lags far behind that of A. fumigatus. Studies of the genomics, taxonomy, population genetics, pathogenicity, allergenicity and antifungal susceptibility of A. flavus are all required.

The Inhibition of aflatoxin production from Aspergillus parasiticus ...

African Journals Online (AJOL)

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

Antifungal Activity and Aflatoxin Degradation of Bifidobacterium Bifidum and Lactobacillus Fermentum Against Toxigenic Aspergillus Parasiticus.

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Ghazvini, Roshanak Daie; Kouhsari, Ebrahim; Zibafar, Ensieh; Hashemi, Seyed Jamal; Amini, Abolfazl; Niknejad, Farhad

2016-01-01

Food and feedstuff contamination with aflatoxins (AFTs) is a serious health problem for humans and animals, especially in developing countries. The present study evaluated antifungal activities of two lactic acid bacteria (LAB ) against growth and aflatoxin production of toxigenic Aspergillus parasiticus . The mycelial growth inhibition rate of A. parasiticus PTCC 5286 was investigated in the presence of Bifidobacterium bifidum PTCC 1644 and Lactobacillus fermentum PTCC 1744 by the pour plate method. After seven days incubation in yeast extract sucrose broth at 30°C, the mycelial mass was weighed after drying. The inhibitory activity of LAB metabolites against aflatoxin production by A. parasiticus was evaluated using HPLC method. B. bifidum and L. fermentum significantly reduced aflatoxin production and growth rate of A. parasiticus in comparison with the controls (p≤0.05). LAB reduced total aflatoxins and B 1 , B 2 , G 1 and G 2 fractions by more than 99%. Moreover, LAB metabolites reduced the level of standard AFB 1 , B 2 , G 1 and G 2 from 88.8% to 99.8% (p≤0.05). Based on these findings, B. bifidum and L. fermentum are recommended as suitable biocontrol agents against the growth and aflatoxin production by aflatoxigenic Aspergillus species.

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

International Nuclear Information System (INIS)

Ito, Hitoshi

1992-01-01

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

Polyphasic approach including maldi-tof mass spectrometry to characterise aflatoxigenic species of aspergillus section flavi

OpenAIRE

Rodrigues, Paula; Santos, Cledir; Kozakiewicz, Zofia; Venâncio, Armando; Lima, Nelson

2009-01-01

Aflatoxins are toxic compounds which are produced as secondary metabolites by the fungi Aspergillus flavus, A. parasiticus and A. nomius growing on a variety of food products and are known to be carcinogenic, mutagenic, teratogenic and immunosuppressive1,2. Aspergillus is a large genus, with a complex taxonomy. The genus is easily identified by its characteristic conidiophore, but species identification and differentiation is complex, mainly because it is traditionally based on a range of mor...

Metabolites Identified during Varied Doses of Aspergillus Species in Zea mays Grains, and Their Correlation with Aflatoxin Levels

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Titilayo D. O. Falade

2018-05-01

Full Text Available Aflatoxin contamination is associated with the development of aflatoxigenic fungi such as Aspergillus flavus and A. parasiticus on food grains. This study was aimed at investigating metabolites produced during fungal development on maize and their correlation with aflatoxin levels. Maize cobs were harvested at R3 (milk, R4 (dough, and R5 (dent stages of maturity. Individual kernels were inoculated in petri dishes with four doses of fungal spores. Fungal colonisation, metabolite profile, and aflatoxin levels were examined. Grain colonisation decreased with kernel maturity: milk-, dough-, and dent-stage kernels by approximately 100%, 60%, and 30% respectively. Aflatoxin levels increased with dose at dough and dent stages. Polar metabolites including alanine, proline, serine, valine, inositol, iso-leucine, sucrose, fructose, trehalose, turanose, mannitol, glycerol, arabitol, inositol, myo-inositol, and some intermediates of the tricarboxylic acid cycle (TCA—also known as citric acid or Krebs cycle were important for dose classification. Important non-polar metabolites included arachidic, palmitic, stearic, 3,4-xylylic, and margaric acids. Aflatoxin levels correlated with levels of several polar metabolites. The strongest positive and negative correlations were with arabitol (R = 0.48 and turanose and (R = −0.53, respectively. Several metabolites were interconnected with the TCA; interconnections of the metabolites with the TCA cycle varied depending upon the grain maturity.

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

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Siavash Maktabi

2016-09-01

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

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...

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

International Nuclear Information System (INIS)

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

2015-01-01

Aflatoxin B 1 (AFB 1 ) 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 B 1 (AFB 1 ) inoculated by Aspergillus parasiticus in raisins (Vitis vinifera L.) and on AFB 1 in contaminated samples, was investigated. Values of the amount of aflatoxin B 1 produced on the 12th day of incubation, after irradiation, showed that gamma radiation exposure at 10 kGy decreased AFB 1 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 AFB 1 which were spiked in raisins resulted in ∼29% reduction of AFB 1 . According to the risk assessment analysis the Provisional Maximum Tolerable Daily Intake (PMTDI) of 1.0 ng AFB 1 kg −1 bw, indicates that consumers are less exposed to AFB 1 from the irradiated raisins. - Highlights: • Aflatoxin B 1 (AFB 1 ) is an extremely toxic and carcinogenic metabolite. • AFB 1 is produced in raisins. • Irradiation at the dose of 10 kGy affects AFB 1 production. • 10 kGy reduced (∼65%) AFB 1 production by A.parasiticus in raisins. • 10 kGy reduced (∼29%) AFB 1 spiked directly in raisins

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

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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.

Evaluation of the detection techniques of toxigenic Aspergillus isolates

African Journals Online (AJOL)

Aflatoxins are difuranocoumarin derivatives produced by some Aspergillus species through a polyketide pathway. Mycotoxins are considered hazardous and there is a need for accurate detection of each toxin. Several screening methods for direct visual determination of aflatoxins and ochratoxin A (OTA) production have ...

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

African Journals Online (AJOL)

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

Occurrence of aflatoxin contamination in maize kernels and ...

African Journals Online (AJOL)

Aflatoxins are toxic metabolites produced mainly by Aspergillus flavus and Aspergillus parasiticus. Aflatoxin B1 (AFB1) is a potent carcinogen, teratogen and mutagen. 660 pre- and post- harvest maize samples were collected from major maize growing areas in Tamil Nadu, India. Aflatoxin contamination was observed in ...

Genome-Wide Transcriptome Analysis of Cotton (Gossypium hirsutum L. Identifies Candidate Gene Signatures in Response to Aflatoxin Producing Fungus Aspergillus flavus.

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Renesh Bedre

Full Text Available Aflatoxins are toxic and potent carcinogenic metabolites produced from the fungi Aspergillus flavus and A. parasiticus. Aflatoxins can contaminate cottonseed under conducive preharvest and postharvest conditions. United States federal regulations restrict the use of aflatoxin contaminated cottonseed at >20 ppb for animal feed. Several strategies have been proposed for controlling aflatoxin contamination, and much success has been achieved by the application of an atoxigenic strain of A. flavus in cotton, peanut and maize fields. Development of cultivars resistant to aflatoxin through overexpression of resistance associated genes and/or knocking down aflatoxin biosynthesis of A. flavus will be an effective strategy for controlling aflatoxin contamination in cotton. In this study, genome-wide transcriptome profiling was performed to identify differentially expressed genes in response to infection with both toxigenic and atoxigenic strains of A. flavus on cotton (Gossypium hirsutum L. pericarp and seed. The genes involved in antifungal response, oxidative burst, transcription factors, defense signaling pathways and stress response were highly differentially expressed in pericarp and seed tissues in response to A. flavus infection. The cell-wall modifying genes and genes involved in the production of antimicrobial substances were more active in pericarp as compared to seed. The genes involved in auxin and cytokinin signaling were also induced. Most of the genes involved in defense response in cotton were highly induced in pericarp than in seed. The global gene expression analysis in response to fungal invasion in cotton will serve as a source for identifying biomarkers for breeding, potential candidate genes for transgenic manipulation, and will help in understanding complex plant-fungal interaction for future downstream research.

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

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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.

Survey of Expression of Aflatoxin Production Regulator Gene (aflR in Aspergillus Parasiticus by Alpinia Galanga L and Dorema Aucheri

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Zahra Arab-Mazar

2018-01-01

Full Text Available Background: Aflatoxins are one of the highly toxic secondary metabolites, which are mainly produced by Aspergillus parasiticus. This species frequently cause of food and agricultural products contamination including cereals, peanuts, and crops in the field. During recent years, researchers have considered research on elimination of aflatoxin and antifungal effects of medicinal herbals, such as Alpinia galanga L and Dorema aucheri. In this study, the effect of A.galanga L and D.aucheri a natural compound was examined on Aspergillus parasiticus growth, aflatoxins production and the aflR gene expression.Materials and Methods: Antifungal susceptibility A.galanga L and D.aucheri was performed according to CLSI document M38-A2. Quantitative changes in aflR gene level of expression were analyzed by Real-time PCR method.Results: Our result obtained that the MIC of extracts on A. parasiticus growth 250 mg/mL for D.aucheri and 800 mg/mL for A.galanga L. D.aucheri has antitoxic properties as well as its effective ability to decrease aflatoxin production. The level of aflR gene expression was decreased significantly after the exposure of fungal cell to D.aucheri extract, but A.galanga L didn’t have significant effect.Conclusion: This research indicated that D.aucheri has antifungal effects more than A.galanga L. Due to our obtained result we can suggest that D.aucheri herbal extract may have antifungal potential in medicine or agriculture.

Period of susceptibility of almonds to aflatoxin contamination during development in the orchard

Science.gov (United States)

Almonds can be contaminated by aflatoxins, mainly produced by Aspergillus flavus and A. parasiticus. Infection by Aspergillus species can be facilitated by insect damage to the kernel during hull split, which occurs 4 to 6 weeks before harvest. Within this period of time, it is unknown which kernel ...

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

Science.gov (United States)

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

2015-04-01

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

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.

New ochratoxin A producing species of Aspergillus section Circumdati

DEFF Research Database (Denmark)

Frisvad, Jens Christian; Frank, J.M.; Houbraken, J.A.M.P.

2004-01-01

Aspergillus section Circumdati contains species with yellow to ochre conidia and non-black sclerotia that produce at least one of the following extrolites: ochratoxins, penicillic acids, xanthomegnins or melleins. The exception to this is A. robustus, which produces black sclerotia, phototropic...... ochratoxin A production in coffee, rice, beverages and other foodstuffs are A. ochraceus, A. westerdijkiae and A. steynii....

Aflatoxigenic Fungi and Aflatoxins in Portuguese Almonds

Science.gov (United States)

Rodrigues, P.; Venâncio, A.; Lima, N.

2012-01-01

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

Aflatoxigenic Fungi and Aflatoxins in Portuguese Almonds

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P. Rodrigues

2012-01-01

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

Molecular detection of mycobiota and aflatoxin contamination of chili

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Gherbawy Youssuf A.

2015-01-01

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

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

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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.

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 (<35 μg/kg). Aspergillus spp. and AFB1 was not detected in any cookies tested. Although this survey was not comprehensive, it provides valuable information on aflatoxin levels in foods marketed in Malaysia. © 2011 Institute of Food Technologists®

Occurrence of mycotoxin producing fungi in bee pollen.

Science.gov (United States)

González, G; Hinojo, M J; Mateo, R; Medina, A; Jiménez, M

2005-11-15

The natural mycobiota occurring in bee pollen is studied in the present report with special attention to analyze the incidence of fungal species that are potential producers of mycotoxins. A total of 90 ready-to-eat bee pollen samples were analyzed. Eighty-seven samples were collected in stores placed in different Spanish areas and three were from Buenos Aires (Argentina). The statistical results (ANOVA) showed that yeasts and Penicillium spp. were the predominant fungi. With regard to the potential mycotoxin producing species, Penicillium verrucosum, Aspergillus niger aggregate, Aspergillus carbonarius, Aspergillus ochraceus, Aspergillus flavus, Aspergillus parasiticus and Alternaria spp. were found. The last genus was isolated very frequently. The potential ability for producing ochratoxin A (OTA) and aflatoxins B(1), B(2), G(1) and G(2) was studied by culturing in vitro the isolates followed by analysis of these mycotoxins in culture extracts by HPLC with fluorescent detection. It was found that 100%, 53.3%, 33.3% and 25% of the isolates of A. carbonarius, A. ochraceus, P. verrucosum and A. niger aggregate, respectively, produced OTA. Moreover, 28.6% of the isolates from the A. flavus plus A. parasiticus group were able to produce aflatoxin B(1). Aflatoxin B(2) was detected in only 10% of the cultures. Aflatoxins G(1) and G(2) were not detected in cultures under the assayed conditions. This is the first report carried out on the natural mycobiota occurring in bee pollen in general and on the toxigenic capability of these isolates in particular.

Emericella astellata, a new producer of aflatoxin B-1, B-2 and sterigmatocystin

DEFF Research Database (Denmark)

Frisvad, Jens Christian; Samson, R.A.; Smedsgaard, Jørn

2004-01-01

To report on aflatoxin B-1 and B-2 production from a species of Emericella. Methods and Results: Aflatoxins and sterigmatocystin were determined by high-pressure liquid chromatography (HPLC) with diode array detection and confirmed by HPLC with mass spectrometry detection. Among 30 known species...... of Emericella only one species produced aflatoxin. Strains originating from the same geographical source material had different patterns of aflatoxin and sterigmatocystin production on different media, indicating that epigenetic factors may be involved in the regulation of aflatoxin production. However, two...

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

Science.gov (United States)

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

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

Science.gov (United States)

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

2015-09-01

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

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...

Techniques used detection and quantification of aflatoxin M1 in milk

OpenAIRE

Adriana Frizzarin; Keila Maria Roncato Duarte

2012-01-01

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

Occurrence of B1 Aflatoxin in diet and M1 Aflatoxin in bovine milk

OpenAIRE

Adriana Frizzarin; Thiago Pereira Motta; Thamires Martins; Livia Castelani; Heloisa Solda de Azevedo; Cláudia Rodrigues Pozzi

2012-01-01

Ensuring food quality is one of the principles of food safety. Food for dairy cattle may be contaminated by fungi of the genus Aspergillus, which produce aflatoxins. The B1 aflatoxin, when ingested by animals, is biotransformed in liver in several other toxic metabolites, including M1 aflatoxin which is excreted in milk. M1 aflatoxin has a carcinogenic effect, which the presence in milk poses a serious risk to public health because milk and dairy products are consumed mainly by children, preg...

Comparison of the aflR gene sequences of strains in Aspergillus section Flavi.

Science.gov (United States)

Lee, Chao-Zong; Liou, Guey-Yuh; Yuan, Gwo-Fang

2006-01-01

Aflatoxins are polyketide-derived secondary metabolites produced by Aspergillus parasiticus, Aspergillus flavus, Aspergillus nomius and a few other species. 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. Although Aspergillus oryzae and Aspergillus sojae, which are used in fermented foods and in ingredient manufacture, have no record of producing aflatoxin, they have been shown to possess an aflR gene. This study examined 34 strains of Aspergillus section Flavi. The aflR gene of 23 of these strains was successfully amplified and sequenced. No aflR PCR products were found in five A. sojae strains or six strains of A. oryzae. These PCR results suggested that the aflR gene is absent or significantly different in some A. sojae and A. oryzae strains. The sequenced aflR genes from the 23 positive strains had greater than 96.6 % similarity, which was particularly conserved in the zinc-finger DNA-binding domain. The aflR gene of A. sojae has two obvious characteristics: an extra CTCATG sequence fragment and a C to T transition that causes premature termination of AFLR protein synthesis. Differences between A. parasiticus/A. sojae and A. flavus/A. oryzae aflR genes were also identified. Some strains of A. flavus as well as A. flavus var. viridis, A. oryzae var. viridis and A. oryzae var. effuses have an A. oryzae-type aflR gene. For all strains with the A. oryzae-type aflR gene, there was no evidence of aflatoxin production. It is suggested that for safety reasons, the aflR gene could be examined to assess possible aflatoxin production by Aspergillus section Flavi strains.

Support vector machines classification of fluorescence hyperspectral image for detection of aflatoxin in corn kernels

Science.gov (United States)

Aflatoxin contamination is a real concern for all classes of livestock. They are produced by certain mold fungi, Aspergillus flavus and Aspergillus parasiticus. Aflatoxin in food is hazardous for humans and animals. In this work, we propose a non-invasive system for detecting aflatoxin and classifyi...

Radiation degradation of biological waste (aflatoxins) produced in food laboratory

International Nuclear Information System (INIS)

Rogovschi, Vladimir Dias

2009-01-01

Many filamentous fungi can produce secondary metabolites, called mycotoxins, which can be found in food and agricultural products. One of the main genera of myco toxigenic fungi related to the food chain is the Aspergillus spp. There are over 400 mycotoxins described in the literature, the most common the aflatoxins B1, B2, G1 and G2. The mycotoxins are commonly found in foods and are considered one of the most dangerous contaminants. The aflatoxin B1 is classified in group one by the International Agency of Research on Cancer. Aflatoxins resisting for more than one hour in autoclave making it necessary to other means of degradation of these toxins. This work aimed to observe the effects of gamma radiation of 60 Co and electron beams in the degradation of aflatoxins and compare the damage caused on the morphology of the Aspergillus flavus. The fungus was grown on potato dextrose agar (PDA) for 10 days and was subsequently transferred to coconut agar medium, and maintained for 14 days at 25 degree C. After this step the coconut agar was ground to become a homogeneous pasty and was irradiated with doses of 2.5, 5.0, 10 and 20 kGy. The samples used in scanning electron microscopy were irradiated with doses of 0, 2.5, 5.0, 10 and 20 kGy with sources of 60 Co and electron beams. Irradiation with electron accelerator showed a slightly higher degradation to gamma radiation, reducing 29.93 %, 34.50 %, 52.63 % and 72.30 % for doses of 2.5, 5.0, 10 and 20 kGy, respectively. The Scanning Electron Microscopy showed that doses of 2.5 to 10 kGy did not cause damage to the fungus, but with a dose of 20 kGy it can be observed fungal damage to structures. (author)

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

The effect of zinc and phytic acid on the incorporation of 1-14C-acetate into aflatoxin by resting mycelia of Aspergillus parasiticus

International Nuclear Information System (INIS)

Gupta, S.K.; Venkitasubramanian, T.A.

1975-01-01

The effect of zinc and phytic acid on [1- 14 C]-acetate incorporation into aflatoxins by resting mycelium was studied. When different levels of ZnSO 4 were used to study its effect on the incorporation of [1- 14 C]-acetate into aflatoxins, it was found that the specific radioactivity incorporation into aflatoxins was maximum at the level of 10 mM-ZnSO 4 . At this concentration the change in the specific radioactivities of aflatoxins B 1 + B 2 and aflatoxins G 1 + G 2 were +74.61% and +29.66%, respectively. On the other hand, phytic acid had an inhibitory effect on the incorporation of [1- 14 C]-acetate. These observations have been correlated in order to find out why soyabean is unable to produce aflatoxins by Aspergillus parasiticus. (orig.) [de

Proteome analysis of Aspergillus flavus isolate-specific responses to oxidative stress in relationship to aflatoxin production capability

Science.gov (United States)

Aspergillus flavus is an opportunistic pathogen that infects host plants such as maize and peanut under conducive conditions such as drought stress resulting in significant aflatoxin production. Drought-associated oxidative stress is known to exacerbate aflatoxin production by A. flavus. The object...

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.

Effect of irradiation on aflatoxin production by Aspergillus flavus

International Nuclear Information System (INIS)

Ito, Hitoshi; Jintana Bunnak; Guzman, Z.M. de; Ishigaki, Isao

1991-01-01

The effects of repeated exposure to gamma irradiation on Aspergillus flavus var. columnaris S46 was studied in terms of the development of increased radioresistance and mutations. Original D 10 value was obtained as 0.22 kGy and increased a little after 6 times exposure at a dose of 0.8 kGy. Mutation ratios such as morphological changes and aflatoxin production were not remarkably changed even after 6 times exposure. A little stimulation of production of aflatoxin B 1 occurred by irradiation of spores of strains S46, E11 and E14 at 0.4 and 0.6 kGy in Synthetic Low Salts broth after incubation for 10 days at 25degC. The levels of aflatoxin B 1 was also increased 13 to 40% by incubation of irradiated spores of S46 strain at 1 kGy on autoclaved polished rice, black pepper and red pepper. However, these stimulation effects were not Observed after infection of these cultivates of irradiated sores to fresh media. (author)

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...

A review of agricultural aflatoxin management strategies and ...

African Journals Online (AJOL)

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

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

uvarum sp. nov. isolates produced secalonic acid, common to other Aspergillus japonicus-related taxa, and geodin, erdin and dihydrogeodin, which are not produced by any other black aspergilli. None of the isolates were found to produce ochratoxin A. The novel species is most closely related to two......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. Aspergillus...

Phytochemicals reduce aflatoxin-induced toxicity in chicken embryos

Science.gov (United States)

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

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)

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

Science.gov (United States)

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

2015-12-01

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

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

Science.gov (United States)

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

2011-05-01

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

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

OpenAIRE

Matome Gabriel Thathana; Hunja Murage; Akebe Luther King Abia; Michael Pillay

2017-01-01

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. ...

Fungi, aflatoxins, and cyclopiazonic acid associated with peanut retailing in Botswana.

Science.gov (United States)

Mphande, Fingani A; Siame, Bupe A; Taylor, Joanne E

2004-01-01

Peanuts are important food commodities, but they are susceptible to fungal infestation and mycotoxin contamination. Raw peanuts were purchased from retail outlets in Botswana and examined for fungi and mycotoxin (aflatoxins and cyclopiazonic acid) contamination. Zygomycetes were the most common fungi isolated; they accounted for 41% of all the isolates and were found on 98% of the peanut samples. Among the Zygomycetes, Absidia corymbifera and Rhizopus stolonifer were the most common. Aspergillus spp. accounted for 35% of all the isolates, with Aspergillus niger being the most prevalent (20.4%). Aspergillus flavus/parasiticus were also present and accounted for 8.5% of all the isolates, with A. flavus accounting for the majority of the A. flavus/parasiticus identified. Of the 32 isolates of A. flavus screened for mycotoxin production, 11 did not produce detectable aflatoxins, 8 produced only aflatoxins B1 and B2, and 13 produced all four aflatoxins (B1, B2, G1, and G2) in varying amounts. Only 6 of the A. flavus isolates produced cyclopiazonic acid at concentrations ranging from 1 to 55 microg/kg. The one A. parasiticus isolate screened also produced all the four aflatoxins (1,200 microg/kg) but did not produce cyclopiazonic acid. When the raw peanut samples (n = 120) were analyzed for total aflatoxins, 78% contained aflatoxins at concentrations ranging from 12 to 329 microg/kg. Many of the samples (49%) contained total aflatoxins at concentrations above the 20 microg/kg limit set by the World Health Organization. Only 21% (n = 83) of the samples contained cyclopiazonic acid with concentrations ranging from 1 to 10 microg/kg. The results show that mycotoxins and toxigenic fungi are common contaminants of peanuts sold at retail in Botswana.

First Report of an Atypical New Aspergillus parasiticus Isolates with Nucleotides Insertion in aflR Gene Identical to Aspergillus sojae

Science.gov (United States)

Aflatoxins are toxic and carcinogenic secondary metabolites produced primarily by the filamentous fungi Aspergillus favus and Aspergillus parasitic and cause toxin contamination in food chain worldwide. Aspergillus oryzae and Aspergillus sojae are highly valued as koji molds in the traditional prep...

A reappraisal of fungi producing aflatoxins

DEFF Research Database (Denmark)

Varga, János; Frisvad, Jens Christian; Samson, Robert A.

2009-01-01

Aflatoxins are decaketide-derived secondary metabolites which are produced by a complex biosynthetic pathway. Aflatoxins are among the economically most important mycotoxins. Aflatoxin B1 exhibits hepatocarcinogenic and hepatotoxic properties, and is frequently referred to as the most potent natu...

Antifungal Activity and Aflatoxin Degradation of Bifidobacterium Bifidum and Lactobacillus Fermentum Against Toxigenic Aspergillus Parasiticus

OpenAIRE

Ghazvini, Roshanak Daie; Kouhsari, Ebrahim; Zibafar, Ensieh; Hashemi, Seyed Jamal; Amini, Abolfazl; Niknejad, Farhad

2016-01-01

Food and feedstuff contamination with aflatoxins (AFTs) is a serious health problem for humans and animals, especially in developing countries. The present study evaluated antifungal activities of two lactic acid bacteria (LAB) against growth and aflatoxin production of toxigenic Aspergillus parasiticus. The mycelial growth inhibition rate of A. parasiticus PTCC 5286 was investigated in the presence of Bifidobacterium bifidum PTCC 1644 and Lactobacillus fermentum PTCC 1744 by the pour plate m...

Influence of sodium chloride on aflatoxin production by irradiated and non-irradiated spores of aspergillus flavus

International Nuclear Information System (INIS)

El-Bazza, Z.E.

1991-01-01

A liquid medium consisting of 2% yeast extract, 4% sucrose and 0-10% sodium chloride was inoculated with aspergillus flavus and incubated at 22.30 and 37 degree C for 8 days. Aflatoxin was determined in the medium by thin layer chromatography. Aflatoxin production was enhanced by 2 and 4% sodium chloride at 22 and 30 degree C and by 2-6% sodium chloride at 37 degree C. Aflatoxin was decreased by 8 and 10% sodium chloride at the three temperatures. Exposure of Asp. flavus spores to gamma radiation enhanced aflatoxin at 1 kGy and inhibited it at 2 kGy, with the different concentrations of sodium chloride.2 tab

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),

Aflatoxigenic Aspergillus flavus and Aspergillus parasiticus strains in Hungarian maize fields.

Science.gov (United States)

Sebők, Flóra; Dobolyi, Csaba; Zágoni, Dóra; Risa, Anita; Krifaton, Csilla; Hartman, Mátyás; Cserháti, Mátyás; Szoboszlay, Sándor; Kriszt, Balázs

2016-12-01

Due to the climate change, aflatoxigenic Aspergillus species and strains have appeared in several European countries, contaminating different agricultural commodities with aflatoxin. Our aim was to screen the presence of aflatoxigenic fungi in maize fields throughout the seven geographic regions of Hungary. Fungi belonging to Aspergillus section Flavi were isolated in the ratio of 26.9% and 42.3% from soil and maize samples in 2013, and these ratios decreased to 16.1% and 34.7% in 2014. Based on morphological characteristics and the sequence analysis of the partial calmodulin gene, all isolates proved to be Aspergillus flavus, except four strains, which were identified as Aspergillus parasiticus. About half of the A. flavus strains and all the A. parasiticus strains were able to synthesize aflatoxins. Aflatoxigenic Aspergillus strains were isolated from all the seven regions of Hungary. A. parasiticus strains were found in the soil of the regions Southern Great Plain and Southern Transdanubia and in a maize sample of the region Western Transdanubia. In spite of the fact that aflatoxins have rarely been detected in feeds and foods in Hungary, aflatoxigenic A. flavus and A. parasiticus strains are present in the maize culture throughout Hungary posing a potential threat to food safety.

RNA-seq analysis of an nsdC mutant in Aspergillus flavus

Science.gov (United States)

The C2H2-type transcription factor NsdC (Never in Sexual Development C) has been shown to play a role in asexual development and secondary metabolite production in Aspergillus flavus, an agriculturally relevant, aflatoxin-producing species. The nsdC knoackout mutant demonstrates perturbed morphologi...

Mycobiota and Natural Incidence of Aflatoxins, Ochratoxin A, and Citrinin in Indian Spices Confirmed by LC-MS/MS

Science.gov (United States)

Jeswal, Punam; Kumar, Dhiraj

2015-01-01

Nine different Indian spices (red chilli, black pepper, turmeric, coriander, cumin, fennel, caraway, fenugreek, and dry ginger) commonly cultivated and highly used in India were analysed for natural occurrence of toxigenic mycoflora and aflatoxins (AFs), ochratoxin A (OTA), and citrinin (CTN) contamination. Aspergillus flavus and Aspergillus niger were the most dominant species isolated from all types of spices. Red chilli samples were highly contaminated with aflatoxins (85.4%) followed by dry ginger (77.7%). 56% Aspergillus flavus from red chilli and 45% Aspergillus ochraceus from black pepper were toxigenic and produced aflatoxins and ochratoxin A, respectively. Qualitative detection and quantitative detection of mycotoxins in spices were analyzed by ELISA and further confirmed by LC-MS/MS. Penicillium citrinum produced citrinin in red chilli, black pepper, coriander, cumin, fenugreek, and dry ginger samples. The highest amount of AFs was found in red chilli (219.6 ng/g), OTA was in black pepper (154.1 ng/g), and CTN was in dry ginger samples (85.1 ng/g). The results of this study suggest that the spices are susceptible substrate for growth of mycotoxigenic fungi and further mycotoxin production. This is the first report of natural occurrence of citrinin in black pepper and dry ginger from India. PMID:26229535

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...

Monitoring of Aflatoxins in Peanuts

OpenAIRE

UÇKUN, Okşan; VAR, Işıl

2014-01-01

Peanuts (Arachis hypogaea L.) are one of the most important oilseed crops and snack foods in the world Agro-food trade market. The major producers/exporters of peanuts are the United States, China, Argentina, Sudan, Senegal, and Brazil. Peanuts are a perishable commodity, easily spoiled by fungi. Aflatoxins are a group of natural compounds mainly produced by Aspergillus flavus and Aspergillus parasiticus. They have been found to be carcinogenic, teratogenic, and mutagenic to humans and animal...

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

Science.gov (United States)

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

2013-12-01

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

Comparison of the side-needle and knife techniques for inducing Aspergillus flavus infection and aflatoxin accumulation in corn hybrids

Science.gov (United States)

Aflatoxin in corn grain is a problem in many areas of the world. Any combination of environmentally stressful or agronomically unfavorable conditions can increase the likelihood of Aspergillus flavus infection and production of aflatoxin in the corn grain. In the absence of a consistent natural A....

Fluorescence imaging spectroscopy (FIS) for comparing spectra from corn ears naturally and artificially infected with aflatoxin producing fungus

Science.gov (United States)

In an effort to address the aflatoxin problem in grain, the current study assessed the spectral differences of aflatoxin production in kernels from a cornfield inoculated with spores from two different strains of toxigenic Aspergillus flavus. Aflatoxin production in corn from the same field due to n...

Genotypic regulation of aflatoxin accumulation but not Aspergillus fungal growth upon post-harvest infection of peanut (Arachis hypogaea L.) seeds

Science.gov (United States)

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 green fluorescent protein (GFP) - expression Aspergillus flavus strain. Per...

An efficient Agrobacterium-mediated transformation method for aflatoxin generation fungus Aspergillus flavus.

Science.gov (United States)

Han, Guomin; Shao, Qian; Li, Cuiping; Zhao, Kai; Jiang, Li; Fan, Jun; Jiang, Haiyang; Tao, Fang

2018-05-01

Aspergillus flavus often invade many important corps and produce harmful aflatoxins both in preharvest and during storage stages. The regulation mechanism of aflatoxin biosynthesis in this fungus has not been well explored mainly due to the lack of an efficient transformation method for constructing a genome-wide gene mutant library. This challenge was resolved in this study, where a reliable and efficient Agrobacterium tumefaciens-mediated transformation (ATMT) protocol for A. flavus NRRL 3357 was established. The results showed that removal of multinucleate conidia, to collect a homogenous sample of uninucleate conidia for use as the transformation material, is the key step in this procedure. A. tumefaciens strain AGL-1 harboring the ble gene for zeocin resistance under the control of the gpdA promoter from A. nidulans is suitable for genetic transformation of this fungus. We successfully generated A. flavus transformants with an efficiency of ∼ 60 positive transformants per 10 6 conidia using our protocol. A small-scale insertional mutant library (∼ 1,000 mutants) was constructed using this method and the resulting several mutants lacked both production of conidia and aflatoxin biosynthesis capacity. Southern blotting analysis demonstrated that the majority of the transformants contained a single T-DNA insert on the genome. To the best of our knowledge, this is the first report of genetic transformation of A. flavus via ATMT and our protocol provides an effective tool for construction of genome-wide gene mutant libraries for functional analysis of important genes in A. flavus.

Redox systems are a potential link between drought stress susceptibility and the exacerbation of aflatoxin contamination in crops

Science.gov (United States)

Drought stress aggravates Aspergillus flavus infection and aflatoxin contamination in oilseed crops such as peanut and maize. Reactive oxygen species (ROS) are produced in plants in response to abiotic and biotic stresses as a means of defense. In the host plant-A. flavus interaction under drought c...

Effect of climate change on Aspergillus flavus and aflatoxin B1 production

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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.

Survey of Aspergillus and Fusarium species and their mycotoxins in raw materials and poultry feeds from Córdoba, Argentina.

Science.gov (United States)

Monge, María Del Pilar; Magnoli, Carina Elizabeth; Chiacchiera, Stella Maris

2012-05-01

The aims of the present work were: (1) to determine both mycobiota in raw materials and finisher poultry feed, as well as the ability to produce aflatoxin B1 by A. flavus strains, and (2) to evaluate the natural co-occurrence of aflatoxins (AFs), fumonisins (FBs), gliotoxin, diacetoxyscirpenol (DAS), HT-2 toxin, and T-2 toxin in poultry feed by LC-MS/MS. Nineteen percent of raw materials and 79% of finisher poultry feed samples exceeded the maximum allowed total fungal count (1 × 10(4) CFU g(-1)) to ensure hygienic quality. Aspergillus flavus was the only species belonging to section Flavi which was isolated while Fusarium verticilliodes was the prevalent species. Forty-seven percent of A. flavus strains were aflatoxin B1 producers and the highest frequency of aflatoxigenic strains was isolated from finisher poultry feeds. Principal component analysis showed that corn grains are closely related with total fungal and Fusarium counts. This positive relationship suggests that total fungal and Fusarium spp. counts in poultry feed might come mainly from corn grains. Regarding poultry feeds, in ground finisher type, Aspergillus spp. counts increased as water activity (aw) diminished. A positive relationship among aw, total fungal and Fusarium spp. counts was observed in both ground finisher and ground starter feed. Several mycotoxins were monitored in feeds by applying the LC MS/MS technique. One hundred percent of poultry samples were contaminated with FB1, and the highest levels were detected in pelleted finisher poultry. AFB1, gliotoxin, DAS, HT-2 toxin, and T-2 toxin were not detected in any poultry feed. The scarcity of available mycotoxicological studies from Argentinean poultry feed using a multitoxin analysis technique enhances the contribution of the findings of this report.

Cyclopiazonic Acid Biosynthesis of Aspergillus flavus and Aspergillus oryzae

Science.gov (United States)

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

Genome sequences of three strains of Aspergillus flavus for the biological control of Aflatoxin

Science.gov (United States)

The genomes of three strains of Aspergillus flavus with demonstrated utility for the biological control of aflatoxin were sequenced. These sequences were assembled with MIRA and annotated with Augustus using A. flavus strain 3357 (NCBI EQ963472) as a reference. Each strain had a genome of 36.3 to ...

Mycoflora and aflatoxin/fumonisin production by fungal isolates from freshly harvested corn hybrids

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Almeida Adriana P.

2000-01-01

Full Text Available The mycoflora of 3 hybrids of freshly harvested corn grains collected from three regions of the state of São Paulo, Brazil (Assis, Capão Bonito and Ribeirão Preto was investigated. A total of 66 samples were analyzed focusing on the influence of abiotic factors (moisture content, water activity, temperature and rainfall on both the prevalence of Aspergillus flavus and Fusarium moniliforme, and the ability of these genera isolates to produce aflatoxins and fumonisins, respectively. In the three surveyed regions, the fungal population comprised mainly Fusarium spp., Penicillium spp., Aspergillus spp. and 2 others filamentous fungal genera, which were isolated from corn kernels showing water activity of 0.30 to 0.99 and moisture content of 5.0% to 20.2%. Among the genera Fusarium and Aspergillus, the most frequent species were F. moniliforme and A. flavus, respectively. Concerning the toxigenic potential of F. moniliforme, all isolated strains (40 produced fumonisins at 20 mug/g to 2168 mug/g (FB1 and/or 10 mug/g to 380 mug/g (FB2. From the 10 A. flavus isolates, 6 strains (60.0% produced aflatoxins at 615 mug/kg to 30.750 mug/kg (AFB1 and/or 11 mug/kg to 22 mug/kg (AFB2.

Techniques used detection and quantification of aflatoxin M1 in milk

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Adriana Frizzarin

2012-02-01

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

Aflatoxin-exposure of Vibrio gazogenes as a novel system for the generation of aflatoxin synthesis inhibitors

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Phani M Gummadidala

2016-06-01

Full Text Available Aflatoxin is a mycotoxin and a secondary metabolite, and the most potent known liver carcinogen that contaminates several important crops, and represents a significant threat to public health and the economy. Available approaches reported thus far have been insufficient to eliminate this threat, and therefore provide the rational to explore novel methods for preventing aflatoxin accumulation in the environment. Many terrestrial plants and microbes that share ecological niches and encounter the aflatoxin producers have the ability to synthesize compounds that inhibit aflatoxin synthesis. However, reports of natural aflatoxin inhibitors from marine ecosystem components that do not share ecological niches with the aflatoxin producers are rare. Here we show that a non-pathogenic marine bacterium, Vibrio gazogenes, when exposed to low non-toxic doses of aflatoxin B1, demonstrates a shift in its metabolic output and synthesizes a metabolite fraction that inhibits aflatoxin synthesis without affecting hyphal growth in the model aflatoxin producer, Aspergillus parasiticus. The molecular mass of the predominant metabolite in this fraction was also different from the known prodigiosins, which are the known antifungal secondary metabolites synthesized by this Vibrio. Gene expression analyses using RT-PCR demonstrate that this metabolite fraction inhibits aflatoxin synthesis by down-regulating the expression of early-, middle- and late- growth stage aflatoxin genes, the aflatoxin pathway regulator, aflR and one global regulator of secondary metabolism, LaeA. Our study establishes a novel system for generation of aflatoxin synthesis inhibitors, and emphasizes the potential of the under-explored Vibrio’s silent genome for generating new modulators of fungal secondary metabolism.

New ochratoxin A or sclerotium producing species in Aspergillus section Nigri

DEFF Research Database (Denmark)

Samson, R.A.; Frisvad, Jens Christian

2004-01-01

in Costa Rica and produces large pink to greyish brown sclerotia. Aspergillus lacticoffeatus was found on coffee beans in Venezuela and Indonesia, and is an effective producer of ochratoxin A. Aspergillus piperis was isolated from black ground pepper and produces large yellow to pink brown sclerotia...

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

Science.gov (United States)

Aflatoxins, highly toxic carcinogens produced by several members of Aspergillus section Flavi, contaminate crops in temperate zones. Maize is cultivated from 0 to 2,100 masl under diverse growing regimes in the state of Sonora, Mexico. This is typical of the nation. In order to design sampling strat...

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

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Josefa B. da Silva

2004-09-01

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

Reversal of aflatoxin induced liver damage by turmeric and curcumin.

Science.gov (United States)

Soni, K B; Rajan, A; Kuttan, R

1992-09-30

The effect of certain food additives on aflatoxin production by Aspergillus parasiticus has been studied in vitro. Extracts of turmeric (Curcuma longa), garlic (Allium sativum) and asafoetida (Ferula asafoetida) inhibited the aflatoxin production considerably (more than 90%) at concentrations of 5-10 mg/ml. Similar results were also seen using butylated hydroxytoluene, butylated hydroxyanisole and ellagic acid at concentration 0.1 mM. Curcumin, the antioxidant principle from Curcuma longa did not have any effect on aflatoxin production. Turmeric and curcumin were also found to reverse the aflatoxin induced liver damage produced by feeding aflatoxin B1 (AFB1) (5 micrograms/day per 14 days) to ducklings. Fatty changes, necrosis and biliary hyperplasia produced by AFB1 were considerably reversed by these food additives.

Extrolites of Aspergillus fumigatus and Other Pathogenic Species in Aspergillus Section Fumigati

Science.gov (United States)

Frisvad, Jens C.; Larsen, Thomas O.

2016-01-01

Aspergillus fumigatus is an important opportunistic human pathogen known for its production of a large array of extrolites. Up to 63 species have been described in Aspergillus section Fumigati, some of which have also been reliably reported to be pathogenic, including A. felis, A. fischeri, A. fumigatiaffinis, A. fumisynnematus, A. hiratsukae, A. laciniosus, A. lentulus, A. novofumigatus, A. parafelis, A. pseudofelis, A. pseudoviridinutans, A. spinosus, A. thermomutatus, and A. udagawae. These species share the production of hydrophobins, melanins, and siderophores and ability to grow well at 37°C, but they only share some small molecule extrolites, that could be important factors in pathogenicity. According to the literature gliotoxin and other exometabolites can be contributing factors to pathogenicity, but these exometabolites are apparently not produced by all pathogenic species. It is our hypothesis that species unable to produce some of these metabolites can produce proxy-exometabolites that may serve the same function. We tabulate all exometabolites reported from species in Aspergillus section Fumigati and by comparing the profile of those extrolites, suggest that those producing many different kinds of exometabolites are potential opportunistic pathogens. The exometabolite data also suggest that the profile of exometabolites are highly specific and can be used for identification of these closely related species. PMID:26779142

Evaluation of aflatoxin B1 in different parts of pistachio fruit and effects of processing stages

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R Dargahi

2014-11-01

Full Text Available Pistachio nut as the most important agricultural export products is facing challenges trough production and conception. Toxigenic Aspergillus species are able to grow and produce dangerous mycotoxins on pistachio nut. Distribution of aflatoxin in different pistachio samples collected pre- (early splitting and healthy pistachios in orchards and post-harvest (steps in processing plants was evaluated. Aflatoxin B1 content of samples was quantified using ELISA.  Overall, high content of aflatoxin B1 in pre-harvest was observed in early splitting pistachios which were 5 times higher than healthy ones. The mean value of aflatoxin B1 content in early splitting and healthy pistachio was 10.2 and 1.8 ng/g, respectively. In processing plant, the content of aflatoxin B1 in stained, small, floater and open shell pistachios was 21, 4, 15 and 2 times higher than unstained, large, sinker and closed shell pistachios, respectively. The presence of aflatoxin B1 in samples taken from orchards and processing plants indicates pre-harvest contamination by aflatoxin-producing fungi, which may exacerbate by inadequate post-harvest conditions. Physical properties of contaminated pistachios may be used to reduce aflatoxin levels in pistachio bulks during or after processing. ELISA, as practical, sensitive and cheap method, may apply to determine the aflatoxin content of pistachios.

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

Science.gov (United States)

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

2017-01-01

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

A survey of xerophilic Aspergillus from indoor environment, including descriptions of two new section Aspergillus species producing eurotium-like sexual states

DEFF Research Database (Denmark)

Visagie, Cobus M.; Yilmaz, Neriman; Renaud, Justin B.

2017-01-01

of 1039 strains; 296 strains belong to Aspergillus and represented 37 species. Reference sequences were generated for all species and deposited in GenBank. Aspergillus sect. Aspergillus (formerly called Eurotium) was one of the most predominant groups from house dust with nine species identified...

Occurrence of toxigenic Aspergillus flavus in commercial Bulgur wheat

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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.

New and revisited species in Aspergillus section Nigri

DEFF Research Database (Denmark)

Varga, J.; Frisvad, Jens Christian; Kocsube, S.

2011-01-01

based on either beta-tubulin or calmodulin sequence data. Aspergillus eucalypticola produced pyranonigrin A, funalenone, aurasperone B and other naphtho-gamma-pyrones. Aspergillus neoniger is also a biseriate species isolated from desert sand in Namibia, and mangrove water in Venezuela, which produces...

Aflatoxigenic Fungi and Aflatoxins in Portuguese Almonds

OpenAIRE

Rodrigues, P.; Venâncio, A.; Lima, N.

2012-01-01

Aflatoxin contamination of nuts is an increasing concern to the consumer’s health. Portugal is a big producer of almonds, but there is no scientific knowledge on the safety of those nuts, in terms of mycotoxins. The aim of this paper was to study the incidence of aflatoxigenic fungi and aflatoxin contamination of 21 samples of Portuguese almonds, and its evolution throughout the various stages of production. All fungi belonging to Aspergillus section Flavi were identified and tested ...

Nanoparticle-based immunosensors and immunoassays for aflatoxins

Energy Technology Data Exchange (ETDEWEB)

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

2016-03-17

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

Allergens/Antigens, toxins and polyketides of important Aspergillus species.

Science.gov (United States)

Bhetariya, Preetida J; Madan, Taruna; Basir, Seemi Farhat; Varma, Anupam; Usha, Sarma P

2011-04-01

The medical, agricultural and biotechnological importance of the primitive eukaryotic microorganisms, the Fungi was recognized way back in 1920. Among various groups of fungi, the Aspergillus species are studied in great detail using advances in genomics and proteomics to unravel biological and molecular mechanisms in these fungi. Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Aspergillus nidulans and Aspergillus terreus are some of the important species relevant to human, agricultural and biotechnological applications. The potential of Aspergillus species to produce highly diversified complex biomolecules such as multifunctional proteins (allergens, antigens, enzymes) and polyketides is fascinating and demands greater insight into the understanding of these fungal species for application to human health. Recently a regulator gene for secondary metabolites, LaeA has been identified. Gene mining based on LaeA has facilitated new metabolites with antimicrobial activity such as emericellamides and antitumor activity such as terrequinone A from A. nidulans. Immunoproteomic approach was reported for identification of few novel allergens for A. fumigatus. In this context, the review is focused on recent developments in allergens, antigens, structural and functional diversity of the polyketide synthases that produce polyketides of pharmaceutical and biological importance. Possible antifungal drug targets for development of effective antifungal drugs and new strategies for development of molecular diagnostics are considered.

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.

Natural postharvest aflatoxin occurrence in food legumes in the smallholder farming sector of Zimbabwe.

Science.gov (United States)

Maringe, David Tinayeshe; Chidewe, Cathrine; Benhura, Mudadi Albert; Mvumi, Brighton Marimanzi; Murashiki, Tatenda Clive; Dembedza, Mavis Precious; Siziba, Lucia; Nyanga, Loveness Kuziwa

2017-03-01

Aflatoxins, mainly produced by Aspergillus flavus and Aspergillus parasiticus, are highly toxic and may lead to health problems such as liver cancer. Exposure to aflatoxins may result from ingestion of contaminated foods. Levels of AFB 1 , AFB 2 , AFG 1 and AFG 2 in samples of groundnuts (Arachis hypogaea), beans (Phaseolus vulgaris), cowpeas (Vigna unguiculata) and bambara nuts (Vigna subterranean) grown by smallholder farmers in Shamva and Makoni districts, Zimbabwe, were determined at harvesting, using high performance liquid chromatography after immunoaffinity clean-up. Aflatoxins were detected in 12.5% of groundnut samples with concentrations ranging up to 175.9 µg/kg. Aflatoxins were present in 4.3% of the cowpea samples with concentrations ranging from 1.4 to 103.4 µg/kg. Due to alarming levels of aflatoxins detected in legumes versus maximum permissible levels, there is a need to assist smallholder farmers to develop harvest control strategies to reduce contamination of aflatoxins in legumes.

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

OpenAIRE

Rank, Christian; Klejnstrup, Marie Louise; Petersen, Lene Maj; Frisvad, Jens Christian; Larsen, Thomas Ostenfeld

2011-01-01

Aspergillus oryzae is a very important species in biotechnology and has been used for centuries in traditional Asian fermentation. The RIB40 strain is particularly interesting as it was one of the first genome sequenced Aspergilli together with A. flavus, a prominent food and feed contaminant 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...

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

Aflatoxin B1 and total fumonisin contamination and their producing fungi in fresh and stored sorghum grain in East Hararghe, Ethiopia.

Science.gov (United States)

Taye, Wondimeneh; Ayalew, Amare; Chala, Alemayehu; Dejene, Mashilla

2016-12-01

Natural contamination of sorghum grains by aflatoxin B 1 and total fumonisin and their producing toxigenic fungi has been studied. A total of 90 sorghum grain samples were collected from small-scale farmers' threshing floors and 5-6 months later from underground pits during 2013 harvest from three districts of East Hararghe, Ethiopia. Mycotoxin analysis was done using enzyme-linked immunosorbent assay (ELISA). The limits of detection were in the range 0.01-0.03 μg kg -1 . The results revealed that all sorghum grain samples were contaminated with both Aspergillus and Fusarium species. Aflatoxin B 1 was detected at levels ranging from fumonisin levels varied between 907 and 2041 µg kg -1 grain across the samples. Lowest total fumonisin was recorded in freshly harvested sorghum grain samples. Sorghum is a main staple cereal in the studied districts and its consumption per day per person is high. Daily intake of low doses of mycotoxin-contaminated food stuff over a period of time could lead to chronic mycotoxicosis.

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...... of the wild molds Aspergillus flavus and Aspergillus parasiticus. All four species are classified to the A. flavus group. Strains of the A. flavus group are characterized by a high degree of morphological similarity. Koji mold species are generally perceived of as being nontoxigenic, whereas wild molds...... are associated with the carcinogenic aflatoxins. Thus, reliable identification of individual strains is very important for application purposes. This review considers the pheno- and genotypic markers used in the classification of A. flavus group strains and specifically in the identification of A. oryzae and A...

Biodiversity of Aspergillus section Flavi in the United States: a review.

Science.gov (United States)

Horn, Bruce W

2007-10-01

Fungi belonging to Aspergillus section Flavi are of great economic importance in the United States due to their ability to produce toxic and carcinogenic aflatoxins in agricultural commodities. Development of control strategies against A. flavus and A. parasiticus, the major aflatoxin-producing species, is dependent upon a basic understanding of their diversity in agricultural ecosystems. This review summarizes our current knowledge of species and population diversity in the United States in relation to morphology, mycotoxin production and genetic characters. The high genetic diversity in populations of aflatoxigenic fungi is a reflection of their versatile habits in nature, which include saprotrophic colonization of plant debris in soil and parasitism of seeds and grain. Genetic variation within populations may originate from a cryptic sexual state. The advent of intensive monoculture agriculture not only increases population size but also may introduce positive selective pressure for aflatoxin production due to its link with pathogenicity in crops. Important goals in population research are to determine how section Flavi diversity in agricultural ecosystems is changing and to measure the direction of this evolution.

Survey of aflatoxins in tomato products Aflatoxinas em produtos de tomate

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Lilian Regina Barros Mariutti

2009-06-01

Full Text Available Tomatoes are highly susceptible to fungi contamination in the field, during transportation, processing, and storage. Aspergillus flavus and Aspergillus parasiticus have been isolated from tomatoes and tomato products, and both fungi species can produce aflatoxin, mycotoxin with hepatotoxic, carcinogenic, teratogenic, and mutagenic effects on all animal species tested so far. In order to verify a possible aflatoxin contamination of tomato products commercialized in Brazil, 63 samples of tomato products (pulp, paste, purée, ketchup, dehydrated tomatoes, and dried tomatoes preserved in oil produced in 5 Brazilian states and 1 imported sample (ketchup, totalizing 29 brands, were analyzed by thin layer chromatography. The analytical method showed an average recovery of 86% for all aflatoxins at two spiking levels. The limits of detection for the aflatoxins B1, B2, G1, and G2 varied with the type of the product ranging from 2 to 7 µg/kg. Aflatoxins were not detected in any evaluated sample indicating that they did not pose a risk to human health since there was no invasion of raw materials by toxigenic fungi or no conditions for toxin production.Os tomates são frutos altamente susceptíveis à contaminação fúngica tanto no campo como durante o transporte, processamento e armazenamento. Aspergillus flavus e Aspergillus parasiticus têm sido isolados em tomate e em produtos de tomate e ambas as espécies são produtoras de aflatoxinas, potentes micotoxinas que apresentam efeitos hepatotóxicos, carcinogênicos, teratogênicos e mutagênicos para todas as espécies animais testadas até o momento. Para verificar a possível contaminação por estas micotoxinas em produtos de tomate comercializados no Brasil, amostras de 63 produtos de tomate (polpa, pasta, purê, catchup, tomate desidratado e tomate seco conservado em óleo provenientes de 5 Estados brasileiros e uma do exterior (catchup, compreendendo a 29 marcas, foram analisadas por

Evaluation of maize inbred lines for resistance to pre-harvest aflatoxin and fumonisin contamination in the field

Science.gov (United States)

Two important mycotoxins, aflatoxin and fumonisin, are among the most potent naturally occurring carcinogens, contaminating maize (Zea mays L.) and affecting the crop yield and quality. Resistance of maize to pre-harvest mycotoxin contamination, specifically aflatoxin produced by Aspergillus flavus ...

Aflatoxin Accumulation in a Maize Diallel Cross

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W. Paul Williams

2015-06-01

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

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 ...

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

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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...

Secondary metabolite profiles and antifungal drug susceptibility of Aspergillus fumigatus and closely related species, Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans.

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Tamiya, Hiroyuki; Ochiai, Eri; Kikuchi, Kazuyo; Yahiro, Maki; Toyotome, Takahito; Watanabe, Akira; Yaguchi, Takashi; Kamei, Katsuhiko

2015-05-01

The incidence of Aspergillus infection has been increasing in the past few years. Also, new Aspergillus fumigatus-related species, namely Aspergillus lentulus, Aspergillus udagawae, and Aspergillus viridinutans, were shown to infect humans. These fungi exhibit marked morphological similarities to A. fumigatus, albeit with different clinical courses and antifungal drug susceptibilities. The present study used liquid chromatography/time-of-flight mass spectrometry to identify the secondary metabolites secreted as virulence factors by these Aspergillus species and compared their antifungal susceptibility. The metabolite profiles varied widely among A. fumigatus, A. lentulus, A. udagawae, and A. viridinutans, producing 27, 13, 8, and 11 substances, respectively. Among the mycotoxins, fumifungin, fumiquinazoline A/B and D, fumitremorgin B, gliotoxin, sphingofungins, pseurotins, and verruculogen were only found in A. fumigatus, whereas auranthine was only found in A. lentulus. The amount of gliotoxin, one of the most abundant mycotoxins in A. fumigatus, was negligible in these related species. In addition, they had decreased susceptibility to antifungal agents such as itraconazole and voriconazole, even though metabolites that were shared in the isolates showing higher minimum inhibitory concentrations than epidemiological cutoff values were not detected. These strikingly different secondary metabolite profiles may lead to the development of more discriminative identification protocols for such closely related Aspergillus species as well as improved treatment outcomes. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Polyphasic approach to the identification and characterization of aflatoxigenic strains of Aspergillus section Flavi isolated from peanuts and peanut-based products marketed in Malaysia.

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Norlia, M; Jinap, S; Nor-Khaizura, M A R; Son, R; Chin, C K; Sardjono

2018-05-31

Peanuts are widely consumed as the main ingredient in many local dishes in Malaysia. However, the tropical climate in Malaysia (high temperature and humidity) favours the growth of fungi from Aspergillus section Flavi, especially during storage. Most of the species from this section, such as A. flavus, A. parasiticus and A. nomius, are natural producers of aflatoxins. Precise identification of local isolates and information regarding their ability to produce aflatoxins are very important to evaluate the safety of food marketed in Malaysia. Therefore, this study aimed to identify and characterize the aflatoxigenic and non-aflatoxigenic strains of Aspergillus section Flavi in peanuts and peanut-based products. A polyphasic approach, consisting of morphological and chemical characterizations was applied to 128 isolates originating from raw peanuts and peanut-based products. On the basis of morphological characters, 127 positively identified as Aspergillus flavus, and the other as A. nomius. Chemical characterization revealed six chemotype profiles which indicates diversity of toxigenic potential. About 58.6%, 68.5%, and 100% of the isolates are positive for aflatoxins, cyclopiazonic acid and aspergillic acid productions respectively. The majority of the isolates originating from raw peanut samples (64.8%) were aflatoxigenic, while those from peanut-based products were less toxigenic (39.1%). The precise identification of these species may help in developing control strategies for aflatoxigenic fungi and aflatoxin contamination in peanuts, especially during storage. These findings also highlight the possibility of the co-occurrence of other toxins, which could increase the potential toxic effects of peanuts. Copyright © 2018. Published by Elsevier B.V.

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

Science.gov (United States)

Mitra, Chandrani

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

A reappraisal of Aspergillus section Nidulantes with descriptions of two new sterigmatocystin-producing species

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Hubka, Vit; Nováková, Alena; Peterson, Stephen W.

2016-01-01

Aspergillus section Nidulantes is a speciose group of microscopic fungi whose species are important in indoor air quality, food spoilage, mycotoxin production and human pathogenicity. We assembled as many species from the section as possible with either type specimens or protologues for analysis...... that both species are able to produce the mycotoxin sterigmatocystin and some additional compounds....

Previously unknown species of Aspergillus.

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Gautier, M; Normand, A-C; Ranque, S

2016-08-01

The use of multi-locus DNA sequence analysis has led to the description of previously unknown 'cryptic' Aspergillus species, whereas classical morphology-based identification of Aspergillus remains limited to the section or species-complex level. The current literature highlights two main features concerning these 'cryptic' Aspergillus species. First, the prevalence of such species in clinical samples is relatively high compared with emergent filamentous fungal taxa such as Mucorales, Scedosporium or Fusarium. Second, it is clearly important to identify these species in the clinical laboratory because of the high frequency of antifungal drug-resistant isolates of such Aspergillus species. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) has recently been shown to enable the identification of filamentous fungi with an accuracy similar to that of DNA sequence-based methods. As MALDI-TOF MS is well suited to the routine clinical laboratory workflow, it facilitates the identification of these 'cryptic' Aspergillus species at the routine mycology bench. The rapid establishment of enhanced filamentous fungi identification facilities will lead to a better understanding of the epidemiology and clinical importance of these emerging Aspergillus species. Based on routine MALDI-TOF MS-based identification results, we provide original insights into the key interpretation issues of a positive Aspergillus culture from a clinical sample. Which ubiquitous species that are frequently isolated from air samples are rarely involved in human invasive disease? Can both the species and the type of biological sample indicate Aspergillus carriage, colonization or infection in a patient? Highly accurate routine filamentous fungi identification is central to enhance the understanding of these previously unknown Aspergillus species, with a vital impact on further improved patient care. Copyright © 2016 European Society of Clinical Microbiology and

Mycoflora and aflatoxigenic species in derivatives of milled rice

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LIMA Carlos A. P.

2000-01-01

Full Text Available Thirty samples of rough rice stored for 6, 12 and 24 months in government authorized warehouses of the state of Rio Grande do Sul, Brazil, were simultaneously collected. After milling of the product, 90 samples (30 of polished rice, 30 of rice bran and 30 of rice hull were evaluated for their mycoflora, aflatoxigenic species and aflatoxin contamination. The following fungi, listed in decreasing order of frequency, were isolated on Potato-Dextrose Agar: Aspergillus spp., Nigrospora spp., Penicillium spp.; Fusarium spp.; Mucor spp.; Cladosporium spp.; Trichosporon spp. and non-sporulated fungi. The degree of fungal contamination (colony forming units per gram of product was lowest in polished rice, increasing progressively in samples of rice bran and rice hull. Among the Aspergillus species, A. flavus and A. candidus were isolated most frequently. Of the A. flavus isolates, 52.6% strains were found to be toxigenic and produced only Group B aflatoxins. Analysis of the 90 samples did not reveal the presence of aflatoxins in the rice derivatives.

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

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

Aspergillus oryzae is a very important species in biotechnology and has been used for centuries in traditional Asian fermentation. The RIB40 strain is particularly interesting as it was one of the first genome sequenced Aspergilli together with A. flavus, a prominent food and feed contaminant...... 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...

Aspergillus fumigatus and Related Species

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Sugui, Janyce A.; Kwon-Chung, Kyung J.; Juvvadi, Praveen R.; Latgé, Jean-Paul; Steinbach, William J.

2015-01-01

The genus Aspergillus contains etiologic agents of aspergillosis. The clinical manifestations of the disease range from allergic reaction to invasive pulmonary infection. Among the pathogenic aspergilli, Aspergillus fumigatus is most ubiquitous in the environment and is the major cause of the disease, followed by Aspergillus flavus, Aspergillus niger, Aspergillus terreus, Aspergillus nidulans, and several species in the section Fumigati that morphologically resemble A. fumigatus. Patients that are at risk for acquiring aspergillosis are those with an altered immune system. Early diagnosis, species identification, and adequate antifungal therapy are key elements for treatment of the disease, especially in cases of pulmonary invasive aspergillosis that often advance very rapidly. Incorporating knowledge of the basic biology of Aspergillus species to that of the diseases that they cause is fundamental for further progress in the field. PMID:25377144

Effect of Piper betle L. and its extracts on the growth and aflatoxin production by Aspergillus parasiticus.

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Chou, C C; Yu, R C

1984-01-01

Ground powder of the leaf and fruit of Piper betle L., a tropical spice plant grown in Southeast Asia, was prepared and extracted by chloroform, ethanol and water with one solvent only or with 3 solvents in sequence. The betel powder and various extracts were added to YES broth to determine their effects on the growth and aflatoxin production by Aspergillus parasiticus. Results showed that betel leaf powder exhibited higher antimycotic activity than fruit. One half percent of ground leaf powder completely inhibited the growth and aflatoxin production by A. parasiticus. Among the solvent extracts, chloroform and ethanol extracts of betel leaf prepared from a single solvent extraction showed more antimycotic activity. The ethanol extract of betel leaf at the level of 450 micrograms/ml would eliminate A. parasiticus growth and aflatoxin production. The antimycotic activity of this ethanol extract was most pronounced at pH 4.

Aspergillus saccharolyticus sp. nov., a new black Aspergillus species isolated in Denmark

DEFF Research Database (Denmark)

Sørensen, Annette; Lübeck, Peter S.; Lübeck, Mette

2011-01-01

A novel species, Aspergillus saccharolyticus sp. nov., belonging to the Aspergillus section Nigri group is described. This species was isolated in Denmark from treated hardwood. Its taxonomic status was determined using a polyphasic taxonomic approach including phenotypic (morphology and extrolite...... Aspergillus species that is morphologically similar to Aspergillus japonicus and Aspergillus aculeatus, but has a totally different extrolite profile compared to any known Aspergillus species. The type strain of A. saccharolyticus sp. nov. is CBS 127449T ( = IBT 28509T)....

Aflatoxin regulations and global pistachio trade: insights from social network analysis.

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Bui-Klimke, Travis R; Guclu, Hasan; Kensler, Thomas W; Yuan, Jian-Min; Wu, Felicia

2014-01-01

Aflatoxins, carcinogenic toxins produced by Aspergillus fungi, contaminate maize, peanuts, and tree nuts in many regions of the world. Pistachios are the main source of human dietary aflatoxins from tree nuts worldwide. Over 120 countries have regulations for maximum allowable aflatoxin levels in food commodities. We developed social network models to analyze the association between nations' aflatoxin regulations and global trade patterns of pistachios from 1996-2010. The main pistachio producing countries are Iran and the United States (US), which together contribute to nearly 75% of the total global pistachio market. Over this time period, during which many nations developed or changed their aflatoxin regulations in pistachios, global pistachio trade patterns changed; with the US increasingly exporting to countries with stricter aflatoxin standards. The US pistachio crop has had consistently lower levels of aflatoxin than the Iranian crop over this same time period. As similar trading patterns have also been documented in maize, public health may be affected if countries without aflatoxin regulations, or with more relaxed regulations, continually import crops with higher aflatoxin contamination. Unlike the previous studies on maize, this analysis includes a dynamic element, examining how trade patterns change over time with introduction or adjustment of aflatoxin regulations.

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)

2014-01-01

Background 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. Results 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. Conclusions 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. PMID:24885088

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

Science.gov (United States)

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

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)

Investigation of Non-Covalent Interactions of Aflatoxins (B1, B2, G1, G2, and M1 with Serum Albumin

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Miklós Poór

2017-10-01

Full Text Available Aflatoxins are widely spread mycotoxins produced mainly by Aspergillus species. Consumption of aflatoxin-contaminated foods and drinks causes serious health risks for people worldwide. It is well-known that the reactive epoxide metabolite of aflatoxin B1 (AFB1 forms covalent adducts with serum albumin. However, non-covalent interactions of aflatoxins with human serum albumin (HSA are poorly characterized. Thus, in this study the complex formation of aflatoxins was examined with HSA applying spectroscopic and molecular modelling studies. Our results demonstrate that aflatoxins form stable complexes with HSA as reflected by binding constants between 2.1 × 104 and 4.5 × 104 dm3/mol. A binding free energy value of −26.90 kJ mol−1 suggests a spontaneous binding process between AFB1 and HSA at room-temperature, while the positive entropy change of 55.1 JK−1 mol−1 indicates a partial decomposition of the solvation shells of the interacting molecules. Modeling studies and investigations with site markers suggest that Sudlow’s Site I of subdomain IIA is the high affinity binding site of aflatoxins on HSA. Interaction of AFB1 with bovine, porcine, and rat serum albumins was also investigated. Similar stabilities of the examined AFB1-albumin complexes were observed suggesting the low species differences of the albumin-binding of aflatoxins.

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

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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.

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

Energy Technology Data Exchange (ETDEWEB)

Durant, J.T.

1996-05-01

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

Aflatoxin production in a meat mix model system in the presence of Pediococcus and Lactobacillus

International Nuclear Information System (INIS)

Luchese, R.H.; Martins, J.F.P.; Harrigan, W.F.

1992-01-01

The effect on aflatoxin production by Aspergillus parasiticus of eight individual strains of Pediococcus and Lactobacillus was determined. The study was conducted in an axenic cultural system in which irradiated meat was employed in the formulation of a meat medium. The medium composition and incubation temperatures were simulations of Brazilian salami processing conditions. All single cultures of A. parasiticus supported aflatoxin production. More aflatoxin was produced in samples treated by the addition of lactic acid than in nontreated ones. Aflatoxin was not detected when A. parasiticus was grown with lactic acid bacteria, although visible mold growth was observed in all such cultures

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

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

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Leigh K. Hawkins

2018-01-01

Full Text Available 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.

The 14-3-3 homolog, ArtA, regulates development and secondary metabolism in the opportunistic plant pathogen Aspergillus flavus

Science.gov (United States)

The opportunistic plant pathogenic fungus Aspergillus flavus produces carcinogenic mycotoxins denominated aflatoxins (AFs). Aflatoxin contamination of agriculturally important crops such as maize, peanut, sorghum and tree nuts is responsible for serious adverse health and economic impacts worldwide....

Pathogenicity of fumonisin-producing and nonproducing strains of Aspergillus species in section Nigri to maize ears and seedlings

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Species of Aspergillus section Nigri are commonly associated with maize kernels, and some strains can produce fumonisin mycotoxins. However, there is little information about the extent to which these fungi contribute to fumonisin contamination in grain, the damage they cause to maize ears, or their...

Aspergillus niger contains the cryptic phylogenetic species A. awamori.

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Perrone, Giancarlo; Stea, Gaetano; Epifani, Filomena; Varga, János; Frisvad, Jens C; Samson, Robert A

2011-11-01

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 within this population, A. awamori. Morphological, physiological, ecological and chemical data overlap occurred between A. niger and the cryptic A. awamori, however the splitting of these two species was also supported by AFLP analysis of the full genome. Isolates in both phylospecies can produce the mycotoxins ochratoxin A and fumonisin B₂, and they also share the production of pyranonigrin A, tensidol B, funalenone, malformins, and naphtho-γ-pyrones. In addition, sequence analysis of four putative A. awamori strains from Japan, used in the koji industrial fermentation, revealed that none of these strains belong to the A. awamori phylospecies. Copyright © 2011 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

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

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Mohsen Farzaneh

2016-06-01

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

Fusarium and Aspergillus mycotoxins contaminating wheat silage for dairy cattle feeding in Uruguay

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Agustina del Palacio

Full Text Available Abstract Wheat is one of the most important cultivated cereals in Uruguay for human consumption; however, when harvest yields are low, wheat is usually used in ensiling for animal feeding. Ensiling is a forage preservation method that allows for storage during extended periods of time while maintaining nutritional values comparable to fresh pastures. Silage is vulnerable to contamination by spoilage molds and mycotoxins because ensilage materials are excellent substrates for fungal growth. The aim of the study was to identify the mycobiota composition and occurrence of aflatoxins and DON from wheat silage. A total of 220 samples of wheat were collected from four farms in the southwest region of Uruguay were silage practices are developed. The main fungi isolated were Fusarium (43% and Aspergillus (36%, with Fusarium graminearum sensu lato and Aspergillus section Flavi being the most prevalent species. Aflatoxin concentrations in silo bags ranged from 6.1 to 23.3 µg/kg, whereas DON levels ranged between 3000 µg/kg and 12,400 µg/kg. When evaluating aflatoxigenic capacity, 27.5% of Aspergillus section Flavi strains produced AFB1, 5% AFB2, 10% AFG1 and 17.5% AFG2. All isolates of F. graminearum sensu lato produced DON and 15-AcDON. The results from this study contribute to the knowledge of mycobiota and mycotoxins present in wheat silage.

Natural incidence of aflatoxins, mycological profile and molecular characterization of aflatoxigenic strains in chickpea flour

International Nuclear Information System (INIS)

Mushtaq, S.; Akram, A.; Qureshi, R.

2015-01-01

The mycological profile of retail chickpea flour (locall called Baisan), sold in the markets in the Rawalpindi district was studied. All the samples were tested for the contamination with aflatoxins. A total of 13 fungal species isolated from the flour and out of which, Aspergillus flavus was recorded the most common species (100%), followed by Rhizopus oryzea (50%), Aspergillus niger (40%), Penicilium digitatum (30%), Cladosporium cladosporoides, Fusarium oxysporium, Mucor recemosus, M. petrinsularis and Rhizopus arrhizus (20% each), Aspergillus oryzea, Botritus cinerea, Mucor circineloides and Penicillium sp. (10% each). Aflatoxin B1 was found in only 20% of the samples ranging from 3.03-4.24ppb. The molecular characterization was carried out by using PCR using simple sequence repeats (SSR) primers. The SSR amplification pattern clearly showed the genetic variability among the 10 strains of A. flavus. A dendrogram was generated through MVSP software program. Genotype AF04 was most diverse among all genotypes. The similarity value was ranged between 0.538 (53.8%)-0.938 (93.8%). (author)

Effects of salicylic acid on Aspergillus flavus infection and aflatoxin B₁ accumulation in pistachio (Pistacia vera L.) fruit.

Science.gov (United States)

Panahirad, Sima; Zaare-Nahandi, Fariborz; Mohammadi, Nilufar; Alizadeh-Salteh, Saeedeh; Safaie, Naser

2014-07-01

One of the most important saprophytic infections in fresh pistachio fruits after harvesting is Aspergillus flavus colonization, which significantly reduces fruit quality. Salicylic acid plays a crucial role in plant tissues and has a suppression effect on some fungi. The inhibitory effect of salicylic acid on the growth of A. flavus was assessed in vitro and in vivo. For this purpose, seven concentrations (0, 1, 3, 5, 7, 9 and 11 mmol L(-1)) of salicylic acid were used in both experiments. Also, aflatoxin B1 contents of the samples were analysed using immunoaffinity chromatography. The results obtained from in vitro experiments showed that salicylic acid significantly reduced Aspergillus growth at all concentrations, and at 9 mmol L(-1) growth was completely suppressed. In vivo evaluation showed relatively high levels of inhibition, though the intact treated fruits as compared with the injured treated fruits demonstrated higher inhibitory effects. Regarding the inhibitory effects of salicylic acid on the control of A. flavus contamination, its application on pistachio fruits after harvesting could be a promising approach to control the fungus infection and reduce aflatoxin production in treated fruits. © 2013 Society of Chemical Industry.

Isolation, identification and toxigenic potential of ochratoxin A-producing Aspergillus species from coffee beans grown in two regions of Thailand

DEFF Research Database (Denmark)

Noonim, P.; Mahakarnchanakul, W.; Nielsen, Kristian Fog

2008-01-01

In 2006 and 2007, 32 Thai dried coffee bean samples (Coffea arabica) from two growing sites of Chiang Mai Province, and 32 Thai dried coffee bean samples (Coffea canephora var. robusta) from two growing sites of Chumphon Province, Thailand, were collected and assessed for the distribution of fungi...... with the potential to produce ochratoxin A (OTA). The overall percentage of fungal contamination in coffee was 98% and reduced to 60% after surface disinfection. There were remarkable ecological differences in the composition of ochratoxigenic species present in these two regions. Arabica coffee bean samples from...... the North had an average of 78% incidence of colonization with Aspergillus of section Circumdati with Aspergillus westerdijkiae and A. melleus as the predominant species. Aspergillus spp. of section Nigri were found in 75% of the samples whereas A. ochraceus was not detected. Robusta coffee beans from...

Screening of aflatoxin B1 and mycobiota related to raw materials and finished feed destined for fish

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Etelvina María Carvalho Gonçalves-Nunes

2015-07-01

Full Text Available The aim of the present study was to determine fungal genera, Aspergillus, Pénicillium and Fusarium species and aflatoxin B1 contamination from raw materials and finished feed intended for fish farm localized in Piaui, Brazil. Aspergillusflavus and P. citrinum were isolated with a high relative density from all samples. In general, a high percent of samples exceeded the levels proposed as feed hygienic quality limits (CFU g-1 according to Good Manufacture Practice. Aflatoxin B1 was analyzed by enzyme-linked immunosorbent assay. All raw materials and finished feed showed aflatoxin B1 levels. Although in this study AFB1 levels below recommended limits (20 μg kg-1 were found, it is important to emphasize the feed intake with toxin in low concentrations along time, since it produce chronic deleterious effects in animal production. This fact requires periodic monitoring to prevent the occurrence of chronic aflatoxicosis in aquaculture, to reduce the economic losses and to minimize hazards to animal health.

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

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Ana-Maria Gurban

2017-12-01

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

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

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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.

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.

Radiation degradation of biological waste (aflatoxins) produced in food laboratory; Degradacao por radiacao de residuos biologicos (aflatoxinas) produzidos em laboratorio de alimentos

Energy Technology Data Exchange (ETDEWEB)

Rogovschi, Vladimir Dias

2009-07-01

Many filamentous fungi can produce secondary metabolites, called mycotoxins, which can be found in food and agricultural products. One of the main genera of myco toxigenic fungi related to the food chain is the Aspergillus spp. There are over 400 mycotoxins described in the literature, the most common the aflatoxins B1, B2, G1 and G2. The mycotoxins are commonly found in foods and are considered one of the most dangerous contaminants. The aflatoxin B1 is classified in group one by the International Agency of Research on Cancer. Aflatoxins resisting for more than one hour in autoclave making it necessary to other means of degradation of these toxins. This work aimed to observe the effects of gamma radiation of {sup 60}Co and electron beams in the degradation of aflatoxins and compare the damage caused on the morphology of the Aspergillus flavus. The fungus was grown on potato dextrose agar (PDA) for 10 days and was subsequently transferred to coconut agar medium, and maintained for 14 days at 25 degree C. After this step the coconut agar was ground to become a homogeneous pasty and was irradiated with doses of 2.5, 5.0, 10 and 20 kGy. The samples used in scanning electron microscopy were irradiated with doses of 0, 2.5, 5.0, 10 and 20 kGy with sources of {sup 60}Co and electron beams. Irradiation with electron accelerator showed a slightly higher degradation to gamma radiation, reducing 29.93 %, 34.50 %, 52.63 % and 72.30 % for doses of 2.5, 5.0, 10 and 20 kGy, respectively. The Scanning Electron Microscopy showed that doses of 2.5 to 10 kGy did not cause damage to the fungus, but with a dose of 20 kGy it can be observed fungal damage to structures. (author)

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...

Fusarium and Aspergillus mycotoxins contaminating wheat silage for dairy cattle feeding in Uruguay.

Science.gov (United States)

Del Palacio, Agustina; Bettucci, Lina; Pan, Dinorah

Wheat is one of the most important cultivated cereals in Uruguay for human consumption; however, when harvest yields are low, wheat is usually used in ensiling for animal feeding. Ensiling is a forage preservation method that allows for storage during extended periods of time while maintaining nutritional values comparable to fresh pastures. Silage is vulnerable to contamination by spoilage molds and mycotoxins because ensilage materials are excellent substrates for fungal growth. The aim of the study was to identify the mycobiota composition and occurrence of aflatoxins and DON from wheat silage. A total of 220 samples of wheat were collected from four farms in the southwest region of Uruguay were silage practices are developed. The main fungi isolated were Fusarium (43%) and Aspergillus (36%), with Fusarium graminearum sensu lato and Aspergillus section Flavi being the most prevalent species. Aflatoxin concentrations in silo bags ranged from 6.1 to 23.3μg/kg, whereas DON levels ranged between 3000μg/kg and 12,400μg/kg. When evaluating aflatoxigenic capacity, 27.5% of Aspergillus section Flavi strains produced AFB1, 5% AFB2, 10% AFG1 and 17.5% AFG2. All isolates of F. graminearum sensu lato produced DON and 15-AcDON. The results from this study contribute to the knowledge of mycobiota and mycotoxins present in wheat silage. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Confirming QTL for aflatoxin resistance from Mp313E in different genetic backgrounds

Science.gov (United States)

The fungus Aspergillus flavus (Link:Fr) causes ear rot of maize (Zea mays L.) and produces the toxic metabolic product aflatoxin. One particularly effective method to control the fungus is via host plant resistance, but while several resistant breeding lines have been identified, transferring the r...

A trispecies Aspergillus microarray: Comparative transcriptomics of three Aspergillus species

DEFF Research Database (Denmark)

Andersen, Mikael Rørdam; Vongsangnak, Wanwipa; Panagiotou, Gianni

2008-01-01

The full-genome sequencing of the filamentous fungi Aspergillus nidulans, Aspergillus niger, and Aspergillus oryzae has opened possibilities for studying the cellular physiology of these fungi on a systemic level. As a tool to explore this, we are making available an Affymetrix GeneChip developed...... data identified 23 genes to be a conserved response across Aspergillus sp., including the xylose transcriptional activator XlnR. A promoter analysis of the up-regulated genes in all three species indicates the conserved XInR-binding site to be 5'-GGNTAAA-3'. The composition of the conserved gene......-set suggests that xylose acts as a molecule, indicating the presence of complex carbohydrates such as hemicellulose, and triggers an array of degrading enzymes. With this case example, we present a validated tool for transcriptome analysis of three Aspergillus species and a methodology for conducting cross...

Effect of pH and pulsed electric field process parameters on the aflatoxin reduction in model system using response surface methodology: Effect of pH and PEF on Aflatoxin Reduction.

Science.gov (United States)

Vijayalakshmi, Subramanian; Nadanasabhapathi, Shanmugam; Kumar, Ranganathan; Sunny Kumar, S

2018-03-01

The presence of aflatoxin, a carcinogenic and toxigenic secondary metabolite produced by Aspergillus species, in food matrix has been a major worldwide problem for years now. Food processing methods such as roasting, extrusion, etc. have been employed for effective destruction of aflatoxins, which are known for their thermo-stable nature. The high temperature treatment, adversely affects the nutritive and other quality attributes of the food, leading to the necessity of application of non-thermal processing techniques such as ultrasonication, gamma irradiation, high pressure processing, pulsed electric field (PEF), etc. The present study was focused on analysing the efficacy of the PEF process in the reduction of the toxin content, which was subsequently quantified using HPLC. The process parameters of different pH model system (potato dextrose agar) artificially spiked with aflatoxin mix standard was optimized using the response surface methodology. The optimization of PEF process effects on the responses aflatoxin B1 and total aflatoxin reduction (%) by pH (4-10), pulse width (10-26 µs) and output voltage (20-65%), fitted 2FI model and quadratic model respectively. The response surface plots obtained for the processes were of saddle point type, with the absence of minimum or maximum response at the centre point. The implemented numerical optimization showed that the predicted and actual values were similar, proving the adequacy of the fitted models and also proved the possible application of PEF in toxin reduction.

Gene Expression Profiling and Identification of Resistance Genes to Aspergillus flavus Infection in Peanut through EST and Microarray Strategies

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Baozhu Guo

2011-06-01

Full Text Available Aspergillus flavus and A. parasiticus infect peanut seeds and produce aflatoxins, which are associated with various diseases in domestic animals and humans throughout the world. The most cost-effective strategy to minimize aflatoxin contamination involves the development of peanut cultivars that are resistant to fungal infection and/or aflatoxin production. To identify peanut Aspergillus-interactive and peanut Aspergillus-resistance genes, we carried out a large scale peanut Expressed Sequence Tag (EST project which we used to construct a peanut glass slide oligonucleotide microarray. The fabricated microarray represents over 40% of the protein coding genes in the peanut genome. For expression profiling, resistant and susceptible peanut cultivars were infected with a mixture of Aspergillus flavus and parasiticus spores. The subsequent microarray analysis identified 62 genes in resistant cultivars that were up-expressed in response to Aspergillus infection. In addition, we identified 22 putative Aspergillus-resistance genes that were constitutively up-expressed in the resistant cultivar in comparison to the susceptible cultivar. Some of these genes were homologous to peanut, corn, and soybean genes that were previously shown to confer resistance to fungal infection. This study is a first step towards a comprehensive genome-scale platform for developing Aspergillus-resistant peanut cultivars through targeted marker-assisted breeding and genetic engineering.

Occurrence of B1 Aflatoxin in diet and M1 Aflatoxin in bovine milk

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Adriana Frizzarin

2012-12-01

Full Text Available Ensuring food quality is one of the principles of food safety. Food for dairy cattle may be contaminated by fungi of the genus Aspergillus, which produce aflatoxins. The B1 aflatoxin, when ingested by animals, is biotransformed in liver in several other toxic metabolites, including M1 aflatoxin which is excreted in milk. M1 aflatoxin has a carcinogenic effect, which the presence in milk poses a serious risk to public health because milk and dairy products are consumed mainly by children, pregnant women and elderly. The objective of this study was to detect the presence of B1 aflatoxin in feed supplied to dairy cows and the presence of M1 aflatoxin in milk. Samples were collected from complete diet (corn silage and concentrate from a batch of 15 lactating cows from a dairy farm in the Campinas region. Two samples of diets were collected directly into the troughs in intervals of 24 hours at every 15 days, totalizing a period of 45 days. Milk samples of those cows were collected 24 hours after diet collection, directly from sample valves in the glass jars.. B1 and M1 aflatoxins were detected by the technique of High Performance Liquid Chromatography after extraction and purification on immunoaffinity columns. From the 40 samples of diets evaluated, 40% were contaminated with B1 aflatoxin, and the levels found ranged from 1.93 to 43.78μg/Kg. One sample showed result higher than the maximum recommended for grain and animal feed in Brazil (20μg/Kg. From the 75 milk samples analyzed, the presence of M1 aflatoxin was detected in 13.3% with levels ranging from 0.03 to 0.16μg/L, not exceeding the maximum permitted for marketing in the country of 0.5μg/L, however 80% of contaminated samples had values above the maximum permissible levels of 0.05μg/L, value found among countries with abundant milk production... The presence of aflatoxins highlights the importance of monitoring the production, the storage and the importance of handling food and

Antifungal activity of some essential oils against toxigenic Aspergillus species.

Science.gov (United States)

Alizadeh, Alireza; Zamani, Elham; Sharaifi, Rohollah; Javan-Nikkhah, Mohammad; Nazari, Somayeh

2010-01-01

Increasing attentions have been paid on the application of essential oils and plant extracts for control of postharvest pathogens due to their natural origin and less appearance of resistance in fungi pathogens. Some Aspergillus species are toxigenic and responsible for many cases of food and feed contamination. Some Toxins that produce with some Aspergillus species are known to be potent hepatocarcinogens in animals and humans. The present work evaluated the parameters of antifungal activity of the essential oils of Zataria multiflora, Thymus migricus, Satureja hortensis, Foeniculum vulgare, Carum capticum and thiabendazol fungicide on survival and growth of different species of Aspergillus. Aerial part and seeds of plant species were collected then dried and its essential oils isolated by means of hydrodistillation. Antifungal activity was evaluated in vitro by poisonous medium technique with PDA medium at six concentrations. Results showed that all essential oils could inhibit the growth of Aspergillus species. The essential oil with the best effect and lowest EC50 and MIC (Minimum Inhibitory Concentration) was Z. multiflora (223 microl/l and 650 microl/l, respectively). The chemical composition of the Z. multiflora essential oil was analyzed by GC-MS.

Production of aflatoxins during storage of gamma-irradiated wheat

International Nuclear Information System (INIS)

Behere, A.G.; Sharma, A.; Padwaldesai, S.R.; Nadkarni, G.B.

1978-01-01

A correlation between relative humidity (RH) during storage and moisture content was obtained in wheat subjected to gamma irradiation at 20 krad. The samples were assessed for storage up to 6 months with and without artificial loading of grains with conidia of Aspergillus flavus. The mycotoxin production seemed to be determined by a critical level of moisture in the grain (13%) at RH over 80% at 28 0 +- 2 0 C. The total aflatoxin produced in the irradiated grains was observed to be lower than in the unirradiated controls. The amount of toxin contained in grains, artificially infected with A. flavus before or after irradiation, did not show appreciable differences. The results, while defining the storage conditions with reference to humidity, did not indicate any alterations in wheat relating to aflatoxin producing potential

Aspergillus brasiliensis sp. nov., a biseriate black Aspergillus species with world-wide distribution

DEFF Research Database (Denmark)

Varga, János; Kocsubé, Sándor; Tóth, Beáta

2007-01-01

to produce ochratoxin A, kotanins, funalenone or pyranonigrins. The novel species was most closely related to A. niger, and was isolated from soil from Brazil, Australia, USA and The Netherlands, and from grape berries from Portugal. The type strain of Aspergillus brasiliensis sp. nov. is CBS 101740(T) (=IM...

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

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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.

Characterization of toxigenic and atoxigenic Aspergillus flavus isolates from pistachio

Science.gov (United States)

Thirty eight Aspergillus flavus isolates collected from a pistachio orchard in California were analyzed for production of aflatoxin (AF), cyclopiazonic acid (CPA), vegetative compatibility groups (VCGs) and mating types. All toxigenic isolates produced both AFB1 and CPA. Twenty-one percent of the i...

RNA Sequencing of Contaminated Seeds Reveals the State of the Seed Permissive for Pre-Harvest Aflatoxin Contamination and Points to a Potential Susceptibility Factor

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Josh Clevenger

2016-11-01

Full Text Available Pre-harvest aflatoxin contamination (PAC is a major problem facing peanut production worldwide. Produced by the ubiquitous soil fungus, Aspergillus flavus, aflatoxin is the most naturally occurring known carcinogen. The interaction between fungus and host resulting in PAC is complex, and breeding for PAC resistance has been slow. It has been shown that aflatoxin production can be induced by applying drought stress as peanut seeds mature. We have implemented an automated rainout shelter that controls temperature and moisture in the root and peg zone to induce aflatoxin production. Using polymerase chain reaction (PCR and high performance liquid chromatography (HPLC, seeds meeting the following conditions were selected: infected with Aspergillus flavus and contaminated with aflatoxin; and not contaminated with aflatoxin. RNA sequencing analysis revealed groups of genes that describe the transcriptional state of contaminated vs. uncontaminated seed. These data suggest that fatty acid biosynthesis and abscisic acid (ABA signaling are altered in contaminated seeds and point to a potential susceptibility factor, ABR1, as a repressor of ABA signaling that may play a role in permitting PAC.

RNA Sequencing of Contaminated Seeds Reveals the State of the Seed Permissive for Pre-Harvest Aflatoxin Contamination and Points to a Potential Susceptibility Factor

Science.gov (United States)

Clevenger, Josh; Marasigan, Kathleen; Liakos, Vasileios; Sobolev, Victor; Vellidis, George; Holbrook, Corley; Ozias-Akins, Peggy

2016-01-01

Pre-harvest aflatoxin contamination (PAC) is a major problem facing peanut production worldwide. Produced by the ubiquitous soil fungus, Aspergillus flavus, aflatoxin is the most naturally occurring known carcinogen. The interaction between fungus and host resulting in PAC is complex, and breeding for PAC resistance has been slow. It has been shown that aflatoxin production can be induced by applying drought stress as peanut seeds mature. We have implemented an automated rainout shelter that controls temperature and moisture in the root and peg zone to induce aflatoxin production. Using polymerase chain reaction (PCR) and high performance liquid chromatography (HPLC), seeds meeting the following conditions were selected: infected with Aspergillus flavus and contaminated with aflatoxin; and not contaminated with aflatoxin. RNA sequencing analysis revealed groups of genes that describe the transcriptional state of contaminated vs. uncontaminated seed. These data suggest that fatty acid biosynthesis and abscisic acid (ABA) signaling are altered in contaminated seeds and point to a potential susceptibility factor, ABR1, as a repressor of ABA signaling that may play a role in permitting PAC. PMID:27827875

Use of electron beam on aflatoxins degradation in coconut agar

International Nuclear Information System (INIS)

Rogovschi, Vladimir D.; Nunes, Thaise C.F.; Villavicencio, Anna L.C.H.; Aquino, Simone; Goncalez, Edlayne; Correa, Benedito

2009-01-01

The fungi Aspergillus flavus are capable of producing toxic metabolites, such as aflatoxin, that is one of the most important human carcinogens, according to the 'International Agency for Research on Cancer'. The aim of this study was to compare the effect of electron beam irradiation on degradation of aflatoxin B1 present in laboratorial residues with a dose of 0 kGy and 5.0 kGy. The fungi were cultivated in potato dextrose agar (PDA) for 7 days and transferred to a coconut agar medium, incubated at a temperature of 25 deg C for 14 days to produce the laboratorial wastes (coconut agar) containing aflatoxins. The samples were conditioned in petri dish for radiation treatment of contaminated material and processed in the Electron Accelerator with 0 kGy and 5.0 kGy. Aflatoxin B 1 was extracted with chloroform and separated on a thin layer chromatography plate (TLC) with chloroform: acetone (9:1). All the control and irradiated samples were analyzed in a Shimadzu Densitometer. The detection limit of this methodology is 0.1μg kg -1 . The results indicate that the irradiated samples had a reduction of 75.49 % in the analyzed dose. (author)

Effect of Carum copticum essential oil on growth and aflatoxin formation by Aspergillus strains.

Science.gov (United States)

Kazemi, M

2015-01-01

The objectives of this study were to determine the antiaflatoxin B1 activity in vitro of the essential oil (EO) extracted from the seeds of Carum copticum and to evaluate its antifungal activity in vivo as a potential food preservative. The C. copticum EO exhibited noticeable inhibition on dry mycelium and synthesis of aflatoxin B1 (AFB1) by Aspergillus flavus, completely inhibiting AFB1 production at 4 μL/mL. C. copticum EOs showed the lowest percentages of decayed cherry tomatoes for all fungi compared with the control at 100 μL/mL with values of 5.01 ± 67% for A. flavus and 5.98 ± 54% for Aspergillus niger. The results indicated that the percentage of infected fruits is significantly (p oil at 100 μL/mL concentration showed the highest inhibition of fungal infection with a value of 80.45% compared with the control. Thus, the EO of dill could be used to control food spoilage and as a potential source of food preservative.

A review on aflatoxin contamination and its implications in the developing world

DEFF Research Database (Denmark)

Gnonlonfin, Gbemenou Joselin Benoit; Hell, K.; Adjovi, Y.

2013-01-01

Mycotoxins contamination in some agricultural food commodities seriously impact human and animal health and reduce the commercial value of crops. Mycotoxins are toxic secondary metabolites produced by fungi that contaminate agricultural commodities pre- or postharvest. Africa is one...... of the continents where environmental, agricultural and storage conditions of food commodities are conducive of Aspergillus fungi infection and aflatoxin biosynthesis. This paper reviews the commodity-wise aetiology and contamination process of aflatoxins and evaluates the potential risk of exposure from common...... African foods. Possible ways of reducing risk for fungal infection and aflatoxin development that are relevant to the African context. The presented database would be useful as benchmark information for development and prioritization of future research. There is need for more investigations on food...

Polyphasic taxonomy of Aspergillus fumigatus and related species

DEFF Research Database (Denmark)

Hong, S.B.; Go, S.J.; Shin, H.D.

2005-01-01

. A. lentulus produces the extrolites auranthine, cyclopiazonic acid, a dimeric indole of unknown structure, neosartorin, some pyripyropens, terrein and some tryptoquivalins and tryptoquivalons. Two pair of isolates (CBS 117194, 117186 and 117520, 117519) Clustered into separate groups from A....... fumigatus and the other Aspergillus section Fumigati species, including the teleomorph Neosartorya, are proposed as two new species. A. fumigatiaffinis spec. nov. produces the extrolites auranthine, cycloechinulin, helvolic acid, neosartorin, palitantin, pyripyropens, tryptoquivalins and tryptoquivalons......, and A. novofumigatus spec. nov. produces the extrolites cycloechinuline, helvolic acid, neosartorin, palitantin and terrein....

Transcriptome, antioxidant enzyme activity and histopathology analysis of hepatopancreas from the white shrimp Litopenaeus vannamei fed with aflatoxin B1(AFB1).

Science.gov (United States)

Zhao, Wei; Wang, Lei; Liu, Mei; Jiang, Keyong; Wang, Mengqiang; Yang, Guang; Qi, Cancan; Wang, Baojie

2017-09-01

Aflatoxin produced by Aspergillus flavus or Aspergillus parasiticus fungi during grain and feed processing and storage. Aflatoxins cause severe health problems reducing the yield and profitability of shrimp cultures. We sought to understand the interaction between shrimp immunity and aflatoxin B1 (AFB1), analyzing transcriptome expression, antioxidant enzyme activity, and histological features of the hepatopancreas of shrimp fed with AFB1. From over 4 million high-quality reads, de novo unigene assembly produced 103,644 fully annotated genes. A total of 1024 genes were differentially expressed in shrimp fed with AFB1, being involved in functions, such as peroxidase metabolism, signal transduction, transcriptional control, apoptosis, proteolysis, endocytosis, and cell adhesion and cell junction. Upon AFB1 challenge, there were severe histological alterations in shrimp hepatopancreas. AFB1 challenge increased the activity of several antioxidant enzymes. Our data contribute to improve the current understanding of host-AFB1 interaction, providing an abundant source for identification of novel genes. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

Ehrlich, Kenneth C; Mack, Brian M

2014-06-23

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

Cowpeas as growth substrate do not support the production of aflatoxinby Aspergillus sp

DEFF Research Database (Denmark)

Houssou, P.A.; Schnidt-Heydt, M.; Geisen, R.

2008-01-01

A number of 21 Aspergillus sp. strains isolated from cowpeas from Benin (Africa) were characterizedby RAPD methodology. Seven of these strains grouped with A. flavus in the dendrogram generated with the RAPD data. Only three were able to produce aflatoxin in significant amounts. Twelve other...... produced high amounts of aflatoxin after growth on YES medium. However after growth on cowpea based medium aflatoxin biosynthesis was strongly ceased, albeit the growth of the colony was only partly reduced. This was true for media made either with the whole cowpea seed or with cowpea seed without seed...... coat. Interestingly when the cowpea medium was heat sterilized the fungus was able to produce high amounts of aflatoxin. This, however, was not the case after the use of gamma irradiation as sterilization method for the medium. The expression of the nor-1 gene, which is one of the early genes involved...

Aspergillus species as emerging causative agents of onychomycosis.

Science.gov (United States)

Nouripour-Sisakht, S; Mirhendi, H; Shidfar, M R; Ahmadi, B; Rezaei-Matehkolaei, A; Geramishoar, M; Zarei, F; Jalalizand, N

2015-06-01

Onychomycosis is a common nail infection caused by dermatophytes, non-dermatophyte molds (NDM), and yeasts. Aspergillus species are emerging as increasing causes of toenail onychomycosis. The purpose of this study was species delineation of Aspergillus spp. isolated from patients with onychomycosis. During a period of one year (2012-2013), nail samples were collected from patients clinically suspected of onychomycosis and subjected to microscopic examination and culture. Species identification was performed based on macro- and micro-morphology of colonies. For precise species identification, PCR-amplification and sequencing of the beta-tubulin gene followed by BLAST queries were performed where required. A total of 463/2,292 (20.2%) tested nails were diagnosed with onychomycosis. Among the positive specimens, 154 cases (33.2%) were identified as saprophytic NDM onychomycosis, 135 (29.2%) of which were attributable to Aspergillus. Aspergillus species isolated from the infected nails included Aspergillus flavus (77.3%, n=119), Aspergillus niger (n=4), Aspergillus tubingensis (n=4), Aspergillus terreus (n=3), Aspergillus sydowii (n=2), Aspergillus spp. (n=2), and Aspergillus candidus (n=1). Among the patients diagnosed with onychomycosis due to Aspergillus (average patient age, 47.4 years), 40 had fingernail and 95 toenail involvement. The large toenails were most commonly affected. This study identified a markedly high occurrence of A. flavus, and this fungus appears to be an emerging cause of saprophytic onychomycosis in Iran. The study moreover highlights the necessity of differentiating between dermatophytic and non-dermatophytic nail infections for informed decisions on appropriate therapy. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Allergens/Antigens, Toxins and Polyketides of Important Aspergillus Species

OpenAIRE

Bhetariya, Preetida J.; Madan, Taruna; Basir, Seemi Farhat; Varma, Anupam; Usha, Sarma P.

2011-01-01

The medical, agricultural and biotechnological importance of the primitive eukaryotic microorganisms, the Fungi was recognized way back in 1920. Among various groups of fungi, the Aspergillus species are studied in great detail using advances in genomics and proteomics to unravel biological and molecular mechanisms in these fungi. Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Aspergillus nidulans and Aspergillus terreus are some of the important specie...

Characterization of Aspergillus species associated with ...

African Journals Online (AJOL)

About 82 triphala powder samples were analyzed for the association of different fungi. Results reveal the predominance of Aspergillus as the major genera with six predominant species namely, A. niger, A. flavus, A. fumigatus, A. terreus, A. nidulans and A. amstelodami. Therefore, these six isolated Aspergillus species were ...

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.

Aflatoxin B1 Detoxification by Aspergillus oryzae from Meju, a Traditional Korean Fermented Soybean Starter.

Science.gov (United States)

Lee, Kyu Ri; Yang, Sun Min; Cho, Sung Min; Kim, Myunghee; Hong, Sung-Yong; Chung, Soo Hyun

2016-11-04

Aflatoxins are classified as Group 1 (carcinogenic to humans) by the International Agency for Research on Cancer (IARC). In this study, a total of 134 fungal strains were isolated from 65 meju samples, and two fungal isolates were selected as potential aflatoxin B₁ (AFB₁)-biodetoxification fungi. These fungi were identified as Aspergillus oryzae MAO103 and A. oryzae MAO104 by sequencing the beta-tubulin gene. The two A. oryzae strains were able to degrade more than 90% of AFB1 (initial concentration: 40 µg/L) in a culture broth in 14 days. The mutagenic effects of AFB₁ treated with A. oryzae MAO103 and MAO104 significantly decreased to 5.7% and 6.4%, respectively, in the frame-shift mutation of Ames tests using Salmonella typhimurium TA 98. The base-substituting mutagenicity of AFB₁ was also decreased by the two fungi. Moreover, AFB1 production by A. flavus was significantly decreased by the two A. oryzae strains on soybean-based agar plates. Our data suggest that the two AFB1-detoxification A. oryzae strains have potential application to control AFB₁ in foods and feeds.

Mycobiota and identification of aflatoxin gene cluster in marketed spices in West Africa

DEFF Research Database (Denmark)

Gnonlonfin, G. J. B.; Adjovi, Y. C.; Tokpo, A. F.

2013-01-01

Fungal infection and aflatoxin contamination were evaluated on 114 samples of dried and milled spices such as ginger, garlic and black pepper from southern Benin and Togo collected in November 2008 -January 2009. These products are dried to preserve them for lean periods available throughout...... of Aspergillus were dominant on all marketed dried and milled spices irrespective of country. Gene characterization and amplification analysis showed that most of the Aspergillus flavus isolates possess the cluster genes for aflatoxin production. Aflatoxin B1 assessment by Thin Layer Chromatography showed...... further for other products such as dried and milled spices. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved....

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

Directory of Open Access Journals (Sweden)

Geromy G Moore

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

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

Volatile compounds of Aspergillus strains with different abilities to produce ochratoxin A.

Science.gov (United States)

Jeleń, Henryk H; Grabarkiewicz-Szczesna, Jadwiga

2005-03-09

Volatile compounds emitted by Aspergillus strains having different abilities to produce ochratoxin A were investigated. Thirteen strains of Aspergillus ochraceus, three belonging to the A. ochraceus group, and eight other species of Aspergillus were examined for their abilities to produce volatile compounds and ochratoxin A on a wheat grain medium. The profiles of volatile compounds, analyzed using SPME, in all A. ochraceus strains, regardless of their toxeginicity, were similar and comprised mainly of 1-octen-3-ol, 3-octanone, 3-octanol, 3-methyl-1-butanol, 1-octene, and limonene. The prevailing compound was always 1-octen-3-ol. Mellein, which forms part of the ochratoxin A molecule, was found in both toxigenic and nontoxigenic strains. Volatile compounds produced by other Aspergillus strains were similar to those of A. ochraceus. Incubation temperatures (20, 24, and 27 degrees C) and water content in the medium (20, 30, and 40%) influenced both volatile compounds formation and ochratoxin A biosynthesis efficiency, although conditions providing the maximum amount of volatiles were different from those providing the maximum amount of ochratoxin A. The pattern of volatiles produced by toxigenic A. ochraceus strains does not facilitate their differentiation from nontoxigenic strains.

Controlling Aspergillus flavus and Aspergillus parasiticus growth and aflatoxin production in poultry feed using carvacrol and trans-cinnamaldehyde.

Science.gov (United States)

Yin, Hsin-Bai; Chen, Chi-Hung; Kollanoor-Johny, Anup; Darre, Michael J; Venkitanarayanan, Kumar

2015-09-01

Aflatoxins (AF) are toxic metabolites primarily produced by molds, Aspergillus flavus and Aspergillus parasiticus. Contamination of poultry feed with AF is a major concern to the poultry industry due to severe economic losses stemming from poor performance, reduced egg production, and diminished egg hatchability. This study investigated the inhibitory effect of 2 generally regarded as safe (GRAS), natural plant compounds, namely carvacrol (CR) and trans-cinnamaldehyde (TC), on A. flavus and A. parasiticus growth and AF production in potato dextrose broth (PDB) and in poultry feed. In broth culture, PDB supplemented with CR (0%, 0.02%, 0.04% and 0.08%) or TC (0%, 0.005%, 0.01% and 0.02%) was inoculated with A. flavus or A. parasiticus (6 log CFU/mL), and mold counts and AF production were determined on days 0, 1, 3, and 5. Similarly, 200 g portions of poultry feed supplemented with CR or TC (0%, 0.4%, 0.8%, and 1.0%) were inoculated with each mold, and their counts and AF concentrations in the feed were determined at 0, 1, 2, 3, 4, 8, and 12 weeks of storage. Moreover, the effect of CR and TC on the expression of AF synthesis genes in A. flavus and A. parasiticus (aflC, nor1, norA, and ver1) was determined using real-time quantitative PCR (RT-qPCR). All experiments had duplicate samples and were replicated 3 times. Results indicated that CR and TC reduced A. flavus and A. parasiticus growth and AF production in broth culture and chicken feed (P<0.05). All tested concentrations of CR and TC decreased AF production in broth culture and chicken feed by at least 60% when compared to controls (P<0.05). In addition, CR and TC down-regulated the expression of major genes associated with AF synthesis in the molds (P<0.05). Results suggest the potential use of CR and TC as feed additives to control AF contamination in poultry feed. © 2015 Poultry Science Association Inc.

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

Institute of Scientific and Technical Information of China (English)

Negero Gemeda; Yimtubezinash Woldeamanuel; Daniel Asrat; Asfaw Debella

2014-01-01

Objective: To investigate effect of essential oils on Aspergillus spore germination, growth and mycotoxin production.Method: 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.Results: 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.Conclusions: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.

REVIEW ON AFLATOXIN IN INDONESIAN FOOD- AND FEEDSTUFFS AND THEIR PRODUCTS

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OKKY SETYAWATI DHARMAPUTRA

2002-01-01

Full Text Available Aflatoxin is a human carcinogen that could contaminate food- and feedstuffs, and hence is a major food qua lity problem throughout the world. Afiatoxi n is produced by certain strains of AspergillusJlavus and //. parasiticus. A number of studies have been carried out in Indonesia on atlatoxin contamination in Indonesian food- and feedstuffs and their products from 1990 up to present. They were maize, maize product, peanuts, soybean and soybean meal, black and white pepper, feed ingredients; chicken and duck feeds. Samples were collected from farmers, traders (middlemen, retailers (markets, supermarkets, exporters; poultry and duck community-based farms; and feed mi ll industries. High levels of aflatoxins were often found in maize, peanuts, chicken feed derived from markets, and duck feed. Low levels of aflatoxins were found in soybean meal and chicken feedstuff. Aflatoxins were not detected in soybean, black and white pepper. Other studies have also been carried out on the effect of carbondioxide (CO2, phosphine, black pepper extract and antagonistic fungi on aflatoxin production of A. flavus in vitro and the effect of airtight storage, phosphine, ammonium hydroxide, fermentation process, bag types, and phosphine in combination with different bag types on atlatoxin contents of maize, peanuts and soybean meal. Some of these methods reduced aflatoxin contents significantly

Influence of chosen microbes and some chemical substances on the production of aflatoxins

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Iveta Brožková

2015-03-01

Full Text Available Aflatoxins are produced as secondary metabolites by A. flavus, A. parasiticus, A. nomius and A. tamarii. The aflatoxin biosynthetic pathway involves several enzymatic steps and genes (apa-2, ver-1 that appear to be regulated by the aflR gene in these fungi. The aim of this work was the detection of aflatoxins by the HPLC method and the ascertainment of factors influencing their production. A. parasiticus CCM F-108, A. parasiticus CCF 141, A. parasiticus CCF 3137 and two isolates A. flavus were used. These toxigenic isolates were recovered from spice (strain 1 and wraps (strain 2. The gene for the production of aflatoxin B1 for each species of fungi was detected using an optimized PCR method. Rhodotorula spp.*, Lactococcus lactis subsp. lactis CCM 1881, Flavobacterium spp. and fungal strain Pythium oligandrum* were tested for inhibition of aflatoxins production and fungal growth. Having used the HPLC detection, various preservatives (propionic acid, citric acid, potassium sorbate were tested from the viewpoint of their influence on the growth of aflatoxigenic fungi followed by the production of aflatoxins. The growth of A. flavus and A. parasiticus and aflatoxin production in Potato Dextrose Agar supplemented with propionic acid (1000-2000-3000 mg/kg, citric acid (2000-3000-4000 mg/kg and potassium sorbate (500-800-1000 mg/kg was tested by Agar Dilution Method. After 72 h of incubation was evaluated growth of fungi, all samples were frozen for later extraction and aflatoxins quantification by HPLC. Effect of peptone and sucrose additions were studied in yeast extract (2% supplemented with peptone (5-10-15% or sucrose (15%. Growth inhibition of Aspergillus by Pythium oligandrum was tested on wood surface. As shown, the highest inhibition effect on the aflatoxins production was obtained when propionic acid was applied in concentrations since 1000 mg/kg. A total inhibition of the fungi growth and aflatoxins production was observed in all samples

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

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Jake C. Fountain

2015-06-01

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

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

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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.

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.

Ohcratoxin producing Aspergillus spp. Isolated from tropical soils in Sarawak, Malaysia

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J.S.S. Seelan

2010-03-01

Full Text Available Aspergillus strains isolated from tropical soils were selected for additional characterization and for ochratoxin analysis, which was determined by ELISA method and high performance liquid chromatography (HPLC profiles. Because of its great morphological variability and mycotoxin production availability, 18 isolates of Aspergillus species were selected for this study. Only two isolates of these tropical soils, A. sulphureus and A. carbonarius, showed positive results for ohcratoxin (OA in lower concentration (0.05-0.10 µg/ml. Ochratoxin production by these species was confirmed by high performance liquid chromatography. HPLC analysis for ochratoxin producing A. sulphureus and A. carbonarius showed retention time, Rt value = 4.417 and Rt value = 4.081 respectively.

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

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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

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®

Determination of aflatoxins in nuts of Tabriz confectionaries by ELISA and HPLC methods

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Siahi Shadbad Mohammad Reza

2012-06-01

Full Text Available Purpose: Aflatoxins (AFs are a group of mycotoxins and secondary metabolites of various species of Aspergillus. There are various forms of aflatoxins including B1, B2, G1, G2, M1 and M2 types. Aflatoxins cause important health problems and have high potential effect on liver cancer. Therefore, numerous investigations have been conducted during last three decades. The aim of this work is to determine the contamination levels of nuts used by the confectionaries in Tabriz. Methods: A total of 142 samples including 35 almond , 26 walnut, 4 seeds of apricot, 6 sunflower seeds kernel, 6 sesame seed, 6 peanuts , 32 pistachio,13 hazelnuts and 14 cashews samples were collected from Tabriz confectionaries. The ELISA method was employed for the screening of total aflatoxins. Results: In 13 cases (28.1% of pistachios, 5.1% of walnuts and 7.1% of cashews contamination rate of higher than 15 ppb were observed. The HPLC method was applied for the confirmation of ELISA results. Aflatoxin B1 was the highest detected AFs. Conclusion: The overall results of the tested samples indicated that the rate of contamination of pistachios is higher than the other tested samples.

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.

Inhibition of aflatoxin biosynthesis in Aspergillus flavus by phenolic compounds extracted of Piper betle L.

Science.gov (United States)

Yazdani, Darab; Mior Ahmad, Zainal Abidin; Yee How, Tan; Jaganath, Indu Bala; Shahnazi, Sahar

2013-12-01

Food contamination by aflatoxins is an important food safety concern for agricultural products. In order to identify and develop novel antifungal agents, several plant extracts and isolated compounds have been evaluated for their bioactivities. Anti-infectious activity of Piper betle used in traditional medicine of Malaysia has been reported previously. Crude methanol extract from P. betel powdered leaves was partitioned between chloroform and water. The fractions were tested against A. flavus UPMC 89, a strong aflatoxin producing strain. Inhibition of mycelial growth and aflatoxin biosynthesis were tested by disk diffusion and macrodillution techniques, respectively. The presence of aflatoxin was determined by thin-layer chromatography (TLC) and fluorescence spectroscopy techniques using AFB1 standard. The chloroform soluble compounds were identified using HPLC-Tandem mass spectrometry technique. The results, evaluated by measuring the mycelial growth and quantification of aflatoxin B1(AFLB1) production in broth medium revealed that chloroform soluble compounds extract from P. betle dried leaves was able to block the aflatoxin biosynthesis pathway at concentration of 500μg/ml without a significant effect on mycelium growth. In analyzing of this effective fractions using HPLC-MS(2) with ESI ionization technique, 11 phenolic compounds were identified. The results showed that the certain phenolic compounds are able to decline the aflatoxin production in A. flavus with no significant effect on the fungus mycelia growth. The result also suggested P. betle could be used as potential antitoxin product.

Influence of Gamma-Irradiation on the Growth of Aspergillus spp. on Feeds for Ensuring Feed Safety

International Nuclear Information System (INIS)

Nam, B.R.; Kim, K.Y.; Ryu, H.J.

2010-01-01

Aspergillus spp. is widely spread in the world on feeds and foods. They have been known to produce aflatoxins, which are mutagenic and carcinogenic to humans. The objective of this study was to determine the optimum gamma-irradiation dose for controlling the growth of Aspergillus spp. to ensure safety of feeds. Four species fungal spore (10?7 spore/mL) exposed to 0, 1, 3, 5, 7 and 10 kGy of gamma radiation were inhibited in their growth and AFB? productivity by greater-than or equal to 5 kGy. Meantime, the growth of fungal inoculated on feeds was inhibited at greater-than or equal to 3 kGy. However, AFB? presented in aqueous solution was not be inactivated completely by less-than or equal to 10 kGy irradiation. These results indicate that Aspergillus spp. on feeds could be controlled by 5 kGy gamma-irradiation but detoxification of AFB? demands a higher dose of gamma-irradiation (greater-than or equal to 10 kGy)

Aspergillus saccharolyticus sp. nov., a new black Aspergillus species isolated in Denmark

DEFF Research Database (Denmark)

Sørensen, Annette; Lübeck, Peter S.; Lübeck, Mette

2011-01-01

A novel species, Aspergillus saccharolyticus sp. nov., belonging to the Aspergillus section Nigri group is described. This species was isolated in Denmark from treated hardwood. Its taxonomic status was determined using a polyphasic taxonomic approach including phenotypic (morphology and extrolite...... profiles) and molecular (β-tubulin, internal transcribed spacer and calmodulin gene sequences, and universally primed PCR fingerprinting) analysis. Phenotypic and molecular data enabled this novel species to be clearly distinguished from other black aspergilli. A. saccharolyticus is a uniseriate...

Aspergillus baeticus sp. nov. and Aspergillus thesauricus sp. nov., two species in section Usti from Spanish caves.

Science.gov (United States)

Nováková, Alena; Hubka, Vit; Saiz-Jimenez, Cesareo; Kolarik, Miroslav

2012-11-01

Two novel species of Aspergillus that are clearly distinct from all known species in section Usti were revealed during a study of microfungal communities in Spanish caves. The novel species identified in this study and additional species of Aspergillus section Usti are associated with places and substrates related to human activities in caves. Novel species are described using data from four loci (ITS, benA, caM and rpb2), morphology and basic chemical and physiological analyses. Members of the species Aspergillus thesauricus sp. nov. were isolated from various substrates, including decaying organic matter, cave air and cave sediment of the Cueva del Tesoro Cave (the Treasure cave); the species is represented by twelve isolates and is most closely related to the recently described Aspergillus germanicus. Members of the species Aspergillus baeticus sp. nov. were isolated from cave sediment in the Gruta de las Maravillas Cave (the Grotto of the Marvels); the species is represented by two isolates. An additional isolate was found in the Cueva del Tesoro Cave and in the Demänovská Peace Cave (Slovakia), suggesting a potentially wide distribution of this micro-organism. The species is related to Aspergillus ustus and Aspergillus pseudoustus. Both species were unable to grow at 37 °C, and a weakly positive, light greenish yellow Ehrlich reaction was observed in A. thesauricus. Unique morphological features alone are sufficient to distinguish both species from related taxa.

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

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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.

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

African Journals Online (AJOL)

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

[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.

Comparison of species composition and fumonisin production in Aspergillus section Nigri populations in maize kernels from USA and Italy.

Science.gov (United States)

Susca, Antonia; Moretti, Antonio; Stea, Gaetano; Villani, Alessandra; Haidukowski, Miriam; Logrieco, Antonio; Munkvold, Gary

2014-10-01

Fumonisin contamination of maize is considered a serious problem in most maize-growing regions of the world, due to the widespread occurrence of these mycotoxins and their association with toxicosis in livestock and humans. Fumonisins are produced primarily by species of Fusarium that are common in maize grain, but also by some species of Aspergillus sect. Nigri, which can also occur on maize kernels as opportunistic pathogens. Understanding the origin of fumonisin contamination in maize is a key component in developing effective management strategies. Although some fungi in Aspergillus sect. Nigri are known to produce fumonisins, little is known about the species which are common in maize and whether they make a measurable contribution to fumonisin contamination of maize grain. In this work, we evaluated populations of Aspergillus sect. Nigri isolated from maize in USA and Italy, focusing on analysis of housekeeping genes, the fum8 gene and in vitro capability of producing fumonisins. DNA sequencing was used to identify Aspergillus strains belonging to sect. Nigri, in order to compare species composition between the two populations, which might influence specific mycotoxicological risks. Combined beta-tubulin/calmodulin sequences were used to genetically characterize 300 strains (199 from Italy and 101 from USA) which grouped into 4 clades: Aspergillus welwitschiae (syn. Aspergillus awamori, 14.7%), Aspergillus tubingensis (37.0%) and Aspergillus niger group 1 (6.7%) and group 2 (41.3%). Only one strain was identified as Aspergillus carbonarius. Species composition differed between the two populations; A. niger predominated among the USA isolates (69%), but comprised a smaller percentage (38%) of Italian isolates. Conversely, A. tubingensis and A. welwitschiae occurred at higher frequencies in the Italian population (42% and 20%, respectively) than in the USA population (27% and 5%). The evaluation of FB2 production on CY20S agar revealed 118 FB2 producing and 84

Comparative Analysis of Aflatoxin Contamination of Maize in Two ...

African Journals Online (AJOL)

Background: Aflatoxicosis resulting from consumption of contaminated maize poses a significant public health problem in many countries including Kenya, and many people living in developing countries could be chronically exposed to aflatoxin through their diet. It is caused by Aflatoxins produced by fungus of species ...

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

Science.gov (United States)

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

Fluorescence imaging spectroscopy (FIS) for comparing spectra from corn ears naturally and artificially infected with aflatoxin producing fungus.

Science.gov (United States)

Hruska, Zuzana; Yao, Haibo; Kincaid, Russell; Darlington, Dawn; Brown, Robert L; Bhatnagar, Deepak; Cleveland, Thomas E

2013-08-01

In an effort to address the problem of rapid detection of aflatoxin in grain, particularly oilseeds, the current study assessed the spectral differences of aflatoxin production in kernels from a cornfield inoculated with spores from 2 different strains of toxigenic Aspergillus flavus. Aflatoxin production in corn from the same field due to natural infestation was also assessed. A small corn plot in Baton Rouge, La., U.S.A., was used during the 2008-growing season. Two groups of 400 plants were inoculated with 2 different inocula and 1 group of 400 plants was designated as controls. Any contamination detected in the controls was attributed to natural infestation. A subset of each group was imaged with a visible near infra red (VNIR) hyperspectral system under ultra violet (UV) excitation and subsequently analyzed for aflatoxin using affinity column fluorometry. Group differences were statistically analyzed. Results indicate that when all the spectral data across all groups were averaged, any potential differences between groups (treated and untreated) were obscured. However, spectral analysis based on contaminated "hot" pixel classification showed a distinct spectral shift/separation between contaminated and clean ears with fluorescence peaks at 501 and 478 nm, respectively. All inoculated and naturally infected control ears had fluorescence peaks at 501 nm that differed from uninfected corn ears. Results from this study may be useful in evaluating rapid, noninvasive instrumentation and/or methodology for aflatoxin detection in grain. © 2013 Institute of Food Technologists®

A two-dimensional proteome map of the aflatoxigenic fungus Aspergillus flavus.

Science.gov (United States)

Pechanova, Olga; Pechan, Tibor; Rodriguez, Jose M; Williams, W Paul; Brown, Ashli E

2013-05-01

The filamentous fungus Aspergillus flavus is an opportunistic soil-borne pathogen that produces aflatoxins, the most potent naturally occurring carcinogenic compounds known. This work represents the first gel-based profiling analysis of A. flavus proteome and establishes a 2D proteome map. Using 2DE and MALDI-TOF-MS/MS, we identified 538 mycelial proteins of the aflatoxigenic strain NRRL 3357, the majority of which were functionally annotated as related to various cellular metabolic and biosynthetic processes. Additionally, a few enzymes from the aflatoxin synthesis pathway were also identified. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Causative Agents of Aspergillosis Including Cryptic Aspergillus Species and A. fumigatus.

Science.gov (United States)

Toyotome, Takahito

2016-01-01

Aspergillosis is an important deep mycosis. The causative agents are Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, and Aspergillus terreus, of which A. fumigatus is the most prevalent. Cryptic Aspergillus spp., which morphologically resemble representative species of each Aspergillus section, also cause aspergillosis. Most of the cryptic species reveal different susceptibility patterns and/or different secondary metabolite profiles, also called exometabolome in this manuscript, from those representative species. On the other hand, azole-resistant A. fumigatus strains in clinical specimens and in the environment have been reported. Therefore, it is imperative to precisely identify the species, including cryptic Aspergillus spp., and evaluate the susceptibility of isolates.In this manuscript, some of the causative cryptic Aspergillus spp. are briefly reviewed. In addition, the exometabolome of Aspergillus section Fumigati is described. Finally, azole resistance of A. fumigatus is also discussed, in reference to several studies from Japan.

Fungal contamination and aflatoxins content of dry raisins fruits in Sanaa City, Republic of Yemen

International Nuclear Information System (INIS)

Alghalibi, S.M.; Battah, M.G.; Al-Zubairy, M.A.

2008-01-01

This study was designed to study mycoflora and aflatoxin content of dry raisins in Yemen Republic. Thirty six raisins samples collected from different shops and markets in Sana'a city were analyzed mycologically for the presence of fungi. A total of forty eight species belonging to 20 genera were recovered from the analyzed raisins samples on three cultural media. Aspergillus was the most dominant genera on the three types of media, of which A. niger was the most common species. A. flavus was isolated in moderate, low and rare frequency on 1% and 20% sucrose Czapek's and Sabouraud dextrose agar media. Pencillium was isolated in moderate frequency on 1 and 20% sucrose Czapek's agar media, but in low frequency on Sabouraud dextrose agar medium. The raisin samples were analyzed for the presence of total aflatoxin using ELISA technique. The results revealed that 3 out of 7 samples of raisins analyzed were contaminated with total aflatoxin at levels raged from 2678.66 to 11556.88 ppt (ng Kg-1). (author)

Aspergillus species isolated from mangrove forests in Borneo Island, Sarawak, Malaysia

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J.S.S. Seelan

2009-06-01

Full Text Available A study on the occurrence of Aspergillus spp. on selected mangrove forests in Sarawak was conducted to find out their diversity and distribution. Samples were obtained from mangrove soils and leaf litters at different locations, i.e. Sematan, Lundu, Kampung Bako, Bako in Sarawak. Soil and leaf litter samples were taken randomly at different locations with five replicates from each area. A total of 138 isolates of Aspergillus species were obtained from the soil and leaf litter samples by using direct plating and Warcup method. Based on both macroscopic and microscopic observations, using an identification key, individual isolates were classified within the genus Aspergillus, belonging to three subgenera, four sections and five species. The fungi isolates were identified as A. terreus, A. flavipes, A. carneus, A. fumigatus and A. clavatus. The most frequent isolated species was A. flavipes (63.04%, followed by A. fumigatus (16.7%, A. terreus (13.04%, A. carneus (5.8% and A. clavatus (1.44%. All of the isolated Aspergillus species grew well on MEA and CYA at 25°C. A. carneus produced reddish sclerotia on MEA after seven days and this could be used as an important characteristic in this species identification. A. clavatus from mangrove soil in Kampung Bako has shown long conidiophores (ranging from 3-5 cm with swollen hyphal structures, while A. clavatus from Sematan area has shorter conidiophores (ranging from 2.5-3.5 cm on MEA.

Characterization of Aspergillus species based on fatty acid profiles.

Science.gov (United States)

Fraga, Marcelo E; Santana, Djalva Maria N; Gatti, Mario Jorge; Direito, Gloria Maria; Cavaglieri, Lilia R; Rosa, Carlos Alberto R

2008-09-01

Cellular fatty acid (FA) composition was utilized as a taxonomic tool to discriminate between different Aspergillus species. Several of the tested species had the same FA composition and different relative FA concentrations. The most important FAs were palmitic acid (C16:0), estearic acid (C18:0), oleic acid (C18:1) and linoleic acid (C18:2), which represented 95% of Aspergillus FAs. Multivariate data analysis demonstrated that FA analysis is a useful tool for differentiating species belonging to genus Aspergillus. All the species analyzed showed significantly FA acid profiles (p < 0.001). Furthermore, it will be possible to distinguish among Aspergillus spp. in the Flavi Section. FA composition can serve as a useful tool for the identification of filamentous fungi.

Aspergillus mulundensis sp. nov., a new species for the fungus producing the antifungal echinocandin lipopeptides, mulundocandins

DEFF Research Database (Denmark)

Bills, Gerald F.; Yue, Qun; Chen, Li

2016-01-01

The invalidly published name Aspergillus sydowii var. mulundensis was proposed for a strain of Aspergillus that produced new echinocandin metabolites designated as the mulundocadins. Reinvestigation of this strain (Y-30462=DSMZ 5745) using phylogenetic, morphological, and metabolic data indicated...

Innovative technologies to manage aflatoxins in foods and feeds and the profitability of application - A review.

Science.gov (United States)

Udomkun, Patchimaporn; Wiredu, Alexander Nimo; Nagle, Marcus; Müller, Joachim; Vanlauwe, Bernard; Bandyopadhyay, Ranajit

2017-06-01

Aflatoxins are mainly produced by certain strains of Aspergillus flavus , which are found in diverse agricultural crops. In many lower-income countries, aflatoxins pose serious public health issues since the occurrence of these toxins can be considerably common and even extreme. Aflatoxins can negatively affect health of livestock and poultry due to contaminated feeds. Additionally, they significantly limit the development of international trade as a result of strict regulation in high-value markets. Due to their high stability, aflatoxins are not only a problem during cropping, but also during storage, transport, processing, and handling steps. Consequently, innovative evidence-based technologies are urgently required to minimize aflatoxin exposure. Thus far, biological control has been developed as the most innovative potential technology of controlling aflatoxin contamination in crops, which uses competitive exclusion of toxigenic strains by non-toxigenic ones. This technology is commercially applied in groundnuts maize, cottonseed, and pistachios during pre-harvest stages. Some other effective technologies such as irradiation, ozone fumigation, chemical and biological control agents, and improved packaging materials can also minimize post-harvest aflatoxins contamination in agricultural products. However, integrated adoption of these pre- and post-harvest technologies is still required for sustainable solutions to reduce aflatoxins contamination, which enhances food security, alleviates malnutrition, and strengthens economic sustainability.

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.

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.

Chronological aging in conidia of pathogenic Aspergillus: Comparison between species.

Science.gov (United States)

Oliveira, Manuela; Pereira, Clara; Bessa, Cláudia; Araujo, Ricardo; Saraiva, Lucília

2015-11-01

Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus and Aspergillus niger are common airborne fungi, and the most frequent causative agents of human fungal infections. However, the resistance and lifetime persistence of these fungi in the atmosphere, and the mechanism of aging of Aspergillus conidia are unknown.With this work, we intended to study the processes underlying conidial aging of these four relevant and pathogenic Aspergillus species. Chronological aging was therefore evaluated in A. fumigatus, A. flavus, A. terreus and A. niger conidia exposed to environmental and human body temperatures. The results showed that the aging process in Aspergillus conidia involves apoptosis,with metacaspase activation, DNA fragmentation, and reactive oxygen species production, associated with secondary necrosis. Distinct results were observed for the selected pathogenic species. At environmental conditions, A. niger was the species with the highest resistance to aging, indicating a higher adaption to environmental conditions, whereas A. flavus followed by A. terreus were the most sensitive species. At higher temperatures (37 °C), A. fumigatus presented the longest lifespan, in accordance with its good adaptation to the human body temperature. Altogether,with this work new insights regarding conidia aging are provided, which may be useful when designing treatments for aspergillosis.

Studies on Aspergillus flavus

International Nuclear Information System (INIS)

Padwal-Desai, S.R.; Ghanekar, A.S.; Sreenivasan, A.

1976-01-01

In vitro studies were conducted on conidia of Aspergillus flavus Link (aflatoxin producing) and Aspergillus flavus oryzae (non-toxigenic) strains isolated and identified in this laboratory. These strains differed in resistance to heat and gamma radiation, the toxigenic strain being more resistant to both treatments. Results of tests on dose-modifying factors indicated that composition, temperature and pH of suspending media affected radiation resistance. On the other hand, the size of the initial population and the age of the conidia did not influence the radiation resistance of either strain. Studies on thermal inactivation of the conidia suggested that the temperature employed was more important than the time of heat treatment. Conidia of both strains showed a synergistic effect of combined heat and radiation treatments, although a heat-radiation sequence was more effective than a radiation-heat sequence. (author)

Aspergillus korhogoensis, a novel aflatoxin producing species from the Côte d’Ivoire

Science.gov (United States)

Based on examination of four isolates, this new species is described using a polyphasic approach. A concatenated alignment comprised of nine genes (ITS, benA, cmdA, mcm7, amdS, rpb1, preB, ppgA, preA) was subjected to phylogenetic analysis, and resulted in all four strains being inferred as a distin...

Variability of Germinative Potential among Pathogenic Species of Aspergillus

OpenAIRE

Araujo, Ricardo; Rodrigues, Acacio Gonçalves

2004-01-01

The objective of our study was to evaluate parameters influencing the germination of Aspergillus conidia. Inoculum concentration and age significantly influenced germination. Different incubation temperatures revealed significant differences among Aspergillus species. The internal human milieu provides the ideal conditions for the development of invasive disease by Aspergillus fumigatus but restricts invasion by Aspergillus flavus and Aspergillus niger.

Glufosinate-ammonium reduces growth and aflatoxin B1 production by Aspergillus flavus.

Science.gov (United States)

Tubajikat, K M; Damann, K E

2002-09-01

The herbicide glufosinate-ammonium (GA) [butanoic acid, 2-amino-4-(hydroxymethylphosphinyl)-ammonium salt] was tested at concentrations from 2 to 2,000 g GA per ml for activity against growth and aflatoxin B1 (AFB) production by the mycotoxigenic fungus Aspergillus flavus Link:Fr. The highest concentration (2,000 microg GA per ml) reduced colony diameter of A. flavus strain AF13 by 80%. AFB1 production was inhibited by 90% at this concentration. Reduction in mycelial dry weight and AFB1 production in response to GA application ranged from 17.2 to 97.1% and from 39.1 to 90.1%, respectively. Of four concentrations tested, 2 microg GA per ml was weakly inhibitory. In the kernel screening assay, AFB1 production was inhibited 60 to 91% when kernels were preimmersed or immersed 5 days after incubation in 200 microg GA per ml. Both concentrations (2 and 200 microg GA per ml) reduced seed germination by 25 to 50%. Results indicate that GA has an inhibitory effect on growth and AFB1 production by A. flavus.

Production of mycotoxins by Aspergillus lentulus and other medically important and closely related species in section Fumigati

DEFF Research Database (Denmark)

Larsen, Thomas Ostenfeld; Smedsgaard, Jørn; Nielsen, Kristian Fog

2007-01-01

The production of mycotoxins and other secondary metabolites have been studied by LC-DAD-MS from six species in Aspergillus section Fumigati. This includes the three new species Aspergillus lentulus, A. novofumigatus and A. fumigatiaffinis as well as A. fumigatus, Neosartoria fisheri and N. pseud...... by direct injection mass spectrometry and cluster analysis. Separate groupings were seen for all the six species even though only one isolate was included in this study for the two species A. novofumigatus and A. fumigatiaffinis.......The production of mycotoxins and other secondary metabolites have been studied by LC-DAD-MS from six species in Aspergillus section Fumigati. This includes the three new species Aspergillus lentulus, A. novofumigatus and A. fumigatiaffinis as well as A. fumigatus, Neosartoria fisheri and N....... pseudofisheri. A major finding was detection of gliotoxin from N. pseudofisheri, a species not previously reported to produce this mycotoxin. Gliotoxin was also detected from A. fumigatus together with fumagillin, fumigaclavine C, fumitremorgin C, fumiquinazolines, trypacidin, methyl- sulochrin, TR-2...

Formation of Sclerotia and Production of Indoloterpenes by Aspergillus niger and Other Species in Section Nigri

DEFF Research Database (Denmark)

Frisvad, Jens Christian; Petersen, Lene Maj; Lyhne, Ellen Kirstine

2014-01-01

Several species in Aspergillus section Nigri have been reported to produce sclerotia on well-known growth media, such as Czapek yeast autolysate (CYA) agar, with sclerotia considered to be an important prerequisite for sexual development. However Aspergillus niger sensu stricto has not been repor...

Inhibition of aflatoxin-producing aspergilli by lactic acid bacteria ...

African Journals Online (AJOL)

A total of six lactic acid bacteria (LAB) isolates were selected from five indigenously fermented cereal gruels and identified as Lactobacillus fermentum OYB, Lb. fermentum RS2, Lb. plantarum MW, Lb. plantarum YO, Lb. brevis WS3, and Lactococcus spp. RS3. Six aflatoxin-producing aspergilli were also selected from the ...

Comparative genomics of citric-acid-producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

DEFF Research Database (Denmark)

Andersen, Mikael Rørdam; Salazar, Margarita Pena; Schaap, Peter J.

2011-01-01

The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme......-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compel additional exploration. We therefore undertook whole-genome sequencing of the acidogenic A. niger wild-type strain (ATCC 1015) and produced a genome sequence of very high quality. Only 15...

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...

Influence of Gamma-Irradiation on the Growth of Aspergillus spp. on Feeds for Ensuring Feed Safety

International Nuclear Information System (INIS)

Kim, J.S.; Woo, J.H.; Kim, J.T.; Park, N.H.; Kim, C.G.

2010-01-01

Aspergillus spp. is widely spread in the world on feeds and foods. They have been known to produce aflatoxins, which are mutagenic and carcinogenic to humans. The objective of this study was to determine the optimum gamma-irradiation dose for controling the growth of Aspergillus spp. to ensure safety of feeds. Four species fungal spore (10∨7 spore/mL) exposed to 0, 1, 3, 5, 7 and 10 kGy of gamma radiation were inhibited in their growth and AFBâ‚ productivity by greater-than or equal to 5 kGy. Meantime, the growth of fungal inoculated on feeds was inhibited at greater-than or equal to 3 kGy. However, AFBâ‚ presented in aqueous solution was not be inactivated completely by less-than or equal to 10 kGy irradiation. These results indicate that Aspergillus spp. on feeds could be controlled by 5 kGy gamma-irradiation but detoxification of AFBâ‚ demands a higher dose of gamma-irradiation (greater-than or equal to 10 kGy)

Inhibitory Effects of Respiration Inhibitors on Aflatoxin Production

Directory of Open Access Journals (Sweden)

Shohei Sakuda

2014-03-01

Full Text Available Aflatoxin production inhibitors, which do not inhibit the growth of aflatoxigenic fungi, may be used to control aflatoxin without incurring a rapid spread of resistant strains. A respiration inhibitor that inhibits aflatoxin production was identified during a screening process for natural, aflatoxin-production inhibitors. This prompted us to evaluate respiration inhibitors as potential aflatoxin control agents. The inhibitory activities of four natural inhibitors, seven synthetic miticides, and nine synthetic fungicides were evaluated on aflatoxin production in Aspergillus parasiticus. All of the natural inhibitors (rotenone, siccanin, aptenin A5, and antimycin A inhibited fungal aflatoxin production with IC50 values around 10 µM. Among the synthetic miticides, pyridaben, fluacrypyrim, and tolfenpyrad exhibited strong inhibitory activities with IC50 values less than 0.2 µM, whereas cyflumetofen did not show significant inhibitory activity. Of the synthetic fungicides, boscalid, pyribencarb, azoxystrobin, pyraclostrobin, and kresoxim-methyl demonstrated strong inhibitory activities, with IC50 values less than 0.5 µM. Fungal growth was not significantly affected by any of the inhibitors tested at concentrations used. There was no correlation observed between the targets of respiration inhibitors (complexes I, II, and III and their IC50 values for aflatoxin-production inhibitory activity. This study suggests that respiration inhibitors, including commonly used pesticides, are useful for aflatoxin control.

Inhibitory Effects of Respiration Inhibitors on Aflatoxin Production

Science.gov (United States)

Sakuda, Shohei; Prabowo, Diyan Febri; Takagi, Keiko; Shiomi, Kazuro; Mori, Mihoko; Ōmura, Satoshi; Nagasawa, Hiromichi

2014-01-01

Aflatoxin production inhibitors, which do not inhibit the growth of aflatoxigenic fungi, may be used to control aflatoxin without incurring a rapid spread of resistant strains. A respiration inhibitor that inhibits aflatoxin production was identified during a screening process for natural, aflatoxin-production inhibitors. This prompted us to evaluate respiration inhibitors as potential aflatoxin control agents. The inhibitory activities of four natural inhibitors, seven synthetic miticides, and nine synthetic fungicides were evaluated on aflatoxin production in Aspergillus parasiticus. All of the natural inhibitors (rotenone, siccanin, aptenin A5, and antimycin A) inhibited fungal aflatoxin production with IC50 values around 10 µM. Among the synthetic miticides, pyridaben, fluacrypyrim, and tolfenpyrad exhibited strong inhibitory activities with IC50 values less than 0.2 µM, whereas cyflumetofen did not show significant inhibitory activity. Of the synthetic fungicides, boscalid, pyribencarb, azoxystrobin, pyraclostrobin, and kresoxim-methyl demonstrated strong inhibitory activities, with IC50 values less than 0.5 µM. Fungal growth was not significantly affected by any of the inhibitors tested at concentrations used. There was no correlation observed between the targets of respiration inhibitors (complexes I, II, and III) and their IC50 values for aflatoxin-production inhibitory activity. This study suggests that respiration inhibitors, including commonly used pesticides, are useful for aflatoxin control. PMID:24674936

Development of narrow-band fluorescence index for the detection of aflatoxin contaminated corn

Science.gov (United States)

Yao, Haibo; Hruska, Zuzana; Kincaid, Russell; Ononye, Ambrose; Brown, Robert L.; Bhatnagar, Deepak; Cleveland, Thomas E.

2011-06-01

Aflatoxin is produced by the fungus Aspergillus flavus when the fungus invades developing corn kernels. Because of its potent toxicity, the levels of aflatoxin are regulated by the Food and Drug Administration (FDA) in the US, allowing 20 ppb (parts per billion) limits in food, and feed intended for interstate commerce. Currently, aflatoxin detection and quantification methods are based on analytical tests. These tests require the destruction of samples, can be costly and time consuming, and often rely on less than desirable sampling techniques. Thus, the ability to detect aflatoxin in a rapid, non-invasive way is crucial to the corn industry in particular. This paper described how narrow-band fluorescence indices were developed for aflatoxin contamination detection based on single corn kernel samples. The indices were based on two bands extracted from full wavelength fluorescence hyperspectral imagery. The two band results were later applied to two large sample experiments with 25 g and 1 kg of corn per sample. The detection accuracies were 85% and 95% when 100 ppb threshold was used. Since the data acquisition period is significantly lower for several image bands than for full wavelength hyperspectral data, this study would be helpful in the development of real-time detection instrumentation for the corn industry.

Genetic diversity of Aspergillus species isolated from onychomycosis and Aspergillus hongkongensis sp. nov., with implications to antifungal susceptibility testing.

Science.gov (United States)

Tsang, Chi-Ching; Hui, Teresa W S; Lee, Kim-Chung; Chen, Jonathan H K; Ngan, Antonio H Y; Tam, Emily W T; Chan, Jasper F W; Wu, Andrea L; Cheung, Mei; Tse, Brian P H; Wu, Alan K L; Lai, Christopher K C; Tsang, Dominic N C; Que, Tak-Lun; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

2016-02-01

Thirteen Aspergillus isolates recovered from nails of 13 patients (fingernails, n=2; toenails, n=11) with onychomycosis were characterized. Twelve strains were identified by multilocus sequencing as Aspergillus spp. (Aspergillus sydowii [n=4], Aspergillus welwitschiae [n=3], Aspergillus terreus [n=2], Aspergillus flavus [n=1], Aspergillus tubingensis [n=1], and Aspergillus unguis [n=1]). Isolates of A. terreus, A. flavus, and A. unguis were also identifiable by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The 13th isolate (HKU49(T)) possessed unique morphological characteristics different from other Aspergillus spp. Molecular characterization also unambiguously showed that HKU49(T) was distinct from other Aspergillus spp. We propose the novel species Aspergillus hongkongensis to describe this previously unknown fungus. Antifungal susceptibility testing showed most Aspergillus isolates had low MICs against itraconazole and voriconazole, but all Aspergillus isolates had high MICs against fluconazole. A diverse spectrum of Aspergillus species is associated with onychomycosis. Itraconazole and voriconazole are probably better drug options for Aspergillus onychomycosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of various surfactants (cationic, anionic and non-ionic) on the growth of Aspergillus parasiticus (NRRL 2999) in relation to aflatoxin production.

Science.gov (United States)

Tanuja, Kosuri; Hemalatha, K; Karuna, Rupula; Sashidhar Rao, B

2010-08-01

The effect of surfactants (two cationic, one anionic and three non-ionic) at 0.001, 0.01, 0.1 and 1.0 % concentrations on aflatoxin production, ergosterol content and sugar consumption by Aspergillus parasiticus (NRRL 2999) in YES liquid culture medium is reported. At 0.01% concentration, the cationic surfactants, cetyl dimethyl ammonium bromide (CDAB) and dodecyl trimethyl ammonium bromide (DTAB), and the anionic surfactant, sodium dodecyl sulfate (SDS), completely inhibited spore germination, while DTAB also inhibited the production of ergosterol and toxin (p lauryl ether (Brij-35) and ethoxylated p-tert-octylphenol (Triton X-100) delayed the spore germination up to day 5 at all concentrations and inhibited toxin and ergosterol production at 0.001% concentration. The affect was found to be dose-dependent from 0.001% to 1%, for Triton X-100 only. Positive correlation between ergosterol content and toxin production in the presence of different surfactants at various time periods (3, 5, 7, 9 and 12 days) was found. Tween-20 was most effective in inhibiting toxin production on day 7, when aflatoxin production was found to be maximal in control group. Sugar consumption was directly proportional to the ergosterol content, showing a significant correlation with aflatoxin production.

Mycological and toxicological analysis of peanuts and derivatives

Directory of Open Access Journals (Sweden)

Robson de Lima

2012-08-01

Full Text Available The filamentous fungi Aspergillus flavus, Aspergillus parasiticus and Aspergillus nomius produce toxins, which are secondary metabolites called aflatoxins. These toxin-producing species grow rapidly on peanuts and cereals in favorable conditions of temperature and humidity. Their toxins can either cause acute effects, and even be lethal or accumulate in the organism, resulting in liver cancer in the long term. Based on the health risks of aflatoxins in food, a research was conducted on peanuts and derivatives sold in Alfenas, MG, Brazil, to evaluate the presence of Aspergillus sp. and aflatoxins. The samples were randomly collected at “popular stores”, from November 2008 to May 2009, to assess the occurrence of aflatoxins B1 , B2, G1 and G2by thin layer chromatography (TLC. The mycological analysis revealed the presence of fungi in 50% of the samples: Penicillium sp. (53.85%, A. flavus (19.23%, A. niger (15.38% and A. fumigatus (11.54%, and 63.64% of these showed the presence of aflatoxins : B1 (43.14%, B2 (25.49%, G1 (23.53% and G2 (7.84%. Itis concluded that the results reported here are a cause for concern, given the harmfulness of these cumulative and carcinogenic toxins.

Using biotechnology to enhance host resistance to aflatoxin ...

African Journals Online (AJOL)

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

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.)

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

Science.gov (United States)

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

1994-09-01

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

Expression of a Human Cytochrome P450 in Yeast Permits Analysis of Pathways for Response to and Repair of Aflatoxin-Induced DNA Damage†

OpenAIRE

Guo, Yingying; Breeden, Linda L.; Zarbl, Helmut; Preston, Bradley D.; Eaton, David L.

2005-01-01

Aflatoxin B1 (AFB1) is a human hepatotoxin and hepatocarcinogen produced by the mold Aspergillus flavus. In humans, AFB1 is primarily bioactivated by cytochrome P450 1A2 (CYP1A2) and 3A4 to a genotoxic epoxide that forms N7-guanine DNA adducts. A series of yeast haploid mutants defective in DNA repair and cell cycle checkpoints were transformed with human CYP1A2 to investigate how these DNA adducts are repaired. Cell survival and mutagenesis following aflatoxin B1 treatment was assayed in str...

Identification of thermostable β-xylosidase activities produced by Aspergillus brasiliensis and Aspergillus niger

DEFF Research Database (Denmark)

Pedersen, Mads; Lauritzen, Henrik Klitgaard; Frisvad, Jens Christian

2007-01-01

Twenty Aspergillus strains were evaluated for production of extracellular cellulolytic and xylanolytic activities. Aspergillus brasiliensis, A. niger and A. japonicus produced the highest xylanase activities with the A. brasiliensis and A. niger strains producing thermostable beta......-xylosidases. The beta-xylosidase activities of the A. brasiliensis and A. niger strains had similar temperature and pH optima at 75 degrees C and pH 5 and retained 62% and 99%, respectively, of these activities over 1 h at 60 degrees C. At 75 degrees C, these values were 38 and 44%, respectively. Whereas A. niger...

Could biorational insecticides be used in the management of aflatoxigenic Aspergillus parasiticus and its insect vectors in stored wheat?

Directory of Open Access Journals (Sweden)

Tiyyabah Khan

2016-02-01

Full Text Available Insect pests in stored wheat cause significant losses and play an important role in the dispersal of viable fungal spores of various species including aflatoxin producing Aspergillus parasiticus. The problem of insecticide resistance in stored insects and environmental hazards associated with fumigants and conventional grain protectants underscore the need to explore reduced risk insecticides to control stored insects with the ultimate effect on aflatoxin production. The purpose of this study was to investigate the insecticidal potential of four biorational insecticides: spinosad, thiamethoxam, imidacloprid and indoxacarb, on wheat grains artificially infested with Rhyzopertha dominica/Sitophilus oryzae and/or A. parasiticus spores, and the subsequent effect on aflatoxin production. Spinosad and thiamethoxam were the most effective insecticides against R. dominica compared to S. oryzae followed by imidacloprid. Spinosad applied at 0.25–1 ppm and thiamethoxam at 2 and 4 ppm concentrations resulted in complete mortality of R. dominica. However, indoxacarb was more toxic against S. oryzae compared to R. dominica. Wheat grains inoculated with R. dominica/S. oryzae +spores elicited higher aflatoxin levels than wheat grains inoculated with or without insecticide+spores. In all the treatment combinations containing insects, aflatoxin production was dependent on insects’ survival rate. In addition, thiamethoxam and imidacloprid had also a significant direct effect on reducing aflatoxin production. Aflatoxin levels were lower in the treatment combinations with any concentration of thiamethoxam/imidacloprid+spores as compared to wheat grains inoculated with spores only. Correlation analyses revealed highly significant and positive association between moisture contents/insect survival rate and production of aflatoxin levels, and insect survival rate and moisture contents of the wheat grains. In conclusion, the results of the present study provide

Polyphasic taxonomy of Aspergillus section Aspergillus (formerly Eurotium, and its occurrence in indoor environments and food

Directory of Open Access Journals (Sweden)

A.J. Chen

2017-09-01

Full Text Available Aspergillus section Aspergillus (formerly the genus Eurotium includes xerophilic species with uniseriate conidiophores, globose to subglobose vesicles, green conidia and yellow, thin walled eurotium-like ascomata with hyaline, lenticular ascospores. In the present study, a polyphasic approach using morphological characters, extrolites, physiological characters and phylogeny was applied to investigate the taxonomy of this section. Over 500 strains from various culture collections and new isolates obtained from indoor environments and a wide range of substrates all over the world were identified using calmodulin gene sequencing. Of these, 163 isolates were subjected to molecular phylogenetic analyses using sequences of ITS rDNA, partial β-tubulin (BenA, calmodulin (CaM and RNA polymerase II second largest subunit (RPB2 genes. Colony characteristics were documented on eight cultivation media, growth parameters at three incubation temperatures were recorded and micromorphology was examined using light microscopy as well as scanning electron microscopy to illustrate and characterize each species. Many specific extrolites were extracted and identified from cultures, including echinulins, epiheveadrides, auroglaucins and anthraquinone bisanthrons, and to be consistent in strains of nearly all species. Other extrolites are species-specific, and thus valuable for identification. Several extrolites show antioxidant effects, which may be nutritionally beneficial in food and beverages. Important mycotoxins in the strict sense, such as sterigmatocystin, aflatoxins, ochratoxins, citrinin were not detected despite previous reports on their production in this section. Adopting a polyphasic approach, 31 species are recognized, including nine new species. ITS is highly conserved in this section and does not distinguish species. All species can be differentiated using CaM or RPB2 sequences. For BenA, Aspergillus brunneus and A. niveoglaucus share identical

Effects of sugar and amino acid supplementation on Aureobasidium pullulans NRRL 58536 antifungal activity against four Aspergillus species.

Science.gov (United States)

Prasongsuk, Sehanat; Ployngam, Saowaluck; Wacharasindhu, Sumrit; Lotrakul, Pongtharin; Punnapayak, Hunsa

2013-09-01

Cultured cell extracts from ten tropical strains of Aureobasidium pullulans were screened for antifungal activity against four pathogenic Aspergillus species (Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus, and Aspergillus terreus) using the well diffusion and conidial germination inhibition assays. The crude cell extract from A. pullulans NRRL 58536 resulted in the greatest fungicidal activity against all four Aspergillus species and so was selected for further investigation into enhancing the production of antifungal activity through optimization of the culture medium, carbon source (sucrose and glucose) and amino acid (phenylalanine, proline, and leucine) supplementation. Sucrose did not support the production of any detectable antifungal activity, while glucose did with the greatest antifungal activity against all four Aspergillus species being produced in cells grown in medium containing 2.5 % (w/v) glucose. With respect to the amino acid supplements, variable trends between the different Aspergillus species and amino acid combinations were observed, with the greatest antifungal activities being obtained when grown with phenylalanine plus leucine supplementation for activity against A. flavus, proline plus leucine for A. terreus, and phenylalanine plus proline and leucine for A. niger and A. fumigatus. Thin layer chromatography, spectrophotometry, high-performance liquid chromatography, (1)H-nuclear magnetic resonance, and MALDI-TOF mass spectrometry analyses were all consistent with the main component of the A. pullulans NRRL 58536 extracts being aureobasidins.

Characterization of expressed sequence tag-derived simple sequence repeat markers for Aspergillus flavus: emphasis on variability of isolates from the southern United States.

Science.gov (United States)

Wang, Xinwang; Wadl, Phillip A; Wood-Jones, Alicia; Windham, Gary; Trigiano, Robert N; Scruggs, Mary; Pilgrim, Candace; Baird, Richard

2012-12-01

Simple sequence repeat (SSR) markers were developed from Aspergillus flavus expressed sequence tag (EST) database to conduct an analysis of genetic relationships of Aspergillus isolates from numerous host species and geographical regions, but primarily from the United States. Twenty-nine primers were designed from 362 tri-nucleotide EST-SSR sequences. Eighteen polymorphic loci were used to genotype 96 Aspergillus species isolates. The number of alleles detected per locus ranged from 2 to 24 with a mean of 8.2 alleles. Haploid diversity ranged from 0.28 to 0.91. Genetic distance matrix was used to perform principal coordinates analysis (PCA) and to generate dendrograms using unweighted pair group method with arithmetic mean (UPGMA). Two principal coordinates explained more than 75 % of the total variation among the isolates. One clade was identified for A. flavus isolates (n = 87) with the other Aspergillus species (n = 7) using PCA, but five distinct clusters were present when the others taxa were excluded from the analysis. Six groups were noted when the EST-SSR data were compared using UPGMA. However, the latter PCA or UPGMA comparison resulted in no direct associations with host species, geographical region or aflatoxin production. Furthermore, there was no direct correlation to visible morphological features such as sclerotial types. The isolates from Mississippi Delta region, which contained the largest percentage of isolates, did not show any unusual clustering except for isolates K32, K55, and 199. Further studies of these three isolates are warranted to evaluate their pathogenicity, aflatoxin production potential, additional gene sequences (e.g., RPB2), and morphological comparisons.

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.

Aspergillus waksmanii sp. nov. and Aspergillus marvanovae sp. nov., two closely related species in section Fumigati

DEFF Research Database (Denmark)

Hubka, Vit; Peterson, Stephen W.; Frisvad, Jens Christian

2013-01-01

Two new and phylogenetically closely related species in Aspergillus section Fumigati are described and illustrated. Homothallic Aspergillus waksmanii sp. nov. was isolated from New Jersey soil (USA) and is represented by the ex-type isolate NRRL 179T (=CCF 4266T=Thom 4138.HS2T=IBT 31900T......). Aspergillus marvanovae sp. nov. was isolated from water with high boracic acid anions content in Dukovany nuclear power station (Czech Republic). The sexual stage of this species is unknown, but the MAT1-1 locus was successfully amplified suggesting that the species is probably heterothallic and teleomorphic...... but is represented by only the ex-type isolate CCM 8003T (=CCF 4037T=NRRL 62486T=IBT 31279T=IFM 60873T). Both species can be distinguished from all previously described species in section Fumigati based on morphology, maximum growth temperature, sequence data from five unlinked loci and unique secondary metabolites...

A review on aflatoxin contamination and its implications in the developing world: a sub-Saharan African perspective.

Science.gov (United States)

Gnonlonfin, G J B; Hell, K; Adjovi, Y; Fandohan, P; Koudande, D O; Mensah, G A; Sanni, A; Brimer, L

2013-01-01

Mycotoxins contamination in some agricultural food commodities seriously impact human and animal health and reduce the commercial value of crops. Mycotoxins are toxic secondary metabolites produced by fungi that contaminate agricultural commodities pre- or postharvest. Africa is one of the continents where environmental, agricultural and storage conditions of food commodities are conducive of Aspergillus fungi infection and aflatoxin biosynthesis. This paper reviews the commodity-wise aetiology and contamination process of aflatoxins and evaluates the potential risk of exposure from common African foods. Possible ways of reducing risk for fungal infection and aflatoxin development that are relevant to the African context. The presented database would be useful as benchmark information for development and prioritization of future research. There is need for more investigations on food quality and safety by making available advanced advanced equipments and analytical methods as well as surveillance and awareness creation in the region.

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)

Influence of essential oils on the growth of aspergillus flavus

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Denisa Foltinová

2017-01-01

Full Text Available This paper was focused on the determination of the inhibitory effect of selected essential oils on growth of ten isolates of Aspergillus flavus and their potential ability to produce mycotoxins in vitro by TLC method. The isolates were obtained from moldy bread of domestic origin. We followed the impact of five essential oils at 100% concentration - lemon, eucalyptus, oregano, sage and thyme. The effect of the essential oils we tested the gaseous diffusion method. We isolates grown on CYA (Czapek yeast extract agar, in the dark at 25 ±1 °C, 14 days. The diameter of colonies grown we continuously measured on the 3rd, 7th, 11th, and 14th day of cultivation. The results of the paper suggest that oregano and thyme essential oil had 100% inhibited the growth of all tested isolates of Aspergillus flavus. Lemon, eucalyptus and sage essential oil had not significant inhibitory effects on tested isolates Aspergillus flavus, but affected the growth of colonies throughout the cultivation. In addition to the inhibitory effect we witnessed the stimulative effect of lemon, eucalyptus and sage essential oil to some isolates. Together with the antifungal effect of essential oils, we monitored the ability of Aspergillus flavus isolates to produce mycotoxins - aflatoxin B1 (AFB1 and cyclopiazonic acid (CPA in the presence of essential oils. Production mycotoxins we have seen in the last (14th day of cultivation. Lemon and eucalyptus essential oil did not affect the production of mycotoxins. In the case of sage essential oil we were recorded cyclopiazonic acid production in three of the ten isolates from the all three repetitions, while neither isolate did not produced aflatoxin B1. The production of secondary metabolites was detected in all control samples. From the results we can say that oregano and thyme essential oil could be used as a natural preservative useful in the food industry.

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

Aspergillus fumigatus-Related Species in Clinical Practice.

Science.gov (United States)

Lamoth, Frédéric

2016-01-01

Aspergillus fumigatus is the main etiologic agent of invasive aspergillosis (IA). Other Aspergillus species belonging to the section Fumigati (A. fumigatus complex) may occasionally be the cause of IA. These strains are often misidentified, as they cannot be distinguished from A. fumigatus by conventional morphological analysis and sequencing methods. This lack of recognition may have important consequences as these A. fumigatus-related species often display some level of intrinsic resistance to azoles and other antifungal drugs. A. lentulus, A. udagawae, A. viridinutans, and A. thermomutatus (Neosartorya pseudofischeri) have been associated with refractory cases of IA. Microbiologists should be able to suspect the presence of these cryptic species behind a putative A. fumigatus isolate on the basis of some simple characteristics, such as defect in sporulation and/or unusual antifungal susceptibility profile. However, definitive species identification requires specific sequencing analyses of the beta-tubulin or calmodulin genes, which are not available in most laboratories. Multiplex PCR assays or matrix-assisted laser desorption ionization - time-of-flight mass spectrometry (MALDI-TOF MS) gave promising results for rapid and accurate distinction between A. fumigatus and other Aspergillus spp. of the section Fumigati in clinical practice. Improved diagnostic procedures and antifungal susceptibility testing may be helpful for the early detection and management of these particular IA cases.

Natural occurrence of aflatoxins in bread in Nigeria | Efuntoye ...

African Journals Online (AJOL)

A study was conducted in Nigeria on samples of brown bread for growth of moulds and natural occurrence of aflatoxins. Mycological analysis showed the presence of six genera of filamentous fungi, Aspergillus, Rhizopus, Mucor, Penicillium, Alternaria and Geotrichum. Thin layer chromatography (TLC) analysis of bread ...

HRAS: a webserver for early warning of human health risk brought by aflatoxin.

Science.gov (United States)

Hu, Ruifeng; Zeng, Xu; Gao, Weiwei; Wang, Qian; Liu, Zhihua

2013-02-01

Most people are aware that outdoor air pollution can damage their health, but many do not know that indoor air pollution can also exhibit significant negative health effects. Fungi parasitizing in air conditioning and ventilation systems can be one of indoor air pollution sources. Aflatoxin produced by Aspergillus flavus (A. flavus) became a central focus of indoor air pollution, especially in farmer markets. Therefore we developed an early warning system, Health Risk Assessment System, to estimate the growth rate of A. flavus, predict the amount of aflatoxin and provide early warning information. Firstly, the growth of A. flavus and the production of aflatoxin under different conditions were widely obtained through a comprehensive literature review. Secondly, three mathematical models were established to predict the A. flavus colony growth rate, lag phase duration and aflatoxin content, as functions of temperature and water activity based on present studies. Finally, all the results were evaluated by the user-supplied data using PHP programming language. We utilized the web page to show the results and display warning information. The JpGraph library was used to create a dynamic line chart, refreshing the warning information dynamically in real-time. The HARS provides accurate information for early warning purposes to let us take timely steps to protect ourselves.

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

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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 ...

Relationship between Aflatoxin Contamination and Physiological Responses of Corn Plants under Drought and Heat Stress

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Nacer Bellaloui

2012-11-01

Full Text Available Increased aflatoxin contamination in corn by the fungus Aspergillus flavus is associated with frequent periods of drought and heat stress during the reproductive stages of the plants. The objective of this study was to evaluate the relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress. The study was conducted in Stoneville, MS, USA under irrigated and non-irrigated conditions. Five commercial hybrids, P31G70, P33F87, P32B34, P31B13 and DKC63-42 and two inbred germplasm lines, PI 639055 and PI 489361, were evaluated. The plants were inoculated with Aspergillus flavus (K-54 at mid-silk stage, and aflatoxin contamination was determined on the kernels at harvest. Several physiological measurements which are indicators of stress response were determined. The results suggested that PI 639055, PI 489361 and hybrid DKC63-42 were more sensitive to drought and high temperature stress in the non-irrigated plots and P31G70 was the most tolerant among all the genotypes. Aflatoxin contamination was the highest in DKC63-42 and PI 489361 but significantly lower in P31G70. However, PI 639055, which is an aflatoxin resistant germplasm, had the lowest aflatoxin contamination, even though it was one of the most stressed genotypes. Possible reasons for these differences are discussed. These results suggested that the physiological responses were associated with the level of aflatoxin contamination in all the genotypes, except PI 639055. These and other physiological responses related to stress may help examine differences among corn genotypes in aflatoxin contamination.

Relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress.

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Kebede, Hirut; Abbas, Hamed K; Fisher, Daniel K; Bellaloui, Nacer

2012-11-20

Increased aflatoxin contamination in corn by the fungus Aspergillus flavus is associated with frequent periods of drought and heat stress during the reproductive stages of the plants. The objective of this study was to evaluate the relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress. The study was conducted in Stoneville, MS, USA under irrigated and non-irrigated conditions. Five commercial hybrids, P31G70, P33F87, P32B34, P31B13 and DKC63-42 and two inbred germplasm lines, PI 639055 and PI 489361, were evaluated. The plants were inoculated with Aspergillus flavus (K-54) at mid-silk stage, and aflatoxin contamination was determined on the kernels at harvest. Several physiological measurements which are indicators of stress response were determined. The results suggested that PI 639055, PI 489361 and hybrid DKC63-42 were more sensitive to drought and high temperature stress in the non-irrigated plots and P31G70 was the most tolerant among all the genotypes. Aflatoxin contamination was the highest in DKC63-42 and PI 489361 but significantly lower in P31G70. However, PI 639055, which is an aflatoxin resistant germplasm, had the lowest aflatoxin contamination, even though it was one of the most stressed genotypes. Possible reasons for these differences are discussed. These results suggested that the physiological responses were associated with the level of aflatoxin contamination in all the genotypes, except PI 639055. These and other physiological responses related to stress may help examine differences among corn genotypes in aflatoxin contamination.

Aflatoxins and ochratoxin A in different cocoa clones (Theobroma cacao L.) developed in the southern region of Bahia, Brazil.

Science.gov (United States)

Maciel, Leonardo Fonseca; Felício, Ana Lúcia de Souza Madureira; Miranda, Lucas Caldeirão Rodrigues; Pires, Tassia Cavalcante; Bispo, Eliete da Silva; Hirooka, Elisa Yoko

2018-01-01

Brazil is the sixth largest producer of cocoa beans in the world, after Côte d'Ivoire, Ghana, Indonesia, Nigeria and Cameroon. The southern region of Bahia stands out as the country's largest producer, accounting for approximately 60% of production. Due to damage caused by infestation of the cocoa crop with the fungus Moniliophthora perniciosa, which causes 'witch's broom disease', research in cocoa beans has led to the cloning of species that are resistant to the disease; however, there is little information about the development of other fungal genera in these clones, such as Aspergillus, which do not represent a phytopathogenicity problem but can grow during the pre-processing of cocoa beans and produce mycotoxins. Thus, the aim of this work was to determine the presence of aflatoxin (AF) and ochratoxin A (OTA) in cocoa clones developed in Brazil. Aflatoxin and ochratoxin A contamination were determined in 130 samples from 13 cocoa clones grown in the south of Bahia by ultra-performance liquid chromatography with a fluorescence detector. The method was evaluated for limit of detection (LOD) (0.05-0.90 μg kg -1 ), limit of quantification (0.10-2.50 μg kg -1 ) and recovery (RSD) (89.40-95.80%) for AFB 1 , AFB 2 , AFG 1 , AFG 2 and OTA. Aflatoxin contamination was detected in 38% of the samples in the range of

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

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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...

Production of aflatexin B1 in wheat grains under different environmental storage conditions

International Nuclear Information System (INIS)

Mahrous, S.R.; Shahin, A.A.M.; Bothaina, M.Y.

2000-01-01

Fungal flora of stored wheat grains and the production of aflatoxin B 1 by Aflavus in wheat grains under different environmental conditions were examined. Aspergillus, Penicillium,. Fusarium, Cladosporium, Curvularia, Epicouccum, Verticilium, Rhizopus, Mucor and Altenaria were the predominant fungi isolated from the collected non-disinfected grains. Aspergillus spp, were only isolated from surface disinfected grains. Of 223 aspergillus spp, isolates only 128 found to aflatoxin producing and all aflatoxin producing-fungi belonged to the Aflavus group. Results demonstrate that Aflavus could produce maximum concentration of aflatoxin B 1 in grains at 20% moisture (163.5 MOU g/kg). The highest concentration of aflatoxin B 1 was produced by Aflavus (10 5 spores/g) in wheat grains with 20% moisture after 20 days at 30 degree and 92.40 % R.H. The aflatoxin production did not increase monotonously as a function of inoculum density

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

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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.

Two novel species of Aspergillus section Nigri from Thai coffee beans

DEFF Research Database (Denmark)

Noonim, Paramee; Mahakarnchanakul, Warapa; Varga, Janos

2008-01-01

Two novel species of Aspergillus section Nigri from Thai coffee beans are described as Aspergillus aculeatinus sp. nov. and Aspergillus sclerotiicarbonarius sp. nov. Their taxonomic status was determined using a polyphasic taxonomic approach with phenotypic (morphology and extrolite profiles...

Transfer of aflatoxin from feed to milk and curd in Sarda ewes with different milk production level

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G. Pulina

2011-03-01

Full Text Available Aflatoxin B1 (AFB1 is a toxin produced by some strains of Aspergillus growing in feedstuffs. Dairy animals fed with diet containing AFB1 excrete aflatoxin M1 (AFM1 into the milk. The carry over ratio (AFM1 excreted in milk/ AFB1 ingested has been found lower in sheep (Battacone et al., 2002a than in cattle (Veldman et al., 1992. Being AFM1 linked to milk proteins, its concentration in curd is higher than in milk. The AFM1 concentration in milk resulted not influenced by milk production level in cattle, therefore the total amount of AFM1 excreted in milk and, consequently, the carry-over ratio increased with milk yield (Munksgaard et al., 1987; Veldman et al., 1992...

Two novel species of Aspergillus section Nigri from Thai coffee beans.

NARCIS (Netherlands)

Noonim, P.; Mahakarnchanakul, W.; Varga, J.; Frisvad, J.C.; Samson, R.A.

2008-01-01

Two novel species of Aspergillus section Nigri from Thai coffee beans are described as Aspergillus aculeatinus sp. nov. and Aspergillus sclerotiicarbonarius sp. nov. Their taxonomic status was determined using a polyphasic taxonomic approach with phenotypic (morphology and extrolite profiles) and

Mycobiota and Aflatoxin B1 in Feed for Farmed Sea Bass (Dicentrarchus labrax

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Fernando Manuel d´Almeida Bernardo

2011-02-01

Full Text Available The safety characteristics of feed used in fish and crustacean aquaculture systems are an essential tool to assure the productivity of those animal exploitations. Safety of feed may be affected by different hazards, including biological and chemical groups. The aim of this preliminary study was to evaluate fungi contamination and the presence of aflatoxins in 87 samples of feed for sea bass, collected in Portugal. Molds were found in 35 samples (40.2% in levels ranging from 1 to 3.3 log10 CFU∙g−1. Six genera of molds were found. Aspergillus flavus was the most frequent, found in all positive samples, with a range from 2 to 3.2 log10 CFU∙g−1. Aspergillus niger was found in 34 samples (39.1%, ranging from 1 to 2.7 log10 CFU∙g−1. Aspergillus glaucus was found in 26 samples (29.9% with levels between 1 and 2.4 log10 CFU∙g−1. Penicillium spp. and Cladosporium spp. were both found in 25 samples (28.7%. Fusarium spp. was found in 22 samples (25.3%, ranging from 1 to 2.3 log10 CFU∙g−1. All feed samples were screened for aflatoxins using a HPLC technique, with a detection limit of 1.0 μg∙kg−1. All samples were aflatoxin negative.

Differential impact of some Aspergillus species on Meloidogyne javanica biocontrol by Pseudomonas fluorescens strain CHA0.

Science.gov (United States)

Siddiqui, I A; Shaukat, S S; Khan, A

2004-01-01

The aim was to determine the influence of some Aspergillus species on the production of nematicidal agent(s) in vitro and biocontrol of Meloidogyne javanica in tomato by Pseudomonas fluorescens strains CHA0 and CHA0/pME3424. Six species of Aspergillus, isolated from the rhizosphere of certain crops, produced a variety of secondary metabolites in vitro. Culture filtrate (CF) obtained from Ps. fluorescens strain CHA0 and its2,4-diacetylphloroglucinol overproducing mutant CHA0/pME3424 grown in King's B liquid medium caused significant mortality of M. javanica juveniles in vitro. Bacterial growth medium amended with CF of A. niger enhanced nematicidal and beta-galactosidase activities of fluorescent pseudomonads while A. quadrilineatus repressed such activities. Methanol or ethyl acetate extracts of the CF of A. niger markedly optimized bacterial efficacy to cause nematode deaths while hexane extract of the fungus had no influence on the nematicidal activity of the bacterial strains. A. niger applied alone or in conjunction with the bacterial inoculants inhibited root-knot nematode galling in tomato. On the other hand, A. quadrilineatus used alone or together with CHA0 did not inhibit nematode galling but when used in combination with strain CHA0/pME3424 did reduce galling intensity. Aspergillus niger enhances the production of nematicidal compounds by Ps. fluorescensin vitro and improves biocontrol potential of the bacterial inoculants in tomato while A. quadrilineatus reduces bacterial performance to suppress root-knot nematodes. Rhizosphere harbours a variety of micro-organisms including bacteria, fungi and viruses. Aspergillus species are ubiquitous in most agricultural soils and generally produce a variety of secondary metabolites. Such metabolites synthesized by Aspergillus species may influence the production of nematicidal agents and subsequent biocontrol performance of the bacterial inoculants against plant-parasitic nematodes. This fact needs to be taken into

Aspergillus fumigatus-Related Species in Clinical Practice

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Frederic eLamoth

2016-05-01

Full Text Available Aspergillus fumigatus is the main etiologic agent of invasive aspergillosis (IA. Other Aspergillus species belonging to the section Fumigati (A. fumigatus complex may occasionally be the cause of IA. These strains are often misidentified, as they cannot be distinguished from A. fumigatus by conventional morphological analysis and sequencing methods. This lack of recognition may have important consequences as these A. fumigatus-related species often display some level of intrinsic resistance to azoles and other antifungal drugs. A. lentulus, A. udagawae, A. viridinutans and A. thermomutatus (Neosartorya pseudofischeri have been associated with refractory cases of IA. Microbiologists should be able to suspect the presence of these cryptic species behind a putative A. fumigatus isolate on the basis of some simple characteristics, such as defect in sporulation and/or unusual antifungal susceptibility profile. However, definitive species identification requires specific sequencing analyses of the beta-tubulin or calmodulin genes, which are not available in most laboratories. Multiplex PCR assays or matrix-assisted laser desorption ionization – time-of-flight mass spectrometry (MALDI-TOF MS gave promising results for rapid and accurate distinction between A. fumigatus and other Aspergillus spp. of the section Fumigati in clinical practice. Improved diagnostic procedures and antifungal susceptibility testing may be helpful for the early detection and management of these particular IA cases.

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

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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.

PCR-RFLP on β-tubulin gene for rapid identification of the most clinically important species of Aspergillus.

Science.gov (United States)

Nasri, Tuba; Hedayati, Mohammad Taghi; Abastabar, Mahdi; Pasqualotto, Alessandro C; Armaki, Mojtaba Taghizadeh; Hoseinnejad, Akbar; Nabili, Mojtaba

2015-10-01

Aspergillus species are important agents of life-threatening infections in immunosuppressed patients. Proper speciation in the Aspergilli has been justified based on varied fungal virulence, clinical presentations, and antifungal resistance. Accurate identification of Aspergillus species usually relies on fungal DNA sequencing but this requires expensive equipment that is not available in most clinical laboratories. We developed and validated a discriminative low-cost PCR-based test to discriminate Aspergillus isolates at the species level. The Beta tubulin gene of various reference strains of Aspergillus species was amplified using the universal fungal primers Bt2a and Bt2b. The PCR products were subjected to digestion with a single restriction enzyme AlwI. All Aspergillus isolates were subjected to DNA sequencing for final species characterization. The PCR-RFLP test generated unique patterns for six clinically important Aspergillus species, including Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus terreus, Aspergillus clavatus and Aspergillus nidulans. The one-enzyme PCR-RFLP on Beta tubulin gene designed in this study is a low-cost tool for the reliable and rapid differentiation of the clinically important Aspergillus species. Copyright © 2015 Elsevier B.V. All rights reserved.

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

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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.

Variation in the Microbiome, Trichothecenes, and Aflatoxins in Stored Wheat Grains in Wuhan, China

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Qing-Song Yuan

2018-04-01

Full Text Available Contamination by fungal and bacterial species and their metabolites can affect grain quality and health of wheat consumers. In this study, sequence analyses of conserved DNA regions of fungi and bacteria combined with determination of trichothecenes and aflatoxins revealed the microbiome and mycotoxins of wheat from different silo positions (top, middle, and bottom and storage times (3, 6, 9, and 12 months. The fungal community in wheat on the first day of storage (T0 included 105 classified species (81 genera and 41 unclassified species. Four species had over 10% of the relative abundance: Alternaria alternata (12%, Filobasidium floriforme (27%, Fusarium graminearum (12%, and Wallemia sebi (12%. Fungal diversity and relative abundance of Fusarium in wheat from top silo positions were significantly lower than at other silo positions during storage. Nivalenol and deoxynivalenol in wheat were 13–34% higher in all positions at 3 months compared to T0, and mycotoxins in wheat from middle and bottom positions at 6 to 12 months were 24–57% higher than at T0. The relative abundance of toxigenic Aspergillus and aflatoxins were low at T0 and during storage. This study provides information on implementation and design of fungus and mycotoxin management strategies as well as prediction models.

Evaluation of maize inbred lines for resistance to pre-harvest aflatoxin and fumonisin contamination in the field

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Baozhu Guo

2017-06-01

Full Text Available Two important mycotoxins, aflatoxin and fumonisin, are among the most potent naturally occurring carcinogens, contaminating maize (Zea mays and affecting crop yield and quality. Resistance of maize to pre-harvest mycotoxin contamination, specifically aflatoxin produced by Aspergillus flavus and fumonisin produced by Fusarium verticillioides, is a goal in breeding programs that screen for these important traits with the aim of developing resistant commercial hybrids. We conducted two years of field evaluations on 87 inbred lines originating primarily in China and Mexico and not previously screened for resistance. The objectives of our study were to identify resistant germplasm for breeding purposes and to examine possible relationships between resistances to the two mycotoxins. Aflatoxin and fumonisin were present in samples harvested from all lines in both years. Concentrations of total aflatoxin ranged from 52.00 ± 20.00 to 1524.00 ± 396.00 μg kg−1, while those of fumonisin ranged from 0.60 ± 0.06 to 124.00 ± 19.50 mg kg−1. The inbred lines TUN15, TUN61, TUN37, CY2, and TUN49 showed the lowest aflatoxin accumulation and CN1, GT601, TUN09, TUN61, and MP717 the lowest fumonisin accumulation. TUN61 showed the lowest accumulation of both mycotoxins. This study confirmed previous observations that high levels of aflatoxin can coexist with fumonisin, with 55 maize lines showing a positive correlation coefficient between the concentrations of aflatoxin and fumonisin and 32 lines showing a negative correlation coefficient. These selected lines, particularly TUN61, may provide sources of resistance to mycotoxin contamination in breeding programs. However, the mechanism of resistance in this germplasm remains to be identified. Future research should also address factors that influence the fungus–plant interaction, such as herbivory and environmental stress.

Formation of sclerotia and production of indoloterpenes by Aspergillus niger and other species in section Nigri.

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Jens C Frisvad

Full Text Available Several species in Aspergillus section Nigri have been reported to produce sclerotia on well-known growth media, such as Czapek yeast autolysate (CYA agar, with sclerotia considered to be an important prerequisite for sexual development. However Aspergillus niger sensu stricto has not been reported to produce sclerotia, and is thought to be a purely asexual organism. Here we report, for the first time, the production of sclerotia by certain strains of Aspergillus niger when grown on CYA agar with raisins, or on other fruits or on rice. Up to 11 apolar indoloterpenes of the aflavinine type were detected by liquid chromatography and diode array and mass spectrometric detection where sclerotia were formed, including 10,23-dihydro-24,25-dehydroaflavinine. Sclerotium induction can thus be a way of inducing the production of new secondary metabolites from previously silent gene clusters. Cultivation of other species of the black aspergilli showed that raisins induced sclerotium formation by A. brasiliensis, A. floridensis A. ibericus, A. luchuensis, A. neoniger, A. trinidadensis and A. saccharolyticus for the first time.

Formation of Sclerotia and Production of Indoloterpenes by Aspergillus niger and Other Species in Section Nigri

Science.gov (United States)

Frisvad, Jens C.; Petersen, Lene M.; Lyhne, E. Kirstine; Larsen, Thomas O.

2014-01-01

Several species in Aspergillus section Nigri have been reported to produce sclerotia on well-known growth media, such as Czapek yeast autolysate (CYA) agar, with sclerotia considered to be an important prerequisite for sexual development. However Aspergillus niger sensu stricto has not been reported to produce sclerotia, and is thought to be a purely asexual organism. Here we report, for the first time, the production of sclerotia by certain strains of Aspergillus niger when grown on CYA agar with raisins, or on other fruits or on rice. Up to 11 apolar indoloterpenes of the aflavinine type were detected by liquid chromatography and diode array and mass spectrometric detection where sclerotia were formed, including 10,23-dihydro-24,25-dehydroaflavinine. Sclerotium induction can thus be a way of inducing the production of new secondary metabolites from previously silent gene clusters. Cultivation of other species of the black aspergilli showed that raisins induced sclerotium formation by A. brasiliensis, A. floridensis A. ibericus, A. luchuensis, A. neoniger, A. trinidadensis and A. saccharolyticus for the first time. PMID:24736731

Plasma-Based Degradation of Mycotoxins Produced by Fusarium, Aspergillus and Alternaria Species

Directory of Open Access Journals (Sweden)

Lars ten Bosch

2017-03-01

Full Text Available The efficacy of cold atmospheric pressure plasma (CAPP with ambient air as working gas for the degradation of selected mycotoxins was studied. Deoxynivalenol, zearalenone, enniatins, fumonisin B1, and T2 toxin produced by Fusarium spp., sterigmatocystin produced by Aspergillus spp. and AAL toxin produced by Alternaria alternata were used. The kinetics of the decay of mycotoxins exposed to plasma discharge was monitored. All pure mycotoxins exposed to CAPP were degraded almost completely within 60 s. Degradation rates varied with mycotoxin structure: fumonisin B1 and structurally related AAL toxin were degraded most rapidly while sterigmatocystin exhibited the highest resistance to degradation. As compared to pure compounds, the degradation rates of mycotoxins embedded in extracts of fungal cultures on rice were reduced to a varying extent. Our results show that CAPP efficiently degrades pure mycotoxins, the degradation rates vary with mycotoxin structure, and the presence of matrix slows down yet does not prevent the degradation. CAPP appears promising for the decontamination of food commodities with mycotoxins confined to or enriched on surfaces such as cereal grains.

Comparison of Aspergillus species-complexes detected in different environmental settings

OpenAIRE

Sabino, Raquel; Viegas, Carla; Veríssimo, Carla; Clemons, K. V.; Stevens, D. A.

2014-01-01

Purpose: Samples from different environmental sources were screened for the presence of Aspergillus, and the distribution of the different species-complexes was determined in order to understand differences among that distribution in the several environmental sources and which of these species complexes are present in specific environmental settings. Methods: Four distinct environments (beaches, poultries, swineries and hospital) were studied and analyzed for which Aspergillus complexes were ...

Effect of gamma radiation on the inactivation of aflatoxin B1 in food and feed crops

Energy Technology Data Exchange (ETDEWEB)

Ghanem, I; Orfi, M; Shamma, M [Atomic Energy Commission, Damascus (Syrian Arab Republic), Dept. of Molecular Biology and Biotechnology

2008-09-15

Samples of food crops (peanut, peeled pistachio, unpeeled pistachio, rice, and corn) and feed (barley, bran, corn) were autoclave-sterilized, and inoculated with 106 of spore suspension of an isolate of Aspergillus flavus fungus known to produce aflatoxin B1. Food and feed samples were irradiated with gamma radiation at the doses 4, 6, and 10 kGy. Results indicated that degradation of Aflatoxin B1 was positively correlated with the increase in the applied dose of gamma ray for each tested sample. At a dose of 4 KGy percentages of aflatoxin B1 degradation were 8.4, 9.7, 16.6 and 23.5, and 43.97% for peanuts, peeled pistachios, unpeeled pistachios, corn and rice, respectively. Whereas, at a dose of 10 KGy percentages of aflatoxin degradation reached highest values at 58.6, 68.8, 84.6, 81.1 and 87.8% for peanuts, peeled pistachios, unpeeled pistachios, corn and rice, respectively. In feed samples percentages of aflatoxin degradation were 45, 66, and 90% in barley, 47, 75 and 86% in bran and 31, 72 and 84% in corn for the doses of 4, 6 and 10 KGy, respectively, Aflatoxin degradation in food samples correlated negatively with oil content in irradiated samples. Thus, in peanuts, which contained the highest oil content, percentage of aflatoxin degradation at 10 KGy was not more than 56.6% whereas, the corresponding value in corn, which contained the highest oil content, reached as high as 80%. The above results indicate the possibility of using gamma radiation as a means of degradation of aflatoxin B1 in food and feed crops to levels lower than the maximum allowed levels.(author)

Effect of gamma radiation on the inactivation of aflatoxin B1 in food and feed crops

International Nuclear Information System (INIS)

Ghanem, I.; Orfi, M.; Shamma, M.

2008-01-01

Samples of food crops (peanut, peeled pistachio, unpeeled pistachio, rice, and corn) and feed (barley, bran, corn) were autoclave-sterilized, and inoculated with 106 of spore suspension of an isolate of Aspergillus flavus fungus known to produce aflatoxin B1. Food and feed samples were irradiated with gamma radiation at the doses 4, 6, and 10 kGy. Results indicated that degradation of Aflatoxin B1 was positively correlated with the increase in the applied dose of gamma ray for each tested sample. At a dose of 4 KGy percentages of aflatoxin B1 degradation were 8.4, 9.7, 16.6 and 23.5, and 43.97% for peanuts, peeled pistachios, unpeeled pistachios, corn and rice, respectively. Whereas, at a dose of 10 KGy percentages of aflatoxin degradation reached highest values at 58.6, 68.8, 84.6, 81.1 and 87.8% for peanuts, peeled pistachios, unpeeled pistachios, corn and rice, respectively. In feed samples percentages of aflatoxin degradation were 45, 66, and 90% in barley, 47, 75 and 86% in bran and 31, 72 and 84% in corn for the doses of 4, 6 and 10 KGy, respectively, Aflatoxin degradation in food samples correlated negatively with oil content in irradiated samples. Thus, in peanuts, which contained the highest oil content, percentage of aflatoxin degradation at 10 KGy was not more than 56.6% whereas, the corresponding value in corn, which contained the highest oil content, reached as high as 80%. The above results indicate the possibility of using gamma radiation as a means of degradation of aflatoxin B1 in food and feed crops to levels lower than the maximum allowed levels.(author)

Gene duplication, modularity and adaptation in the evolution of the aflatoxin gene cluster

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Jakobek Judy L

2007-07-01

Full Text Available Abstract Background The biosynthesis of aflatoxin (AF involves over 20 enzymatic reactions in a complex polyketide pathway that converts acetate and malonate to the intermediates sterigmatocystin (ST and O-methylsterigmatocystin (OMST, the respective penultimate and ultimate precursors of AF. Although these precursors are chemically and structurally very similar, their accumulation differs at the species level for Aspergilli. Notable examples are A. nidulans that synthesizes only ST, A. flavus that makes predominantly AF, and A. parasiticus that generally produces either AF or OMST. Whether these differences are important in the evolutionary/ecological processes of species adaptation and diversification is unknown. Equally unknown are the specific genomic mechanisms responsible for ordering and clustering of genes in the AF pathway of Aspergillus. Results To elucidate the mechanisms that have driven formation of these clusters, we performed systematic searches of aflatoxin cluster homologs across five Aspergillus genomes. We found a high level of gene duplication and identified seven modules consisting of highly correlated gene pairs (aflA/aflB, aflR/aflS, aflX/aflY, aflF/aflE, aflT/aflQ, aflC/aflW, and aflG/aflL. With the exception of A. nomius, contrasts of mean Ka/Ks values across all cluster genes showed significant differences in selective pressure between section Flavi and non-section Flavi species. A. nomius mean Ka/Ks values were more similar to partial clusters in A. fumigatus and A. terreus. Overall, mean Ka/Ks values were significantly higher for section Flavi than for non-section Flavi species. Conclusion Our results implicate several genomic mechanisms in the evolution of ST, OMST and AF cluster genes. Gene modules may arise from duplications of a single gene, whereby the function of the pre-duplication gene is retained in the copy (aflF/aflE or the copies may partition the ancestral function (aflA/aflB. In some gene modules, the

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

Thermostable crude endoglucanase produced by Aspergillus ...

African Journals Online (AJOL)

Cellulases are used in many industries worldwide and there is an ever increasing need to isolate, produce or develop thermostable cellulases. Manipulation of fermentation techniques in order to obtain desirable product(s) can be one line of action. In this study Aspergillus fumigatus was grown on chopped wheat straw in a ...

Identification of New Aflatoxin B1-Degrading Bacteria from Iran

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Fahimeh Sangi

2018-04-01

Full Text Available Background: Aflatoxin B1 (AFB1 is a mutagenic and carcinogenic compound mainly produced by the Aspergillus parasiticus, A. flavus, A. nomius, A. tamari, and A. pseudotamarii. AFB1 biodegradation is the most important strategy for reducing AFB1 in plant tissues. Bacteria can deactivate and biodegrade AFB1 for effective detoxification of contaminated products. The present study investigated the efficiency of AFB1 degradation by soil bacteria from the Southern Khorasan Province in Eastern Iran by thin-layer and high-performance liquid chromatography during 2014–2015. Methods: DNA was extracted from AFB1-degrading isolates by the cetyltrimethylammonium bromide method and the 16S rRNA gene was amplified with the 27f and 1492r general bacterial primers and the sequences were used to identify the isolates based on their similarity to Gene Bank sequences of known bacterial species. Results: We isolated five strains from four species of AFB1-degrading bacteria from Birjand plain, including Bacillus pumilus, two isolates of Ochrobactrum pseudogrigonens, Pseudomonas aeruginosa, and Enterobacter cloace, which had AFB1-degrading activities of 88%, 78%, 61%, 58%, and 51%, respectively. Conclusion: We provide the first demonstration of AFB1 degradation by B. pumilus in from Iran and the first report identifying O. pseudogrigonens and E. cloace species as having AFB1-degrading activity.

Distribution of sterigmatocystin in filamentous fungi

DEFF Research Database (Denmark)

Rank, Christian; Nielsen, Kristian Fog; Larsen, Thomas Ostenfeld

2011-01-01

. Six new ST producing fungi were discovered: Aspergillus asperescens, Aspergillus aureolatus, Aspergillus eburneocremeus, Aspergillus protuberus, Aspergillus tardus, and Penicillium inflatum and one new aflatoxin producer: Aspergillus togoensis (=Stilbothamnium togoense). ST was confirmed in 23...

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

Science.gov (United States)

Lee, Kim-Chung; Tam, Emily W T; Lo, Ka-Ching; Tsang, Alan K L; Lau, Candy C Y; To, Kelvin K W; Chan, Jasper F W; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

2015-06-17

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-(sulfooxy)benzoic acid and (sulfooxy)benzoic acid, may possess anti-inflammatory properties, as 2-(sulfooxy)benzoic acid possesses a structure similar to those of aspirin [2-(acetoxy)benzoic 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-(sulfooxy)benzoic acid and (sulfooxy)benzoic acid are virulent factors of the pathogenic Aspergillus species.

Isolation and identification of fungi from a meju contaminated with aflatoxins.

Science.gov (United States)

Jung, Yu Jung; Chung, Soo Hyun; Lee, Hyo Ku; Chun, Hyang Sook; Hong, Seung Beom

2012-12-01

A home-made meju sample contaminated naturally with aflatoxins was used for isolation of fungal strains. Overall, 230 fungal isolates were obtained on dichloran rosebengal chloramphenicol (DRBC) and dichloran 18% glycerol (DG18) agar plates. Morphological characteristics and molecular analysis of a partial beta-tubulin gene and the internal transcribed spacer (ITS) of rDNA were used for the identification of the isolates. The fungal isolates were divided into 7 genera: Aspergillus, Eurotium, Penicillium, Eupenicillium, Mucor, Lichtheimia, and Curvularia. Three strains from 56 isolates of the A. oryzae/flavus group were found to be aflatoxigenic A. flavus, by the presence of the aflatoxin biosynthesis genes and confirmatory aflatoxin production by high-performance liquid chromatography (HPLC). The predominant isolate from DRBC plates was A. oryzae (42 strains, 36.2%), whereas that from DG18 was A. candidus (61 strains, 53.5%). Out of the 230 isolates, the most common species was A. candidus (34.3%) followed by A. oryzae (22.2%), Mucor circinelloides (13.0%), P. polonicum (10.0%), A. tubingensis (4.8%), and L. ramosa (3.5%). A. flavus and E. chevalieri presented occurrence levels of 2.2%, respectively. The remaining isolates of A. unguis, P. oxalicum, Eupenicillium cinnamopurpureum, A. acidus, E. rubrum, P. chrysogenum, M. racemosus, and C. inaequalis had lower occurrence levels of < 2.0%.

Influence of yield on in vitro accumulation of aflatoxins in pecan (Carya illinoensis (Wang.) K. Koch) nutmeats.

Science.gov (United States)

McMeans, J L

1983-02-01

Pecans were harvested from trees (Carya illinoensis (Wang.) K. Koch) in November of 1977 through 1979. Kernel meals from high-, medium-, and low-yielding trees were inoculated with a spore suspension of Aspergillus parasiticus and incubated for 7 days at 25 degrees C. Significant differences in aflatoxin accumulation were found among the three substrates, with a direct correlation between high aflatoxin concentration and tree yield.

Influence of yield on in vitro accumulation of aflatoxins in pecan (Carya illinoensis (Wang.) K. Koch) nutmeats.

OpenAIRE

McMeans, J L

1983-01-01

Pecans were harvested from trees (Carya illinoensis (Wang.) K. Koch) in November of 1977 through 1979. Kernel meals from high-, medium-, and low-yielding trees were inoculated with a spore suspension of Aspergillus parasiticus and incubated for 7 days at 25 degrees C. Significant differences in aflatoxin accumulation were found among the three substrates, with a direct correlation between high aflatoxin concentration and tree yield.

Effect of gamma radiation on the inactivation of aflatoxin B1 in food and feed crops

Energy Technology Data Exchange (ETDEWEB)

Ghanem, I; Orfi, M; Shamma, M [Atomic Energy Commission, Damascus (Syrian Arab Republic), Dept. of Molecular Biology and Biotechnology

2007-08-15

Samples of food crops (peanut, peeled pistachio, unpeeled pistachio, rice, and corn) and feed (barley, bran, corn) were sterilized then inoculated with 10{sup 6} of spore suspension of an isolate of Aspergillus flavus fungus known to produce aflatoxin B1 . Food and feed samples were irradiated with gamma radiation at the doses 4, 6, and 10 kGy. Results indicated that degradation of Aflatoxin B1 was positively correlated with the increase in the applied dose of gamma ray for each tested sample. For example, at a dose of 4 KGy. Percentages of aflatoxin B1 degradation were 8.4, 9.7, 16.6 and 23.5, and 43.97% for peanuts, peeled pistachios, unpeeled pistachios, corn and rice, consecutively . Whereas, at a dose of 10 KGy percentages of aflatoxin degradation reached highest values at 58.6, 68.8, 84.6, 81.1 and 87.8% for peanuts, peeled pistachios, unpeeled pistachios, corn and rice, consecutively In feed samples percentages of aflatoxin degradation were 45, 66, and 90% in barley, 47, 75, and 86% in bran, and 31, 72, and 84% in corn for the doses of 4, 6, and 10 KGy, consecutively. Aflatoxin degradation in food samples correlated negatively with oil content in irradiated samples. Thus, in peanuts, which contained the highest oil content, percentage of aflatoxin degradation at 10 KGy was not more than 56.6%, whereas, the corresponding value in corn, which contained the highest oil content, reached as high as 80%. The above results indicate the possibility of using gamma irradiation as a means of degradation of aflatoxin B1 in food and feed crops to lower than the maximum allowed levels using a maximum dose of radiation of 10 KGy which represents the permitted dose of radiation for such type of crops.(author)

Effect of gamma radiation on the inactivation of aflatoxin B1 in food and feed crops

International Nuclear Information System (INIS)

Ghanem, I.; Orfi, M.; Shamma, M.

2007-08-01

Samples of food crops (peanut, peeled pistachio, unpeeled pistachio, rice, and corn) and feed (barley, bran, corn) were sterilized then inoculated with 10 6 of spore suspension of an isolate of Aspergillus flavus fungus known to produce aflatoxin B1 . Food and feed samples were irradiated with gamma radiation at the doses 4, 6, and 10 kGy. Results indicated that degradation of Aflatoxin B1 was positively correlated with the increase in the applied dose of gamma ray for each tested sample. For example, at a dose of 4 KGy. Percentages of aflatoxin B1 degradation were 8.4, 9.7, 16.6 and 23.5, and 43.97% for peanuts, peeled pistachios, unpeeled pistachios, corn and rice, consecutively . Whereas, at a dose of 10 KGy percentages of aflatoxin degradation reached highest values at 58.6, 68.8, 84.6, 81.1 and 87.8% for peanuts, peeled pistachios, unpeeled pistachios, corn and rice, consecutively In feed samples percentages of aflatoxin degradation were 45, 66, and 90% in barley, 47, 75, and 86% in bran, and 31, 72, and 84% in corn for the doses of 4, 6, and 10 KGy, consecutively. Aflatoxin degradation in food samples correlated negatively with oil content in irradiated samples. Thus, in peanuts, which contained the highest oil content, percentage of aflatoxin degradation at 10 KGy was not more than 56.6%, whereas, the corresponding value in corn, which contained the highest oil content, reached as high as 80%. The above results indicate the possibility of using gamma irradiation as a means of degradation of aflatoxin B1 in food and feed crops to lower than the maximum allowed levels using a maximum dose of radiation of 10 KGy which represents the permitted dose of radiation for such type of crops.(author)

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.

Hepatitis infections, aflatoxin and hepatocellular carcinoma

Directory of Open Access Journals (Sweden)

Pierre Hainaut

2007-02-01

Full Text Available

The incidence rates of hepatocellular carcinoma (HCC show large geographic variations, globally reflecting the prevalence of two main aetiologic factors, hepatitis B (HBV and/or C (HCV virus infection and exposure to high levels of aflatoxin in the diet (Chen et al. 1997. The highest incidence rates are observed in regions where most of the population is exposed to both factors, such as in parts of eastern Asia and in sub-Saharan Africa (Parkin et al. 2001. These high incidences are consistent with the fact that HBV chronicity and exposure to aflatoxin have a multiplicative effect of risk for HCC. Depending on aetiology and geographic area, mutations in TP53 show striking differences in prevalence and pattern. In Europe and the US, where alcohol is a major risk factor in addition to viral infections, mutations occur in about 25% of HCC and show as much diversity in their type and codon position as in most other epithelial cancers. However, in high incidence areas such as Mozambique, Senegal, The Gambia (Africa and Qidong county (China, TP53 is mutated in over 50% of the cases and the vast majority of these mutations are a single missense, hotspot mutation at codon 249, AGG to AGT, resulting in the substitution of arginine into serine (249ser. This mutation is uncommon in regions where aflatoxin is not present at significant levels in the diet. In areas of intermediate exposure to aflatoxin, as for example in Thailand, the prevalence of the 249ser mutation is intermediate between high- and low-incidence areas. Thus, there is a dose-dependent relationship between exposure to aflatoxin, incidence of HCC and prevalence of 249ser mutation. Aflatoxins are toxic and carcinogenic metabolites produced by several varieties of molds, mainly Aspergillus flavus and Aspergillus parasiticum. These molds contaminate a wide range of traditional agricultural products in countries

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.

Aspergillus oerlinghausenensis, a new mould species closely related to A. fumigatus

NARCIS (Netherlands)

Houbraken, Jos; Weig, Michael; Groß, Uwe; Meijer, Martin; Bader, Oliver

2015-01-01

Two isolates belonging to Aspergillus section Fumigati were recovered from German soil on itraconazole containing agar media. Phylogenetic analysis and phenotypic characterization of both isolates show that they represent a novel species named Aspergillus oerlinghausenensis (holotype CBS

Diversity of black Aspergilli isolated from raisins in Argentina: Polyphasic approach to species identification and development of SCAR markers for Aspergillus ibericus.

Science.gov (United States)

Giaj Merlera, G; Muñoz, S; Coelho, I; Cavaglieri, L R; Torres, A M; Reynoso, M M

2015-10-01

Aspergillus section Nigri is a heterogeneous fungal group including some ochratoxin A producer species that usually contaminate raisins. The section contains the Series Carbonaria which includes the toxigenic species Aspergillus carbonarius and nontoxigenic Aspergillus ibericus that are phenotypically undistinguishable. The aim of this study was to examine the diversity of black aspergilli isolated from raisins and to develop a specific genetic marker to distinguish A. ibericus from A. carbonarius. The species most frequently found in raisins in this study were Aspergillus tubingensis (35.4%) and A. carbonarius (32.3%), followed by Aspergillus luchuensis (10.7%), Aspergillus japonicus (7.7%), Aspergillus niger (6.2%), Aspergillus welwitschiae (4.6%) and A. ibericus (3.1%). Based on inter-simple sequence repeat (ISSR) fingerprinting profiles of major Aspergillus section Nigri members, a sequence-characterized amplified region (SCAR) marker was identified. Primers were designed based on the conserved regions of the SCAR marker and were utilized in a PCR for simultaneous identification of A. carbonarius and A. ibericus. The detection level of the SCAR-PCR was found to be 0.01 ng of purified DNA. The present SCAR-PCR is rapid and less cumbersome than conventional identification techniques and could be a supplementary strategy and a reliable tool for high-throughput sample analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

Aspergillus atacamensis and A. salisburgensis: two new halophilic species from hypersaline/arid habitats with a phialosimplex-like morphology.

Science.gov (United States)

Martinelli, Livia; Zalar, Polona; Gunde-Cimerman, Nina; Azua-Bustos, Armando; Sterflinger, Katja; Piñar, Guadalupe

2017-07-01

Halophilic fungal strains isolated from historical wooden staircase in a salt mine in Austria, and from wall biofilm and soil of a cave in the Coastal Range of the hyperarid Atacama Desert in Chile were characterised and described newly as Aspergillus salisburgensis and Aspergillus atacamensis. Morphological characters including solitary phialides producing solitary conidia and conidia in chains and/or heads suggested affinity to Aspergillus subgenus Polypaecilum. Strains required salt for growth, grew optimally on media with 10-25% NaCl and at 15-28 °C. These values are similar to those observed for Aspergillus salinarus comb. nov. (Phialosimplex salinarum), while the ex-type strains of Aspergillus sclerotialis, Aspergillus chlamydosporus and Aspergillus caninus (all belonging to Aspergillus subgen. Polypaecilum) grew optimally at 0-5% NaCl and showed fastest growth at 28-37 °C. Phylogenetic analyses on the basis of rDNA sequences, RAPD-PCR fingerprint patterns, and cellobiohydrolase gene (cbh-I) polymorphism clustered the strains into three groups and supported their taxonomic recognition as A. salinarus, A. atacamensis and A. salisburgensis. On the basis of phylogenetic inferences, also Sagenomella keratitidis is newly combined as Aspergillus keratitidis and inferred as a species of Aspergillus subgenus Polypaecilum.

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

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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.

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...

Efficacy of chemically characterized Piper betle L. essential oil against fungal and aflatoxin contamination of some edible commodities and its antioxidant activity.

Science.gov (United States)

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

2010-08-15

The study investigates fungal contamination in some dry fruits, spices and areca nut and evaluation of the essential oil (EO) of Piper betle var. magahi for its antifungal, antiaflatoxigenic and antioxidant properties. A total of 1651 fungal isolates belonging to 14 species were isolated from the samples and Aspergillus was recorded as the dominant genus with 6 species. Eleven aflatoxin B(1) (AFB(1)) producing strains of A. flavus were recorded from the samples. Eugenol (63.39%) and acetyleugenol (14.05%) were the major components of 32 constituents identified from the Piper betle EO through GC and GC-MS analysis. The minimum inhibitory concentration (MIC) of P. betle EO was found 0.7 microl/ml against A.flavus. The EO reduced AFB(1) production in a dose dependent manner and completely inhibited at 0.6 microl/ml. This is the first report on efficacy of P. betle EO as aflatoxin suppressor. EO also exhibited strong antioxidant potential as its IC(50) value (3.6 microg/ml) was close to that of ascorbic acid (3.2 microg/ml) and lower than that of the synthetic antioxidants such as butylated hydroxytouene (BHT) (7.4 microg/ml) and butylated hydroxyanisole (BHA) (4.5 microg/ml). P. betle EO thus exhibited special merits possessing antifungal, aflatoxin suppressive and antioxidant characters which are desirable for an ideal preservative. Hence, its application as a plant based food additive in protection and enhancement of shelf life of edible commodities during storage and processing is strongly recommended in view of the toxicological implications by synthetic preservatives. Copyright 2010 Elsevier B.V. All rights reserved.

Mould and mycotoxin exposure assessment of melon and bush mango seeds, two common soup thickeners consumed in Nigeria.

Science.gov (United States)

Ezekiel, Chibundu N; Sulyok, Michael; Somorin, Yinka; Odutayo, Foluke I; Nwabekee, Stella U; Balogun, Afeez T; Krska, Rudolf

2016-11-21

An examination of the mould and fungal metabolite pattern in melon and bush mango seeds locally produced in Nigeria was undertaken in order to understand the mycotoxicological risk posed to consumers of both of these important and commonly consumed soup thickeners. The variation in mycotoxin levels in graded categories of both foodstuffs were also determined. Aspergillus, Fusarium, Penicillium, Mucorales and Trichoderma were the recovered fungi from the foodstuffs with Aspergillus species dominating (melon=97.8%; bush mango=89.9%). Among the Aspergillus species identified Aspergillus section Flavi dominated (melon: 72%; bush mango: 57%) and A. flavus, A. parasiticus, A. parvisclerotigenus and A. tamarii were the recovered species. About 56% and 73% of the A. flavus isolates from melon and bush mango seed samples, respectively were aflatoxigenic. Thirty-four and 59 metabolites including notable mycotoxins were found in the melon and bush mango seeds respectively. Mean aflatoxin levels (μg/kg) in melon (aflatoxin B 1 (AFB 1 )=37.5 and total aflatoxins=142) and bush mango seeds (AFB 1 =68.1 and total aflatoxins=61.7) were higher than other mycotoxins, suggesting potential higher exposure for consumer populations. Significantly (p<0.05) higher levels of mycotoxins were found in hand-peeled melon and discoloured bush mango seeds than in machine-peeled melon and non-discoloured seeds except for HT-2 and T-2 toxins which occurred conversely. All melon and bush mango seeds exceeded the 2μg/kg AFB 1 limit whereas all melon and 55% of bush mango seeds exceeded the 4μg/kg total aflatoxin EU limit adopted in Nigeria. This is the first report of (1) mycotoxin co-occurrence in bush mango seeds, (2) cyclopiazonic acid, HT-2 toxin, moniliformin, mycophenolic acid, T-2 toxin and tenuazonic acid occurrence, and (3) mycotoxin exposure assessment of both foodstuffs. Copyright © 2016 Elsevier B.V. All rights reserved.

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

Hygienic assessment of ionizing radiation effect on wheat contaminated with Aspergillus flavus

International Nuclear Information System (INIS)

Uralova, M.; Patzeltova, N.; Havlik, F.

1985-01-01

Wheat contaminated with Aspergillus flavus fungus was irradited with doses of gamma radiation of up to 6000 Gy. It was found that while fungus growth is limited with increased doses of radiation, aflatoxin production increases. Aflatoxin production heavily depends on the moisture of the wheat. Toxicological and genetic tests of dominant lethal mutations were negative. Contaminated wheat irradiated with a dose of 6000 Gy may be used as feed for livestock. (M.D.)

Advances in molecular and genomic research to safeguard food and feed supply from aflatoxin contamination

Science.gov (United States)

Worldwide recognition that aflatoxin contamination of agricultural commodities by the fungus Aspergillus flavus is a global problem which has significantly benefitted from global collaboration for understanding the contaminating fungus as well as for developing and implementing solutions against the...

Combined molecular and biochemical approach identifies Aspergillus japonicus and Aspergillus aculeatus as two species

DEFF Research Database (Denmark)

Parenicova, L.; Skouboe, P.; Frisvad, Jens Christian

2001-01-01

of the internal transcribed spacers (ITS1 and ITS2) and the 5.8S rRNA gene could not be used to distinguish between A. japonicus and A. aculeatus but did show that these two taxa are more closely related to each other than to other species of black aspergilli. Aspergillus niger pyruvate kinase (pkiA) and pectin...... variation when they were probed with the pelA gene. The secondary-metabolite profiles supported division of the isolates into the two species and differed from those of other black aspergilli. The strains classified as A. japonicus produced indole alkaloids and a polar metabolite, while the A. aculeatus...... lyase A (pelA) and Agaricus bisporus 28S rRNA genes, which were used as probes in the RFLP analysis, revealed clear polymorphism between these two taxa. The A. niger pkiA and pelA probes placed six strains in an A. japonicus group and 12 isolates in an A. aculeatus group, which exhibited intraspecific...

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

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OKKY SETYAWATI DHARMAPUTRA

2005-01-01

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

Aflatoxin contamination of groundnut and maize in Zambia: observed and potential concentrations.

Science.gov (United States)

Kachapulula, P W; Akello, J; Bandyopadhyay, R; Cotty, P J

2017-06-01

The aims of the study were to quantify aflatoxins, the potent carcinogens associated with stunting and immune suppression, in maize and groundnut across Zambia's three agroecologies and to determine the vulnerability to aflatoxin increases after purchase. Aflatoxin concentrations were determined for 334 maize and groundnut samples from 27 districts using lateral-flow immunochromatography. Seventeen per cent of crops from markets contained aflatoxin concentrations above allowable levels in Zambia (10 μg kg -1 ). Proportions of crops unsafe for human consumption differed significantly (P agroecologies with more contamination (38%) in the warmest (Agroecology I) and the least (8%) in cool, wet Agroecology III. Aflatoxin in groundnut (39 μg kg -1 ) and maize (16 μg kg -1 ) differed (P = 0·032). Poor storage (31°C, 100% RH, 1 week) increased aflatoxin in safe crops by over 1000-fold in both maize and groundnut. The L morphotype of Aspergillus flavus was negatively correlated with postharvest increases in groundnut. Aflatoxins are common in Zambia's food staples with proportions of unsafe crops dependent on agroecology. Fungal community structure influences contamination suggesting Zambia would benefit from biocontrol with atoxigenic A. flavus. Aflatoxin contamination across the three agroecologies of Zambia is detailed and the case for aflatoxin management with atoxigenic biocontrol agents provided. The first method for evaluating the potential for aflatoxin increase after purchase is presented. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of The Society for Applied Microbiology.

SVM-based feature extraction and classification of aflatoxin contaminated corn using fluorescence hyperspectral data

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Support Vector Machine (SVM) was used in the Genetic Algorithms (GA) process to select and classify a subset of hyperspectral image bands. The method was applied to fluorescence hyperspectral data for the detection of aflatoxin contamination in Aspergillus flavus infected single corn kernels. In the...

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

Science.gov (United States)

Chang, Perng-Kuang; Scharfenstein, Leslie L; Solorzano, Cesar D; Abbas, Hamed K; Hua, Sui-Sheng T; Jones, Walker A; Zablotowicz, Robert M

2015-05-04

Aspergillus oryzae and Aspergillus flavus are closely related fungal species. The A. flavus morphotype that produces numerous small sclerotia (S strain) and aflatoxin has a unique 1.5 kb deletion in the norB-cypA region of the aflatoxin gene cluster (i.e. the S genotype). Phylogenetic studies have indicated that an isolate of the nonaflatoxigenic A. flavus with the S genotype is the ancestor of A. oryzae. Genome sequence comparison between A. flavus NRRL3357, which produces large sclerotia (L strain), and S-strain A. flavus 70S identified a region (samA-rosA) that was highly variable in the two morphotypes. A third type of samA-rosA region was found in A. oryzae RIB40. The three samA-rosA types were later revealed to be commonly present in A. flavus L-strain populations. Of the 182 L-strain A. flavus field isolates examined, 46%, 15% and 39% had the samA-rosA type of NRRL3357, 70S and RIB40, respectively. The three types also were found in 18 S-strain A. flavus isolates with different proportions. For A. oryzae, however, the majority (80%) of the 16 strains examined had the RIB40 type and none had the NRRL3357 type. The results suggested that A. oryzae strains in the current culture collections were mostly derived from the samA-rosA/RIB40 lineage of the nonaflatoxigenic A. flavus with the S genotype. Published by Elsevier B.V.

Extrolites of Aspergillus fumigatus and Other Pathogenic Species in Aspergillus Section Fumigati

DEFF Research Database (Denmark)

Frisvad, Jens Christian; Larsen, Thomas Ostenfeld

2016-01-01

Aspergillus fumigatus is an important opportunistic human pathogen known for its production of a large array of extrolites. Up to 63 species have been described in Aspergillus section Fumigati, some of which have also been reliably reported to be pathogenic, including A. felis, A. fischeri, A....... fumigatiaffinis, A. fumisynnematus, A. hiratsukae, A. laciniosus, A. lentulus, A. noyofumigatus, A. parafelis, A. pseudofelis, A. pseudoyiridinutans, A. spinosus, A. therrnornutatus, and A. udagawae. These species share the production of hydrophobins, melanins, and siderophores and ability to grow well at 37 °C...

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.

Characterization of the Far Transcription Factor Family in Aspergillus flavus

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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.

Aflatoxin contamination of locallyprocessed cereal-based ...

African Journals Online (AJOL)

Feeding children with cereal-based foods has potential to expose them to aflatoxins (AFs).This study was conducted to determine the occurrence and levels of aflatoxins (AFB1, AFB2, AFG1 and AFG2) in 64 commercial locally produced cereal-based complementary foods obtained from producers and popular markets in ...

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

DEFF Research Database (Denmark)

Lamboni, Yendouban; Frisvad, Jens Christian; Hell, Kerstin

2016-01-01

-MS/MS). The average water content and the cashew nuts count were respectively 8.6% and 172 nuts/kg in NG and 8.7% and 174 nuts/kg in SS. Significant differences between villages in both zones were found for both water content and nuts count. In disinfected samples, strains of Aspergillus section Nigri were...... contamination, a total of 100 kernels/sample (with disinfection) and 40 kernels/sample (without disinfection) were plated. Seventy samples from fourteen villages were used. Aflatoxins occurrence was analysed on 84 samples by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC...

Variation in fungal microbiome (mycobiome and aflatoxin in stored in-shell peanuts at four different areas of China

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Ning eDing

2015-10-01

Full Text Available The contamination of peanuts with Aspergillus sp. and subsequently aflatoxins is considered to be one of the most serious safety problems in the world. Mycobiome in peanuts is critical for aflatoxin production and food safety. To evaluate the biodiversity and ecological characteristics of whole communities in stored peanuts, the barcoded Illumina paired-end sequencing (BIPES of the internal transcribed spacer 2 (ITS2 region of rDNA was used to characterize the peanut mycobiome monthly over a period of one year at four main peanut grown areas i.e Liaoning (LN, North East, Shandong (SD, East, Hubei (HB, Central and Guangdong (GD, South provinces. The fungal diversity of peanuts stored in SD was the highest with 98 OTUs and 43 genera, followed by LN, HB and GD. In peanuts stored in SD, Rhizopus, Emericella and Clonostachys were predominant. In peanuts from LN, Penicillium, Eurotium and Clonostachys were abundant. In peanuts from HB, Penicillium, Eurotium and Aspergillus were higher. In GD peanuts, Eurotium, Aspergillus and Emericella were mainly seen. The abundances of Aspergillus in LN, SD, HB and GD were 0.53%, 6.29%, 10.86% and 25.75%, respectively. From the North of China to the South, that increased over the latitude, suggesting that the higher temperature and relative humidity might increase the risk of peanuts contaminated with Aspergillus and aflatoxins. During the storage, Aspergillus levels were higher at 7-12 months than in 0-6 months, suggesting that the risk increases over storage time. At 7-10 months, AFB1 was higher in four areas, while declined further. The reduction of AFB1 might be attributed to the inhibition and degradation of AFB1 by A. niger or to the combination with the compounds of peanuts. This is the first study that identified the mycobiome and its variation in stored peanuts using ITS2 sequencing technology, and provides the basis for a detailed characterization of whole mycobiome in peanuts.

Prevalence of potential toxigenic Aspergillus species isolated from ...

African Journals Online (AJOL)

ADEYEYE

2015-12-17

Dec 17, 2015 ... Aspergillus species) in feeds used in poultry farms in Sokoto metropolis. During a ... potential exists for the production of mycotoxins that may be of both veterinary public health significance and ..... The effect of antioxidant and.

Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs

Science.gov (United States)

Greco, Mariana; Kemppainen, Minna; Pose, Graciela; Pardo, Alejandro

2015-01-01

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. PMID:26364643

Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs

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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.

Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs.

Science.gov (United States)

Greco, Mariana; Kemppainen, Minna; Pose, Graciela; Pardo, Alejandro

2015-09-02

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.

Aflatoxin B1 inhibition in Aspergillus flavus by Aspergillus niger through down-regulating expression of major biosynthetic genes and AFB1 degradation by atoxigenic A. flavus.

Science.gov (United States)

Xing, Fuguo; Wang, Limin; Liu, Xiao; Selvaraj, Jonathan Nimal; Wang, Yan; Zhao, Yueju; Liu, Yang

2017-09-01

Twenty Aspergillus niger strains were isolated from peanuts and 14 strains were able to completely inhibit AFB 1 production with co-cultivation. By using a Spin-X centrifuge system, it was confirmed that there are some soluble signal molecules or antibiotics involved in the inhibition by A. niger, although they are absent during the initial 24h of A. flavus growth when it is sensitive to inhibition. In A. flavus, 19 of 20 aflatoxin biosynthetic genes were down-regulated by A. niger. Importantly, the expression of aflS was significantly down-regulated, resulting in a reduction of AflS/AflR ratio. The results suggest that A. niger could directly inhibit AFB 1 biosynthesis through reducing the abundance of aflS to aflR mRNAs. Interestingly, atoxigenic A. flavus JZ2 and GZ15 effectively degrade AFB 1 . Two new metabolites were identified and the key toxic lactone and furofuran rings both were destroyed and hydrogenated, meaning that lactonase and reductase might be involved in the degradation process. Copyright © 2017 Elsevier B.V. All rights reserved.

Measurement of Aflatoxin M1 in Raw and Pasteurized Cow Milk Samples by HPLC

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afshin Nazari

2007-10-01

Full Text Available Nazari A1, Noroozi H2, Movahedi M3, Khaksarian M1 1. Instructor, Department of Physiology, Faculty of Medicine, Lorestan University of Medical Sciences 2. Assistant Professor, Department of Mycology, Faculty of Medicine, Iran University of Medical Sciences 3. Assistant Professor, Department of Genetic Epidemiology, Faculty of Medicine, Lorestan University of Medical Sciences Abstract Background: Aflatoxin M1 is a hydroxylated form of aflatoxin B1 which is produced by Aspergillus flavus. This toxin is produced when cows or other ruminants eat foods contaminated with these mycotoxins and then excrete them in the milk. The toxin is a potent liver and kidney carcinogenetic agent. Materials and methods: Forty two raw cows milk samples from local sources of milk collection and forty samples of commercial pasteurized market milk from Khorramabad, Lorestan, Iran were collected in summer and winter season of 2005. Twenty-one cow milk samples and 20 pasteurized milk samples in each season were analyzed for the presence of aflatoxin M1 (AFM1 by HPLC immunoaffinity columns. Results: Four of 21 raw milk samples in summer showed AFM1 levels between 0.017-0.046 ng/ml and all samples (100% in winter showed the presence of AFM1 levels between 0.003-0.041ng/ ml. AFM1 was detected in 55% of market pasteurized cow milk samples ranging from 0.017 to 0.533 ng/ml in summer and 100% ranging from 0.005-0.0054 ng/ml in winter.,Only one of all milk samples of pasteurized milk in summer had toxin level (0.533 ng/ml more than the maximum permissive limit (0.5 ng/ml. No significant difference was observed among mean contamination level of raw and pasteurized cow milk in two seasons. Key words: Aflatoxin M1, raw milk, pasteurized milk, Khoramabad, HPLC

Occurrence and biodiversity of Aspergillus section Nigri on 'Tannat' grapes in Uruguay.

Science.gov (United States)

Garmendia, Gabriela; Vero, Silvana

2016-01-04

Ochratoxin A (OTA) is a nephrotoxic mycotoxin which has been found worldwide as a contaminant in wines. It is produced on grapes mainly by molds from Aspergillus section Nigri. This study has demonstrated for the first time the occurrence of black aspergilli on Tannat grapes from Uruguay, in a two year survey. Aspergillus uvarum (uniseriate) and Aspergillus welwitschiae (from Aspergillusniger aggregate) were the prevalent species whereas Aspergillus carbonarius which is considered the main OTA producing species was not detected. OTA production in culture medium was evaluated for native isolates from A. niger aggregate and compared to levels produced by a type strain of A. carbonarius. This work also includes the development of quick and easy molecular methods to identify black aspergilli to species level, avoiding sequencing. Copyright © 2015 Elsevier B.V. All rights reserved.

Proteomic analysis of the maize rachis: potential roles of constitutive and induced proteins in resistance to Aspergillus flavus infection and aflatoxin accumulation.

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Pechanova, Olga; Pechan, Tibor; Williams, W Paul; Luthe, Dawn S

2011-01-01

Infection of the maize (Zea mays L.) with aflatoxigenic fungus Aspergillus flavus and consequent contamination with carcinogenic aflatoxin is a persistent and serious agricultural problem causing disease and significant crop losses worldwide. The rachis (cob) is an important structure of maize ear that delivers essential nutrients to the developing kernels and A. flavus spreads through the rachis to infect kernels within the ear. Therefore, rachis plays an important role in fungal proliferation and subsequent kernel contamination. We used proteomic approaches and investigated the rachis tissue from aflatoxin accumulation resistant (Mp313E and Mp420) and susceptible (B73 and SC212m) maize inbred lines. First, we compared rachis proteins from resistant and susceptible inbred lines, which revealed that the young resistant rachis contains higher levels of abiotic stress-related proteins and proteins from phenylpropanoid metabolism, whereas susceptible young rachis contains pathogenesis-related proteins, which are generally inducible upon biotic stress. Second, we identified A. flavus-responsive proteins in rachis of both resistant and susceptible genotypes after 10- and 35-day infection. Differential expression of many stress/defense proteins during rachis juvenility, maturation and after A. flavus challenge demonstrates that resistant rachis relies on constitutive defenses, while susceptible rachis is more dependent on inducible defenses. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Potential producers of aflatoxin in working environment

Energy Technology Data Exchange (ETDEWEB)

Jesenska, Z.; Polakova, O.; Polster, M.; Koskova, L.; Vaszilkova, A.

1981-01-01

It has been investigated the amount of the viable germs of A. flavus in the environment of the food-stuff establishment, where peanuts and hazel nuts, almonds, crushed coconuts, tea and other food-stuffs, imported from tropical and subtropical countries, were processed and packed. In the air of the store-hall have occurred the most 3.73 x 10(2) and in the air of the working-halls, where they were manipulating with food-stuffs - the most 6.2 x 10(3) germs of A. flavus/m3. From the samples of the sedimented dust were isolated at least 0.4 x 10(1), the most 1.3 x 10(4) colonies of A. flavus/g. From 57 investigated strains produced aflatoxin B1 64.9%. The authors are discussing about a professional risk for the workers of some establishments during the manipulation with food-stuffs or feeds, which are contaminated with germs of toxinogenic moulds and with mycotoxins.

Selection of tannase-producing Aspergillus niger strains

OpenAIRE

Pinto,Gustavo A.S.; Leite,Selma G.F.; Terzi,Selma C.; Couri,Sonia

2001-01-01

The aim of this work was to select strains of Aspergillus niger for tannase production. Growth of colonies in plates with tannic acid-containing medium indicated their ability to synthesize tannase. Tannase activity was also measured in solid-state fermentation. A. niger 11T25A5 was the best tannase producer (67.5 U.g-1/72 hours of fermentation).

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

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Tao, Lin; Chung, Soo Hyun

2014-08-01

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

Volatile profiling reveals intracellular metabolic changes in Aspergillus parasiticus: veA regulates branched chain amino acid and ethanol metabolism

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Roze Ludmila V

2010-08-01

Full Text Available Abstract Background Filamentous fungi in the genus Aspergillus produce a variety of natural products, including aflatoxin, the most potent naturally occurring carcinogen known. Aflatoxin biosynthesis, one of the most highly characterized secondary metabolic pathways, offers a model system to study secondary metabolism in eukaryotes. To control or customize biosynthesis of natural products we must understand how secondary metabolism integrates into the overall cellular metabolic network. By applying a metabolomics approach we analyzed volatile compounds synthesized by Aspergillus parasiticus in an attempt to define the association of secondary metabolism with other metabolic and cellular processes. Results Volatile compounds were examined using solid phase microextraction - gas chromatography/mass spectrometry. In the wild type strain Aspergillus parasiticus SU-1, the largest group of volatiles included compounds derived from catabolism of branched chain amino acids (leucine, isoleucine, and valine; we also identified alcohols, esters, aldehydes, and lipid-derived volatiles. The number and quantity of the volatiles produced depended on media composition, time of incubation, and light-dark status. A block in aflatoxin biosynthesis or disruption of the global regulator veA affected the volatile profile. In addition to its multiple functions in secondary metabolism and development, VeA negatively regulated catabolism of branched chain amino acids and synthesis of ethanol at the transcriptional level thus playing a role in controlling carbon flow within the cell. Finally, we demonstrated that volatiles generated by a veA disruption mutant are part of the complex regulatory machinery that mediates the effects of VeA on asexual conidiation and sclerotia formation. Conclusions 1 Volatile profiling provides a rapid, effective, and powerful approach to identify changes in intracellular metabolic networks in filamentous fungi. 2 VeA coordinates the

Genome mining of the genetic diversity in the Aspergillus genus - from a collection of more than 30 Aspergillus species

DEFF Research Database (Denmark)

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

In the era of high-throughput sequencing, comparative genomics can be applied for evaluating species diversity. In this project we aim to compare the genomes of 300 species of filamentous fungi from the Aspergillus genus, a complex task. To be able to define species, clade, and core features......, this project uses BLAST on the amino acid level to discover orthologs. With a potential of 300 Aspergillus species each having ~12,000 annotated genes, traditional clustering will demand supercomputing. Instead, our approach reduces the search space by identifying isoenzymes within each genome creating...... intragenomic protein families (iPFs), and then connecting iPFs across all genomes. The initial findings in a set of 31 species show that ~48% of the annotated genes are core genes (genes shared between all species) and 2-24% of the genes are defining the individual species. The methods presented here...

Aflatoxin effect on erythrocyte profile and histopathology of broilers given different additives

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Karimy, M. F.; Sutrisno, B.; Agus, A.; Suryani, A. E.; Istiqomah, L.; Damayanti, E.

2017-12-01

The aim of this study was to evaluate erythrocyte profile and microscopic changes effect of AF induces by low level (57.18 ppb) and chronic exposure (34 days) with administration of additive (Lactobacillus plantarum G7 and methionine). Aflatoxin-contaminated corn was prepared by inoculate Aspergillus flavus FNCC 6002 on corn. Total number of 576 broiler Lohman strain (MB202) unsexed DOC were allocated completely randomized into four treatments and 12 replicates, with 12 broiler chicks each. The treatments as follows: T1 = aflatoxin-contaminated diet, T2 = aflatoxin-contaminated diet + 1% of LAB (w/w), T3 = aflatoxin-contaminated diet + 0.8% of methionine (w/w), and T4 = aflatoxin-contaminated diet + 1% of LAB + 0.8% of methionine (w/w). The effect of treatments was evaluated using ANOVA and the difference among mean treatments were analyzed using DMRT. The result showed that administration of additives had no significant effect (P>0.05) on erythrocyte profile, liver, and bursa of Fabricius. The dose of additive in each treatment (T2, T3, T4) were insufficient to reduce adverse effect of chronic aflatoxicosis. It was concluded that the LAB dose for binding AF (57.18%) should be evaluated and the dose for methionine should be reduced for chronic treatment of aflatoxicosis.

Molecular characterization of black Aspergillus species from onion and their potential for ochratoxin A and fumonisin B2 production.

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Gherbawy, Youssuf; Elhariry, Hesham; Kocsubé, Sándor; Bahobial, Abdulaziz; Deeb, Bahig El; Altalhi, Abdulla; Varga, János; Vágvölgyi, Csaba

2015-05-01

Onion bulbs can become contaminated with various molds during the storage period, the most important causal agents being black aspergilli (Aspergillus section Nigri). Taxonomic studies have revealed that this group of Aspergillus contains many species that cannot be reliably identified using standard morphological methods. Therefore, it is necessary to define the fungus causing this problem in the onion exactly, especially since some species assigned to section Nigri are well known as ochratoxin and/or fumonisin producers. Sixty fungal isolates belonging to 10 fungal genera were isolated from 40 onion samples originated from the Taif region in Saudi Arabia. Black aspergilli were detected in 37 onion samples. Using primer pairs (awaspec and Cmd6) designed based on partial calmodulin gene sequence data, 37 isolates were identified as A. welwitschiae. The ochratoxin A and fumonisin B2 contents of the onion samples were examined. No ochratoxins were detected in the collected samples, while fumonisin B2 was detected in 37.5% of the onion samples. Eighteen of 37 isolates of Aspergillus welwitschiae were recognized as potential producers for fumonisin B2. Multiplex polymerase chain reactions designed to detect biosynthetic genes of fumonisins confirmed these results.

Identification of ochratoxin A producing fungi associated with fresh and dry liquorice.

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Amanda Juan Chen

Full Text Available The presence of fungi on liquorice could contaminate the crop and result in elevated levels of mycotoxin. In this study, the mycobiota associated with fresh and dry liquorice was investigated in 3 producing regions of China. Potential toxigenic fungi were tested for ochratoxin A (OTA and aflatoxin B1 (AFB1 production using liquid chromatography/mass spectrometry/mass spectrometry. Based on a polyphasic approach using morphological characters, β-tubulin and RNA polymerase II second largest subunit gene phylogeny, a total of 9 genera consisting of 22 fungal species were identified, including two new Penicillium species (Penicillium glycyrrhizacola sp. nov. and Penicillium xingjiangense sp. nov.. The similarity of fungal communities associated with fresh and dry liquorice was low. Nineteen species belonging to 8 genera were detected from fresh liquorice with populations affiliated with P. glycyrrhizacola, P. chrysogenum and Aspergillus insuetus comprising the majority (78.74%, 33.33% and 47.06% of total of the community from Gansu, Ningxia and Xinjiang samples, respectively. In contrast, ten species belonging to 4 genera were detected from dry liquorice with populations affiliated with P. chrysogenum, P. crustosum and Aspergillus terreus comprising the majority (64.00%, 52.38% and 90.91% of total of the community from Gansu, Ningxia and Xinjiang samples, respectively. Subsequent LC/MS/MS analysis indicated that 5 fungal species were able to synthesize OTA in vitro including P. chrysogenum, P. glycyrrhizacola, P. polonicum, Aspergillus ochraceus and A. westerdijkiae, the OTA concentration varied from 12.99 to 39.03 µg/kg. AFB1 was absent in all tested strains. These results demonstrate the presence of OTA producing fungi on fresh liquorice and suggest that these fungi could survive on dry liquorice after traditional sun drying. Penicillium chrysogenum derived from surrounding environments is likely to be a stable contributor to high OTA level in

Malic acid production from thin stillage by Aspergillus species.

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West, Thomas P

2011-12-01

The ability of Aspergillus strains to utilize thin stillage to produce malic acid was compared. The highest malic acid was produced by Aspergillus niger ATCC 9142 at 17 g l(-1). Biomass production from thin stillage was similar with all strains but ATCC 10577 was the highest at 19 g l(-1). The highest malic acid yield (0.8 g g(-1)) was with A. niger ATCC 9142 and ATCC 10577 on the stillage. Thus, thin stillage has the potential to act as a substrate for the commercial production of food-grade malic acid by the A. niger strains. © Springer Science+Business Media B.V. 2011

Integrated database for identifying candidate genes for Aspergillus flavus resistance in maize.

Science.gov (United States)

Kelley, Rowena Y; Gresham, Cathy; Harper, Jonathan; Bridges, Susan M; Warburton, Marilyn L; Hawkins, Leigh K; Pechanova, Olga; Peethambaran, Bela; Pechan, Tibor; Luthe, Dawn S; Mylroie, J E; Ankala, Arunkanth; Ozkan, Seval; Henry, W B; Williams, W P

2010-10-07

Aspergillus flavus Link:Fr, an opportunistic fungus that produces aflatoxin, is pathogenic to maize and other oilseed crops. Aflatoxin is a potent carcinogen, and its presence markedly reduces the value of grain. Understanding and enhancing host resistance to A. flavus infection and/or subsequent aflatoxin accumulation is generally considered an efficient means of reducing grain losses to aflatoxin. Different proteomic, genomic and genetic studies of maize (Zea mays L.) have generated large data sets with the goal of identifying genes responsible for conferring resistance to A. flavus, or aflatoxin. In order to maximize the usage of different data sets in new studies, including association mapping, we have constructed a relational database with web interface integrating the results of gene expression, proteomic (both gel-based and shotgun), Quantitative Trait Loci (QTL) genetic mapping studies, and sequence data from the literature to facilitate selection of candidate genes for continued investigation. The Corn Fungal Resistance Associated Sequences Database (CFRAS-DB) (http://agbase.msstate.edu/) was created with the main goal of identifying genes important to aflatoxin resistance. CFRAS-DB is implemented using MySQL as the relational database management system running on a Linux server, using an Apache web server, and Perl CGI scripts as the web interface. The database and the associated web-based interface allow researchers to examine many lines of evidence (e.g. microarray, proteomics, QTL studies, SNP data) to assess the potential role of a gene or group of genes in the response of different maize lines to A. flavus infection and subsequent production of aflatoxin by the fungus. CFRAS-DB provides the first opportunity to integrate data pertaining to the problem of A. flavus and aflatoxin resistance in maize in one resource and to support queries across different datasets. The web-based interface gives researchers different query options for mining the database

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

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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.

Use of Probiotics to Control Aflatoxin Production in Peanut Grains

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Juliana Fonseca Moreira da Silva

2015-01-01

Full Text Available Probiotic microorganisms (Saccharomyces cerevisiae var. boulardii, S. cerevisiae UFMG 905, and Lactobacillus delbrueckii UFV H2b20 were evaluated as biological control agents to reduce aflatoxin and spore production by Aspergillus parasiticus IMI 242695 in peanut. Suspensions containing the probiotics alone or in combinations were tested by sprinkling on the grains followed by incubation for seven days at 25°C. All probiotic microorganisms, in live and inactivated forms, significantly reduced A. parasiticus sporulation, but the best results were obtained with live cells. The presence of probiotics also altered the color of A. parasiticus colonies but not the spore morphology. Reduction in aflatoxin production of 72.8 and 65.8% was observed for S. boulardii and S. cerevisiae, respectively, when inoculated alone. When inoculated in pairs, all probiotic combinations reduced significantly aflatoxin production, and the best reduction was obtained with S. boulardii plus L. delbrueckii (96.1% followed by S. boulardii plus S. cerevisiae and L. delbrueckii plus S. cerevisiae (71.1 and 66.7%, resp.. All probiotics remained viable in high numbers on the grains even after 300 days. The results of the present study suggest a different use of probiotics as an alternative treatment to prevent aflatoxin production in peanut grains.

Spread of Aspergillus flavus by navel orangeworm (Amyelois transitella) on almonds

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Navel orangeworm (NOW) damage to almonds is correlated with increased incidence of aflatoxin contamination caused by Aspergillus flavus. However, no reports demonstrate a causative relationship between NOW feeding and A. flavus infection. To demonstrate the potential of NOW to act as a vector of A. ...

Variability in Galactomannan detection by platelia Aspergillus EIA™ according to the Aspergillus species Variabilidade na detecção de galactomanana pelo Platelia Aspergillus EIA® de acordo com a espécie de Aspergillus

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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.O estudo objetivou investigar a liberação in vitro de galactomanana (GM em distintas espécies patogênicas de fungos do gênero Aspergillus. Grande variabilidade foi detectada tanto intra quanto inter espécies, sendo as cepas da espécie A. terreus relacionadas aos maiores índices de GM detectados. O significado in vivo destes achados permanece em aberto, porém merece investigação.

Peanut gene expression profiling in developing seeds at different reproduction stages during Aspergillus parasiticus infection

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Liang Xuanqiang

2008-02-01

Full Text Available Abstract Background Peanut (Arachis hypogaea L. is an important crop economically and nutritionally, and is one of the most susceptible host crops to colonization of Aspergillus parasiticus and subsequent aflatoxin contamination. Knowledge from molecular genetic studies could help to devise strategies in alleviating this problem; however, few peanut DNA sequences are available in the public database. In order to understand the molecular basis of host resistance to aflatoxin contamination, a large-scale project was conducted to generate expressed sequence tags (ESTs from developing seeds to identify resistance-related genes involved in defense response against Aspergillus infection and subsequent aflatoxin contamination. Results We constructed six different cDNA libraries derived from developing peanut seeds at three reproduction stages (R5, R6 and R7 from a resistant and a susceptible cultivated peanut genotypes, 'Tifrunner' (susceptible to Aspergillus infection with higher aflatoxin contamination and resistant to TSWV and 'GT-C20' (resistant to Aspergillus with reduced aflatoxin contamination and susceptible to TSWV. The developing peanut seed tissues were challenged by A. parasiticus and drought stress in the field. A total of 24,192 randomly selected cDNA clones from six libraries were sequenced. After removing vector sequences and quality trimming, 21,777 high-quality EST sequences were generated. Sequence clustering and assembling resulted in 8,689 unique EST sequences with 1,741 tentative consensus EST sequences (TCs and 6,948 singleton ESTs. Functional classification was performed according to MIPS functional catalogue criteria. The unique EST sequences were divided into twenty-two categories. A similarity search against the non-redundant protein database available from NCBI indicated that 84.78% of total ESTs showed significant similarity to known proteins, of which 165 genes had been previously reported in peanuts. There were

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

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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

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 .

Assessment of aflatoxin exposure of laboratory worker during food contamination analyses. Assessment of the procedures adopted by an A.R.P.A.L. laboratory (Liguria Region Environmental Protection Agency).

Science.gov (United States)

Traverso, A; Bassoli, Viviana; Cioè, A; Anselmo, Silvia; Ferro, Marta

2010-01-01

Aflatoxins are mycotoxins derived from foodstuffs colonized by fungal species of the genus Aspergillus; they are common food contaminants with immunosuppressive, mutagenic and carcinogenic activity. Aflatoxins are heat-resistant and are thus easily transmitted along the food chain. They are hepatotoxic and have the potential to induce hepatocellular carcinoma. Agri-food industry workers are thus at risk of ingestion as well as transmucosal absorption or inhalation of toxins released during product preparation or processing. To measure the levels of airborne mycotoxins, particularly aflatoxins, in a laboratory analysing imported foodstuffs for mycotoxin contamination. The protocol used to analyse a batch of shelled peanuts from Vietnam, especially the grinding phase, which is held to be at the highest risk ofgenerating airborne toxins, was assessed at the A.R.PA.L. laboratory (Liguria Region Environmental Protection Agency) of Genoa, Italy, which participates in a European aflatoxin monitoring project. Wet grinding was performed to avoid production of large amounts of dust. Comparison of airborne concentrations before and after grinding with legal thresholds disclosed that the analytical procedures involved negligible aflatoxin levels for operators (environmental burden 0.11 pg/ m3). Given the toxicity of aflatoxins, worker protection measures should be consistently adopted and enforced. Threshold limit values for working environments should be introduced besides the existing ones for public health.

Aspergillus asper sp. nov. and Aspergillus collinsii sp. nov., from Aspergillus section Usti.

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Jurjevic, Zeljko; Peterson, Stephen W

2016-07-01

In sampling fungi from the built environment, two isolates that could not confidently be placed in described species were encountered. Phenotypic analysis suggested that they belonged in Aspergillus sect. Usti. In order to verify the sectional placement and to assure that they were undescribed rather than phenotypically aberrant isolates, DNA was isolated and sequenced at the beta-tubulin, calmodulin, internal transcribed spacer and RNA polymerase II loci and sequences compared with those from other species in the genus Aspergillus. At each locus, each new isolate was distant from existing species. Phylogenetic trees calculated from these data and GenBank data for species of the section Usti excluded the placement of these isolates in existing species, with statistical support. Because they were excluded from existing taxa, the distinct species Aspergillus asper (type strain NRRL 35910 T ) and Aspergillus collinsii (type strain NRRL 66196 T ) in sect. Usti are proposed to accommodate these strains.

Natamycin and Azithromycin are Synergistic in vitro against Ocular Pathogenic Aspergillus flavus species complex and Fusarium solani species complex Isolates.

Science.gov (United States)

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

2018-05-07

The interaction of natamycin-azithromycin combination against 60 ocular fungal isolates was tested in vitro The combination produced 100% synergistic interactions when natamycin added azithromycin at 20, 40, 50 μg/ml against Aspergillus flavus species complex (AFSC) isolates and added azithromycin at 50 μg/ml against Fusarium solani species complex isolates. The combination with 50 μg/ml azithromycin enhanced natamycin's effect against AFSC isolates by reducing natamycin MICs from MIC 90 64μg/ml to MIC 90 0.031μg/ml. No antagonism was observed. Copyright © 2018 American Society for Microbiology.

Phylogeny of xerophilic aspergilli (subgenus Aspergillus and taxonomic revision of section Restricti

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F. Sklenář

2017-09-01

The vast majority of species in sect. Restricti produce asperglaucide, asperphenamate or both in contrast to species in sect. Aspergillus. Mycophenolic acid was detected for the first time in at least six members of the section. The ascomata of A. halophilicus do not contain auroglaucin, epiheveadride or flavoglaucin which are common in sect. Aspergillus, but shares the echinulins with sect. Aspergillus.

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.

Collision-induced dissociation of aflatoxins.

Science.gov (United States)

Tóth, Katalin; Nagy, Lajos; Mándi, Attila; Kuki, Ákos; Mézes, Miklós; Zsuga, Miklós; Kéki, Sándor

2013-02-28

The aflatoxin mycotoxins are particularly hazardous to health when present in food. Therefore, from an analytical point of view, knowledge of their mass spectrometric properties is essential. The aim of the present study was to describe the collision-induced dissociation behavior of the four most common aflatoxins: B1, B2, G1 and G2. Protonated aflatoxins were produced using atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) combined with high-performance liquid chromatography (HPLC). For the tandem mass spectrometry (MS/MS) experiments nitrogen was used as the collision gas and the collision energies were varied in the range of 9-44 eV (in the laboratory frame). The major APCI-MS/MS fragmentations of protonated aflatoxins occurred at 30 eV collision energy. The main fragmentation channels were found to be the losses of a series of carbon monoxide molecules and loss of a methyl radical, leading to the formation of radical-type product ions. In addition, if the aflatoxin molecule contained an ether- or lactone-oxygen atom linked to a saturated carbon atom, loss of a water molecule was observed from the [M + H](+) ion, especially in the case of aflatoxins G1 and G2. A relatively small modification in the structure of aflatoxins dramatically altered the fragmentation pathways and this was particularly true for aflatoxins B1 and B2. Due to the presence of a C = C double bond connected to the ether group in aflatoxin B1 no elimination of water was observed but, instead, formation of radical-type product ions occurred. Fragmentation of protonated aflatoxin B1 yielded the most abundant radical-type cations. Copyright © 2013 John Wiley & Sons, Ltd.

Assessing the impact of aflatoxin consumption on animal health and ...

African Journals Online (AJOL)

They are toxic to humans, fish and many other animals, even in low concentrations. Susceptibility to aflatoxins varies by age, health status, species and other factors. Most research has focused on aflatoxins in maize or groundnuts and their impacts on human health. However, aflatoxins are found in other foods and can also ...

The use of powder and essential oil of Cymbopogon citratus against mould deterioration and aflatoxin contamination of "egusi" melon seeds.

Science.gov (United States)

Bankole, S A; Joda, A O; Ashidi, J S

2005-01-01

Experiments were carried out to determine the potential of using the powder and essential oil from dried ground leaves of Cymbopogon citratus (lemon grass) to control storage deterioration and aflatoxin contamination of melon seeds. Four mould species: Aspergillus flavus, A. niger, A. tamarii and Penicillium citrinum were inoculated in the form of conidia suspension (approx. 10(6) conidia per ml) unto shelled melon seeds. The powdered dry leaves and essential oil from lemon grass were mixed with the inoculated seeds at levels ranging from 1-10 g/100 g seeds and 0.1 to 1.0 ml/100 g seeds respectively. The ground leaves significantly reduced the extent of deterioration in melon seeds inoculated with different fungi compared to the untreated inoculated seeds. The essential oil at 0.1 and 0.25 ml/100 g seeds and ground leaves at 10 g/100 g seeds significantly reduced deterioration and aflatoxin production in shelled melon seeds inoculated with toxigenic A. flavus. At higher dosages (0.5 and 1.0 ml/100 g seeds), the essential oil completely prevented aflatoxin production. After 6 months in farmers' stores, unshelled melon seeds treated with 0.5 ml/ 100 g seeds of essential oil and 10 g/100 g seeds of powdered leaves of C. citratus had significantly lower proportion of visibly diseased seeds and Aspergillus spp. infestation levels and significantly higher seed germination compared to the untreated seeds. The oil content, free fatty acid and peroxide values in seeds protected with essential oil after 6 months did not significantly differ from the values in seeds before storage. The efficacy of the essential oil in preserving the quality of melon seeds in stores was statistically at par with that of fungicide (iprodione) treatment. ((c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

Workflow to study genetic biodiversity of aflatoxigenic Aspergillus spp. in Georgia, USA

Science.gov (United States)

Peanut seeds were sampled from the entire state of Georgia in 2014. More than 600 isolates of Aspergillus spp. were collected using modified-dichloran rose Bengal (MDRB) medium, 240 of those isolates were fingerprinted with 25 InDel markers within the aflatoxin-biosynthesis gene cluster (ABC). Clust...

Antibiotic effective against Saccharomyces produced by Aspergillus oryzae

Energy Technology Data Exchange (ETDEWEB)

Nakata, H.; Sakai, T.; Takeda, M.; Tsukahara, T.

1980-01-01

Production of an antibiotic effective against Saccharomyces cerevisiae was investigated in 85 strains of Aspergillus oryzae, isolated from commercial koji molds. The antibiotic was produced by 50 strains. A. oryzae was cultivated at 30 degrees for 15-20 days in koji extract. The crude preparation was obtained by precipitation from the culture filtrate with EtOH, MeOH, or Me/sub 2/CO.

Linking secondary metabolites to gene clusters through genome sequencing of six diverse Aspergillus species

DEFF Research Database (Denmark)

Kjærbølling, Inge; Vesth, Tammi C.; Frisvad, Jens C.

2018-01-01

The fungal genus of Aspergillus is highly interesting, containing everything from industrial cell factories, model organisms, and human pathogens. In particular, this group has a prolific production of bioactive secondary metabolites (SMs). In this work, four diverse Aspergillus species (A...

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.

Biodiversity of Aspergillus section Nigri populations in Argentinian vineyards and ochratoxin A contamination.

Science.gov (United States)

Chiotta, María L; Ponsone, María L; Sosa, Débora M; Combina, Mariana; Chulze, Sofía N

2013-12-01

Aspergillus section Nigri are described as the main source of ochratoxin A (OTA) contamination in grapes and wine worldwide. The knowledge of the factors affecting grape contamination by species included in this section and OTA production is essential to be able to reduce their presence, not only to improve wine quality, but also to maintain their safety. Therefore, the aims of this study were to determine the incidence of Aspergillus section Nigri species harvested in different grape-growing regions from Argentina, their ability to produce OTA, to correlate with meteorological conditions and geographical coordinates with their prevalence and to evaluate the OTA natural occurrence in grapes and wines. The morphological identification showed that Aspergillus niger aggregate species were the most prevalent ones, followed by Aspergillus carbonarius and Aspergillus uniseriate. These populations were confirmed through using AFLP markers and sequencing and, Aspergillus tubingensis was separated from A. niger aggregate. Climatic factors, altitude, longitude and latitude have influenced on the distribution of species included in the section. A. carbonarius and A. niger were OTA producers but differed in their OTA producing ability. Temperature was the factor which influenced the most over the highest incidence of A. carbonarius in La Rioja and San Juan regions. The trellis system in vineyards and drip irrigation also influenced the species isolation. The OTA levels detected in grapes and wines were low, but grape variety was more important in susceptibility to fungal infection and OTA levels. Copyright © 2013 Elsevier Ltd. All rights reserved.

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.

Evaluation of the atoxigenic Aspergillus flavus strain AF36 in pistachio orchards

Science.gov (United States)

The atoxigenic strain Aspergillus flavus AF36, which has been extensively used as a biocontrol agent in commercial corn and cotton fields to reduce aflatoxin contamination, was applied in research pistachio orchards from 2002 to 2005 and in commercial pistachio orchards from 2008 to 2011. AF36 was a...

Diversity of Aspergillus section Nigri on the surface of Vitis labrusca and its hybrid grapes

DEFF Research Database (Denmark)

Ferranti, Larissa de Souza; Fungaro, Maria Helena P; Massi, Fernanda Pelisson

2018-01-01

This study investigated the presence of Aspergillus species belonging to Aspergillus section Nigri on Vitis labrusca and its hybrid grapes grown in Brazil. The ability of the fungi isolates to produce ochratoxin A (OTA) and fumonisin B2 (FB2) as well as the presence of these mycotoxins in the gra......This study investigated the presence of Aspergillus species belonging to Aspergillus section Nigri on Vitis labrusca and its hybrid grapes grown in Brazil. The ability of the fungi isolates to produce ochratoxin A (OTA) and fumonisin B2 (FB2) as well as the presence of these mycotoxins...

Geographically predominant genotypes of Aspergillus terreus species complex in Austria: s microsatellite typing study

NARCIS (Netherlands)

Lackner, M.; Coassin, S.; Haun, M.; Binder, U.; Kronenberg, F.; Haas, H. de; Jank, M.; Maurer, E.; Meis, J.F.; Hagen, F.; Lass-Florl, C.

2016-01-01

Aspergillus terreus species complex is recognized as a frequent agent of invasive aspergillosis in Tyrol. The reason for this specific epidemiological situation is unclear. Aspergillus terreus strains isolated from environmental and clinical sources were genotyped using a novel panel of short tandem

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

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.

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.

Production of α-amylase from some thermophilic Aspergillus species ...

African Journals Online (AJOL)

In this study, thermostable amylase activities of some thermophilic Aspergillus species were evaluated. The suitable medium and microorganisms for α-amylase synthesis were selected. Subsequently, the α-amylase activity of the microorganism was researched. In the measurements made on the 7th day of production on ...

Characterization and differentiation of aflatoxigenic species of Aspergillus section Flavi by MALDI-TOF MS

OpenAIRE

Rodrigues, P.; Kallow, W.; Erhard, M.; Welker, M.; Kozakiewicz, Z.; Lima, Nelson; Venâncio, Armando

2007-01-01

Aspergillus is a large genus, with a complex taxonomy. The genus is easily identifiedd by its characteristic conidiophore, but species identification and differentiation is complex, mainly because it is traditionally based on a range of morphological features. Aspergillus subgenus Circumdati section Flavi, also refered to as the A.dflavus group, has attracted worldwide attention for its industrial use and toxigenic potential. Sectiond Flavi is divided in two groups of species. One includes th...

Elucidation of primary metabolic pathways in Aspergillus species: Orphaned research in characterizing orphan genes

DEFF Research Database (Denmark)

Andersen, Mikael Rørdam

2014-01-01

metabolites and extracellular enzymes. In this review, all annotated genes from four Aspergillus species have been examined. In this process, it becomes evident that 80-96% of the genes (depending on the species) are still without verified function. A significant proportion of the genes with verified......, applications of this from the Aspergillus genes will be examined, and it is proposed that, where feasible, this should be a standard part of functional annotation of fungal genomes....

Characteristics of culture-positive invasive pulmonary aspergillosis in patients with hematologic diseases: Comparison between Aspergillus fumigatus and non-fumigatus Aspergillus species.

Science.gov (United States)

Cho, Sung-Yeon; Lee, Dong-Gun; Choi, Jae-Ki; Lee, Hyo-Jin; Kim, Si-Hyun; Park, Sun Hee; Choi, Su-Mi; Choi, Jung-Hyun; Yoo, Jin-Hong; Park, Yeon-Joon; Lee, Jong-Wook

2017-12-01

While the epidemiology and clinical differences of various Candida spp. has been relatively well-identified, data regarding invasive aspergillosis (IA) caused by different Aspergillus spp. are insufficient.We aimed to determine the epidemiology of culture-positive invasive pulmonary aspergillosis (IPA) and to compare the characteristics and outcomes of Aspergillus fumigatus IPA with those of non-fumigatus IPA in patients with hematologic diseases. All consecutive cases of IPA from 2011 to 2015 were reviewed retrospectively.There were 430 proven/probable IPA and 76 culture-positive proven/probable IPA. Excluding cases of multiple species of fungi or cases having difficulties in species-level identification, 41 A fumigatus and 22 non-fumigatus IPA (Aspergillus flavus [n = 11], Aspergillus niger [n = 6], and Aspergillus terreus [n = 5]) were compared. There were no significant differences in baseline characteristics between the 2 groups. However, disseminated IA was more common in non-fumigatus IPA (2.4% vs 18.2%; P = .046). Paranasal sinus (PNS) involvement was more common in non-fumigatus IPA. There was a trend towards higher peak serum galactomannan values in non-fumigatus IPA than in A fumigatus IPA group (median 1.33 [interquartile 0.98-3.29] vs 0.97 [0.66-1.97]; P = .084). Clinical response and mortality did not differ between groups.The culture-positive rate of proven/probable IPA was 17.7%, of which non-fumigatus Aspergillus accounted for about one-third. Disseminated IA, especially involving the PNS, was more frequent in non-fumigatus IPA than in A fumigatus IPA.

Natural infection of cowpea (Vigna unguiculata (L.) Walp.) by toxigenic fungi and mycotoxin contamination in Benin, West Africa

DEFF Research Database (Denmark)

Houssou, P.A.; Ahohuendo, B.C.; Fandohan, P.

2009-01-01

for the two periods. About 23 fungal species were identified on cowpea seed samples across zones of which Aspergillus flavus, a fungus that produces aflatoxins, was most frequently encountered. Fusarium species shown to produce fumonisins were not recorded from cowpea seeds. Overall incidence of A. flavus...... infection was found to increase after storage from 7.6% at T0 to 28.25% at T3. In spite of this natural infection of cowpea, very low levels of fumonisin and aflatoxin were detected. Only three out of the 92 cowpea samples, all collected at T0, were found to be fumonisin B1 positive with a mean level of 0.......03 mg/g. Similarly, only six samples out of the 92, all collected at T3, were aflatoxin B1 positive with mean levels of 3.58 µg/kg. Fumonisin (B2 and B3) and aflatoxin (B2, G1 and G2) were not detected in any of the samples. Contrary to the situation with maize and groundnut where high levels of toxin...

The Black Aspergillus Species of Maize and Peanuts and Their Potential for Mycotoxin Production

Science.gov (United States)

Palencia, Edwin R.; Hinton, Dorothy M.; Bacon, Charles W.

2010-01-01

The black spored fungi of the subgenera Circumdata, the section Nigri (=Aspergillus niger group) is reviewed relative to their production of mycotoxins and their effects on plants as pathogens. Molecular methods have revealed more than 18 cryptic species, of which several have been characterized as potential mycotoxin producers. Others are defined as benign relative to their ability to produce mycotoxins. However, these characterizations are based on in vitro culture and toxins production. Several can produce the ochratoxins that are toxic to livestock, poultry, and humans. The black aspergilli produce rots of grapes, maize, and numerous other fruits and grain and they are generally viewed as post-harvest pathogens. Data are review to suggest that black aspergilli, as so many others, are symptomless endophytes. These fungi and their mycotoxins contaminate several major grains, foodstuffs, and products made from them such as wine, and coffee. Evidence is presented that the black aspergilli are producers of other classes of mycotoxins such as the fumonisins, which are known carcinogenic and known prior investigations as being produced by the Fusarium species. Three species are identified in U.S. maize and peanuts as symptomless endophytes, which suggests the potential for concern as pathogens and as food safety hazards. PMID:22069592

In vivo confocal microscopy appearance of Fusarium and Aspergillus species in fungal keratitis.

Science.gov (United States)

Chidambaram, Jaya Devi; Prajna, Namperumalsamy Venkatesh; Larke, Natasha; Macleod, David; Srikanthi, Palepu; Lanjewar, Shruti; Shah, Manisha; Lalitha, Prajna; Elakkiya, Shanmugam; Burton, Matthew J

2017-08-01

Clinical outcomes in fungal keratitis vary between Fusarium and Aspergillus spp, therefore distinguishing between species using morphological features such as filament branching angles, sporulation along filaments (adventitious sporulation) or dichotomous branching may be useful. In this study, we assessed these three features within Heidelberg Retina Tomograph 3 in vivo confocal microscopy (IVCM) images from culture-positive Fusarium and Aspergillus spp keratitis participants. Prospective observational cohort study in Aravind Eye Hospital (February 2011-February 2012). Eligibility criteria: age ≥18 years, stromal infiltrate ≥3 mm diameter, Fusarium or Aspergillus spp culture-positive. previous/current herpetic keratitis, visual acuity 80% corneal thinning. IVCM was performed and images analysed for branch angle, presence/absence of adventitious sporulation or dichotomous branching by a grader masked to the microbiological diagnosis. 98 participants were included (106 eligible, 8 excluded as no measurable branch angles); 68 were positive for Fusarium spp, 30 for Aspergillus spp. Mean branch angle for Fusarium spp was 59.7° (95% CI 57.7° to 61.8°), and for Aspergillus spp was 63.3° (95% CI 60.8° to 65.8°), p=0.07. No adventitious sporulation was detected in Fusarium spp ulcers. Dichotomous branching was detected in 11 ulcers (7 Aspergillus spp, 4 Fusarium spp). There was very little difference in the branching angle of Fusarium and Aspergillus spp. Adventitious sporulation was not detected and dichotomous branching was infrequently seen. Although IVCM remains a valuable tool to detect fungal filaments in fungal keratitis, it cannot be used to distinguish Fusarium from Aspergillus spp and culture remains essential to determine fungal species. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

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

Science.gov (United States)

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

[Biological contamination by micromycetes in dried Boletus edulis: research of aflatoxin B1, B2 G1, G2 and ochratoxin A].

Science.gov (United States)

Lorini, C; Rossetti, F; Palazzoni, S; Comodo, N; Bonaccorsi, G

2008-01-01

Aim of this survey is to identify those filamentous fungi which parasite Boletus edulis and its group and check the potential presence of secondary metabolites, specifically aflatoxin B1, total aflatoxins and ochratoxin A, in order to assess the risk to consumers' health. Forty samples of dried Boletus edulis, collected by two food industries which distribute the product in many Italian regions, have been analysed. The sampling plan has been conducted from November 2005 to March 2006, collecting 50 g from each commercial category of dried Boletus edulis available in the factory at the time of sampling. All the samples have been tested by visual macroscopic and stereoscopic assays; for some samples--those referred to commercial category presumably at higher risk--we have performed cultural assays as well, typization of isolated micromycetes, extraction and quantification of aflatoxins and ochratoxin A. Mycotoxin detection has been made by HPLC, using the UNI EN 14123 and UNI EN 14132 standard methods, respectively applied to aflatoxins determination in peanuts, pistachios, figs and paprika and to ochratoxin A in barley and coffee. Non pathogenic micromycetes, common in food products, have been frequently observed in cultural assays, while Aspergillus flavus and Aspergillus niger have been found in some samples. However the concentration of aflatoxins was always under the quantification limit. The survey confirm that, if the cold chain is kept throughout the process and the distribution, Boletus edulis and analogue mycetes are not a favourable substratum for the growth and the development of moulds.

Antibodies 'green' against aflatoxins for consumer protection

International Nuclear Information System (INIS)

Capodicasa, Cristina; Catellani, Marcello

2015-01-01

Among the natural toxins that can contaminate products food or feed intended for animal, a particular concern is aroused by mycotoxins. They are toxic substances produced as secondary metabolites, in appropriate conditions micro climate, mainly by members of fungi the genera Aspergillus, Penicillium and Fusarium. The attention paid to these contaminants is justified from the serious effects (teratogenic, carcinogenic, estrogen, neurotoxic and immunosuppression) on health of humans and animals resulting from their intake through food. The Laboratory of Biotechnology Biotechnology Division and agro-industry, at the Research Center Casaccia, has been engaged for years in antibody production in alternative systems to animal cells, such as plants for various applications, the biomedical field to the food industry. Me.Di.T.A. the project under (Methodologies Diagnostic and Advanced Technologies for the quality and the safety of food of the South of Italy), in particular, they have been isolated antibody to develop a diagnostic assay for quantification of aflatoxins in food matrices. [it

Comments on "Screening and identification of novel ochratoxin A-producing fungi from grapes. Toxins 2016,8,833" - in reporting ochratoxin A production from strains of Aspergillus, Penicillium and talaromcyes

DEFF Research Database (Denmark)

Perrone, Giancarlo; Logrieco, Antonio F.; Frisvad, Jens Christian

2017-01-01

Recently a species in the genus Talaromyces, a uniseriate species of Aspergillus section Nigri and an isolate each of two widespread species, Penicillium rubens and P. commune, were reported to produce ochratoxin A. This claim was based on insufficient biological and chemical data. We propose a l...

Effect of competition on the production and activity of secondary metabolites in Aspergillus species

DEFF Research Database (Denmark)

Losada, L.; Ajayi, O.; Frisvad, Jens Christian

2009-01-01

and in the presence of other fungal species. However, it is not known whether secreted secondary metabolites provide a competitive advantage over other fungal species, or whether competition has any effect on the production of those metabolites. Here, we have performed co-cultivation competition assays among......Secondary metabolites are of intense interest to humans due to their pharmaceutical and/or toxic properties. Also, these metabolites are clinically relevant because of their importance in fungal pathogenesis. Aspergillus species secrete secondary metabolites when grown individually...... different species of Aspergillus to determine relative species fitness in culture, and to analyze the presence of possible antifungal activity of secondary metabolites in extracts. The results show that, for the most part, at 30C only one species is able to survive direct competition with a second species...

Mycoflora of Some Smoked Fish Varieties in Benin City Nigeria ...

African Journals Online (AJOL)

Rhizopus sp. and Trichoderma sp. in their order of decreasing frequency in all the fish samples. The highest mean mycoflora count (17.833 x103cfu) was recorded in Tilapia sp., while the lowest mean value (11.16 x103cfu) was recorded in Drepane africana. Aspergillus species are known to produce aflatoxins which are ...

Aflatoxin M1 contamination of raw and pasteurized milk produced in Sanandaj, Iran

Directory of Open Access Journals (Sweden)

Mafakheri, Sh.

2010-07-01

Full Text Available This study was conducted to evaluate and compare the levels of aflatoxin M1 in raw and pasteurized milk samples during different seasons by Enzyme- Linked Immuno Sorbent Assay in Sanandaj, Iran. In 257 (94.49% out of 272 milk samples the presence of aflatoxin M1 was detected in concentrations ranging between 0.007 and 115.930 ng/l. AFM1 level in 12 (4.4% of positive samples were higher than the maximum tolerance limit (50 ng/l accepted by Iran and European Union countries. Statistical evaluations showed that the differences between raw and pasteurized samples were not significant (p<0.05. There was no significant difference between spring and summer but the differences between other seasons were statistically significant. Winter samples with 22.35 ng/l and summer samples with 5.14 ng/l had the highest and lowest concentration, respectively (p<0.05. Since contamination of milk with aflatoxin is a potential risk for human health, milk and milk products should be controlled periodically for Aflatoxin contamination.

Sexual reproduction in Aspergillus flavus sclerotia: acquisition of novel alleles from soil populations and uniparental mitochondrial inheritance

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Aspergillus flavus colonizes agricultural commodities worldwide and contaminates them with carcinogenic aflatoxins. The high genetic diversity of A. flavus populations is largely due to sexual reproduction characterized by the formation of ascospore-bearing ascocarps embedded within sclerotia. A. ...

Prospecting for the incidence of genes involved in ochratoxin and fumonisin biosynthesis in Brazilian strains of Aspergillus niger and Aspergillus welwitschiae.

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Massi, Fernanda Pelisson; Sartori, Daniele; de Souza Ferranti, Larissa; Iamanaka, Beatriz Thie; Taniwaki, Marta Hiromi; Vieira, Maria Lucia Carneiro; Fungaro, Maria Helena Pelegrinelli

2016-03-16

Aspergillus niger "aggregate" is an informal taxonomic rank that represents a group of species from the section Nigri. Among A. niger "aggregate" species Aspergillus niger sensu stricto and its cryptic species Aspergillus welwitschiae (=Aspergillus awamori sensu Perrone) are proven as ochratoxin A and fumonisin B2 producing species. A. niger has been frequently found in tropical and subtropical foods. A. welwitschiae is a new species, which was recently dismembered from the A. niger taxon. These species are morphologically very similar and molecular data are indispensable for their identification. A total of 175 Brazilian isolates previously identified as A. niger collected from dried fruits, Brazil nuts, coffee beans, grapes, cocoa and onions were investigated in this study. Based on partial calmodulin gene sequences about one-half of our isolates were identified as A. welwitschiae. This new species was the predominant species in onions analyzed in Brazil. A. niger and A. welwitschiae differ in their ability to produce ochratoxin A and fumonisin B2. Among A. niger isolates, approximately 32% were OTA producers, but in contrast only 1% of the A. welwitschiae isolates revealed the ability to produce ochratoxin A. Regarding fumonisin B2 production, there was a higher frequency of FB2 producing isolates in A. niger (74%) compared to A. welwitschiae (34%). Because not all A. niger and A. welwitschiae strains produce ochratoxin A and fumonisin B2, in this study a multiplex PCR was developed for detecting the presence of essential genes involved in ochratoxin (polyketide synthase and radHflavin-dependent halogenase) and fumonisin (α-oxoamine synthase) biosynthesis in the genome of A. niger and A. welwitschiae isolates. The frequency of strains harboring the mycotoxin genes was markedly different between A. niger and A. welwitschiae. All OTA producing isolates of A. niger and A. welwitschiae showed in their genome the pks and radH genes, and 95.2% of the nonproducing

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

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