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Sample records for aspergillus flavus growth

  1. 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.

  2. Growth Identification of Aspergillus flavus and Aspergillus parasiticus by Visible/Near-Infrared Hyperspectral Imaging

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    Xuan Chu

    2018-03-01

    Full Text Available Visible/near-infrared (Vis/NIR hyperspectral imaging (400–1000 nm was applied to identify the growth process of Aspergillus flavus and Aspergillus parasiticus. The hyperspectral images of the two fungi that were growing on rose bengal medium were recorded daily for 6 days. A band ratio using two bands at 446 nm and 460 nm separated A. flavus and A. parasiticus on day 1 from other days. Image at band of 520 nm classified A. parasiticus on day 6. Principle component analysis (PCA was performed on the cleaned hyperspectral images. The score plot of the second to sixth principal components (PC2 to PC6 gave a rough clustering of fungi in the same incubation time. However, in the plot, A. flavus on day 3 and day 4 and A. parasiticus on day 2 and day 3 overlapped. The average spectra of each fungus in each growth day were extracted, then PCA and support vector machine (SVM classifier were applied to the full spectral range. SVM models built by PC2 to PC6 could identify fungal growth days with accuracies of 92.59% and 100% for A. flavus and A. parasiticus individually. In order to simplify the prediction models, competitive adaptive reweighted sampling (CARS was employed to choose optimal wavelengths. As a result, nine (402, 442, 487, 502, 524, 553, 646, 671, 760 nm and seven (461, 538, 542, 742, 753, 756, 919 nm wavelengths were selected for A. flavus and A. parasiticus, respectively. New optimal wavelengths SVM models were built, and the identification accuracies were 83.33% and 98.15% for A. flavus and A. parasiticus, respectively. Finally, the visualized prediction images for A. flavus and A. parasiticus in different growth days were made by applying the optimal wavelength’s SVM models on every pixel of the hyperspectral image.

  3. 76 FR 16297 - Aspergillus flavus

    Science.gov (United States)

    2011-03-23

    ... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 180 [EPA-HQ-OPP-2010-0101; FRL-8868-7] Aspergillus... for residues of the microbial pesticide, Aspergillus flavus AF36, in or on corn food and feed... to the existing exemption from the requirement of a tolerance for Aspergillus flavus AF36. This...

  4. 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

  5. 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)

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

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

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

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    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.

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

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    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.

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

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    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

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

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    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.

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

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    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.

  12. Studies on Aspergillus flavus

    International Nuclear Information System (INIS)

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

    1976-01-01

    The response of germinating conidia of Asphergillus flavus (aflatoxin producing) and A.flavus oryzae (non-toxigenic) to heat, radiation and combination treatments has been studied. Germinating conidia of both strains of fungi were more susceptible to heat injury than non-germinating conidia and the susceptibility was enhanced with increased incubation period before treatment. Susceptibility to radiation injury, however, increased only for a short period followed by development of resistance. The germinating stage which was highly resistant to radiation was very sensitive to heat (50 0 /5 min). With combinations of heat and radiation, an irradiation-heat sequence was more effective than the reverse sequence for all germinating stages of A.flavus (toxigenic). However, in the case of the non-toxigenic strain, irrespective of germinating stage, irradiation of conidia before heating proved to be less effective than the reverse sequence. (author)

  13. Analysis of secreted proteins from Aspergillus flavus.

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    Medina, Martha L; Haynes, Paul A; Breci, Linda; Francisco, Wilson A

    2005-08-01

    MS/MS techniques in proteomics make possible the identification of proteins from organisms with little or no genome sequence information available. Peptide sequences are obtained from tandem mass spectra by matching peptide mass and fragmentation information to protein sequence information from related organisms, including unannotated genome sequence data. This peptide identification data can then be grouped and reconstructed into protein data. In this study, we have used this approach to study protein secretion by Aspergillus flavus, a filamentous fungus for which very little genome sequence information is available. A. flavus is capable of degrading the flavonoid rutin (quercetin 3-O-glycoside), as the only source of carbon via an extracellular enzyme system. In this continuing study, a proteomic analysis was used to identify secreted proteins from A. flavus when grown on rutin. The growth media glucose and potato dextrose were used to identify differentially expressed secreted proteins. The secreted proteins were analyzed by 1- and 2-DE and MS/MS. A total of 51 unique A. flavus secreted proteins were identified from the three growth conditions. Ten proteins were unique to rutin-, five to glucose- and one to potato dextrose-grown A. flavus. Sixteen secreted proteins were common to all three media. Fourteen identifications were of hypothetical proteins or proteins of unknown functions. To our knowledge, this is the first extensive proteomic study conducted to identify the secreted proteins from a filamentous fungus.

  14. The role of Aspergillus flavus veA in the production of extracellular proteins during growth on starch substrates.

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    Duran, Rocio M; Gregersen, Scott; Smith, Timothy D; Bhetariya, Preetida J; Cary, Jeffrey W; Harris-Coward, Pamela Y; Mattison, Christopher P; Grimm, Casey; Calvo, Ana M

    2014-06-01

    The aflatoxin-producer and opportunistic plant pathogenic, filamentous fungus Aspergillus flavus is responsible for the contamination of corn and other important agricultural commodities. In order to obtain nutrients from the host A. flavus produces a variety of extracellular hydrolytic enzymes. Interestingly, A. flavus amylase and protease activity are dependent on the global regulator veA, a gene known to regulate morphogenesis and secondary metabolism in numerous fungi. Analysis of starch degradation by fungal enzymes secreted into broths of starch- or corn kernel-based media showed a notable accumulation of glucose in samples of the A. flavus control strain while the deletion veA sample accumulated high levels of maltose and maltotriose and only a small amount of glucose. Furthermore, SDS-PAGE and proteomics analysis of culture broths from starch- or corn kernel-based media demonstrated differential production of a number of proteins that included a reduction in the amount of a glucoamylase protein in the veA mutant compared to the control strain, while an alpha-amylase was produced in greater quantities in the veA mutant. Quantitative real-time PCR and western blot analyses using anti-glucoamylase or alpha-amylase antisera supported the proteomics results. Additionally, an overall reduction in protease activity was observed in the veA mutant including production of the alkaline protease, oryzin, compared to the control strain. These findings contribute to our knowledge of mechanisms controlling production of hydrolases and other extracellular proteins during growth of A. flavus on natural starch-based substrates.

  15. 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

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

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    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.

  17. Experimental study of Aspergillus flavus fungus from uranium mines

    Energy Technology Data Exchange (ETDEWEB)

    Kusak, V. (Ceskoslovenska Akademie Ved, Prague. Ustav Experimentalni Mediciny)

    1982-06-01

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

  18. Experimental study of Aspergillus flavus fungus from uranium mines

    International Nuclear Information System (INIS)

    Kusak, V.

    1982-01-01

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

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

    Science.gov (United States)

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

    2016-07-02

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

  20. 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.

  1. 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...

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

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    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.

  3. 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...

  4. 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.

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

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    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.

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

    Directory of Open Access Journals (Sweden)

    Riza Zainuddin Ahmad

    2017-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Marina M. Pinto

    2001-06-01

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

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Xingyu Luo

    2016-10-01

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

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

    International Nuclear Information System (INIS)

    Sussa, Fabio Vitorio

    2011-01-01

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

  12. 40 CFR 180.1206 - Aspergillus flavus AF36; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Aspergillus flavus AF36; exemption... FOOD Exemptions From Tolerances § 180.1206 Aspergillus flavus AF36; exemption from the requirement of a... pesticide Aspergillus flavus AF36 in or on cotton, gin byproducts; cotton, hulls; cotton, meal; cotton...

  13. 40 CFR 180.1254 - Aspergillus flavus NRRL 21882; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Aspergillus flavus NRRL 21882... RESIDUES IN FOOD Exemptions From Tolerances § 180.1254 Aspergillus flavus NRRL 21882; exemption from the... of Aspergillus flavus NRRL 21882 on peanut; peanut, hay; peanut, meal; and peanut, refined oil. (b...

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

    Directory of Open Access Journals (Sweden)

    Eni Kusumaningtyas

    2006-12-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2017-01-01

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

  17. Lactic acid bacteria as functional probiotic isolates for inhibiting the growth of Aspergillus flavus, A. parasiticus, A. niger and Penicillium chrysogenum.

    Science.gov (United States)

    Abbaszadeh, S; Tavakoli, R; Sharifzadeh, A; Shokri, H

    2015-12-01

    The aim of this study was to assess the potential of lactic acid bacteria (LAB) such as Lactobacillus acidophilus, L. rhamnosus, L. casei, L. paracasei and Bifidobacterium bifidum to inhibit the outgrowth of some common food-spoiling fungi including Aspergillus niger, A. flavus, A. parasiticus and Penicillium chrysogenum. Bacterial isolates were cultured on Mann Rogosa Sharpe (MRS) broth and liquid cultures and supernatants were prepared. The antifungal activity was tested using the agar well diffusion method. Both liquid culture and supernatant of L. casei isolate exhibited high antifungal activity, followed by L. acidophilus and L. paracasei isolates. The least activity was recorded for the isolates B. bifidum, while the isolate L. rhamnosus was moderately active against tested fungi. The antifungal activity of the supernatants obtained from all probiotic isolates against fungi was significantly less than that of liquid cultures (Pniger and A. parasiticus. These results suggest that probiotic bacteria strains have the ability to prevent the growth of pathogenic and mycotoxigenic fungi as antifungal agents for various biomedical applications. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  18. 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...

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

    African Journals Online (AJOL)

    USER

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

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

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, R.; Samuel, C.T.

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

  1. Aspergillus flavus secondary metabolites: more than just aflatoxins

    Science.gov (United States)

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

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

    Science.gov (United States)

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

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

    African Journals Online (AJOL)

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

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

    African Journals Online (AJOL)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Sussa, Fabio Vitorio

    2011-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Xiaoyun Han

    2016-11-01

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

  7. Occurrence of toxigenic Aspergillus flavus in commercial Bulgur wheat

    Directory of Open Access Journals (Sweden)

    Carla Bertechini FARIA

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

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

    Directory of Open Access Journals (Sweden)

    Karim Mardani

    2010-09-01

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

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

    Science.gov (United States)

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

    2015-10-01

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

  10. 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)

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

    African Journals Online (AJOL)

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

  12. 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.)

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

    Science.gov (United States)

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

    1972-11-01

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

  14. Study of effect ultraviolet radiation on Aspergillus Flavus and Aspergillus Parasiticus

    International Nuclear Information System (INIS)

    Ghafourian, H.; Kafaei, F.; Raouf, J.B.

    2000-01-01

    In this article the results of ultraviolet radiation effects on Aspergillus Flavus and Aspergillus parasiticus to reach the quality control standards are presented. The purpose was to test the effect of ultraviolet radiation in 254 nanometer wavelength for fungi decontamination with respect to the exposure time of radiation and the distance between samples and radiation source. The ultraviolet radiation effects on plates containing Aspergillus Flavus and Aspergillus Parasiticus fungi were studied in the exposure time duration of 30, to 360 seconds of a fixed distance, and also for variable distances from 10 to 40 cm at a given exposure time. It is shown that in the exposure time of more than 360 second the ultraviolet radiation exposure highly decreases the number of Aspergillus Flavus and Aspergillus Parasiticus fungi colonies. By reducing the distance, the number of colonies decreases and it is minimized at a 10 cm distance in the time exposure of 360 second. The above results show that the ultraviolet radiation is an effective method for food decontamination and can be used in industry

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    Jun Tian

    2013-01-01

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

  17. 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.

  18. 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...

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

    Science.gov (United States)

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

    2012-01-01

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

  20. 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.

  1. 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)

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

    Directory of Open Access Journals (Sweden)

    Mohamed A. Yassin

    2017-09-01

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

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

    Science.gov (United States)

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

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

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

    Directory of Open Access Journals (Sweden)

    Elson de C. Viegas

    2005-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Bashir Ahmad

    2016-11-01

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

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

    African Journals Online (AJOL)

    Nelciele

    Aspergillus flavus produced high levels of xylanase on agricultural residues with ... addition of 5% glycerol, mannitol or xylitol protected the xylanase from thermal inactivation at 50°C. The .... most often included in nutrient media for microbial.

  7. 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 (...

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

    Science.gov (United States)

    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. ...

  9. 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 ...

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

    Science.gov (United States)

    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. ...

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    Jeffrey W. Cary

    2017-10-01

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

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

    International Nuclear Information System (INIS)

    Mahrous, S.R.

    2007-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jenny Hidayat

    2015-12-01

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

  15. 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)

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    Aspergillus oryzae and A. flavus are important species in industrial biotechnology and food safety and have been some of the first aspergilli to be fully genome sequenced. Bioinformatic analysis has revealed 99.5% gene homology between the two species pointing towards a large coherence in the sec...... alkaloids related to the A. flavus metabolites ditryptophenalines and miyakamides. Generally the secondary metabolite capability of A. oryzae presents several novel end products likely to result from the domestication process from A. flavus.......Aspergillus oryzae and A. flavus are important species in industrial biotechnology and food safety and have been some of the first aspergilli to be fully genome sequenced. Bioinformatic analysis has revealed 99.5% gene homology between the two species pointing towards a large coherence...

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

    OpenAIRE

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

    2012-01-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    The disinfection process for inactivating microorganisms at drinking water treatment plants is aimed for safety of drinking water for humans from a microorganism, such as bacteria, viruses, algae, fungi by using chlorination, ozonation, UV irradiation, etc. In the present study, a combination of two disinfectants, UV irradiation followed by chlorination, was evaluated for inactivating Aspergillus flavus under low contact time and low dosage of UV irradiation. The results indicated an inverse correlation between the inactivation of A. flavus by using UV irradiation only or chlorination alone. By using UV radiation, the 2 log 10 control of A. flavus was achieved after 30 s of irradiation, while chlorination was observed to be more effective than UV, where the 2 log was achieved at chlorine concentration of 0.5, 1, 2 and 3 mg/l, in contact time of 60, 5, 1 and 1 min, respectively. However, combined use (UV irradiation followed by chlorination) was more effective than using either UV or chlorination alone; 5 s UV irradiation followed by chlorination produced 4 log 10 reduction of A. flavus at chlorine concentrations of 2 and 3 mg/l under a contact time of 15 min. The results indicated that efficiency of UV irradiation improves when followed by chlorination at low concentrations. - Highlights: • As a disinfectant, chlorine is more effective than UV in inactivating Aspergillus flavus. • As a combined method, UV irradiation followed by chlorination shows high efficiency. • UV irradiation can improve effectiveness of chlorination in reducing Aspergillus flavus

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

    Directory of Open Access Journals (Sweden)

    F

    1981-05-01

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

  20. 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.

  1. Impact of the antifungal protein PgAFP from Penicillium chrysogenum on the protein profile in Aspergillus flavus.

    Science.gov (United States)

    Delgado, Josué; Owens, Rebecca A; Doyle, Sean; Asensio, Miguel A; Núñez, Félix

    2015-10-01

    Antifungal proteins produced by molds are generally small, highly basic, and cysteine-rich. The best known effects of these proteins include morphological changes, metabolic inactivation, and membrane perturbation on sensitive fungi. Reactive oxygen species (ROS) generation leads to apoptosis, with G -protein playing a key role in transduction of cell death signals. The antifungal protein PgAFP from Penicillium chrysogenum inhibits growth of some toxigenic molds. Here we analyzed the effect of the antifungal protein PgAFP on the growth of Aspergillus flavus. For this, comparative proteomic analysis was used to identify the whole protein profile and protein change in abundance after PgAFP treatment. PgAFP provoked metabolic changes related to reduced energy metabolism, cell wall integrity alteration, and increased stress response due to higher levels of ROS. The observed changes in protein abundance, favoring a higher glutathione concentration as well as the increased abundance in heat shock proteins, do not seem to be enough to avoid necrosis. The decreased chitin deposition observed in PgAFP-treated A. flavus is attributed to a lower relative quantity of Rho1. The reduced relative abundance of a β subunit of G -protein seems to be the underlying reason for modulation of apoptosis in PgAFP-treated A. flavus hyphae. We propose Rho1 and G -protein subunit β CpcB to be the main factors in the mode of action of PgAFP in A. flavus. Additionally, enzymes essential for the biosynthesis of aflatoxin were no longer detectable in A. flavus hyphae at 24 h, following treatment with PgAFP. This presents a promising effect of PgAFP, which may prevent A. flavus from producing mycotoxins. However, the impact of PgAFP on actual aflatoxin production requires further study.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Ajay Kumar Gautam

    2014-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Ming-Yueh Wu

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

  5. Quantitative proteomics reveals new insights into calcium-mediated resistance mechanisms in Aspergillus flavus against the antifungal protein PgAFP in cheese.

    Science.gov (United States)

    Delgado, Josué; Owens, Rebecca A; Doyle, Sean; Núñez, Félix; Asensio, Miguel A

    2017-09-01

    The ability of Aspergillus flavus to produce aflatoxins in dairy products presents a potential hazard. The antifungal protein PgAFP from Penicillium chrysogenum inhibits various foodborne toxigenic fungi, including Aspergillus flavus. However, PgAFP did not inhibit A. flavus growth in cheese, which was related to the associated cation content. CaCl 2 increased A. flavus permeability and prevented PgAFP-mediated inhibition in potato dextrose broth (PDB). PgAFP did not elicit any additional increase in permeability of CaCl 2 -incubated A. flavus. Furthermore, PgAFP did not alter metabolic capability, chitin deposition, or hyphal viability of A. flavus grown with CaCl 2 . Comparative proteomic analysis after PgAFP treatment of A. flavus in calcium-enriched PDB revealed increased abundance of 125 proteins, including oxidative stress-related proteins, as determined by label-free mass spectrometry (MS)-based proteomics. Seventy proteins were found at lower abundance, with most involved in metabolic pathways and biosynthesis of secondary metabolites. These changes do not support the blockage of potential PgAFP receptors in A. flavus by calcium as the main cause of the protective role. A. flavus resistance appears to be mediated by calcineurin, G-protein, and γ-glutamyltranspeptidase that combat oxidative stress and impede apoptosis. These findings could serve to design strategies to improve PgAFP activity against aflatoxigenic moulds in dairy products. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

  7. 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...

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

    NARCIS (Netherlands)

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

    2015-01-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

  11. 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...

  12. 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...

  13. [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.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Melissa Orzechowski Xavier

    2009-02-01

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

  16. A survey on distribution and toxigenicity of Aspergillus flavus from indoor and outdoor hospital environments.

    Science.gov (United States)

    Sepahvand, Asghar; Shams-Ghahfarokhi, Masoomeh; Allameh, Abdolamir; Jahanshiri, Zahra; Jamali, Mojdeh; Razzaghi-Abyaneh, Mehdi

    2011-11-01

    In the present study, genetic diversity and mycotoxin profiles of Aspergillus flavus isolated from air (indoors and outdoors), levels (surfaces), and soils of five hospitals in Southwest Iran were examined. From a total of 146 Aspergillus colonies, 63 isolates were finally identified as A. flavus by a combination of colony morphology, microscopic criteria, and mycotoxin profiles. No Aspergillus parasiticus was isolated from examined samples. Chromatographic analyses of A. flavus isolates cultured on yeast extract-sucrose broth by tip culture method showed that approximately 10% and 45% of the isolates were able to produce aflatoxin B(1) (AFB(1)) and cyclopiazonic acid (CPA), respectively. Around 40% of the isolates produced sclerotia on Czapek-Dox agar. The isolates were classified into four chemotypes based on the ability to produce AF and CPA that majority of them (55.5%) belonged to chemotype IV comprising non-mycotoxigenic isolates. Random amplified polymorphic DNA (RAPD) profiles generated by a combination of four selected primers were used to assess genetic relatedness of 16 selected toxigenic and non-toxigenic isolates. The resulting dendrogram demonstrated the formation of two separate clusters for the A. flavus comprised both mycotoxigenic and non-toxigenic isolates in a random distribution. The obtained results in this study showed that RAPD profiling is a promising and efficient tool to determine intra-specific genetic variation among A. flavus populations from hospital environments. A. flavus isolates, either toxigenic or non-toxigenic, should be considered as potential threats for hospitalized patients due to their obvious role in the etiology of nosocomial aspergillosis.

  17. Antifungal Metabolites (Monorden, Monocillin IV, and Cerebrosides) from Humicola fuscoatra Traaen NRRL 22980, a Mycoparasite of Aspergillus flavus Sclerotia

    OpenAIRE

    Wicklow, Donald T.; Joshi, Biren K.; Gamble, William R.; Gloer, James B.; Dowd, Patrick F.

    1998-01-01

    The mycoparasite Humicola fuscoatra NRRL 22980 was isolated from a sclerotium of Aspergillus flavus that had been buried in a cornfield near Tifton, Ga. When grown on autoclaved rice, this fungus produced the antifungal metabolites monorden, monocillin IV, and a new monorden analog. Each metabolite produced a clear zone of inhibition surrounding paper assay disks on agar plates seeded with conidia of A. flavus. Monorden was twice as inhibitory to A. flavus mycelium extension (MIC > 28 μg/ml) ...

  18. 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.

  19. Carbon dioxide mediates the response to temperature and water activity levels in Aspergillus flavus during infection of maize kernels

    Science.gov (United States)

    Aspergillus flavus is a saprophytic fungus that may colonize several important crops, including cotton, maize, peanuts and tree nuts. Concomitant with A. flavus colonization is its potential to secrete mycotoxins, of which the most prominent is aflatoxin. Temperature, water activity (aw) and carbon ...

  20. 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...

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

    Science.gov (United States)

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

    2018-03-01

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

  2. Extracellular Xylanolytic and Pectinolytic Hydrolase Production by Aspergillus flavus Isolates Contributes to Crop Invasion

    Directory of Open Access Journals (Sweden)

    Jay E. Mellon

    2015-08-01

    Full Text Available Several atoxigenic Aspergillus flavus isolates, including some being used as biocontrol agents, and one toxigenic isolate were surveyed for the ability to produce extracellular xylanolytic and pectinolytic hydrolases. All of the tested isolates displayed good production of endoxylanases when grown on a medium utilizing larch xylan as a sole carbon substrate. Four of the tested isolates produced reasonably high levels of esterase activity, while the atoxigenic biocontrol agent NRRL 21882 isolate esterase level was significantly lower than the others. Atoxigenic A. flavus isolates 19, 22, K49, AF36 (the latter two are biocontrol agents and toxigenic AF13 produced copious levels of pectinolytic activity when grown on a pectin medium. The pectinolytic activity levels of the atoxigenic A. flavus 17 and NRRL 21882 isolates were significantly lower than the other tested isolates. In addition, A. flavus isolates that displayed high levels of pectinolytic activity in the plate assay produced high levels of endopolygalacturonase (pectinase P2c, as ascertained by isoelectric focusing electrophoresis. Isolate NRRL 21882 displayed low levels of both pectinase P2c and pectin methyl esterase. A. flavus appears capable of producing these hydrolytic enzymes irrespective of aflatoxin production. This ability of atoxigenic isolates to produce xylanolytic and pectinolytic hydrolases mimics that of toxigenic isolates and, therefore, contributes to the ability of atoxigenic isolates to occupy the same niche as A. flavus toxigenic isolates.

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

    African Journals Online (AJOL)

    Administrator

    Available online at http://www.academicjournals.org/AJB. ISSN 1684–5315 ... Spores of A. flavus in control medium commenced germination after 2 h while ... known to produce aflatoxins, a group of acutely toxic and ... The genus is widely ... control of various fungal diseases of plants in the green ..... Indian Phytopathol.

  4. 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)

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

    Directory of Open Access Journals (Sweden)

    Angel eMedina

    2014-07-01

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

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    Jake C. Fountain

    2015-06-01

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

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

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... consumption of aflatoxin contaminated food and feed. (Reddy and ..... intervals by artificial inoculation of A. parasiticus on rice grains. ... additive for culture media for rapid identification of aflatoxin producing. Aspergillus strains ...

  9. 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...

  10. 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

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  13. 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

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

    Directory of Open Access Journals (Sweden)

    Z. Jurjevic

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mohammad Hashemi

    2016-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Adeela Hussain

    2015-02-01

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

  17. 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

  18. Molecular characterisation of Aspergillus flavus isolates from peanut fields in India using AFLP

    Directory of Open Access Journals (Sweden)

    Diwakar Singh

    2015-09-01

    Full Text Available Aflatoxin contamination of peanut, due to infection by Aspergillus flavus, is a major problem of rain-fed agriculture in India. In the present study, molecular characterisation of 187 Aspergillus flavus isolates, which were sampled from the peanut fields of Gujarat state in India, was performed using AFLP markers. On a pooled cluster analysis, the markers could successfully discriminate among the ‘A’, ‘B’ and ‘G’ group A. flavus isolates. PCoA analysis also showed equivalent results to the cluster analysis. Most of the isolates from one district could be clustered together, which indicated genetic similarity among the isolates. Further, a lot of genetic variability was observed within a district and within a group. The results of AMOVA test revealed that the variance within a population (84% was more than that between two populations (16%. The isolates, when tested by indirect competitive ELISA, showed about 68.5% of them to be atoxigenic. Composite analysis between the aflatoxin production and AFLP data was found to be ineffective in separating the isolate types by aflatoxigenicity. Certain unique fragments, with respect to individual isolates, were also identified that may be used for development of SCAR marker to aid in rapid and precise identification of isolates.

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

    Science.gov (United States)

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

    2015-12-01

    Chronic subcutaneous infections caused by Aspergillus species are considered to be extremely rare. Because these fungi are among the most common laboratory contaminants, their role as eumycetoma causative agents is difficult to ascertain. Here, we report the first case of A. flavus eumycetoma confirmed by isolation, molecular identification and immunohistochemical analysis. Patient was a 55-year-old male from Sudan suffering from eumycetoma on his left foot for a period of 17 years. He developed swelling, sinuses and white grain discharge was observed. He has been operated nine times and was treated with several regimens of ketoconazole and itraconazole without improvement. Initial diagnosis based on histology and radiology was Scedosporium eumycetoma. However, examination of the biopsy revealed A. flavus, which was identified by molecular analysis and MALDI-TOF MS. Immunohistochemistry using antibody directed against Aspergillus species was positive. Because of the earlier treatment failures with ketoconazole and itraconazole, therapy with voriconazole was initiated. However, in vitro susceptibility testing yielded a lower Minimum Inhibitory Concentration (MIC) value for itraconazole (0.25 μg ml(-1) ) than for voriconazole (1 μg ml(-1) ). Based on the presented results, A. flavus can be considered as one of the agents of white-grain eumycetoma. © 2015 Blackwell Verlag GmbH.

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

    Directory of Open Access Journals (Sweden)

    Ramu Muthu Selvam

    2015-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Sahar Omidpanah

    2015-01-01

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

  2. Proteomic analysis of rutin-induced secreted proteins from Aspergillus flavus.

    Science.gov (United States)

    Medina, Martha L; Kiernan, Urban A; Francisco, Wilson A

    2004-03-01

    Few studies have been conducted to identify the extracellular proteins and enzymes secreted by filamentous fungi, particularly with respect to dispensable metabolic pathways. Proteomic analysis has proven to be the most powerful method for identification of proteins in complex mixtures and is suitable for the study of the alteration of protein expression under different environmental conditions. The filamentous fungus Aspergillus flavus can degrade the flavonoid rutin as the only source of carbon via an extracellular enzyme system. In this study, a proteomic analysis was used to differentiate and identify the extracellular rutin-induced and non-induced proteins secreted by A. flavus. The secreted proteins were analyzed by two-dimensional electrophoresis and MALDI-TOF mass spectrometry. While 15 rutin-induced proteins and 7 non-induced proteins were identified, more than 90 protein spots remain unidentified, indicating that these proteins are either novel proteins or proteins that have not yet been sequenced.

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

    OpenAIRE

    Ehrlich, Kenneth C.; Mack, Brian M.

    2014-01-01

    Fifty six secondary metabolite biosynthesis gene clusters are predicted to be in the Aspergillus flavus genome. In spite of this, the biosyntheses of only seven metabolites, including the aflatoxins, kojic acid, cyclopiazonic acid and aflatrem, have been assigned to a particular gene cluster. We used RNA-seq to compare expression of secondary metabolite genes in gene clusters for the closely related fungi A. parasiticus, A. oryzae, and A. flavus S and L sclerotial morphotypes. The data help ...

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

    Directory of Open Access Journals (Sweden)

    Hongbo Li

    2015-04-01

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

  5. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-15

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

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

    DEFF Research Database (Denmark)

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

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

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

    International Nuclear Information System (INIS)

    Correa, Marivaldo J.C.; Nunes, Fatima M.; Bitencourt, Heriberto R.; Borges, Fabio C.; Guilhon, Giselle M.S.P.; Arruda, Mara S.P.; Marinho, Andrey M. R.; Santos, Alberdan S.; Alves, Claudio N.; Santos, Lourivaldo S.; Brasil, Davi S.B.

    2011-01-01

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

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

    Science.gov (United States)

    Devipriya, Duraipandi; Roopan, Selvaraj Mohana

    2017-11-01

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

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

    Science.gov (United States)

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

    2017-07-01

    Aspergillus flavus and Aspergillus parasiticus are primary pathogen moulds on brown rice and barley. This study investigated the effects of microwave irradiation (MWI) (2450 MHz, 700 W, 10-50 s) on inactivation of A. flavus and A. parasiticus on brown rice and barley and the quality of these samples. The counts of both strains were significantly (p  90% reduction of mould without causing deleterious changes to the colour, moisture content and sensory qualities of these cereals.

  12. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Dong Ying Wang

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

  16. Frequent Shifts in Aspergillus flavus Populations Associated with Maize Production in Sonora, Mexico.

    Science.gov (United States)

    Ortega-Beltran, A; Cotty, P J

    2018-03-01

    Aspergillus flavus frequently contaminates maize, a critical staple for billions of people, with aflatoxins. Diversity among A. flavus L morphotype populations associated with maize in Sonora, Mexico was assessed and, in total, 869 isolates from 83 fields were placed into 136 vegetative compatibility groups (VCGs) using nitrate-nonutilizing mutants. VCG diversity indices did not differ in four agroecosystems (AES) but diversity significantly differed among years. Frequencies of certain VCGs changed manyfold over single years in both multiple fields and multiple AES. Certain VCGs were highly frequent (>1%) in 2006 but frequencies declined repeatedly in each of the two subsequent years. Other VCGs that had low frequencies in 2006 increased in 2007 and subsequently declined. None of the VCGs were consistently associated with any AES. Fourteen VCGs were considered dominant in at least a single year. However, frequencies often varied significantly among years. Only 9% of VCGs were detected all 3 years whereas 66% were detected in only 1 year. Results suggest that the most realistic measurements of both genetic diversity and the frequency of A. flavus VCGs are obtained by sampling multiple locations in multiple years. Single-season sampling in many locations should not be substituted for sampling over multiple years.

  17. In vivo screening antifungal activity of methanolic extract of Protoparmeliopsis muralis against Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Somaye Rashki

    2017-06-01

    Full Text Available Background & Objective: Lichens are the result of the symbiosis of fungi and algae or a cyanobacterium. Various biological activities of some lichen and their components such as: antifungal, anti-bacterial, anti-tumor, anti-inflammatory, antiprotozoal substances are known. In the present study, antifungal activity of methanolic extract of Protoparmeliopsis muralis against Aspergillus flavus is investigated on rats. Materials & Methods: 500 g of Protoparmeliopsis muralis was collected from KaneGonbad mountains in Ilam province, the methanol extract was prepared by soxhle. In order to determine the antifungal activity in in vivo conditions, a wound was created and infected with Aspergillus flavus. Having infected the wound, the researchers divided the rats into 4 subgroups: negative control group, treated with Kotrimoksazol, %5 ointment extract methanolic P. muralis, and with %10 ointment extract methanolic P. muralis. Treatment continued until complete healing of the wound. Finally, the percentage of wound healing was calculated. Results: The result of the present study demonstrated that methanolic extract of P. muralis decreased the area of wound in the treatment group compared to the control group. Conclusion: The antifungal and antioxidant activity of the extract of Protoparmeliopsis muralis accelerated the wound healing process.

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

    Directory of Open Access Journals (Sweden)

    Evandro eDe Souza

    2015-07-01

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

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

    Science.gov (United States)

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

    2009-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Ednei Assuncao Antunes

    2012-07-01

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

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  2. 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....

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2015-01-01

    Aspergillus flavus is an efficient producer of mycotoxins, particularly aflatoxin B1, probably the most hepatocarcinogenic naturally-occurring compound. Although the inducing agents of toxin synthesis are not unanimously identified, there is evidence that oxidative stress is one of the main actors in play. In our study, we use menadione, a quinone extensively implemented in studies on ROS response in animal cells, for causing stress to A. flavus. For uncovering the molecular determinants that drive A. flavus in challenging oxidative stress conditions, we have evaluated a wide spectrum of several different parameters, ranging from metabolic (ROS and oxylipin profile) to transcriptional analysis (RNA-seq). There emerges a scenario in which A. flavus activates several metabolic processes under oxidative stress conditions for limiting the ROS-associated detrimental effects, as well as for triggering adaptive and escape strategies. PMID:26512693

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

    Directory of Open Access Journals (Sweden)

    Marco Zaccaria

    2015-10-01

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

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

    Science.gov (United States)

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

    2015-10-23

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

  9. Antifungal metabolites (monorden, monocillin IV, and cerebrosides) from Humicola fuscoatra traaen NRRL 22980, a mycoparasite of Aspergillus flavus sclerotia.

    Science.gov (United States)

    Wicklow, D T; Joshi, B K; Gamble, W R; Gloer, J B; Dowd, P F

    1998-11-01

    The mycoparasite Humicola fuscoatra NRRL 22980 was isolated from a sclerotium of Aspergillus flavus that had been buried in a cornfield near Tifton, Ga. When grown on autoclaved rice, this fungus produced the antifungal metabolites monorden, monocillin IV, and a new monorden analog. Each metabolite produced a clear zone of inhibition surrounding paper assay disks on agar plates seeded with conidia of A. flavus. Monorden was twice as inhibitory to A. flavus mycelium extension (MIC > 28 microg/ml) as monocillin IV (MIC > 56 microg/ml). Cerebrosides C and D, metabolites known to potentiate the activity of cell wall-active antibiotics, were separated from the ethyl acetate extract but were not inhibitory to A. flavus when tested as pure compounds. This is the first report of natural products from H. fuscoatra.

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

    International Nuclear Information System (INIS)

    Coelho, Ednei Assuncao Antunes

    2012-01-01

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

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

    Science.gov (United States)

    Aspergillus flavus aswA (AFLA_085170) is a gene encoding a Zn(II)2Cys6 DNA-binding domain. Partial deletion of aswA yielded strains that made a truncated gene transcript and generated a fungus that produced a greatly increased number of sclerotia. These sclerotia were odd-shaped and non-pigmented (w...

  12. In vitro susceptibility of 188 clinical and environmental isolates of Aspergillus flavus for the new triazole isavuconazole and seven other antifungal drugs

    NARCIS (Netherlands)

    Shivaprakash, M.R.; Geertsen, E.; Chakrabarti, A.; Mouton, J.W.; Meis, J.F.G.M.

    2011-01-01

    Recently isavuconazole, an experimental triazole agent, was found to be active against Aspergillus species. As Aspergillus flavus is the second-most common Aspergillus species isolated from human infection and the fungus has not been widely tested against the drug, we studied a large collection of

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

    Directory of Open Access Journals (Sweden)

    Jake C. Fountain

    2015-08-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Comparative Histological and Transcriptional Analysis of Maize Kernels Infected with Aspergillus flavus and Fusarium verticillioides

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    Xiaomei Shu

    2017-12-01

    Full Text Available Aspergillus flavus and Fusarium verticillioides infect maize kernels and contaminate them with the mycotoxins aflatoxin, and fumonisin, respectively. Genetic resistance in maize to these fungi and to mycotoxin contamination has been difficult to achieve due to lack of identified resistance genes. The objective of this study was to identify new candidate resistance genes by characterizing their temporal expression in response to infection and comparing expression of these genes with genes known to be associated with plant defense. Fungal colonization and transcriptional changes in kernels inoculated with each fungus were monitored at 4, 12, 24, 48, and 72 h post inoculation (hpi. Maize kernels responded by differential gene expression to each fungus within 4 hpi, before the fungi could be observed visually, but more genes were differentially expressed between 48 and 72 hpi, when fungal colonization was more extensive. Two-way hierarchal clustering analysis grouped the temporal expression profiles of the 5,863 differentially expressed maize genes over all time points into 12 clusters. Many clusters were enriched for genes previously associated with defense responses to either A. flavus or F. verticillioides. Also within these expression clusters were genes that lacked either annotation or assignment to functional categories. This study provided a comprehensive analysis of gene expression of each A. flavus and F. verticillioides during infection of maize kernels, it identified genes expressed early and late in the infection process, and it provided a grouping of genes of unknown function with similarly expressed defense related genes that could inform selection of new genes as targets in breeding strategies.

  16. Modification of the radiation resistance of Aspergillus flavus mycelial units by some chemicals

    International Nuclear Information System (INIS)

    Mohyuddin, M.; Skoropad, W.P.

    1977-01-01

    Survival curves for the mycelium of Aspergillus flavus Link var. columnaris Raper and Fennell were constructed after irradiation with gamma rays in the presence of NaCl, NaBr, NaI, KCl, KBr, KI, CaCl 2 , CaBr 2 , CaI 2 , Ca(NO 3 ) 2 , NaNO 2 , NaNO 3 , KNO 2 , iodoacetic acid, iodoacetamide and vitamin K 5 . In addition iodized salt was also tested. All the chemicals tested exhibited initial toxicity at zero dose. However, most of the chemicals demonstrated a synergism when present during irradiation. Compounds containing iodine were invariably the strongest radiosensitizers. The iodine present as an admixture in salt also retained its radiosensitizing character. Sodium bromide and calcium bromide behaved in a different way. The initial toxicity was reduced along with an increase in radiation dose resulting in more survival. (orig.) [de

  17. 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

  18. 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),

  19. 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....

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

    Directory of Open Access Journals (Sweden)

    Rajtilak Majumdar

    2018-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Smita Tripathi

    2009-03-01

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

  2. 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.

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

    Science.gov (United States)

    Tao, Lin; Chung, Soo Hyun

    2014-08-01

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

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

    Science.gov (United States)

    Gupta, Saurabh; Bector, Shruti

    2013-05-01

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

  5. Fungicidal and anti-aflatoxigenic effects of the essential oil of Cymbopogon citratus (DC.) Stapf. (lemongrass) against Aspergillus flavus Link. isolated from stored rice.

    Science.gov (United States)

    Paranagama, P A; Abeysekera, K H T; Abeywickrama, K; Nugaliyadde, L

    2003-01-01

    To develop a natural fungicide against aflatoxigenic fungi, to protect stored rice, using the essential oil of lemongrass. Aspergillus flavus Link. was isolated from stored rice and identified as an aflatoxigenic strain. Lemongrass oil was tested against A. flavus and the test oil was fungistatic and fungicidal against the test pathogen at 0.6 and 1.0 mg ml(-1), respectively. Aflatoxin production was completely inhibited at 0.1 mg ml(-1). The results obtained from the thin layer chromatographic bioassay and gas chromatography indicated citral a and b as the fungicidal constituents in lemongrass oil. During the fumigant toxicity assay of lemongrass oil, the sporulation and the mycelial growth of the test pathogen were inhibited at the concentrations of 2.80 and 3.46 mg ml(-1), respectively. Lemongrass oil could be used to manage aflatoxin formation and fungal growth of A. flavus in stored rice. Currently, fungicides are not used to control fungal pests or mycotoxin production on stored rice. Rice treated with the essential oil of lemongrass could be used to manage fungal pests as well as the insect pests in stored rice. The essential oil is chemically safe and acceptable to consumers, as synthetic chemical fungicides can cause adverse health effects to consumers.

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

    Science.gov (United States)

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

    2015-08-01

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

  7. 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.

  8. 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. ...

  9. Data set of Aspergillus flavus induced alterations in tear proteome: Understanding the pathogen-induced host response to fungal infection

    OpenAIRE

    Kandhavelu, Jeyalakshmi; Demonte, Naveen Luke; Namperumalsamy, Venkatesh Prajna; Prajna, Lalitha; Thangavel, Chitra; Jayapal, Jeya Maheshwari; Kuppamuthu, Dharmalingam

    2016-01-01

    Fungal keratitis is one of the leading causes of blindness in the tropical countries affecting individuals in their most productive age. The host immune response during this infection is poorly understood. We carried out comparative tear proteome analysis of Aspergillus flavus keratitis patients and uninfected controls. Proteome was separated into glycosylated and non-glycosylated fractions using lectin column chromatography before mass spectrometry. The data revealed the major processes acti...

  10. A Histological Study of Aspergillus flavus Colonization of Wound Inoculated Maize Kernels of Resistant and Susceptible Maize Hybrids in the Field

    Directory of Open Access Journals (Sweden)

    Gary L. Windham

    2018-04-01

    Full Text Available Aspergillus flavus colonization in developing kernels of maize single-cross hybrids resistant (Mp313E × Mp717 and susceptible (GA209 × T173 to aflatoxin accumulation was determined in the field over three growing seasons (2012–2014. Plants were hand pollinated, and individual kernels were inoculated with a needle dipped in a suspension of A. flavus conidia 21 days after pollination. Kernels were harvested at 1- to 2-day intervals from 1 to 21 days after inoculation (DAI. Kernels were placed in FAA fixative, dehydrated, embedded in paraffin, sectioned, and stained with toluidine blue. Kernels were also collected additional kernels for aflatoxin analyses in 2013 and 2014. At 2 DAI, A. flavus hyphae were observed among endosperm cells in the susceptible hybrid, but colonization of the endosperm in the resistant hybrid was limited to the wound site of the resistant hybrid. Sections of the scutellum of the susceptible hybrid were colonized by A. flavus by 5 DAI. Fungal growth was slower in the resistant hybrid compared to the susceptible hybrid. By 10 DAI, A. flavus had colonized a large section of the embryo in the susceptible hybrid; whereas in the resistant hybrid, approximately half of the endosperm had been colonized and very few cells in the embryo were colonized. Fungal colonization in some of the kernels of the resistant hybrid was slowed in the aleurone layer or at the endosperm-scutellum interface. In wounded kernels with intact aleurone layers, the fungus spread around the kernel between the pericarp and aleurone layer with minimal colonization of the endosperm. Aflatoxin B1 was first detected in susceptible kernel tissues 8 DAI in 2013 (14 μg/kg and 2014 (18 μg/kg. The resistant hybrid had significantly lower levels of aflatoxin accumulation compared to the susceptible hybrid at harvests 10, 21, and 28 DAI in 2013, and 20 and 24 DAI in 2014. Our study found differential A. flavus colonization of susceptible and resistant kernel

  11. Identification of alternative splice variants in Aspergillus flavus through comparison of multiple tandem MS search algorithms

    Directory of Open Access Journals (Sweden)

    Chang Kung-Yen

    2011-07-01

    Full Text Available Abstract Background Database searching is the most frequently used approach for automated peptide assignment and protein inference of tandem mass spectra. The results, however, depend on the sequences in target databases and on search algorithms. Recently by using an alternative splicing database, we identified more proteins than with the annotated proteins in Aspergillus flavus. In this study, we aimed at finding a greater number of eligible splice variants based on newly available transcript sequences and the latest genome annotation. The improved database was then used to compare four search algorithms: Mascot, OMSSA, X! Tandem, and InsPecT. Results The updated alternative splicing database predicted 15833 putative protein variants, 61% more than the previous results. There was transcript evidence for 50% of the updated genes compared to the previous 35% coverage. Database searches were conducted using the same set of spectral data, search parameters, and protein database but with different algorithms. The false discovery rates of the peptide-spectrum matches were estimated Conclusions We were able to detect dozens of new peptides using the improved alternative splicing database with the recently updated annotation of the A. flavus genome. Unlike the identifications of the peptides and the RefSeq proteins, large variations existed between the putative splice variants identified by different algorithms. 12 candidates of putative isoforms were reported based on the consensus peptide-spectrum matches. This suggests that applications of multiple search engines effectively reduced the possible false positive results and validated the protein identifications from tandem mass spectra using an alternative splicing database.

  12. 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.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

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

    Science.gov (United States)

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

    2017-04-01

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

  15. Comparative analysis of NBS-LRR genes and their response to Aspergillus flavus in Arachis.

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    Hui Song

    Full Text Available Studies have demonstrated that nucleotide-binding site-leucine-rich repeat (NBS-LRR genes respond to pathogen attack in plants. Characterization of NBS-LRR genes in peanut is not well documented. The newly released whole genome sequences of Arachis duranensis and Arachis ipaënsis have allowed a global analysis of this important gene family in peanut to be conducted. In this study, we identified 393 (AdNBS and 437 (AiNBS NBS-LRR genes from A. duranensis and A. ipaënsis, respectively, using bioinformatics approaches. Full-length sequences of 278 AdNBS and 303 AiNBS were identified. Fifty-one orthologous, four AdNBS paralogous, and six AiNBS paralogous gene pairs were predicted. All paralogous gene pairs were located in the same chromosomes, indicating that tandem duplication was the most likely mechanism forming these paralogs. The paralogs mainly underwent purifying selection, but most LRR 8 domains underwent positive selection. More gene clusters were found in A. ipaënsis than in A. duranensis, possibly owing to tandem duplication events occurring more frequently in A. ipaënsis. The expression profile of NBS-LRR genes was different between A. duranensis and A. hypogaea after Aspergillus flavus infection. The up-regulated expression of NBS-LRR in A. duranensis was continuous, while these genes responded to the pathogen temporally in A. hypogaea.

  16. Statistical optimization of process parameters for the production of tannase by Aspergillus flavus under submerged fermentation.

    Science.gov (United States)

    Mohan, S K; Viruthagiri, T; Arunkumar, C

    2014-04-01

    Production of tannase by Aspergillus flavus (MTCC 3783) using tamarind seed powder as substrate was studied in submerged fermentation. Plackett-Burman design was applied for the screening of 12 medium nutrients. From the results, the significant nutrients were identified as tannic acid, magnesium sulfate, ferrous sulfate and ammonium sulfate. Further the optimization of process parameters was carried out using response surface methodology (RSM). RSM has been applied for designing of experiments to evaluate the interactive effects through a full 31 factorial design. The optimum conditions were tannic acid concentration, 3.22 %; fermentation period, 96 h; temperature, 35.1 °C; and pH 5.4. Higher value of the regression coefficient (R 2  = 0.9638) indicates excellent evaluation of experimental data by second-order polynomial regression model. The RSM revealed that a maximum tannase production of 139.3 U/ml was obtained at the optimum conditions.

  17. Misidentification of Aspergillus nomius and Aspergillus tamarii as Aspergillus flavus: characterization by internal transcribed spacer, β-Tubulin, and calmodulin gene sequencing, metabolic fingerprinting, and matrix-assisted laser desorption ionization-time of flight mass spectrometry.

    Science.gov (United States)

    Tam, Emily W T; Chen, Jonathan H K; Lau, Eunice C L; Ngan, Antonio H Y; Fung, Kitty S C; Lee, Kim-Chung; Lam, Ching-Wan; Yuen, Kwok-Yung; Lau, Susanna K P; Woo, Patrick C Y

    2014-04-01

    Aspergillus nomius and Aspergillus tamarii are Aspergillus species that phenotypically resemble Aspergillus flavus. In the last decade, a number of case reports have identified A. nomius and A. tamarii as causes of human infections. In this study, using an internal transcribed spacer, β-tubulin, and calmodulin gene sequencing, only 8 of 11 clinical isolates reported as A. flavus in our clinical microbiology laboratory by phenotypic methods were identified as A. flavus. The other three isolates were A. nomius (n = 2) or A. tamarii (n = 1). The results corresponded with those of metabolic fingerprinting, in which the A. flavus, A. nomius, and A. tamarii strains were separated into three clusters based on ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC MS) analysis. The first two patients with A. nomius infections had invasive aspergillosis and chronic cavitary and fibrosing pulmonary and pleural aspergillosis, respectively, whereas the third patient had A. tamarii colonization of the airway. Identification of the 11 clinical isolates and three reference strains by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) showed that only six of the nine strains of A. flavus were identified correctly. None of the strains of A. nomius and A. tamarii was correctly identified. β-Tubulin or the calmodulin gene should be the gene target of choice for identifying A. flavus, A. nomius, and A. tamarii. To improve the usefulness of MALDI-TOF MS, the number of strains for each species in MALDI-TOF MS databases should be expanded to cover intraspecies variability.

  18. Misidentification of Aspergillus nomius and Aspergillus tamarii as Aspergillus flavus: Characterization by Internal Transcribed Spacer, β-Tubulin, and Calmodulin Gene Sequencing, Metabolic Fingerprinting, and Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

    Science.gov (United States)

    Tam, Emily W. T.; Chen, Jonathan H. K.; Lau, Eunice C. L.; Ngan, Antonio H. Y.; Fung, Kitty S. C.; Lee, Kim-Chung; Lam, Ching-Wan; Yuen, Kwok-Yung

    2014-01-01

    Aspergillus nomius and Aspergillus tamarii are Aspergillus species that phenotypically resemble Aspergillus flavus. In the last decade, a number of case reports have identified A. nomius and A. tamarii as causes of human infections. In this study, using an internal transcribed spacer, β-tubulin, and calmodulin gene sequencing, only 8 of 11 clinical isolates reported as A. flavus in our clinical microbiology laboratory by phenotypic methods were identified as A. flavus. The other three isolates were A. nomius (n = 2) or A. tamarii (n = 1). The results corresponded with those of metabolic fingerprinting, in which the A. flavus, A. nomius, and A. tamarii strains were separated into three clusters based on ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC MS) analysis. The first two patients with A. nomius infections had invasive aspergillosis and chronic cavitary and fibrosing pulmonary and pleural aspergillosis, respectively, whereas the third patient had A. tamarii colonization of the airway. Identification of the 11 clinical isolates and three reference strains by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) showed that only six of the nine strains of A. flavus were identified correctly. None of the strains of A. nomius and A. tamarii was correctly identified. β-Tubulin or the calmodulin gene should be the gene target of choice for identifying A. flavus, A. nomius, and A. tamarii. To improve the usefulness of MALDI-TOF MS, the number of strains for each species in MALDI-TOF MS databases should be expanded to cover intraspecies variability. PMID:24452174

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

    Science.gov (United States)

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

    2017-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Matome Gabriel Thathana

    2017-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Mohammad Moradi

    2017-04-01

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

  2. Influence of the host contact sequence on the outcome of competition among aspergillus flavus isolates during host tissue invasion.

    Science.gov (United States)

    Mehl, H L; Cotty, P J

    2011-03-01

    Biological control of aflatoxin contamination by Aspergillus flavus is achieved through competitive exclusion of aflatoxin producers by atoxigenic strains. Factors dictating the extent to which competitive displacement occurs during host infection are unknown. The role of initial host contact in competition between pairs of A. flavus isolates coinfecting maize kernels was examined. Isolate success during tissue invasion and reproduction was assessed by quantification of isolate-specific single nucleotide polymorphisms using pyrosequencing. Isolates were inoculated either simultaneously or 1 h apart. Increased success during competition was conferred to the first isolate to contact the host independent of that isolate's innate competitive ability. The first-isolate advantage decreased with the conidial concentration, suggesting capture of limited resources on kernel surfaces contributes to competitive exclusion. Attempts to modify access to putative attachment sites by either coating kernels with dead conidia or washing kernels with solvents did not influence the success of the first isolate, suggesting competition for limited attachment sites on kernel surfaces does not mediate first-isolate advantage. The current study is the first to demonstrate an immediate competitive advantage conferred to A. flavus isolates upon host contact and prior to either germ tube emergence or host colonization. This suggests the timing of host contact is as important to competition during disease cycles as innate competitive ability. Early dispersal to susceptible crop components may allow maintenance within A. flavus populations of genetic types with low competitive ability during host tissue invasion.

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

    Directory of Open Access Journals (Sweden)

    Rosane Tamara da Silva Medeiros

    2011-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Josefa B. da Silva

    2004-09-01

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

  5. 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

  6. Molecular and biochemical characterization of Iranian surfactin-producing Bacillus subtilis isolates and evaluation of their biocontrol potential against Aspergillus flavus and Colletotrichum gloeosporioides.

    Science.gov (United States)

    Mohammadipour, Matin; Mousivand, Maryam; Salehi Jouzani, Gholamreza; Abbasalizadeh, Saeed

    2009-04-01

    The characterization of surfactin-producing Bacillus subtilis isolates collected from different ecological zones of Iran is presented. Characterization was performed using blood agar, PCR, drop-collapse, and reverse-phase high-performance liquid chromatography (HPLC) analyses, and the isolates' biocontrol effects against the aflatoxin-producing agent Aspergillus flavus and the citrus antracnosis agent Colletotrichum gloeosporioides were studied. In total, 290 B. subtilis isolates were isolated from phylosphere and rhizosphere samples collected from fields and gardens of 5 provinces of Iran. Blood agar assays showed that 185 isolates produced different biosurfactants. Isolates containing the sfp gene, coding for surfactin, were detected using the PCR method. It was found that 14 different isolates contained the sfp gene. Drop-collapse assays, which detect isolates with high production of surfactin, showed that 7 isolates produced high levels of surfactin. It was found from HPLC analysis that the isolates containin the sfp gene produced between 55 and 1610 mg of surfactin per litre of broth medium. Four isolates, named BS119m, BS116l, N3dn, and BS113c, produced more than 1000 mg of surfactin per litre of broth. The highest surfactin production level was observed for isolate BS119m (1610 mg/L). The antagonistic potential of the sfp gene-containing isolates was determined using dual culture and chloroform vapour methods. Our bioassay results indicated that isolate BS119m showed high inhibitory effects against A. flavus (100%) and C. gloeosporioides (88%). Furthermore, the effect of purified surfactin on the growth of A. flavus was evaluated. Mycelia growth was considerably reduced with increasing concentration of surfactin, and 36%, 54%, 84%, and 100% inhibitions of mycelia growth were, respectively, observed at 20, 40, 80, and 160 mg/L after 7 days of incubation.

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

    Directory of Open Access Journals (Sweden)

    Hamed K. Abbas

    2012-01-01

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

  8. Detection of alternative splice variants at the proteome level in Aspergillus flavus.

    Science.gov (United States)

    Chang, Kung-Yen; Georgianna, D Ryan; Heber, Steffen; Payne, Gary A; Muddiman, David C

    2010-03-05

    Identification of proteins from proteolytic peptides or intact proteins plays an essential role in proteomics. Researchers use search engines to match the acquired peptide sequences to the target proteins. However, search engines depend on protein databases to provide candidates for consideration. Alternative splicing (AS), the mechanism where the exon of pre-mRNAs can be spliced and rearranged to generate distinct mRNA and therefore protein variants, enable higher eukaryotic organisms, with only a limited number of genes, to have the requisite complexity and diversity at the proteome level. Multiple alternative isoforms from one gene often share common segments of sequences. However, many protein databases only include a limited number of isoforms to keep minimal redundancy. As a result, the database search might not identify a target protein even with high quality tandem MS data and accurate intact precursor ion mass. We computationally predicted an exhaustive list of putative isoforms of Aspergillus flavus proteins from 20 371 expressed sequence tags to investigate whether an alternative splicing protein database can assign a greater proportion of mass spectrometry data. The newly constructed AS database provided 9807 new alternatively spliced variants in addition to 12 832 previously annotated proteins. The searches of the existing tandem MS spectra data set using the AS database identified 29 new proteins encoded by 26 genes. Nine fungal genes appeared to have multiple protein isoforms. In addition to the discovery of splice variants, AS database also showed potential to improve genome annotation. In summary, the introduction of an alternative splicing database helps identify more proteins and unveils more information about a proteome.

  9. 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.

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

    OpenAIRE

    López-Malo Vigil, Aurelio

    2000-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Zuzana eHruska

    2014-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Uyar Guliz

    2007-07-01

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

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

    Science.gov (United States)

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

    2016-10-28

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

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

    Directory of Open Access Journals (Sweden)

    Matthew K. Gilbert

    2017-12-01

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

  15. 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.

  16. Laetiporus sulphureus, edible mushroom from Serbia: investigation on volatile compounds, in vitro antimicrobial activity and in situ control of Aspergillus flavus in tomato paste.

    Science.gov (United States)

    Petrović, Jovana; Glamočlija, Jasmina; Stojković, Dejan S; Ćirić, Ana; Nikolić, Miloš; Bukvički, Danka; Guerzoni, Maria Elisabetta; Soković, Marina D

    2013-09-01

    The volatile compounds of fruiting bodies of wild Laetiporus sulphureus (Bull.) Murrill, growing on willow trees from Serbia, were isolated and extracted using methanol, acetone and dichloromethane and investigated by GC/MS-SPME. A total of 56 components were identified in the extracts. Hydrocarbons predominated (76.90%, 77.20%, and 43.10%) in dichloromethane, acetone and methanol extracts, respectively. Fatty acids, esters and sesquiterpenes were present in amounts equal or lower than 2.00%. Ketones were represented with moderate amount with the exception of methanol extract where it reached as much as 28.90% of the total investigated compounds. Extracts were also tested for antimicrobial activity with and without the addition of food additive - potassium disulfite in vitro against eight bacterial and eight fungal species, and in situ in tomato paste against Aspergillus flavus. All the tested extracts showed good antimicrobial activity, but methanol extract with addition of E224 showed the best antimicrobial activity in vitro. In situ results indicate complete inhibition of A. flavus growth in tomato paste after 15 days of the treatment. This study is the first report on volatile composition of L. sulphureus growing wild in Serbia. We describe for the first time the application of its extract as antifungal food preservative. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Data set of Aspergillus flavus induced alterations in tear proteome: Understanding the pathogen-induced host response to fungal infection

    Directory of Open Access Journals (Sweden)

    Jeyalakshmi Kandhavelu

    2016-12-01

    Full Text Available Fungal keratitis is one of the leading causes of blindness in the tropical countries affecting individuals in their most productive age. The host immune response during this infection is poorly understood. We carried out comparative tear proteome analysis of Aspergillus flavus keratitis patients and uninfected controls. Proteome was separated into glycosylated and non-glycosylated fractions using lectin column chromatography before mass spectrometry. The data revealed the major processes activated in the human host in response to fungal infection and reflected in the tear. Extended analysis of this dataset presented here complements the research article entitled “Aspergillus flavus induced alterations in tear protein profile reveal pathogen-induced host response to fungal infection [1]” (Jeyalakhsmi Kandhavelu, Naveen Luke Demonte, Venkatesh Prajna Namperumalsamy, Lalitha Prajna, Chitra Thangavel, Jeya Maheshwari Jayapal, Dharmalingam Kuppamuthu, 2016. The mass spectrometry proteomics data have been deposited in the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PRIDE:PXD003825.

  18. 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)

  19. 75 FR 9596 - Notice of Filing of a Pesticide Petition for Residues of a Aspergillus flavus AF36 on Corn Food...

    Science.gov (United States)

    2010-03-03

    ... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0111; FRL-8811-2] Notice of Filing of a Pesticide Petition for Residues of a Aspergillus flavus AF36 on Corn Food/Feed Commodities AGENCY: Environmental... for residues of the antifungal [[Page 9598

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

    Science.gov (United States)

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

  1. Aspergillus flavus infection triggered immune responses and host-pathogen cross-talks in groundnut during in-vitro seed colonization

    Science.gov (United States)

    Aflatoxin contamination, caused by fungal pathogen Aspergillus flavus, is a major quality and health problem delimiting the trade and consumption of groundnut (Arachis hypogaea L.) worldwide. RNA-seq approach was deployed to understand the host-pathogen interaction by identifying differentially expr...

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

    Science.gov (United States)

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

  3. Modelling the effect of ethanol on growth rate of food spoilage moulds

    NARCIS (Netherlands)

    Dantigny, P.; Guilmart, A.; Radoi, F.; Bensoussan, M.; Zwietering, M.H.

    2005-01-01

    The effect of ethanol (E) on the radial growth rate (¿) of food spoilage moulds (Aspergillus candidus, Aspergillus flavus, Aspergillus niger, Cladosporium cladosporioides, Eurotium herbariorum, Mucor circinelloides, Mucor racemosus, Paecilomyces variotii, Penicillium chrysogenum, Penicillium

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

    Directory of Open Access Journals (Sweden)

    Rauf Foroutan

    2017-06-01

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

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

    Science.gov (United States)

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

    2013-11-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  7. 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 .

  8. Surface ultrastructural studies on the germination, penetration and conidial development of Aspergillus flavus Link:Fries infecting silkworm, Bombyx mori Linn.

    Science.gov (United States)

    Kumar, Vineet; Singh, G P; Babu, A M

    2004-01-01

    Aspergillosis is a common disease of the silkworm Bombyx mori Linn., caused by an insect mycopathogen Aspergillus flavus Link:Fries. The present study reveals the germination, penetration and conidial development of A. flavus on the larval integument of B. mori under SEM. Four different strains (NB18, KA, NB4D2 and NB7) of B. mori was surface inoculated with ca. of 1 x 10(6) conidia/ml. Each conidium germinated on the cuticle approximately 6 h after inoculation, forming a humpy or suctorial appressoria within 24 h. The hyphae which entered into haemocoel 2 day post-inoculation, grew and multiplied extensively, forming a mycelial complex, causing death of the host larva in about 4-5 days. This occurred with minimal breakdown of the internal tissues. Death of the host was followed by ramification of the fungus through the mesodermal and epidermal tissues, leading to larval mummification about 5-6 days after inoculation. Extensive fungal growths on the entire larval body followed, consisting of aerial hyphae, which developed branched conidiophores. The aerial hyphae with abundant conidiophores formed a confluent yellowish green fungal mat over the entire larval body in 6-7 days of post-inoculation. The tip of each emerging conidiophores gradually dilated and developed to become a bulbous head known as the vesicle. A large number of conidiogenous cells were produced over the entire surface of vesicle, which later developed into finger-like projections termed as sterigmata or phialides. The phialides matured within 2 days after the aerial hyphae emerged as evidenced by chains of conidia at their tips. The conidia were globose with externally roughened walls. The life cycle of the fungus on B. mori was completed in six to seven days.

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

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... 1School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia,. 2Department of Botany, Osmania University, Hyderabad, India. ... the biocontrol agents tested, culture filtrate of Rhodococcus ...

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

    Science.gov (United States)

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

    2009-01-01

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

  11. 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.

  12. Screening of antifungal susceptibility in cave-dwelling aspergilli and report of an amphotericin B-resistant Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Erika L.S. Taylor

    2017-09-01

    Full Text Available Caves are stable environments that favour the development of several microorganisms. The aspergilli represent a large number of species isolated from caves including strains capable of causing serious invasive opportunistic infections in humans. Considering that caves may harbour resistant strains to many antibiotics, investigation on the response of opportunistic aspergilli, isolated from pristine and tourist caves to antifungal agents and the mechanisms involved in resistance might be clinically relevant. A total of 32 strains of the species Aspergillus candidus, A. flavus, A. fumigatus, A. niger, A. tamarii, and A. terreus were isolated from caves in the iron quadrangle in Brazil. The strains were tested for their susceptibility to amphotericin B (AMB, itraconazole, voriconazole and terbinafine. One strain was analysed for the mechanism involved in the AMB-resistance, i.e., ergosterol content, lipid peroxidation and enzymatic activity of the antioxidant system. Terbinafine minimum inhibitory concentrations (MICs ranged between 0.003 and 1.0 µg/mL; voriconazole MICs ranged between 2.0 and >16.0 µg/mL; itraconazole MICs ranged between 0.25 and 8.0 µg/mL and amphotericin B MICs ranged between 0.03 and 4.0 µg/mL. The AMB-resistant strain of A. flavus was detected with MIC value of 4 µg/mL. Resistance to AMB relied on higher ergosterol levels and increased enzymatic activity of the peroxidase and superoxide-dismutase, with lower lipid peroxidation. These results enhance the knowledge of natural antifungal resistance in the subterranean ecosystem, and broaden the knowledge about the subterranean microbiota.

  13. Salt tolerance of Glycine max.L induced by endophytic fungus Aspergillus flavus CSH1, via regulating its endogenous hormones and antioxidative system.

    Science.gov (United States)

    Lubna; Asaf, Sajjad; Hamayun, Muhammad; Khan, Abdul Latif; Waqas, Muhammad; Khan, Muhammad Aaqil; Jan, Rahmatullah; Lee, In-Jung; Hussain, Anwar

    2018-07-01

    Abiotic stress resistance strategies are powerful approaches to sustainable agriculture because they reduce chemical input and enhance plant productivity. In current study, an endophytic fungus, Aspergillus flavus CHS1 was isolated from Chenopodium album Roots. CHS1 was initially screened for growth promoting activities like siderphore, phosphate solubilization, and the production of indole acetic acid and gibberellins and were further assayed for its ability to promote the growth of mutant Waito-C rice. The results revealed that different plant growth characteristic such as chlorophyll content, root-shoot length, and biomass production were significantly promoted during CHS1 treatment. This growth promotion action was due to the presence of various types of GAs and IAA in the endophyte culture filtrate. Significant up regulation with respect to levels in the control was observed in all endogenous plant GAs, after treatment with CHS1. Furthermore, to evaluate the potential of CHS1 against NaCl stress up to 400 mM, it was tested for its ability to improve soybean plant growth under NaCl stress. In endophyte-soybean interaction, CHS1 association significantly increased plant growth and attenuated the NaCl stress by down regulating ABA and JA synthesis. Similarly, it significantly elevated antioxidant activities of enzymes catalase, polyphenoloxidase, superoxide dismutase and peroxidase as compared to non-inoculated salt stress plants. Thus, CHS1 ameliorated the adverse effect of high NaCl stress and rescued soybean plant growth by regulating the endogenous plant hormones and antioxidative system. We conclude that CHS1 isolate could be exploited to increase salt resistant and yield in crop plants. Copyright © 2018. Published by Elsevier Masson SAS.

  14. Assessment of Aspergillus niger biofilm growth kinetics in ...

    African Journals Online (AJOL)

    Jane

    2011-10-12

    Oct 12, 2011 ... other hand, A. niger biofilm growth followed a logistic model having higher maximal specific growth rate than ...... Growth estimation of Aspergillus oryzae cultured on ... Initial intracellular proteome profile of Aspergillus niger.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-15

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

  16. Use of a repetitive DNA probe to type clinical and environmental isolates of Aspergillus flavus from a cluster of cutaneous infections in a neonatal intensive care unit.

    Science.gov (United States)

    James, M J; Lasker, B A; McNeil, M M; Shelton, M; Warnock, D W; Reiss, E

    2000-10-01

    Aspergillus flavus is second to A. fumigatus as a cause of invasive aspergillosis, but no standard method exists for molecular typing of strains from human sources. A repetitive DNA sequence cloned from A. flavus and subcloned into a pUC19 vector, pAF28, was used to type 18 isolates from diverse clinical, environmental, and geographic sources. The restriction fragment length polymorphisms generated with EcoRI- or PstI-digested genomic DNA and probed with digoxigenin-labeled pAF28 revealed complete concordance between patterns. Eighteen distinct fingerprints were observed. The probe was used to investigate two cases of cutaneous A. flavus infection in low-birth-weight infants in a neonatal intensive care unit (NICU). Both infants were transported by the same ambulance and crew to the NICU on the same day. A. flavus strains of the same genotype were isolated from both infants, from a roll of tape used to fasten their umbilical catheters, from a canvas bag used to store the tape in the ambulance, and from the tape tray in the ambulance isolette. These cases highlight the need to consider exposures in critically ill neonates that might occur during their transport to the NICU and for stringent infection control practices. The hybridization profiles of strains from a second cluster of invasive A. flavus infections in two pediatric hematology-oncology patients revealed a genotype common to strains from a definite case patient and a health care worker. A probable case patient was infected with a strain with a genotype different from that of the strain from the definite case patient but highly related to that of an environmental isolate. The high degree of discrimination and reproducibility obtained with the pAF28 probe underscores its utility for typing clinical and environmental isolates of A. flavus.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  18. 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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    K. V. Avdiyuk

    2013-06-01

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

  1. Biotechnological advances for combating Aspergillus flavus and aflatoxin contamination in crops.

    Science.gov (United States)

    Bhatnagar-Mathur, Pooja; Sunkara, Sowmini; Bhatnagar-Panwar, Madhurima; Waliyar, Farid; Sharma, Kiran Kumar

    2015-05-01

    Aflatoxins are toxic, carcinogenic, mutagenic, teratogenic and immunosuppressive byproducts of Aspergillus spp. that contaminate a wide range of crops such as maize, peanut, and cotton. Aflatoxin not only affects crop production but renders the produce unfit for consumption and harmful to human and livestock health, with stringent threshold limits of acceptability. In many crops, breeding for resistance is not a reliable option because of the limited availability of genotypes with durable resistance to Aspergillus. Understanding the fungal/crop/environment interactions involved in aflatoxin contamination is therefore essential in designing measures for its prevention and control. For a sustainable solution to aflatoxin contamination, research must be focused on identifying and improving knowledge of host-plant resistance factors to aflatoxin accumulation. Current advances in genetic transformation, proteomics, RNAi technology, and marker-assisted selection offer great potential in minimizing pre-harvest aflatoxin contamination in cultivated crop species. Moreover, developing effective phenotyping strategies for transgenic as well as precision breeding of resistance genes into commercial varieties is critical. While appropriate storage practices can generally minimize post-harvest aflatoxin contamination in crops, the use of biotechnology to interrupt the probability of pre-harvest infection and contamination has the potential to provide sustainable solution. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Loise M. Njoki

    2017-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hala A. Amin

    2018-03-01

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

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

    OpenAIRE

    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. flav...

  6. 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.

  7. 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.)

  8. 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.

  9. Aspergillus flavus induced alterations in tear protein profile reveal pathogen-induced host response to fungal infection.

    Science.gov (United States)

    Kandhavelu, Jeyalakshmi; Demonte, Naveen Luke; Namperumalsamy, Venkatesh Prajna; Prajna, Lalitha; Thangavel, Chitra; Jayapal, Jeya Maheshwari; Kuppamuthu, Dharmalingam

    2017-01-30

    Aspergillus flavus and Fusarium sp. are primary causative agents of keratitis that results in corneal tissue damage leading to vision loss particularly in individuals from the tropical parts of the world. Proteins in the tear film collected from control and keratitis patients was profiled and compared. A total of 1873 proteins from control and 1400 proteins from patient tear were identified by mass spectrometry. While 847 proteins were found to be glycosylated in the patient tear, only 726 were glycosylated in control tear. And, some of the tear proteins showed alterations in their glycosylation pattern after infection. Complement system proteins, proteins specific for neutrophil extracellular traps and proteins involved in would healing were found only in the patient tear. The presence of these innate immune system proteins in the tear film of patients supports the previous data indicating the involvement of neutrophil and complement pathways in antifungal defense. High levels of wound healing proteins in keratitis patient tear implied activation of tissue repair during infection. The early appearance of the host defense proteins and wound healing response indicates that tear proteins could be used as an early marker system for monitoring the progression of pathogenesis. Identification of negative regulators of the above defense pathways in keratitis tear indicates an intricate balance of pro and anti-defense mechanisms operating in fungal infection of the eye. Tear proteins from control and mycotic keratitis patients were separated into glycoproteins and non-glycosylated proteins and then identified by mass spectrometry. Tear proteins from keratitis patients showed alteration in the glycosylation pattern indicating the alteration of glycosylation machinery due to infection. Neutrophil extracellular traps specific proteins, complement pathway proteins, as well as wound healing proteins, were found only in patient tear showing the activation of antifungal defense

  10. 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...

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

    Directory of Open Access Journals (Sweden)

    Xueyan Shan

    2011-06-01

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

  12. 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...

  13. In vitro experimental environments lacking or containing soil disparately affect competition experiments of Aspergillus flavus and co-occurring fungi in maize grains.

    Science.gov (United States)

    Falade, Titilayo D O; Syed Mohdhamdan, Sharifah H; Sultanbawa, Yasmina; Fletcher, Mary T; Harvey, Jagger J W; Chaliha, Mridusmita; Fox, Glen P

    2016-07-01

    In vitro experimental environments are used to study interactions between microorganisms, and to predict dynamics in natural ecosystems. This study highlights that experimental in vitro environments should be selected to match closely the natural environment of interest during in vitro studies to strengthen extrapolations about aflatoxin production by Aspergillus and competing organisms. Fungal competition and aflatoxin accumulation were studied in soil, cotton wool or tube (water-only) environments, for Aspergillus flavus competition with Penicillium purpurogenum, Fusarium oxysporum or Sarocladium zeae within maize grains. Inoculated grains were incubated in each environment at two temperature regimes (25 and 30°C). Competition experiments showed interaction between the main effects of aflatoxin accumulation and the environment at 25°C, but not so at 30°C. However, competition experiments showed fungal populations were always interacting with their environments. Fungal survival differed after the 72-h incubation in different experimental environments. Whereas all fungi incubated within the soil environment survived, in the cotton wool environment none of the competitors of A. flavus survived at 30°C. With aflatoxin accumulation, F. oxysporum was the only fungus able to interdict aflatoxin production at both temperatures. This occurred only in the soil environment and fumonisins accumulated instead. Smallholder farmers in developing countries face serious mycotoxin contamination of their grains, and soil is a natural reservoir for the associated fungal propagules, and a drying and storage surface for grains on these farms. Studying fungal dynamics in the soil environment and other environments in vitro can provide insights into aflatoxin accumulation post-harvest.

  14. Development of a droplet digital PCR assay for population analysis of aflatoxigenic and atoxigenic Aspergillus flavus mixtures in soil

    Science.gov (United States)

    Application of atoxigenic strains to compete against aflatoxigenic strains of A. flavus strains has emerged as one of the practical strategy for reducing aflatoxins contamination in food. Droplet digital PCR (ddPCR) is a new DNA quantification platform without an external DNA calibrator. For ddPCR, ...

  15. 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.

  16. Distribution and incidence of atoxigenic Aspergillus flavus VCG in tree crop orchards in California: A strategy for identifying potential antagonists, the example of almonds.

    Science.gov (United States)

    Picot, Adeline; Doster, Mark; Islam, Md-Sajedul; Callicott, Kenneth; Ortega-Beltran, Alejandro; Cotty, Peter; Michailides, Themis

    2018-01-16

    To identify predominant isolates for potential use as biocontrol agents, Aspergillus flavus isolates collected from soils of almond, pistachio and fig orchard in the Central Valley of California were tested for their membership to 16 atoxigenic vegetative compatibility groups (VCGs), including YV36, the VCG to which AF36, an atoxigenic isolate commercialized in the United States as biopesticide, belongs. A surprisingly large proportion of isolates belonged to YV36 (13.3%, 7.2% and 6.6% of the total almond, pistachio and fig populations, respectively), while the percentage of isolates belonging to the other 15 VCGs ranged from 0% to 2.3%. In order to gain a better insight into the structure and diversity of atoxigenic A. flavus populations and to further identify predominant isolates, seventeen SSR markers were then used to genetically characterize AF36, the 15 type-isolates of the VCGs and 342 atoxigenic isolates of the almond population. There was considerable genetic diversity among isolates with a lack of differentiation among micro-geographical regions or years. Since isolates sharing identical SSR profiles from distinct orchards were rare, we separated them into groups of at least 3 closely-related isolates from distinct orchards that shared identical alleles for at least 15 out of the 17 loci. This led to the identification of 15 groups comprising up to 24 closely-related isolates. The group which contained the largest number of isolates were members of YV36 while five groups were also found to be members of our studied atoxigenic VCGs. These results suggest that these 15 groups, and AF36 in particular, are well adapted to various environmental conditions in California and to tree crops and, as such, are good candidates for use as biocontrol agents. Published by Elsevier B.V.

  17. Perfil bioquímico do soro de frangos de corte alimentados com dieta suplementada com alfa-amilase de Cryptococcus flavus e Aspergillus niger HM2003 Biochemichal serum profile of broilers fed diets suplemented with alfa-amylase from Cryptococcus flavus and Aspergillus niger HM2003

    Directory of Open Access Journals (Sweden)

    Cibele Silva Minafra

    2010-12-01

    Full Text Available Avaliou-se o perfil bioquímico do soro de frangos de corte alimentados com a enzima α-amilase produzida por dois microrganismos. Produziram-se dois extratos, um com a-amilase obtida a partir de Cryptococcus flavus em meio de levedura comercial e outro com Aspergillus niger HM2003 em meio de proteína de soja e amido comercial, com atividade de 9,58 U/mL e 10,0 U/mL, respectivamente. Utilizaram-se 360 pintos de corte Cobb 500 de 1 dia de idade e com 49,72 ± 0,68 g de peso vivo inicial. As aves foram alojadas em baterias e foram criadas até os 21 dias de idade. Foram utilizados três dietas, cada uma com cinco repetições de 12 aves, em delineamento inteiramente casualizado. A primeira dieta (basal foi formulada sem adição de enzima e as outras duas receberam a suplementação de a-amilase produzida por cultivo de Cryptococcus flavus e Aspergillus niger HM2003. Dietas à base de milho e soja foram formuladas em duas fases: pré-inicial (1-7 dias e inicial (8-21 dias. Na fase pré-inicial, foram observados os seguintes valores médios para cálcio (6,90 e 5,99 mg/dL, proteína plasmática (2,0 e 2,50 g/dL e fosfatase alcalina (979,98 e 974,66 UI/L, respectivamente para Cryptococcus flavus e Aspergillus niger HM2003. A dieta acrescida de a-amilase obtida a partir de Aspergillus niger HM2003 determinou maior concentração sérica de fósforo. Na fase inicial, os resultados significativos relacionaram-se a potássio quando avaliadas dietas com adição de a-amilase pelas duas fontes. A incorporação das enzimas testadas não proporciona alterações metabólicas ou toxicidade nos animais.It was evaluated the biochemical serum profile of broilers fed rations supplemented with α-amylase produced by two microorganisms. Two extracts were produced, one was produced with a-amylase obtained from Cryptococcus flavus in a commercial yeast-based medium and the other with Aspergillus niger HM2003 produced in soybean protein and commercial starch medium

  18. Self-affine fractal growth front of Aspergillus oryzae

    Science.gov (United States)

    Matsuura, Shu; Miyazima, Sasuke

    1992-12-01

    Aspergillus oryzae have been grown in various environmental conditions and analyzed from the viewpoint of self-affinity. The growth behavior can be described by the Eden model in favorable conditions, and by DLA in unfavorable conditions.

  19. 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®

  20. Defense Responses to Mycotoxin-Producing Fungi Fusarium proliferatum, F. subglutinans, and Aspergillus flavus in Kernels of Susceptible and Resistant Maize Genotypes.

    Science.gov (United States)

    Lanubile, Alessandra; Maschietto, Valentina; De Leonardis, Silvana; Battilani, Paola; Paciolla, Costantino; Marocco, Adriano

    2015-05-01

    Developing kernels of resistant and susceptible maize genotypes were inoculated with Fusarium proliferatum, F. subglutinans, and Aspergillus flavus. Selected defense systems were investigated using real-time reverse transcription-polymerase chain reaction to monitor the expression of pathogenesis-related (PR) genes (PR1, PR5, PRm3, PRm6) and genes protective from oxidative stress (peroxidase, catalase, superoxide dismutase and ascorbate peroxidase) at 72 h postinoculation. The study was also extended to the analysis of the ascorbate-glutathione cycle and catalase, superoxide dismutase, and cytosolic and wall peroxidases enzymes. Furthermore, the hydrogen peroxide and malondialdehyde contents were studied to evaluate the oxidation level. Higher gene expression and enzymatic activities were observed in uninoculated kernels of resistant line, conferring a major readiness to the pathogen attack. Moreover expression values of PR genes remained higher in the resistant line after inoculation, demonstrating a potentiated response to the pathogen invasions. In contrast, reactive oxygen species-scavenging genes were strongly induced in the susceptible line only after pathogen inoculation, although their enzymatic activity was higher in the resistant line. Our data provide an important basis for further investigation of defense gene functions in developing kernels in order to improve resistance to fungal pathogens. Maize genotypes with overexpressed resistance traits could be profitably utilized in breeding programs focused on resistance to pathogens and grain safety.

  1. Production of thermostable glucoamylase by newly isolated Aspergillus flavus A 1.1 and Thermomyces lanuginosus A 13.37 Produção e glucoamilase por Aspergillus flavus A1.1 e Thermomyces lanuginosus A13.37

    Directory of Open Access Journals (Sweden)

    Eleni Gomes

    2005-03-01

    Full Text Available Thirteen thermophilic fungal strains were isolated from agricultural soil, tubers and compost samples in tropical Brazil. Two strains were selected based on of their ability to produce considerable glucoamylase activity while growing in liquid medium at 45ºC with starch as the only carbon source. They were identified as Aspergillus flavus A1.1 and Thermomyces lanuginosus A 13.37 Tsiklinsky. The experiment to evaluate the effect of carbon source, temperature and initial pH of the medium on enzyme production was developed in a full factorial design (2x2x3. Enzyme productivity was influenced by the type of starch used as carbon source. Cassava starch showed to be a better substrate than corn starch for glucoamylase production by A. flavus but for T. lanuginosus the difference was not significant. Enzyme activities were determined using as substrates 0.3% soluble starch, 0.3% maltose or 0.3% of starch plus 0.1% maltose. The enzymes from A. flavus A1.1 hydrolyzed soluble starch preferentially but also exhibited a significant maltase activity. Moreover higher quantities of glucose were released when the substrate used was a mixture of starch and maltose, suggesting that this fungus produced two types of enzyme. In the case T. lanuginosus A 13.37, the substrate specificity test indicated that the enzyme released also hydrolyzed starch more efficiently than maltose, but there was no increase in the liberation of glucose when a mixture of starch and maltose was used as substrate, suggesting that only one type of enzyme was secreted. Glucoamylases produced from A. flavus A1.1 and T. lanuginous A.13-37 have high optimum temperature (65ºC and 70ºC and good thermostability in the absence of substrate (maintaining 50% of activity for 5 and 8 hours, respectively, at 60ºC and are stable over in a wide pH range. These new strains offer an attractive alternative source of enzymes for industrial starch processing.Entre 13 linhagens de fungos filamentosos

  2. EVALUATION OF GROWTH OF SOME FUNGI IN CRUDE OIL ...

    African Journals Online (AJOL)

    The two species of Aspergillus A. niger and flavus used in the study appreciably tolerated the oil though the growth of A. flavus was retarded as the concentration of oil increased. Botrytis cinerea, Curvularia lunata and Colletotrichum sp. could not grow beyond the concentration of 1ml/10mls of oil Potato Dextrose Dextrose ...

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

    Science.gov (United States)

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

    2018-01-10

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

  4. 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...

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

    Directory of Open Access Journals (Sweden)

    Walid Ahmed Korani

    2017-07-01

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

  6. 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.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Alexsandro Machado Conceição

    2010-04-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2010v23n2p145 Amplamente difundido na alimentação de psitacídeos em razão do preço baixo, elevada palatabilidade, e por razões culturais, o Helianthus annuus, conhecido como girassol, vem se mostrando importante na clínica aviária em decorrência do excesso de calorias, e da alta incidência na contaminação por alguns fungos, principalmente do gênero Aspergillus, especificamente A. flavus e A. fumigatus. O objetivo deste estudo foi avaliar a contaminação por Aspegillus ssp. em sementes de girassol destinada à alimentação de psitacídeos comercializadas em Aracaju, estado de Sergipe. As análises foram realizadas no Laboratório de Microbiologia, do Hospital Veterinário Dr. Vicente Borreli, na Faculdade Pio Décimo. Avaliaram-se quatro amostras de sementes de girassol, sendo uma comercializada no mercado público municipal, de forma granel e três marcas comerciais, envasadas e de diferentes hipermercados, processadas segundo Forsythe (2002. De acordo com a pesquisa realizada, foi possível observar um elevado desenvolvimento de A. flavus e A. fumigatus nas sementes de girassol. Esta contaminação pode estar relacionada a vários fatores: colheita e fases de secagem, beneficiamento e armazenamento do grão inadequado. Além disso, é importante destacar a necessidade de que haja um melhor armazenamento de grãos, com controle de temperatura e umidade relativa, visando reduzir a possibilidade de contaminação por Aspergillus spp. que causa prejuízos na alimentação de psitacídeos, e de outras espécies animais.

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

    Directory of Open Access Journals (Sweden)

    Parjo Umi Kalthsom

    2017-01-01

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

  10. 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.

  11. 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.

  12. Growth of Aspergillus repens in Flue-Cured Tobacco 1

    Science.gov (United States)

    Welty, Ronald E.; Nelson, Larry A.

    1971-01-01

    In laboratory tests, flue-cured tobacco inoculated with Aspergillus repens was stored at 75, 80, 85, 87, and 95% relative humidity at 20 and 30 C. Samples were taken weekly for 4 weeks and evaluated for mold growth (colony count) and moisture content (MC). The weekly rate of fungus increase was slower at 20 C than at 30 C. Tobacco at 20 C with MC between 25 to 30% supported a slight to moderate increase in A. repens after 3 weeks of storage. However, tobacco at the same MC stored at 30 C was subject to rapid invasion by the fungus in as few as 1 to 2 weeks. Tobacco with MC above 30% stored at either 20 or 30 C became moldy in about 1 week. A mold index is proposed for evaluating populations of A. repens in tobacco. PMID:16349905

  13. Growth of Aspergillus repens in Flue-Cured Tobacco.

    Science.gov (United States)

    Welty, R E; Nelson, L A

    1971-05-01

    In laboratory tests, flue-cured tobacco inoculated with Aspergillus repens was stored at 75, 80, 85, 87, and 95% relative humidity at 20 and 30 C. Samples were taken weekly for 4 weeks and evaluated for mold growth (colony count) and moisture content (MC). The weekly rate of fungus increase was slower at 20 C than at 30 C. Tobacco at 20 C with MC between 25 to 30% supported a slight to moderate increase in A. repens after 3 weeks of storage. However, tobacco at the same MC stored at 30 C was subject to rapid invasion by the fungus in as few as 1 to 2 weeks. Tobacco with MC above 30% stored at either 20 or 30 C became moldy in about 1 week. A mold index is proposed for evaluating populations of A. repens in tobacco.

  14. Movilidad de Aspergillus flavus link ex fries en mazorcas de cinco genotipos de maiz (Zea Mays L. empleando tres métodos de inoculación (ING

    Directory of Open Access Journals (Sweden)

    Néstor Villalobos

    2016-03-01

    Full Text Available Three inoculation techniques for evaluating reaction of corn to kernel infection by Aspergillus flavus were tested in the field of five different genotypes. Inoculations were made 20 days after midsilk stage, using 0.5 ml of 105 conidial suspensions. The methods were: a injection of small amounts of inoculum in each kernel of a vertical row (M1; b injection in the first well developed kernels around the top part of the ear (M2; c injection of inoculum in the kernels at the lower part of the ear, forming a semicircle (M3. Two weeks after inoculation ears were harvested, and kernels not wounded were separated according to its position to the inoculated kernels, then surface sterilized and planted on PDA, to determine the infection percentage. M1 and M2 were found very efficient because they produced higher infection levels. M1 is considered the best because it provided a larger number of kernels for assay and was easy to use. No statistical difference was found among genotypes.

  15. 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...

  16. 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...

  17. Growth pattern of the surface of fungus Aspergillus colony

    Science.gov (United States)

    Matsuura, Shu; Miyazima, Sasuke

    1992-05-01

    Aspergillus oryzae colonies were grown under various glucose concentrations, temperatures, and agar concentrations, and the effects on the pattern were investigated. Patterns of colony were found to vary from uniform to diffusion-limited aggregation type.

  18. The in vitro effect of selected essential oils on the growth and mycotoxin production of Aspergillus species.

    Science.gov (United States)

    Císarová, Miroslava; Tančinová, Dana; Medo, Juraj; Kačániová, Miroslava

    2016-10-02

    The aim of the present study was to assess the antifungal and anti-toxinogenic activity of 15 essential oils (EOs) against three fungi of the genus Aspergillus (A. parasiticus KMi-227-LR, A. parasiticus KMi-220-LR and A. flavus KMi-202-LR). The minimum inhibitory doses (MIDs) of the tested essential oils and their antifungal activity were determined using the micro-atmosphere method. The original commercial essential oil samples of Jasminum officinale L., Thymus vulgaris L., Syzygium aromaticum (L.) Merrill & Perry, Rosmarinus officinalis L., Ocimum basilicum L., Eucalyptus globulus Labill., Salvia officinalis L., Citrus limon (L.) Burm, Origanum vulgare L., Lavandula angustifolia Mill., Carum carvi L., Citrus sinensis (L.) Osbeck., Zingiber officinalis Rosc., Mentha piperita L. and Cinnamomum zeylanicum Nees. (C. verum J.S.Presl.) were produced in Slovakia (Calendula a.s., Nová Ľubovňa, Slovakia). All essential oils exhibited activity against all tested strains of fungi. After 14 days of incubation, A. flavus (KMi-202-LR) showed the highest susceptibility with a growth inhibition percentage (GIP) of 18.70% to C. limon and 5.92% to C. sinensis, while A. parasiticus (KMi-220-LR) exhibited a GIP of 20.56% to J. officinale. The minimum inhibitory doses (MIDs) of EOs with the most significant activity were recorded. The best antifungal activity, using the micro-atmosphere method was found in S. aromaticum with an MID of 62.5 μL L -1 air, T. vulgaris (MID of 62.5 μL L -1 air) and O. vulgare (MID of 31.5 μL L -1 air) against all tested strains. Mycotoxin production of the tested strains was evaluated by the thin layer chromatography (TLC) method. Mycotoxin production of AFB 1 and AFG 1 was inhibited following all treatments with C. carvi, R. officinale and S. officinale, Eucalyptus globulus L. and O. basilicum L. Essential oils exhibited a potential inhibition activity against toxic fungi, although, these affected only the production of AFB 1 .

  19. Identification of secreted proteins of Aspergillus oryzae associated with growth on solid cereal substrates

    NARCIS (Netherlands)

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

    2006-01-01

    Filamentous growth of Aspergillus oryzae on solid cereal substrates involves secretion of substrate converting enzymes and a solid substrate specific polarised hyphal growth phenotype. To identify proteins produced under these specific conditions, the extracts of A. oryzae grown on wheat-based media

  20. Proteomics of eukaryotic microorganisms: The medically and biotechnologically important fungal genus Aspergillus.

    Science.gov (United States)

    Kniemeyer, Olaf

    2011-08-01

    Fungal species of the genus Aspergillus play significant roles as model organisms in basic research, as "cell factories" for the production of organic acids, pharmaceuticals or industrially important enzymes and as pathogens causing superficial and invasive infections in animals and humans. The release of the genome sequences of several Aspergillus sp. has paved the way for global analyses of protein expression in Aspergilli including the characterisation of proteins, which have not designated any function. With the application of proteomic methods, particularly 2-D gel and LC-MS/MS-based methods, first insights into the composition of the proteome of Aspergilli under different growth and stress conditions could be gained. Putative targets of global regulators led to the improvement of industrially relevant Aspergillus strains and so far not described Aspergillus antigens have already been discovered. Here, I review the recent proteome data generated for the species Aspergillus nidulans, Aspergillus fumigatus, Aspergillus niger, Aspergillus terreus, Aspergillus flavus and Aspergillus oryzae. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Inhibition of growth and mycotoxins formation in moulds by marine ...

    African Journals Online (AJOL)

    ... extracts (chloroform, hexane and methanol) had no activity on the microbial growth. Mycotoxins formation in Aspergillus flavus was inhibited by the ethanolic extracts at the concentration of 5%. Key Words: Algae, antimicrobial, minimal inhibitory concentration, moulds. African Journal of Biotechnology Vol.3(1) 2004: 71-75 ...

  2. Gβ-like CpcB plays a crucial role for growth and development of Aspergillus nidulans and Aspergillus fumigatus.

    Directory of Open Access Journals (Sweden)

    Qing Kong

    Full Text Available Growth, development, virulence and secondary metabolism in fungi are governed by heterotrimeric G proteins (G proteins. A Gβ-like protein called Gib2 has been shown to function as an atypical Gβ in Gpa1-cAMP signaling in Cryptococcus neoformans. We found that the previously reported CpcB (cross pathway control B protein is the ortholog of Gib2 in Aspergillus nidulans and Aspergillus fumigatus. In this report, we further characterize the roles of CpcB in governing growth, development and toxigenesis in the two aspergilli. The deletion of cpcB results in severely impaired cellular growth, delayed spore germination, and defective asexual sporulation (conidiation in both aspergilli. Moreover, CpcB is necessary for proper expression of the key developmental activator brlA during initiation and progression of conidiation in A. nidulans and A. fumigatus. Somewhat in accordance with the previous study, the absence of cpcB results in the formation of fewer, but not micro-, cleistothecia in A. nidulans in the presence of wild type veA, an essential activator of sexual development. However, the cpcB deletion mutant cleistothecia contain no ascospores, validating that CpcB is required for progression and completion of sexual fruiting including ascosporogenesis. Furthermore, unlike the canonical GβSfaD, CpcB is not needed for the biosynthesis of the mycotoxin sterigmatocystin (ST as the cpcB null mutant produced reduced amount of ST with unaltered STC gene expression. However, in A. fumigatus, the deletion of cpcB results in the blockage of gliotoxin (GT production. Further genetic analyses in A. nidulans indicate that CpcB may play a central role in vegetative growth, which might be independent of FadA- and GanB-mediated signaling. A speculative model summarizing the roles of CpcB in conjunction with SfaD in A. nidulans is presented.

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

    Science.gov (United States)

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

  4. Correlation of mycelial growth rate with other characters in evolved genotypes of Aspergillus nidulans

    NARCIS (Netherlands)

    Schoustra, S.E.; Punzalan, D.

    2012-01-01

    Fungal populations can adapt to their environment by the generation and fixation of spontaneous beneficial mutations. In this study we examined whether adaptation, measured as an increased mycelial growth rate, has correlated responses in the filamentous fungus Aspergillus nidulans with several

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

    NARCIS (Netherlands)

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

    1999-01-01

    textabstractAfter five patients were diagnosed with nosocomial invasive aspergillosis caused by Aspergillus fumigatus and A. flavus, a 14-month surveillance program for pathogenic and nonpathogenic fungal conidia in the air within and outside the University Hospital in

  6. 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...

  7. 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.

  8. Incubation and Growth of Life Sciences, Medical and Biotechnology Businesses in Proteomics, Genomics, Medicine, and Dentistry

    Science.gov (United States)

    2007-04-01

    Medical and Biotechnology Businesses in Proteomics , Genomics, Medicine, and Dentistry PRINCIPAL INVESTIGATOR: Mark S. Long Brian C...2007 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Incubation and Growth of Life Sciences, Medical and Biotechnology Businesses in Proteomics ...aflatoxins B1 and G1 from Aspergillus flavus. All toxins studied were purchased from Sigma Aldrich and used without further purification. Solutions

  9. 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 ...

  10. Aspergillus fumigatus and Related Species

    Science.gov (United States)

    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

  11. Expression of Aspergillus hemoglobin domain activities in Aspergillus oryzae grown on solid substrates improves growth rate and enzyme production

    NARCIS (Netherlands)

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

    2006-01-01

    DNA fragments coding for hemoglobin domains (HBD) were isolated from Aspergillus oryzae and Aspergillus niger. The HBD activities were expressed in A. oryzae by introduction of HBD gene fragments under the control of the promoter of the constitutively expressed gpdA gene. In the transformants,

  12. Plant growth activities of aspyran, asperentin, and its analogues produced by the fungus Aspergillus sp.

    Science.gov (United States)

    Kimura, Yasuo; Shimomura, Naomi; Tanigawa, Fumiaki; Fujioka, Shozo; Shimada, Atsumi

    2012-01-01

    Aspyran (1), a novel compound, and the known isocoumarin asperentin (2), also known as cladosporin, together with its analogues 3-6 were isolated from Aspergillus sp. and their structures established by spectroscopic methods including 2D NMR spectroscopy. The effects of 1-6 on plant growth were examined by bioassays using lettuce and rice seedlings. Compounds 1 and 3 promoted the root growth of the seedlings, while 2 and 5 were inhibitory. Compounds 4 and 6 did not show any effect on the growth of lettuce and rice seedlings, respectively.

  13. Growth and enzyme production during continuous cultures of a high amylase-producing variant of Aspergillus oryzae

    DEFF Research Database (Denmark)

    Zangirolami, Teresa; Carlsen, M.; Nielsen, J.

    2002-01-01

    Growth and product formation by a selected variant of Aspergillus oryzae showing high alpha-amylase production was studied in continuous cultivations carried out at six different specific growth rates, using glucose as the growth-limiting nutrient. The analysis of the steady-state data revealed...

  14. Effect of gamma radiation (60Co) on the growth of Aspergillus ochraceus coffee (Coffea arabica L.)

    International Nuclear Information System (INIS)

    Rodrigues, Flavio T.; Duarte, Renato C.; Fanaro, Gustavo B.; Santillo, Amanda G.; Villavicencio, Anna Lucia C.H.

    2011-01-01

    Coffee is a major product on the world market. Its acceptance depends strongly on the sensory characteristics of the beverage, that is its aroma and flavor. One of the most important aspects of coffee culture today is the cup quality as such all segments of coffee production network are concentrating efforts to improve this trait. Foods that have been contaminated with fungi may contain may produce many mycotoxins including ochratoxim A (OTA). To prevent OTA in foodstuffs, it is necessary detect the producing fungi early. Ionizing radiation is a safe, environmentally clean, energy efficient process that can be used to increase the quality and reducing the microbiological contamination of the coffee. The aim of the present study was to evaluate the effects of different gamma radiation doses (0.0, 6.0, 12.0 and 18.0 kGy) on the growth of Aspergillus ochraceus in coffee (Coffee arabica L.). The analysis were performed to determine the fungi contamination the results were expressed as the viable counts per gram of sample (CFU/g) coffee samples irradiated and unirradiated. The results shows that microbiological contamination of coffee disagrees when increase doses of irradiation. The radiation doses 6.0, 12.0 and 18.0 kGy used resulted in a elimination of the number of Aspergillus ochraceus CFU/g when compared to the nonirradiated control group. Under the present conditions, gamma radiation was found to be an alternative for the control of Aspergillus ochraceus. (author)

  15. Identification of growth phenotype-related genes in Aspergillus oryzae by heterologous macroarray and suppression subtractive hybridization

    NARCIS (Netherlands)

    Biesebeke, R. te; Levin, A.; Sagt, C.; Bartels, J.; Goosen, T.; Ram, A.; Hondel, C. van den; Punt, P.

    2005-01-01

    Aspergillus oryzae requires polarized growth for colonization of solid substrates, and this growth phenotype differs from that seen in liquid medium. Various experimental approaches were used to identify genes that are differentially expressed when A. oryzae is grown on wheat kernels and in a

  16. 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.

  17. Growth and hydrolase profiles can be used as characteristics to distinguish Aspergillus niger and other black aspergilli

    Science.gov (United States)

    Meijer, M.; Houbraken, J.A.M.P.; Dalhuijsen, S.; Samson, R.A.; de Vries, R.P.

    2011-01-01

    Wild type Aspergillus niger isolates from different biotopes from all over the world were compared to each other and to the type strains of other black Aspergillus species with respect to growth and extracellular enzyme profiles. The origin of the A. niger isolate did not result in differences in growth profile with respect to monomeric or polymeric carbon sources. Differences were observed in the growth rate of the A. niger isolates, but these were observed on all carbon sources and not specific for a particular carbon source. In contrast, carbon source specific differences were observed between the different species. Aspergillus brasiliensis is the only species able to grow on D-galactose, and A. aculeatus had significantly better growth on Locus Bean gum than the other species. Only small differences were found in the extracellular enzyme profile of the A. niger isolates during growth on wheat bran, while large differences were observed in the profiles of the different black aspergilli. In addition, differences were observed in temperature profiles between the black Aspergillus species, but not between the A. niger isolates, demonstrating no isolate-specific adaptations to the environment. These data indicate that the local environment does not result in stable adaptations of A. niger with respect to growth profile or enzyme production, but that the potential is maintained irrespective of the environmental parameters. It also demonstrates that growth, extracellular protein and temperature profiles can be used for species identification within the group of black aspergilli. PMID:21892240

  18. Isolate-dependent growth, virulence, and cell wall composition in the human pathogen Aspergillus fumigatus.

    Directory of Open Access Journals (Sweden)

    Nansalmaa Amarsaikhan

    Full Text Available The ubiquitous fungal pathogen Aspergillus fumigatus is a mediator of allergic sensitization and invasive disease in susceptible individuals. The significant genetic and phenotypic variability between and among clinical and environmental isolates are important considerations in host-pathogen studies of A. fumigatus-mediated disease. We observed decreased radial growth, rate of germination, and ability to establish colony growth in a single environmental isolate of A. fumigatus, Af5517, when compared to other clinical and environmental isolates. Af5517 also exhibited increased hyphal diameter and cell wall β-glucan and chitin content, with chitin most significantly increased. Morbidity, mortality, lung fungal burden, and tissue pathology were decreased in neutropenic Af5517-infected mice when compared to the clinical isolate Af293. Our results support previous findings that suggest a correlation between in vitro growth rates and in vivo virulence, and we propose that changes in cell wall composition may contribute to this phenotype.

  19. Influence of Gibberellic Acid on Enhancement Growth of Aspergillus Niger for Chitosan Production

    International Nuclear Information System (INIS)

    Hazaa, M.M.; Shash, S.M.; Swailam, H.M.; Aziz, N.H.; Emam, D.A.

    2013-01-01

    Chitosan is obtained by chemical conversion of chitin, which is a constituent of the exoskeleton of crustacean and insects. An alternative source of chitosan is the cell wall of fungi. The waste biomass of Aspergillus niger, following citric acid production, was used as a source for fungal chitosan extraction. In this research we study the effect of different production media, different concentrations of molass, the effect of addition of gibberellic acid at different concentrations (1-5 mg/l) on mycelial growth and chitosan production from Aspergillus niger. Studying the effect of different incubation time. The results showed that, the best production medium was molass salt medium (MSM) with molass concentration 50 g/l and incubation time 48h. Maximum enhancement was observed at 2 mg gibberellic acid. Gibberellic acid at high concentrations inhibit both growth and chitosan content. The produced fungal chitosan was characterized with deacetylation degree of 81.3%, a molecular weight of 24.2 kDa and their FT-IR spectra were compared with that of shrimp chitosan.

  20. 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...

  1. The Growth of Aspergillus Niger on a Wood Based Material with 4 Types of Wall Finishing

    Directory of Open Access Journals (Sweden)

    Subramaniam Menega

    2016-01-01

    Full Text Available Buildings are a vital component in a human’s daily life. It provides shelter from the environment, weather and animals. Mold growth within the building might be caused by the moisture problems which directly act on it such as water leaks or indirect factor such as high humidity levels. This growth causes esthetic problems and deterioration of its wall coatings. Spores from the fungi also cause health problems to humans. The fungus species studied in this research is Aspergillus niger. The material is made of wood and its finishing is thick wallpaper, thin wallpaper, acrylic paint and glycerol based paint. ASTMD5590-00 standard was used to evaluate fungal growth and to determine if non antifungal agent was effective in inhibiting the amount of fungal growth on four types of wall finishing used on wooden walls. This research was conducted without using any antifungal agent. Highest percentage of growth of the fungi was found on acrylic paint, followed by glycerol based paint and thin wallpaper. Thick wall paper shows the least growth of fungi. The maximum growth is visible on day 12 which is more than 60% by all the wall finishing.

  2. GROWTH AND ENZYME PRODUCTION DURING CONTINUOUS CULTURES OF A HIGH AMYLASE-PRODUCING VARIANT OF Aspergillus Oryzae

    OpenAIRE

    Zangirolami,T.C.; Carlsen,M.; Nielsen,J.; Jørgensen,S.B.

    2002-01-01

    Growth and product formation by a selected variant of Aspergillus oryzae showing high alpha-amylase production was studied in continuous cultivations carried out at six different specific growth rates, using glucose as the growth-limiting nutrient. The analysis of the steady-state data revealed that the variant and wild-type strains were similar with respect to glucose uptake system and stoichiometric coefficients. However, the variant was capable of maintaining an enzyme production as high a...

  3. The Aspergillus niger growth on the treated concrete substrate using variable antifungals

    Science.gov (United States)

    Parjo, U. K.; Sunar, N. M.; Leman, A. M.; Gani, P.; Embong, Z.; Tajudin, S. A. A.

    2016-11-01

    The aim of this study was to evaluate the Aspergillus niger (A. niger) growth on substrates after incorporates with different compounds of antifungals which is normally used in food industry. The antifungals named as potassium sorbate (PS), calcium benzoate (CB) and zinc salicylate (ZS) were applied on concrete substrate covered with different wall finishing such as acrylic paint (AP), glycerol based paint (GBP), thin wallpaper (THIN) and thick wallpaper (THICK). The concrete substrate were inoculated with spore suspension, incubated at selected temperature (30oC) and relative humidity (90%)in plant growth chamber. The observations were done from the Day 3 until Day 27. The results showed that the growth of the A. niger for concrete treated by PS for AP, GBP, THIN, and THICK were 64%, 32%, 11% and 100%, respectively. Meanwhile for CB, the growth of A. niger on AP, GBP, THIN, and THICK were 100%, 12%, 41%, and 13%, respectively. Similarly, treated concrete by ZS revealed that the growth of A. niger on the same substrate cover were 33%, 47%, 40%, and 39%, respectively. The results obtained in this study provide a valuable knowledge on the abilities of antifungals to remediate A. niger that inoculated on the concrete substrate. Consequently, this study proved that the PS covering with THIN more efficiency compares CB and ZS to prevent A. niger growth.

  4. Stimulating action of continuous γ-irradiation with low dose-rates on the growth and development of Aspergillus niger

    International Nuclear Information System (INIS)

    Kuzin, A.M.; Nikitina, A.N.; Yurov, S.S.; Primak, V.N.

    1976-01-01

    Continuous γ-irradiation (1.6 - 4.1 rad/hr) of Aspergillus niger cultured in a mineral medium has been shown to stimulate markedly the growth of the culture and the production of organic acids. Optimum conditions for the stimulating effect have been found

  5. The weak acid preservative sorbic acid inhibits conidial germination and mycelial growth of Aspergillus niger through intracellular acidification

    NARCIS (Netherlands)

    Plumridge, A.; Hesse, S.J.A.; Watson, A.J.; Lowe, K.C.; Stratford, M.; Archer, D.B.

    2004-01-01

    The growth of the filamentous fungus Aspergillus niger, a common food spoilage organism, is inhibited by the weak acid preservative sorbic acid (trans-trans-2,4-hexadienoic acid). Conidia inoculated at 105/ml of medium showed a sorbic acid MIC of 4.5 mM at pH 4.0, whereas the MIC for the amount of

  6. Unfolded protein response is required for Aspergillus oryzae growth under conditions inducing secretory hydrolytic enzyme production.

    Science.gov (United States)

    Tanaka, Mizuki; Shintani, Takahiro; Gomi, Katsuya

    2015-12-01

    Unfolded protein response (UPR) is an intracellular signaling pathway for adaptation to endoplasmic reticulum (ER) stress. In yeast UPR, Ire1 cleaves the unconventional intron of HAC1 mRNA, and the functional Hac1 protein translated from the spliced HAC1 mRNA induces the expression of ER chaperone genes and ER-associated degradation genes for the refolding or degradation of unfolded proteins. In this study, we constructed an ireA (IRE1 ortholog) conditionally expressing strain of Aspergillus oryzae, a filamentous fungus producing a large amount of amylolytic enzymes, and examined the contribution of UPR to ER stress adaptation under physiological conditions. Repression of ireA completely blocked A. oryzae growth under conditions inducing the production of hydrolytic enzymes, such as amylases and proteases. This growth defect was restored by the introduction of unconventional intronless hacA (hacA-i). Furthermore, UPR was observed to be induced by amylolytic gene expression, and the disruption of the transcriptional activator for amylolytic genes resulted in partial growth restoration of the ireA-repressing strain. In addition, a homokaryotic ireA disruption mutant was successfully generated using the strain harboring hacA-i as a parental host. These results indicated that UPR is required for A. oryzae growth to alleviate ER stress induced by excessive production of hydrolytic enzymes. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Toxicity to Chicks of Aspergillus and Penicillium Species Isolated from Moldy Pecans 1

    Science.gov (United States)

    Doupnik, Ben; Bell, D. K.

    1971-01-01

    Isolates of Aspergillus chevalieri, A. flavus, A. ochraceus, A. repens, and Penicillium funiculosum and complexes of P. citrinum-P. implicatum isolated from moldy pecan meats were toxic to chicks. PMID:5564681

  8. Effect of temperature, water activity, and pH on growth and production of ochratoxin A by Aspergillus niger and Aspergillus carbonarius from Brazilian grapes.

    Science.gov (United States)

    Passamani, Fabiana Reinis Franca; Hernandes, Thais; Lopes, Noelly Alves; Bastos, Sabrina Carvalho; Santiago, Wilder Douglas; Cardoso, Maria das Graças; Batista, Luís Roberto

    2014-11-01

    The growth of ochratoxigenic fungus and the presence of ochratoxin A (OTA) in grapes and their derivatives can be caused by a wide range of physical, chemical, and biological factors. The determination of interactions between these factors and fungal species from different climatic regions is important in designing models for minimizing the risk of OTA in wine and grape juice. This study evaluated the influence of temperature, water activity (aw), and pH on the development and production of OTA in a semisynthetic grape culture medium by Aspergillus carbonarius and Aspergillus niger strains. To analyze the growth conditions and production of OTA, an experimental design was conducted using response surface methodology as a tool to assess the effects of these abiotic variables on fungal behavior. A. carbonarius showed the highest growth at temperatures from 20 to 33°C, aw between 0.95 and 0.98, and pH levels between 5 and 6.5. Similarly, for A. niger, temperatures between 24 and 37°C, aw greater than 0.95, and pH levels between 4 and 6.5 were optimal. The greatest toxin concentrations for A. carbonarius and A. niger (10 μg/g and 7.0 μg/g, respectively) were found at 15°C, aw 0.99, and pH 5.35. The lowest pH was found to contribute to greater OTA production. These results show that the evaluated fungi are able to grow and produce OTA in a wide range of temperature, aw, and pH. However, the optimal conditions for toxin production are generally different from those optimal for fungal growth. The knowledge of optimal conditions for fungal growth and production of OTA, and of the stages of cultivation in which these conditions are optimal, allows a more precise assessment of the potential risk to health from consumption of products derived from grapes.

  9. Biosynthesis of silver nanoparticles synthesized by Aspergillus

    Indian Academy of Sciences (India)

    In the present study, biosynthesis of silver nanoparticles and its antioxidant, antimicrobial and cytotoxic activities were investigated. Silver nanoparticles were extracellularly synthesized using Aspergillus flavus and the formation of nanoparticles was observed after 72 h of incubation. The results recorded from colour ...

  10. Dynamics of actin cables in polarized growth of the filamentous fungus Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Anna eBergs

    2016-05-01

    Full Text Available Highly polarized growth of filamentous fungi requires a continuous supply of proteins and lipids to the hyphal tip. This transport is managed by vesicle trafficking via the actin and microtubule cytoskeletons and their associated motor proteins. Particularly, actin cables originating from the hyphal tip are essential for hyphal growth. Although specific marker proteins to visualize actin cables have been developed in filamentous fungi, the exact organization and dynamics of actin cables has remained elusive. Here we visualized actin cables using tropomyosin (TpmA and Lifeact fused to fluorescent proteins in Aspergillus nidulans and studied the dynamics and regulation. GFP tagged TpmA visualized dynamic actin cables formed from the hyphal tip with cycles of elongation and shrinkage. The elongation and shrinkage rates of actin cables were similar and approximately 0.6 μm/s. Comparison of actin markers revealed that high concentrations of Lifeact reduced actin dynamics. Simultaneous visualization of actin cables and microtubules suggests temporally and spatially coordinated polymerization and depolymerization between the two cytoskeletons. Our results provide new insights into the molecular mechanism of ordered polarized growth regulated by actin cables and microtubules.

  11. Lactobacillus brevis-based bioingredient inhibits Aspergillus niger growth on pan bread

    Directory of Open Access Journals (Sweden)

    Mariaelena Di Biase

    2014-11-01

    Full Text Available Bread shelf life is generally compromised by fungi mainly belonging to Aspergillus and Penicillium genera, which colonise the surface of the product within few days from the production. The aim of this study was to select a Lactobacillus brevis-based bioingredient (LbBio able to inhibit the growth of Aspergillus niger ITEM5132 on pan bread in order to prolong its shelf life. Four LbBio formulations, obtained by growing a selected L. brevis strain in a flour-based medium containing different carbon sources or acid precursors (fructose, LbBio1; fructose and maltose, LbBio2; α-chetoglutaric acid, LbBio3; short-chain fructooligosaccharides, LbBio4, were evaluated for their content of organic acids (lactic, acetic, propionic, phenyllactic, 4-hydroxy-phenyllactic, valeric, isovaleric acids. The LbBio formulations were applied in yeast-leavened bread during bread-making trials and the resulting products were inoculated after baking with A. niger spore’s suspension and the fungal growth was monitored during storage (25°C for 6 days. The formulation showing the highest inhibitory activity was separated by ultra-filtration method, and whole and fractions obtained were evaluated for their in vitro activity. The fraction showing the highest activity was further separated by gel-filtration and the resulting products were investigated for their protein content and in vitro inhibition. The results from the bread-making trials performed using different formulations of LbBio showed a delay in fungal growth (1 day respect to the bread not containing the bioingredient (control or including calcium propionate (0.3% w/w. The formulation LbBio2, prepared with fructose and maltose 1% (w/vol, contained the highest amount of total organic acids, including phenyllactic and hydroxyl-phenyllactic acids, and reduced the visual spoilage of bread. This formulation was separated by ultra-filtration and fractions containing metabolites with molecular weight higher than 30 k

  12. Qualitative ubiquitome unveils the potential significances of protein lysine ubiquitination in hyphal growth of Aspergillus nidulans.

    Science.gov (United States)

    Chu, Xin-Ling; Feng, Ming-Guang; Ying, Sheng-Hua

    2016-02-01

    Protein ubiquitination is an evolutionarily conserved post-translational modification process in eukaryotes, and it plays an important role in many biological processes. Aspergillus nidulans, a model filamentous fungus, contributes to our understanding of cellular physiology, metabolism and genetics, but its ubiquitination is not completely revealed. In this study, the ubiquitination sites in the proteome of A. nidulans were identified using a highly sensitive mass spectrometry combined with immuno-affinity enrichment of the ubiquitinated peptides. The 4816 ubiquitination sites were identified in 1913 ubiquitinated proteins, accounting for 18.1% of total proteins in A. nidulans. Bioinformatic analysis suggested that the ubiquitinated proteins associated with a number of biological functions and displayed various sub-cellular localisations. Meanwhile, seven motifs were revealed from the ubiquitinated peptides, and significantly over-presented in the different pathways. Comparison of the enriched functional catalogues indicated that the ubiquitination functions divergently during growth of A. nidulans and Saccharomyces cerevisiae. Additionally, the proteins in A. nidulans-specific sub-category (cell growth/morphogenesis) were subjected to the protein interaction analysis which demonstrated that ubiquitination is involved in the comprehensive protein interactions. This study presents a first proteomic view of ubiquitination in the filamentous fungus, and provides an initial framework for exploring the physiological roles of ubiquitination in A. nidulans.

  13. Identification by Molecular Methods and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry and Antifungal Susceptibility Profiles of Clinically Significant Rare Aspergillus Species in a Referral Chest Hospital in Delhi, India

    NARCIS (Netherlands)

    Masih, A.; Singh, P.K.; Kathuria, S.; Agarwal, K.; Meis, J.F.G.M.; Chowdhary, A.

    2016-01-01

    Aspergillus species cause a wide spectrum of clinical infections. Although Aspergillus fumigatus and Aspergillus flavus remain the most commonly isolated species in aspergillosis, in the last decade, rare and cryptic Aspergillus species have emerged in diverse clinical settings. The present study

  14. 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)

  15. 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)

  16. 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.

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

    Science.gov (United States)

    Hilmy, N.; Chosdu, R.; Matsuyama, A.

    1995-02-01

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

  18. Intraspecies Volatile Interactions Affect Growth Rates and Exometabolomes in Aspergillus oryzae KCCM 60345.

    Science.gov (United States)

    Singh, Digar; Lee, Choong Hwan

    2018-02-28

    Volatile organic compounds (VOCs) are increasingly been recognized as the chemical mediators of mold interactions, shaping their community dynamics, growth, and metabolism. Herein, we selectively examined the time-correlated (0 D-11 D, where D = incubation days) effects of intraspecies VOC-mediated interactions (VMI) on Aspergillus oryzae KCCM 60345 (S1), following co-cultivation with partner strain A. oryzae KACC 44967 (S2), in a specially designed twin plate assembly. The comparative evaluation of S1 VMI (S1 subjected to VMI with S2) and its control (S1 Con ) showed a notable disparity in their radial growth (S1 VMI S1 Con ) at 3-5 D, amylase activity (S1 VMI S1 Con ) at 3 D. Furthermore, we observed a distinct clustering pattern for gas chromatography-time of flight-mass spectrometry datasets from 5 D extracts of S1 VMI and S1 Con in principle component analysis (PC1: 30.85%; PC2: 10.31%) and partial least squares discriminant analysis (PLS-DA) (PLS1: 30.77; PLS2: 10.15%). Overall, 43 significantly discriminant metabolites were determined for engendering the metabolic variance based on the PLS-DA model (VIP > 0.7, p S1 Con ) at 5 D, organic acids (S1 VMI > S1 Con ) at 5 D, and kojic acid (S1 VMI < S1 Con ) at 5-7 D were observed. Examining the headspace VOCs shared between S1 and S2 in the twin plate for 5 D incubated samples, we observed the relatively higher abundance of C-8 VOCs (1-octen-3-ol, (5Z)-octa-1,5-dien-3-ol, 3-octanone, 1-octen-3-ol acetate) having known semiochemical functions. The present study potentially illuminates the effects of VMI on commercially important A. oryzae's growth and biochemical phenotypes with subtle details of altered metabolomes.

  19. Growth and enzymatic responses of phytopathogenic fungi to glucose in culture media and soil

    Directory of Open Access Journals (Sweden)

    Beatriz de Oliveira Costa

    2012-03-01

    Full Text Available The effect of inoculation of Aspergillus flavus, Fusarium verticillioides, and Penicillium sp. in Dystrophic Red Latosol (DRL and Eutroferric Red Latosol (ERL soils with or without glucose on the total carbohydrate content and the dehydrogenase and amylase activities was studied. The fungal growth and spore production in culture medium with and without glucose were also evaluated. A completely randomized design with factorial arrangement was used. The addition of glucose in the culture medium increased the growth rate of A. flavus and Penicillium sp. but not of F. verticillioides. The number of spores increased 1.2 for F. verticillioides and 8.2 times for A. flavus in the medium with glucose, but was reduced 3.5 times for Penicillium sp. The total carbohydrates contents reduced significantly according to first and second degree equations. The consumption of total carbohydrates by A. flavus and Penicillium sp. was higher than the control or soil inoculated with F. verticillioides. The addition of glucose to soils benefited the use of carbohydrates, probably due to the stimulation of fungal growth. Dehydrogenase activity increased between 1.5 to 1.8 times (p <0.05 in soils with glucose and inoculated with the fungi (except F. verticillioides, in relation to soil without glucose. Amylase activity increased 1.3 to 1.5 times due to the addition of glucose in the soil. Increased amylase activity was observed in the DRL soil with glucose and inoculated with A. flavus and Penicillium sp. when compared to control.

  20. 8-Carbon oxylipins inhibit germination and growth, and stimulate aerial conidiation in Aspergillus nidulans.

    Science.gov (United States)

    Herrero-Garcia, Erika; Garzia, Aitor; Cordobés, Shandra; Espeso, Eduardo A; Ugalde, Unai

    2011-01-01

    Germination of Aspergillus nidulans conidia in liquid cultures was progressively inhibited at inoculum loads above 1×10(5)conidiamL(-1). High conidial densities also inhibited growth of neighbouring mycelia. The eight-carbon oxylipin 1-octen-3-ol was identified as the main inhibitor in a fraction also containing 3-octanone and 3-octanol. These three oxylipins also increased the conidiation rate of dark-grown surface cultures, but had no effect on liquid cultures. 3-octanone was the most conidiogenic compound. The action of 3-octanone required functional forms of developmental activators fluG, flbB-D and brlA, and was not additive to the conidiogenic effect of stress stimuli such as osmotic stress or carbon starvation. Oxylipins were produced shortly after hyphae made contact with the atmosphere and were most effective on aerial mycelia, indicating that they perform their signalling function in the gas phase. Copyright © 2011 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  1. 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...

  2. Inhibitory effect of essential oils on Aspergillus ochraceus growth and ochratoxin A production.

    Directory of Open Access Journals (Sweden)

    Huijuan Hua

    Full Text Available Ochratoxin A (OTA is a mycotoxin which is a common contaminant in grains during storage. Aspergillus ochraceus is the most common producer of OTA. Essential oils play a crucial role as a biocontrol in the reduction of fungal contamination. Essential oils namely natural cinnamaldehyde, cinnamon oil, synthetic cinnamaldehyde, Litsea citrate oil, citral, eugenol, peppermint, eucalyptus, anise and camphor oils, were tested for their efficacy against A. ochraceus growth and OTA production by fumigation and contact assays. Natural cinnamaldehyde proved to be the most effective against A. ochraceus when compared to other oils. Complete fungal growth inhibition was obtained at 150-250 µL/L with fumigation and 250-500 µL/L with contact assays for cinnamon oil, natural and synthetic cinnamaldehyde, L. citrate oil and citral. Essential oils had an impact on the ergosterol biosynthesis and OTA production. Complete inhibition of ergosterol biosynthesis was observed at ≥ 100 µg/mL of natural cinnamaldehyde and at 200 µg/mL of citral, but total inhibition was not observed at 200 µg/mL of eugenol. But, citral and eugenol could inhibit the OTA production at ≥ 75 µg/mL and ≥ 150 µg/mL respectively, while natural cinnamaldehyde couldn't fully inhibit OTA production at ≤ 200 µg/mL. The inhibition of OTA by natural cinnamaldehyde is mainly due to the reduction in fungal biomass. However, citral and eugenol could significant inhibit the OTA biosynthetic pathway. Also, we observed that cinnamaldehyde was converted to cinnamic alcohol by A. ochraceus, suggesting that the antimicrobial activity of cinnamaldehyde was mainly attributed to its carbonyl aldehyde group. The study concludes that natural cinnamaldehyde, citral and eugenol could be potential biocontrol agents against OTA contamination in storage grains.

  3. Modelling growth of Penicillium expansum and Aspergillus niger at constant and fluctuating temperature conditions.

    Science.gov (United States)

    Gougouli, Maria; Koutsoumanis, Konstantinos P

    2010-06-15

    The growth of Penicillium expansum and Aspergillus niger, isolated from yogurt production environment, was investigated on malt extract agar with pH=4.2 and a(w)=0.997, simulating yogurt, at isothermal conditions ranging from -1.3 to 35 degrees C and from 5 to 42.3 degrees C, respectively. The growth rate (mu) and (apparent) lag time (lambda) of the mycelium growth were modelled as a function of temperature using a Cardinal Model with Inflection (CMI). The results showed that the CMI can describe successfully the effect of temperature on fungal growth within the entire biokinetic range for both isolates. The estimated values of the CMI for mu were T(min)=-5.74 degrees C, T(max)=30.97 degrees C, T(opt)=22.08 degrees C and mu(opt)=0.221 mm/h for P. expansum and T(min)=10.13 degrees C, T(max)=43.13 degrees C, T(opt)=31.44 degrees C, and mu(opt)=0.840 mm/h for A. niger. The cardinal values for lambda were very close to the respective values for mu indicating similar temperature dependence of the growth rate and the lag time of the mycelium growth. The developed models were further validated under fluctuating temperature conditions using various dynamic temperature scenarios. The time-temperature conditions studied included single temperature shifts before or after the end of the lag time and continuous periodic temperature fluctuations. The prediction of growth at changing temperature was based on the assumption that after a temperature shift the growth rate is adopted instantaneously to the new temperature, while the lag time was predicted using a cumulative lag approach. The results showed that when the temperature shifts occurred before the end of the lag, they did not cause any significant additional lag and the observed total lag was very close to the cumulative lag predicted by the model. In experiments with temperature shifts after the end of the lag time, accurate predictions were obtained when the temperature profile included temperatures which were inside the

  4. Reduction of IgE binding and nonpromotion of Aspergillus flavus fungal growth by simultaneously silencing Ara h 2 and Ara h 6 in peanut.

    Science.gov (United States)

    The most potent peanut allergens, Ara h 2 and 6, were silenced in transgenic plants by RNA interference. Three independent transgenic lines were recovered after microprojectile bombardment, of which two contained single, integrated copies of the transgene. The third line contained multiple copies ...

  5. 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.

  6. Calcineurin Orchestrates Hyphal Growth, Septation, Drug Resistance and Pathogenesis of Aspergillus fumigatus: Where Do We Go from Here?

    Directory of Open Access Journals (Sweden)

    Praveen R Juvvadi

    2015-12-01

    Full Text Available Studies on fungal pathogens belonging to the ascomycota phylum are critical given the ubiquity and frequency with which these fungi cause infections in humans. Among these species, Aspergillus fumigatus causes invasive aspergillosis, a leading cause of death in immunocompromised patients. Fundamental to A. fumigatus pathogenesis is hyphal growth. However, the precise mechanisms underlying hyphal growth and virulence are poorly understood. Over the past 10 years, our research towards the identification of molecular targets responsible for hyphal growth, drug resistance and virulence led to the elucidation of calcineurin as a key signaling molecule governing these processes. In this review, we summarize our salient findings on the significance of calcineurin for hyphal growth and septation in A. fumigatus and propose future perspectives on exploiting this pathway for designing new fungal-specific therapeutics.

  7. Septic arthritis due to tubercular and Aspergillus co-infection

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar

    2016-01-01

    Full Text Available Aspergillus septic arthritis is a rare and serious medical and surgical problem. It occurs mainly in immunocompromised patients. Aspergillus fumigatus is the most common causative organism followed by Aspergillus flavus. The most common site affected is knee followed by shoulder, ankle, wrist, hip and sacroiliac joint. Debridement and voriconazole are primary treatment of articular aspergilosis. To the best of our knowledge, there are no reported cases of co-infection of tuberculosis (TB and Aspergillus infecting joints. We report a case of co-infection of TB and A. flavus of hip and knee of a 60-year-old male, with type 2 diabetes mellitus. He was treated with debridement, intravenous voriconazole, and antitubercular drugs.

  8. Septic arthritis due to tubercular and Aspergillus co-infection.

    Science.gov (United States)

    Kumar, Mukesh; Thilak, Jai; Zahoor, Adnan; Jyothi, Arun

    2016-01-01

    Aspergillus septic arthritis is a rare and serious medical and surgical problem. It occurs mainly in immunocompromised patients. Aspergillus fumigatus is the most common causative organism followed by Aspergillus flavus. The most common site affected is knee followed by shoulder, ankle, wrist, hip and sacroiliac joint. Debridement and voriconazole are primary treatment of articular aspergilosis. To the best of our knowledge, there are no reported cases of co-infection of tuberculosis (TB) and Aspergillus infecting joints. We report a case of co-infection of TB and A. flavus of hip and knee of a 60-year-old male, with type 2 diabetes mellitus. He was treated with debridement, intravenous voriconazole, and antitubercular drugs.

  9. Radiosensitivity of A. ochraceus, A. flavus, A. niger, A. parasiticus and A. carbonarius in CYA medium and on grains of rice, oat, wheat and peanuts

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Valeria Barbosa [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Faculdade de Veterinaria. Dept. de Tecnologia de Alimentos]. E-mail: niveam@uol.com.br; Vital, Helio de Carvalho; Hernandes, Nilber Kenup [Centro Tecnologico do Exercito, Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear]. E-mail: vital@ctex.eb.br; Rosa, Carlos Alberto da Rocha [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Inst. de Veterinaria. Dept. de Microbiologia e Imunologia Veterinaria]. E-mail: shalako@ufrrj.br

    2007-07-01

    Irradiation is regarded as an efficient process to delay fungi growth in foods. However information on the resistance of toxigenic molds to gamma radiation is still scarce in the literature. This work investigated the radiosensitivity of five species of Aspergillus spp., namely: A. ochraceus, A. flavus, A. niger, A. parasiticus and A. carbonarius grown and irradiated in CYA medium, peanuts and on grains of rice, oat and wheat. After inoculation the colonies were stored for five days at 25 deg C and gamma irradiated with doses ranging from 0 to 5.5 kGy. Six days later the colonies were analyzed for post-irradiation growth. Survival curves were then determined as linear functions of the absorbed doses. Regardless of the substrates, the radiosensitivities of the five species have been grouped in three different levels. Expressed in terms of the parameters D{sub 50} and Do (the doses needed to reduce the number of active colonies by 50% and 100%, respectively), those groups are: D{sub 50} = 2.2 kGy and D0 = 3.2 kGy for A. ochraceus and A. carbonarius; D{sub 50} = 2.5 kGy and D0 = 4.1 kGy for A. niger and A. flavus; and D{sub 50} = 3.1 kGy and D0 = 4.7 kGy for A. parasiticus. (author)

  10. Radiosensitivity of A. ochraceus, A. flavus, A. niger, A. parasiticus and A. carbonarius in CYA medium and on grains of rice, oat, wheat and peanuts

    International Nuclear Information System (INIS)

    Borges, Valeria Barbosa; Vital, Helio de Carvalho; Hernandes, Nilber Kenup; Rosa, Carlos Alberto da Rocha

    2007-01-01

    Irradiation is regarded as an efficient process to delay fungi growth in foods. However information on the resistance of toxigenic molds to gamma radiation is still scarce in the literature. This work investigated the radiosensitivity of five species of Aspergillus spp., namely: A. ochraceus, A. flavus, A. niger, A. parasiticus and A. carbonarius grown and irradiated in CYA medium, peanuts and on grains of rice, oat and wheat. After inoculation the colonies were stored for five days at 25 deg C and gamma irradiated with doses ranging from 0 to 5.5 kGy. Six days later the colonies were analyzed for post-irradiation growth. Survival curves were then determined as linear functions of the absorbed doses. Regardless of the substrates, the radiosensitivities of the five species have been grouped in three different levels. Expressed in terms of the parameters D 50 and Do (the doses needed to reduce the number of active colonies by 50% and 100%, respectively), those groups are: D 50 = 2.2 kGy and D0 = 3.2 kGy for A. ochraceus and A. carbonarius; D 50 = 2.5 kGy and D0 = 4.1 kGy for A. niger and A. flavus; and D 50 = 3.1 kGy and D0 = 4.7 kGy for A. parasiticus. (author)

  11. The Effect of Inoculants of Thiobacillus and Aspergillus on Corn Growth

    Directory of Open Access Journals (Sweden)

    M. Mohammdi Aria

    2011-01-01

    Full Text Available Abstract Phosphorus (P is one of the essential macronutrients for growth and development of plant. Phosphorus is added to soil in the form of phosphatic fertilizers, part of which is utilized by plants and the remainder converted into insoluble fixed forms. Increasingly high cost of chemical fertilizers has been the major stimulus to search for an alternative, naturally-occurring, phosphate source. The researchers offered phosphorus rocks as a valuable alternative source for P. fertilizer. Unfortunately, rock phosphate is not plant available in soils with a pH greater than 6. One method to increase soluble form inorganic P is application of phosphate solublizing microorganisms and sulfur oxidizing bacteria (Thiobacillus with rock phosphate. A greenhouse experiment was carried out with two bio fertilizers (bio fertilizers santes in incubation condition in a soil with low available P on corn growth. The bio fertilizers were: rock phosphate with 20% sulfur, 15% vermicompost, Thiobacillus bacteria and Aspergillus fungi (BFS20V15 at three rates: 440 kg/ha (BF1 , 880 kg/ha (BF2, 1320kg/ha (BF3, rock phosphate with 20% sulfur, 15% vermicompost, Thiobacillus bacteria (BFS20V15 at three rates: 440 kg/ha (B1 , 880 kg/ha (B2, 1320kg/ha (B3, triple super phosphate (TSP, and control without phosphorus. In the greenhouse experiment, shoot dry matter, p uptake in plant and available p in soil were determined. The results showed that maximum yield obtained from BF3 with the shoot dry weight 7.2 g per plant and with no significant difference in relation to the triple super phosphate (7.5g at 5% level. Also highest rate p-uptake resulted from BF3. There was significant difference between treatment BF3 and TSP on p-uptake. Results indicated that it could be possible to substitute rock phosphate inoculated with sulfur-oxidizing bacteria and phosphorous-solublizing fungus for super phosphate. Keywords: Uptake-p, pH Rock phosphate, Solfur, Vermicompost

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

    Directory of Open Access Journals (Sweden)

    Ana Carolina Pessoa Moreira

    2010-03-01

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

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

    Science.gov (United States)

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

    2008-12-01

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

  14. Growth and product formation of Aspergillus oryzae during submerged cultivations: Verification of a morphologically structured model using fluorescent probes

    DEFF Research Database (Denmark)

    Agger, Teit; Spohr, Anders Bendsen; Carlsen, Morten

    1998-01-01

    of Aspergillus oryzae. The model is based on a division of the fungal hyphae into three different regions: an extension zone, representing the tips of the hyphae; an active region, which is responsible for growth and product formation; and an inactive hyphal region. Two metamorphosis reactions describing...... and automated image analysis, has been developed for measuring the fraction of active cells. The method employs the fluorescent dye 3,3'-dihexyloxocarbocyanin to stain organelles inside the hyphae and Calcoflour White to stain the cell wall. The ratio between the projected areas of the organelles...

  15. Fermentation of sugar beet waste by ¤Aspergillus niger¤ facilitates growth and P uptake of external mycelium of mixed populations of arbuscular mycorrhizal fungi

    DEFF Research Database (Denmark)

    Medina, A.; Jakobsen, Iver; Vassilev, N.

    2007-01-01

    Sugar beet waste has potential value as a soil amendment and this work studied whether fermentation of the waste by Aspergillus niger would influence the growth and P uptake of arbuscular mycorrhizal (AM) fungi. Plants were grown in compartmentalised growth units, each with a root compartment (RC...

  16. Gene co-expression analysis identifies gene clusters associated with isotropic and polarized growth in Aspergillus fumigatus conidia.

    Science.gov (United States)

    Baltussen, Tim J H; Coolen, Jordy P M; Zoll, Jan; Verweij, Paul E; Melchers, Willem J G

    2018-04-26

    Aspergillus fumigatus is a saprophytic fungus that extensively produces conidia. These microscopic asexually reproductive structures are small enough to reach the lungs. Germination of conidia followed by hyphal growth inside human lungs is a key step in the establishment of infection in immunocompromised patients. RNA-Seq was used to analyze the transcriptome of dormant and germinating A. fumigatus conidia. Construction of a gene co-expression network revealed four gene clusters (modules) correlated with a growth phase (dormant, isotropic growth, polarized growth). Transcripts levels of genes encoding for secondary metabolites were high in dormant conidia. During isotropic growth, transcript levels of genes involved in cell wall modifications increased. Two modules encoding for growth and cell cycle/DNA processing were associated with polarized growth. In addition, the co-expression network was used to identify highly connected intermodular hub genes. These genes may have a pivotal role in the respective module and could therefore be compelling therapeutic targets. Generally, cell wall remodeling is an important process during isotropic and polarized growth, characterized by an increase of transcripts coding for hyphal growth and cell cycle/DNA processing when polarized growth is initiated. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Potential aflatoxin and ochratoxin a production by Aspergillus species in poultry feed processing.

    Science.gov (United States)

    Fraga, M E; Curvello, F; Gatti, M J; Cavaglieri, L R; Dalcero, A M; da Rocha Rosa, C A

    2007-04-01

    Poultry feeds are prone to fungal growth and mycotoxin production during processing. The identification of biota with the ability to produce mycotoxins is essential. The aims of this study were (1) to monitor the mycobiota counts at different stages of poultry feed processing; (2) to determine the occurrence of Aspergillus species; (3) to evaluate the natural incidence of aflatoxins and ochratoxin A. The ability of Aspergillus spp. and its teleomorphs isolated here to produce these toxins was also investigated. Samples (144) were collected at random from a factory in Brazil. The occurrence of Aspergillus and Eurotium species was demonstrated on DRBC and DG18 media and the production of aflatoxins and ochratoxin A and their natural incidence were determined by TLC and HPLC methods. A. flavus and E. chevalieri were the most prevalent species isolated. Fungal contamination was not found after the pelleting process, though Aspergillus and Eurotium species were recovered from trough samples. High levels of aflatoxin and ochratoxin A producers were found at all stages of poultry feed processing. Also, high natural contamination with aflatoxins and ochratoxin A was found in the samples. Contact of feed with remainder poultry feed could lead to fungal contamination, so the risk of aflatoxin and/or ochratoxin A contamination of feed must be taken into account.

  18. 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.

  19. Systems Analysis Unfolds the Relationship between the Phosphoketolase Pathway and Growth in Aspergillus nidulans

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Andersen, Mikael Rørdam; Grotkjær, Thomas

    2008-01-01

    Background: Aspergillus nidulans is an important model organism for studies on fundamental eukaryotic cell biology and on industrial processes due to its close relation to A. niger and A. oryzae. Here we identified the gene coding for a novel metabolic pathway in A. nidulans, namely...

  20. Biodiversity of Aspergillus species in some important agricultural products.

    Science.gov (United States)

    Perrone, G; Susca, A; Cozzi, G; Ehrlich, K; Varga, J; Frisvad, J C; Meijer, M; Noonim, P; Mahakarnchanakul, W; Samson, R A

    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 species in relation to their different adaptation to environmental and geographical conditions, and to their potential toxigenicity. Here we analyzed the biodiversity of ochratoxin producing species occurring on two important crops: grapes and coffee, and the genetic diversity of A. flavus populations occurring in agricultural fields. Altogether nine different black Aspergillus species can be found on grapes which are often difficult to identify with classical methods. The polyphasic approach used in our studies led to the identification of three new species occurring on grapes: A. brasiliensis, A. ibericus, and A. uvarum. Similar studies on the Aspergillus species occurring on coffee beans have evidenced in the last five years that A. carbonarius is an important source of ochratoxin A in coffee. Four new species within the black aspergilli were also identified in coffee beans: A. sclerotioniger, A. lacticoffeatus, A. sclerotiicarbonarius, and A. aculeatinus. The genetic diversity within A. flavus populations has been widely studied in relation to their potential aflatoxigenicity and morphological variants L- and S-strains. Within A. flavus and other Aspergillus species capable of aflatoxin production, considerable diversity is found. We summarise the main recent achievements in the diversity of the aflatoxin gene cluster in A. flavus populations, A. parasiticus and the non

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

    Science.gov (United States)

    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.

  2. Antifungal Activity of Culture Filtrates and Organic Extracts of Aspergillus spp. against Pythium ultimum

    OpenAIRE

    Rania Aydi-Ben Abdallah; Marwa Hassine; Hayfa Jabnoun-Khiareddine; Rabiaa Haouala; Mejda Daami-Remadi

    2014-01-01

    Culture filtrates, chloroform and ethyl acetate extracts of nine isolates of Aspergillus spp. (A. niger, A. terreus, A. flavus and Aspergillus sp.), isolated from soil and compost, were tested for antifungal activity against Pythium ultimum the causal agent of the potato Pythium leak. Culture filtrates showed a significant antifungal activity at the different tested concentrations. Total inhibition of the pathogen was induced by the filtrate of CH8 of Aspergillus sp., used at 10% ...

  3. 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.

  4. Growth, ruminal measurements, and health characteristics of Holstein bull calves fed an Aspergillus oryzae fermentation extract.

    Science.gov (United States)

    Yohe, T T; O'Diam, K M; Daniels, K M

    2015-09-01

    A fermentation extract of the fungus Aspergillus oryzae can be used as a prebiotic. The objective was to determine if dietary inclusion of a fermentation extract of A. oryzae as well as calf age would alter growth, health, performance parameters, and the growth and development of the rumen in Holstein calves from birth thru 1 wk postweaning; it was hypothesized that it would. Purchased bull calves (n=52) that originated from 1 of 13 farms were used in this experiment. All calves had serum IgG greater than 10 mg/mL. Calves were randomly assigned to a slaughter age, 4 (n=16) or 8 wk (n=36), and treatment, control (n=27) or fermentation extract of A. oryzae (AMF; n=25). Calves were housed and fed individually; no bedding was used and no forage was fed. Calves assigned to AMF were fed 2 g of AMF daily. Liquid AMF was delivered in milk replacer for the first 4 wk of the study; solid AMF was top-dressed on texturized starter thereafter. Calves were fed nonmedicated milk replacer twice daily (22.0% crude protein, 20.0% fat, dry matter basis; 680 g/d) and were weaned upon consumption of 0.91 kg of starter (20% crude protein, 2.0% fat; medicated with decoquinate) for 3 consecutive days or on d 45 of the study, whichever came first. Calves had ad libitum access to starter and water throughout the study. Feed intake as well as fecal and respiratory scores were recorded daily; body weight, withers height, and hip height were recorded weekly. Gross rumen measurements and rumen samples for future gross and histological analyses were taken at 4 and 8 wk. All calves grew similarly; weaning age averaged 40.39±0.77 d. Lifetime average daily gain was 0.60±0.05 kg/d and lifetime gain-to-feed ratio was 0.56±0.05. Milk replacer, starter, total dry matter intake, gross and histological rumen measurements, rumen pH, fecal and respiratory scores, and total medical costs were not affected by treatment. Despite total medical costs not differing by treatment, a lower percentage of AMF

  5. The effect of cocoa fermentation and weak organic acids on growth and ochratoxin A production by Aspergillus species

    DEFF Research Database (Denmark)

    Copetti, Marina V.; Iamanaka, Beatriz T.; Mororó, Raimundo C.

    2012-01-01

    The acidic characteristics of cocoa beans have influence on flavor development in chocolate. Cocoa cotyledons are not naturally acidic, the acidity comes from organic acids produced by the fermentative microorganisms which grow during the processing of cocoa. Different concentrations of these met...... by Aspergillus carbonarius in cocoa, and the effect of weak organic acids such as acetic, lactic and citric at different pH values on growth and ochratoxin A production by A. carbonarius and Aspergillus niger in culture media. A statistical difference (ρ......The acidic characteristics of cocoa beans have influence on flavor development in chocolate. Cocoa cotyledons are not naturally acidic, the acidity comes from organic acids produced by the fermentative microorganisms which grow during the processing of cocoa. Different concentrations...... of these metabolites can be produced according to the fermentation practices adopted in the farms, which could affect the growth and ochratoxin A production by fungi. This work presents two independent experiments carried out to investigate the effect of some fermentation practices on ochratoxin A production...

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

    African Journals Online (AJOL)

    Antagonistic activity of 24 selected bacterial strains detected by previous microbiological studies to Aspergillus flavus was tested in vitro and in vivo conditions. Within 24 strains, only ten strains showed remarkable inhibition zone (6-34 mm) against the pathogen in assays carried out in Petri plates. Both cell suspension and ...

  7. 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 ...

  8. Prevention of melanin formation during aryl alcohol oxidase production under growth-limited conditions using an Aspergillus nidulans cell factory.

    Science.gov (United States)

    Pardo-Planas, Oscar; Prade, Rolf A; Müller, Michael; Atiyeh, Hasan K; Wilkins, Mark R

    2017-11-01

    An Aspergillus nidulans cell factory was genetically engineered to produce an aryl alcohol oxidase (AAO). The cell factory initiated production of melanin when growth-limited conditions were established using stationary plates and shaken flasks. This phenomenon was more pronounced when the strain was cultured in a trickle bed reactor (TBR). This study investigated different approaches to reduce melanin formation in fungal mycelia and liquid medium in order to increase the enzyme production yield. Removal of copper from the medium recipe reduced melanin formation in agar cultures and increased enzyme activities by 48% in agitated liquid cultures. Copper has been reported as a key element for tyrosinase, an enzyme responsible for melanin production. Ascorbic acid (0.44g/L) stopped melanin accumulation, did not affect growth parameters and resulted in AAO activity that was more than two-fold greater than a control treatment with no ascorbic acid. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. On-line study of growth kinetics of single hyphae of Aspergillus oryzae in a flow-through cell

    DEFF Research Database (Denmark)

    Christiansen, Torben; Spohr, Anders Bendsen; Nielsen, Jens Bredal

    1999-01-01

    Using image analysis the growth kinetics of the single hyphae of the filamentous fungus Aspergillus oryzae has been determined on-line in a flow-through cell at different glucose concentrations in the range from 26 mg L-1 to 20 g L-1. The tip extension rate of the individual hyphae can be described...... with saturation type kinetics with respect to the length of the hyphae. The maximum tip extension rate is constant for all hyphae measured at the same glucose concentration, whereas the saturation constant for the hyphae varies significantly between the hyphae even within the same hyphal element. When apical...... branching occurs, it is observed that the tip extension rate decreases temporarily. The number of branches formed on a hypha is proportional to the length of the hypha that exceeds a certain minimum length required to support the growth of a new branch. The observed kinetics has been used to simulate...

  10. 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.

  11. Effect of low oxygen concentrations on growth and alpha-amylase production of Aspergillus oryzae in model solid-state fermentation systems

    NARCIS (Netherlands)

    Rahardjo, Y.S.P.; Sie, S.; Weber, F.J.; Tramper, J.; Rinzema, A.

    2005-01-01

    Oxygen transfer in the fungal mat is a major concern in solid-state fermentation (SSF). Oxygen supply into the mycelial layers is hampered by diffusion limitation. For aerobic fungi, like Aspergillus oryzae, this oxygen depletion can be a severely limiting factor for growth and metabolite

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

    Science.gov (United States)

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

    2011-01-01

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

  13. Genomic sequences of Aspergillus flavus accessions in Georgia USA

    Data.gov (United States)

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

  14. Penicillenols from a deep-sea fungus Aspergillus restrictus inhibit Candida albicans biofilm formation and hyphal growth.

    Science.gov (United States)

    Wang, Jie; Yao, Qi-Feng; Amin, Muhammad; Nong, Xu-Hua; Zhang, Xiao-Yong; Qi, Shu-Hua

    2017-06-01

    Penicillenols (A1, A2, B1, B2, C1 and C2) were isolated from Aspergillus restrictus DFFSCS006, and could differentially inhibit biofilm formation and eradicate pre-developed biofilms of Candida albicans. Their structure-bioactivity relationships suggested that the saturation of hydrocarbon chain at C-8, R-configuration of C-5 and trans-configuration of the double bond between C-5 and C-6 of pyrrolidine-2,4-dione unit were important for their anti-biofilm activities. Penicillenols A2 and B1 slowed the hyphal growth and suppressed the transcripts of hypha specific genes HWP1, ALS1, ALS3, ECE1 and SAP4. Moreover, penicillenols A2 and B1 were found to act synergistically with amphotericin B against C. albicans biofilm formation.

  15. Effects of aqueous extract of Cinnamomum verum on growth of bread spoilage fungi

    Directory of Open Access Journals (Sweden)

    Monir Doudi

    2016-01-01

    Full Text Available Food waste has been identified as a considerable problem and bread is the most wasted food. This study aimed to evaluate In-vitro anti-fungal activity of cinnamon extract on bread spoilage fungi and to determine its anti-fungal effect in the bread slices. At first, the MIC and MFC values of the extract were determined against Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Penicillium chrysogenum, Penicillium notatum and Rhizopus oryzae. Then, Aspergillus sp was selected to assess antifungal activities of different doses of cinnamon extract in bread slices. Cinnamon extract at a dose of 64 mg/ml completely inhibited all standard and bread isolated fungi. This concentration of extract also inhibited Aspergillus growth on bread slices and delayed colony formation but adversely affected the sensory characteristics of bread. Cinnamon extract at 32 mg/ml not only delayed fungal growth, but also improved bread shelf life and delayed its staling. Moreover, 32mg/ml of extract did not adversely affect bread aroma, flavor and texture. However, sodium acetate inhibited the growth of Aspergillus sp but is not recommended for fungal control because it is considered as chemical. Therefore 32 mg/ml of extract is recommended for increasing the shelf-life of flat bread.

  16. Disinfection efficacy of chlorine and peracetic acid alone or in combination against Aspergillus spp. and Candida albicans in drinking water.

    Science.gov (United States)

    Sisti, Maurizio; Brandi, Giorgio; De Santi, Mauro; Rinaldi, Laura; Schiavano, Giuditta F

    2012-03-01

    The aim of the present study was to evaluate the fungicidal activity of chlorine and peracetic acid in drinking water against various pathogenic Aspergillus spp. and Candida albicans strains. A. nidulans exhibited the greatest resistance, requiring 10 ppm of chlorine for 30 min contact time for a complete inactivation. Under the same experimental conditions, peracetic acid was even less fungicidal. In this case, A. niger proved to be the most resistant species (50 ppm for 60 min for complete inactivation). All Aspergillus spp. were insensitive to 10 ppm even with extended exposure (>5 h). The combination of chlorine and peracetic acid against Aspergillus spp. did not show synergistic effects except in the case of A. flavus. Complete growth inhibition of C. albicans was observed after about 3 h contact time with 0.2 ppm. C. albicans was less sensitive to peracetic acid. Hence the concentrations of chlorine that are usually present in drinking water distribution systems are ineffective against several Aspergillus spp. and peracetic acid cannot be considered an alternative to chlorine for disinfecting drinking water. The combination of the two biocides is not very effective in eliminating filamentous fungi at the concentrations permitted for drinking water disinfection.

  17. Lipase Production in Solid-State Fermentation Monitoring Biomass Growth of Aspergillus niger Using Digital Image Processing

    Science.gov (United States)

    Dutra, Julio C. V.; da Terzi, Selma C.; Bevilaqua, Juliana Vaz; Damaso, Mônica C. T.; Couri, Sônia; Langone, Marta A. P.; Senna, Lilian F.

    The aim of this study was to monitor the biomass growth of Aspergillus niger in solid-state fermentation (SSF) for lipase production using digital image processing technique. The strain A. niger 11T53A14 was cultivated in SSF using wheat bran as support, which was enriched with 0.91% (m/v) of ammonium sulfate. The addition of several vegetable oils (castor, soybean, olive, corn, and palm oils) was investigated to enhance lipase production. The maximum lipase activity was obtained using 2% (m/m) castor oil. In these conditions, the growth was evaluated each 24 h for 5 days by the glycosamine content analysis and digital image processing. Lipase activity was also determined. The results indicated that the digital image process technique can be used to monitor biomass growth in a SSF process and to correlate biomass growth and enzyme activity. In addition, the immobilized esterification lipase activity was determined for the butyl oleate synthesis, with and without 50% v/v hexane, resulting in 650 and 120 U/g, respectively. The enzyme was also used for transesterification of soybean oil and ethanol with maximum yield of 2.4%, after 30 min of reaction.

  18. Lipase production in solid-state fermentation monitoring biomass growth of aspergillus niger using digital image processing.

    Science.gov (United States)

    Dutra, Júlio C V; da C Terzi, Selma; Bevilaqua, Juliana Vaz; Damaso, Mônica C T; Couri, Sônia; Langone, Marta A P; Senna, Lilian F

    2008-03-01

    The aim of this study was to monitor the biomass growth of Aspergillus niger in solid-state fermentation (SSF) for lipase production using digital image processing technique. The strain A. niger 11T53A14 was cultivated in SSF using wheat bran as support, which was enriched with 0.91% (m/v) of ammonium sulfate. The addition of several vegetable oils (castor, soybean, olive, corn, and palm oils) was investigated to enhance lipase production. The maximum lipase activity was obtained using 2% (m/m) castor oil. In these conditions, the growth was evaluated each 24 h for 5 days by the glycosamine content analysis and digital image processing. Lipase activity was also determined. The results indicated that the digital image process technique can be used to monitor biomass growth in a SSF process and to correlate biomass growth and enzyme activity. In addition, the immobilized esterification lipase activity was determined for the butyl oleate synthesis, with and without 50% v/v hexane, resulting in 650 and 120 U/g, respectively. The enzyme was also used for transesterification of soybean oil and ethanol with maximum yield of 2.4%, after 30 min of reaction.

  19. SACCHAROMYCES CEREVISIAE AND ASPERGILLUS NIGER

    African Journals Online (AJOL)

    DR. AMINU

    increase in ethanol production and cell growth increased with time of fermentation. ... fuel for automobiles. ... growth was determined by measuring the cell density .... Direct fermentation of potato starch to ethanol by co-cultures of Aspergillus.

  20. GROWTH AND ENZYME PRODUCTION DURING CONTINUOUS CULTURES OF A HIGH AMYLASE-PRODUCING VARIANT OF Aspergillus Oryzae

    Directory of Open Access Journals (Sweden)

    T.C. Zangirolami

    2002-03-01

    Full Text Available Growth and product formation by a selected variant of Aspergillus oryzae showing high alpha-amylase production was studied in continuous cultivations carried out at six different specific growth rates, using glucose as the growth-limiting nutrient. The analysis of the steady-state data revealed that the variant and wild-type strains were similar with respect to glucose uptake system and stoichiometric coefficients. However, the variant was capable of maintaining an enzyme production as high as 40 FAUgDW-1h-1 at a dilution rate of 0.2 h-1, while the wild-type strain reached a maximum specific alpha-amylase production rate of 17 FAUgDW-1h-1 at a dilution rate of 0.1 h-1. Using a morphologically structured model originally proposed for the wild-type strain, it was possible to describe enzyme production, biomass formation and glucose consumption after modification of a few parameters to adjust the model to the characteristics of the selected variant.

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

    Directory of Open Access Journals (Sweden)

    Dhara Vaidya

    2011-01-01

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

  2. Aspergillus triggers phenazine production in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

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

    in the contact area of A. niger, A. flavus, A. oryzae, but not A. fumigatus. In addition, other metabolites with UV chromophores similar to the phenazines were only found in the contact zone between Aspergillus and Pseudomonas. No change in secondary metabolite profiles were seen for the Aspergilli, when......Objectives: Pseudomonas aeruginosa is an opportunistic human pathogen, commonly infecting cystic fibrosis (CF) patients. Aspergilli, especially Aspergillus fumigatus, are also frequently isolated from CF patients. Our aim was to examine the possible interaction between P. aeruginosa and different...... Aspergillus species. Methods: A suspension of fungal spores was streaked onto WATM agar plates. After 24 hours incubation at 37 °C, a P. aeruginosa overnight culture was streaked out perpendicular to the fungal streak. The plates were incubated at 37 °C for five days, examined and plugs were extracted...

  3. Feeding of Aspergillus oryzae fermentation culture (AOFC to growing sheep: 2. Growth rate and feed efficiency

    Directory of Open Access Journals (Sweden)

    D Lubis

    2002-12-01

    Full Text Available Utilization of yeast and or filamentous fungi as feed additive to ruminants has been of interest since the late 1980’s. Two fungi species have been commercially produced in the United States, (1 Yea-Sacc containing living cells of Saccharomyces cerevisiae and (2 Amaferm bearing Aspergillus oryzae fermentation extract. It has been demonstrated and proven that the cultures can enhance rumen development and function in young ruminants. This paper concerns the use of Aspergillus oryzae fermentation culture (AOFC as feed additive for young-growing male ‘Garut’ sheep. The A. oryzae was cultured in a media made of mineral-enriched ‘onggok’ flour, a material of tapioca processing waste. The AOFC was prepared gradually by incubating the fungus at room temperature (26 – 300C for 5 days, dried at 400C and ground. The AOFC was added to a commercial concentrate (GT-03 at 0, 5 and 10% (w/w levels, as treatment C0 (control, C1, and C2, respectively. Fifteen growing ‘Garut’ sheep were used and the concentrate feed treatments were randomly allotted based on a randomized block design. Drinking water was available at all time. The amount of feed offered (chopped King grass and concentrates and their refusals were weighed daily and live-weight of sheep was measured once a week in the morning. Daily feces was collected and weighed in the last 10 days of the 14-week experimental period. All feed and fecal samples were analyzed for dry matter, crude protein, total fiber (NDF, and ash. AOFC supplementation resulted in higher weight gains (P<0.05, which were 94.81; 122.08; and 140.52 g/d for C0, C1, and C2 treatments, respectively. Dry and organic matter, as well as protein intake was also significantly increased by inclusion of AOFC into concentrate diet (P<0.05. The increment in nutrient intake was from increased consumption of concentrates, and not from King grass, however, there was no effect of AOFC supplementation on feed efficiency.

  4. Altering the expression of two chitin synthase genes differentially affects the growth and morphology of Aspergillus oryzae

    DEFF Research Database (Denmark)

    Müller, Christian; Hjort, C.M.; Hansen, K.

    2002-01-01

    In Aspergillus oryzae, one full-length chitin synthase (chsB) and fragments of two other chitin synthases (csmA and chsC) were identified. The deduced amino acid sequence of chsB was similar (87% identity) to chsB from Aspergillus nidulans, which encodes a class III chitin synthase. The sequence...

  5. Phylogeny of fungal hemoglobins and expression analysis of the Aspergillus oryzae flavohemoglobin gene fhbA during hyphal growth

    NARCIS (Netherlands)

    Biesebeke, R. te; Levasseur, A.; Boussier, A.; Record, E.; Hondel, C.A.M.J.J. van den; Punt, P.J.

    2010-01-01

    The fhbA genes encoding putative flavohemoglobins (FHb) from Aspergillus niger and Aspergillus oryzae were isolated. Comparison of the deduced amino acid sequence of the A. niger fhbA gene and other putative filamentous fungal FHb-encoding genes to that of Ralstonia eutropha shows an overall

  6. Inhibition of the Flavin-Dependent Monooxygenase Siderophore A (SidA) Blocks Siderophore Biosynthesis and Aspergillus fumigatus Growth.

    Science.gov (United States)

    Martín Del Campo, Julia S; Vogelaar, Nancy; Tolani, Karishma; Kizjakina, Karina; Harich, Kim; Sobrado, Pablo

    2016-11-18

    Aspergillus fumigatus is an opportunistic fungal pathogen and the most common causative agent of fatal invasive mycoses. The flavin-dependent monooxygenase siderophore A (SidA) catalyzes the oxygen and NADPH dependent hydroxylation of l-ornithine (l-Orn) to N 5 -l-hydroxyornithine in the biosynthetic pathway of hydroxamate-containing siderophores in A. fumigatus. Deletion of the gene that codes for SidA has shown that it is essential in establishing infection in mice models. Here, a fluorescence polarization high-throughput assay was used to screen a 2320 compound library for inhibitors of SidA. Celastrol, a natural quinone methide, was identified as a noncompetitive inhibitor of SidA with a MIC value of 2 μM. Docking experiments suggest that celastrol binds across the NADPH and l-Orn pocket. Celastrol prevents A. fumigatus growth in blood agar. The addition of purified ferric-siderophore abolished the inhibitory effect of celastrol. Thus, celastrol inhibits A. fumigatus growth by blocking siderophore biosynthesis through SidA inhibiton.

  7. Antibacterial Activity Symbiotic Fungi of Marine Sponge Axinella sp., Aspergillus Sydowii on Four Growth Medium

    Science.gov (United States)

    Widyaningsih, S.; Trianto, A.; Radjasa, OK; Wittriansyah, K.

    2018-02-01

    Many infectious diseases caused by Escherichia coli and Staphylococcus aureus which turned into a resistant pathogen. A symbiotic fungi of marine sponge Axinella sp., Aspergillus sydowii from the waters of Riung, East Nusa Tenggara, Indonesia showed antibacterial activity, cultured on the four media, MEB (ST), Noni Juice Media (MG), avocado leaves media (AL), and Soursop leaves media (SR). The symbiotic fungi was cultured for 14 days on each media. The largest weight of symbiotic fungi biomass on ST media 138,95gr and at least 99,12gr of AL media. Purification of bioactive compound is carried out using separatory funnel, and column chromatography. The highest rendemen of extracts on SR media was 3,67%, while the lowest in ST media was 1,22%. The bioactive test used diffusion agar method. Fungi extracts from four mediums have bioactivity against, E. coli and S. aureus. The biggest inhibition zone obtained from the extract of MG KN-15-3-1-3, with inhibition zone 10.71mm and 10.98mm against E. coli and S. aureus.

  8. Estudio de la eficacia de cuatro métodos de inoculación artificial con aspergillus flavus link Ex fries en seis genotipos de maíz (Zea Mays L bajo condición de campo. (ING

    Directory of Open Access Journals (Sweden)

    Miguel Quesada

    2016-03-01

    Full Text Available Four different inoculation methods were tested on six corn genotypes, under field condition. In call cases 1ml. Of 5 x 105 conidial suspension was applied, as follows: injection with a hypodermic needle in the central part of the ear (M1, injection in the silk channel (M2,  inoculum deposition on a wonded section of the ear (M3, inoculum deposition on the ear silk (M4. According to the statistical analysis the most efficient method was M3, followed by M1, M4 and M2. Fusarium spp and A. flavus showed a significative negative correlation (p>0,01 among them. Methods where inoculum was placed on the upper part of the ear showed more Fusarium and other fungi competition with A. flavus, and less efficiency. No statistical differences was found among genotypes.

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

    Directory of Open Access Journals (Sweden)

    A. Lima

    2014-03-01

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

  10. 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.

  11. 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...

  12. GROWTH EVALUATION OF FUNGI (PENICILLIUM AND ASPERGILLUS SPP.) ON CEILING TILES

    Science.gov (United States)

    The paper gives results of an evaluation of the potential for fungal growth on four different ceiling tiles in static chambers. It was found that even new ceiling tiles supported fungal growth under favorable conditions. Used ceiling tiles appeared to be more susceptible to funga...

  13. Comparative Secretome Analysis of Trichoderma reesei and Aspergillus niger during Growth on Sugarcane Biomass

    Science.gov (United States)

    Borin, Gustavo Pagotto; Sanchez, Camila Cristina; de Souza, Amanda Pereira; de Santana, Eliane Silva; de Souza, Aline Tieppo; Leme, Adriana Franco Paes; Squina, Fabio Marcio; Buckeridge, Marcos; Goldman, Gustavo Henrique; Oliveira, Juliana Velasco de Castro

    2015-01-01

    Background Our dependence on fossil fuel sources and concern about the environment has generated a worldwide interest in establishing new sources of fuel and energy. Thus, the use of ethanol as a fuel is advantageous because it is an inexhaustible energy source and has minimal environmental impact. Currently, Brazil is the world's second largest producer of ethanol, which is produced from sugarcane juice fermentation. However, several studies suggest that Brazil could double its production per hectare by using sugarcane bagasse and straw, known as second-generation (2G) bioethanol. Nevertheless, the use of this biomass presents a challenge because the plant cell wall structure, which is composed of complex sugars (cellulose and hemicelluloses), must be broken down into fermentable sugar, such as glucose and xylose. To achieve this goal, several types of hydrolytic enzymes are necessary, and these enzymes represent the majority of the cost associated with 2G bioethanol processing. Reducing the cost of the saccharification process can be achieved via a comprehensive understanding of the hydrolytic mechanisms and enzyme secretion of polysaccharide-hydrolyzing microorganisms. In many natural habitats, several microorganisms degrade lignocellulosic biomass through a set of enzymes that act synergistically. In this study, two fungal species, Aspergillus niger and Trichoderma reesei, were grown on sugarcane biomass with two levels of cell wall complexity, culm in natura and pretreated bagasse. The production of enzymes related to biomass degradation was monitored using secretome analyses after 6, 12 and 24 hours. Concurrently, we analyzed the sugars in the supernatant. Results Analyzing the concentration of monosaccharides in the supernatant, we observed that both species are able to disassemble the polysaccharides of sugarcane cell walls since 6 hours post-inoculation. The sugars from the polysaccharides such as arabinoxylan and β-glucan (that compose the most external

  14. Comparative Secretome Analysis of Trichoderma reesei and Aspergillus niger during Growth on Sugarcane Biomass.

    Directory of Open Access Journals (Sweden)

    Gustavo Pagotto Borin

    Full Text Available Our dependence on fossil fuel sources and concern about the environment has generated a worldwide interest in establishing new sources of fuel and energy. Thus, the use of ethanol as a fuel is advantageous because it is an inexhaustible energy source and has minimal environmental impact. Currently, Brazil is the world's second largest producer of ethanol, which is produced from sugarcane juice fermentation. However, several studies suggest that Brazil could double its production per hectare by using sugarcane bagasse and straw, known as second-generation (2G bioethanol. Nevertheless, the use of this biomass presents a challenge because the plant cell wall structure, which is composed of complex sugars (cellulose and hemicelluloses, must be broken down into fermentable sugar, such as glucose and xylose. To achieve this goal, several types of hydrolytic enzymes are necessary, and these enzymes represent the majority of the cost associated with 2G bioethanol processing. Reducing the cost of the saccharification process can be achieved via a comprehensive understanding of the hydrolytic mechanisms and enzyme secretion of polysaccharide-hydrolyzing microorganisms. In many natural habitats, several microorganisms degrade lignocellulosic biomass through a set of enzymes that act synergistically. In this study, two fungal species, Aspergillus niger and Trichoderma reesei, were grown on sugarcane biomass with two levels of cell wall complexity, culm in natura and pretreated bagasse. The production of enzymes related to biomass degradation was monitored using secretome analyses after 6, 12 and 24 hours. Concurrently, we analyzed the sugars in the supernatant.Analyzing the concentration of monosaccharides in the supernatant, we observed that both species are able to disassemble the polysaccharides of sugarcane cell walls since 6 hours post-inoculation. The sugars from the polysaccharides such as arabinoxylan and β-glucan (that compose the most external

  15. Identifikasi Jamur Genus Aspergillus pada Gaplek di Kabupaten Gunung Kidul

    Directory of Open Access Journals (Sweden)

    H. A. Oramahi

    2006-07-01

    Full Text Available The study was carried out in Gunung Kidul Regency of Yogyakarta special. Dried cassava was taken from the district of Nglipar (north zone, Wonosari (center zone, Semanu and Rongkop (south zones for identification of the genera of Aspergillus growing on the samples. Clasification of the zones was based on the degree of rainfall on the area. Dichloran 18% Glyserol Agar (DG-18 medium was used for isolating pathogen, while Czapek Yeast Extract Agar (CYA, Czapek Yeast Extract Agar with 20% sucrose (CYA 20S and Malt Extract Agar (MEA media were used for identification. The fungi were identified on the basis of both macroscopic and microscopic morphologies. The result showed that The Genera Of Aspergillus growing on dry cassava were A. flavus, A. niger, A. oryzae, A. foetidus, A. zonatus and A. tamarii. A. flavus was a predominant fungus that grow on dry cassava.

  16. Probing the effect of tip pressure on fungal growth: Application to Aspergillus nidulans

    Science.gov (United States)

    González-Bermúdez, Blanca; Li, Qingxuan; Guinea, Gustavo V.; Peñalva, Miguel A.; Plaza, Gustavo R.

    2017-08-01

    The study of fungal cells is of great interest due to their importance as pathogens and as fermenting fungi and for their appropriateness as model organisms. The differential pressure between the hyphal cytoplasm and the bordering medium is essential for the growth process, because the pressure is correlated with the growth rate. Notably, during the invasion of tissues, the external pressure at the tip of the hypha may be different from the pressure in the surrounding medium. We report the use of a method, based on the micropipette-aspiration technique, to study the influence of this external pressure at the hyphal tip. Moreover, this technique makes it possible to study hyphal growth mechanics in the case of very thin hyphae, not accessible to turgor pressure probes. We found a correlation between the local pressure at the tip and the growth rate for the species Arpergillus nidulans. Importantly, the proposed method allows one to measure the pressure at the tip required to arrest the hyphal growth. Determining that pressure could be useful to develop new medical treatments for fungal infections. Finally, we provide a mechanical model for these experiments, taking into account the cytoplasm flow and the wall deformation.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  18. 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...

  19. Efeito da toxicidade de Cr (VI e Zn (II no crescimento do fungo filamentoso Aspergillus niger isolado de efluente industrial Toxicity effect of Cr (VI and Zn (II on growth of filamentous fungi Aspergillus niger isolated from industrial effluent

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Vale

    2011-09-01

    Full Text Available Processos convencionais de tratamento de efluentes utilizam microrganismos vivos, o que sugere limitações relativas À toxicidade de metais para os microrganismos. O experimento consistiu em adicionar soluções monoelementares de Cr (VI e Zn(II em diferentes concentrações (0, 20, 50, 100, 200, 300, 400, 500 mg.L-1 ao meio de crescimento e observar a influência dos metais no crescimento micelial e germinativo do fungo Aspergillus Níger por verificação visual da expansão radial do micélio e da germinação de esporos, seguida de registro fotográfico. Os resultados mostraram que o metabolismo do fungo foi completamente inibido em concentrações acima de 500 mg Zn (II.L-1 e 150 mg Cr (VI.L-1. O ED50 (concentração de ingrediente ativo capaz de inibir 50% do crescimento micelial do fungo para os dois íons metálicos, nas condições estudadas, está na faixa entre 100 e 150 mg.L-1. Palavras-chave: metais pesados; inibição; crescimento micelial; Aspergillus niger; ED50.Many standard processes of wastewater treatment use live microorganisms, which suggests limitations on a metal toxicity to the microorganism. The experiment consisted in adding mono elementary solutions of Cr (VI and Zn (II at different concentrations (0, 20, 50, 100, 200, 300, 400, 500 mg.L-1 to the growth mean, and to observe the influence of metals on mycelial and germinative growth of the Aspergillus niger fungus, by means of visual observation of the radial expansion of the mycelius and the germination of spores, followed by photograph registration. The results showed that the metabolism of the fungus was completely inhibited at concentrations above 500 mg Zn (II.L-1 and 150 mg Cr (VI.L-1. The ED50 (concentration of active ingredient capable of inhibiting 50% of mycelial growth of the fungus for both metal ions, under the studied conditions, is in the range between 100 and 150 mg.L-1.

  20. Overexpression of a novel endogenous NADH kinase in Aspergillus nidulans enhances growth

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Grotkjær, Thomas; Hofmann, Gerald

    2009-01-01

    .7.1.86) has been identified. The enzyme has a predicted molecular weight of 49 kDa. We characterised the role of this NADH kinase by genomic integration of the putative gene AN8837.2 under a strong constitutive promoter. The physiological effects of overexpressed NADH kinase in combination with different...... yield on glucose and the maximum specific growth rate increased from 0.47 g/g and 0.22 h(-1) (wild type) to 0.54 g/g and 0.26 h(-1) (NADH kinase overexpressed), respectively. The results suggest that overexpression of NADH kinase improves the growth efficiency of the cell by increasing the access...

  1. 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.

  2. Growth-Phase Sterigmatocystin Formation on Lactose Is Mediated via Low Specific Growth Rates in Aspergillus nidulans

    Directory of Open Access Journals (Sweden)

    Zoltán Németh

    2016-11-01

    Full Text Available Seed contamination with polyketide mycotoxins such as sterigmatocystin (ST produced by Aspergilli is a worldwide issue. The ST biosynthetic pathway is well-characterized in A. nidulans, but regulatory aspects related to the carbon source are still enigmatic. This is particularly true for lactose, inasmuch as some ST production mutant strains still synthesize ST on lactose but not on other carbon substrates. Here, kinetic data revealed that on d-glucose, ST forms only after the sugar is depleted from the medium, while on lactose, ST appears when most of the carbon source is still available. Biomass-specified ST production on lactose was significantly higher than on d-glucose, suggesting that ST formation may either be mediated by a carbon catabolite regulatory mechanism, or induced by low specific growth rates attainable on lactose. These hypotheses were tested by d-glucose limited chemostat-type continuous fermentations. No ST formed at a high growth rate, while a low growth rate led to the formation of 0.4 mg·L−1 ST. Similar results were obtained with a CreA mutant strain. We concluded that low specific growth rates may be the primary cause of mid-growth ST formation on lactose in A. nidulans, and that carbon utilization rates likely play a general regulatory role during biosynthesis.

  3. 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.

  4. Aspergillus niger mutants affected in conidial pigmentation do not have an increased susceptibility to water stress during growth at low water activity.

    Science.gov (United States)

    Segers, F J J; Wösten, H A B; Dijksterhuis, J

    2018-03-01

    Aspergillus niger forms conidia that contain melanin in their cell wall. This black pigment has been shown to protect fungi against UV radiation, and experimental evidence has indicated that it also protects against drought and high salt concentrations. In this study, growth of A. niger was evaluated at low water activity (a w ) and after changes in relative humidity (RH). In addition, deletion strains of A. niger affected in the melanin synthesis pathway were compared. Germination of conidia of the wild-type and deletion strains was observed at 0·81 a w and germ tubes continued growth at a w  ≥ 0·83. Conidia and microcolonies of the different strains were incubated for 1 week at lowered RH (33-84%). Conidia of all strains germinated and formed colonies after exposure to RH ≥33% when transferred back to malt extract medium at a w 0·98. Conidia germinated and showed limited growth at 84% RH. Microcolonies of all strains did not survive an incubation of 1 week at RH ≤75%, but continued growth after exposure to 84% RH. Together, this is the first genetic evidence that melanin does not play a role during germination and radial extension of fungi at low water conditions. Aspergillus niger, a cosmopolitan fungus with melanized conidia, is used here as a model system for fungal growth at low water activity (a w ) and humidity dynamics. From this study it becomes clear that melanin, contrary to what has been suggested before, is not a key factor in survival and growth during situations that mimic indoor conditions. Indoor fungal growth can lead to cosmetic damage to building materials and health problems. This knowledge makes clear that novel ways to limit indoor fungal growth have to be based on interference with other cellular traits of fungi. © 2018 The Society for Applied Microbiology.

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

    Science.gov (United States)

    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.

  6. Effects of aqueous extract of Cinnamomum verum on growth of bread spoilage fungi

    OpenAIRE

    Monir Doudi; Mahbubeh Setorki; Zahra Rezayatmand

    2016-01-01

    Food waste has been identified as a considerable problem and bread is the most wasted food. This study aimed to evaluate In-vitro anti-fungal activity of cinnamon extract on bread spoilage fungi and to determine its anti-fungal effect in the bread slices. At first, the MIC and MFC values of the extract were determined against Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Penicillium chrysogenum, Penicillium notatum and Rhizopus oryzae. Then, Aspergillus sp was sele...

  7. Modelling the effect of temperature, water activity and carbon dioxide on the growth of Aspergillus niger and Alternaria alternata isolated from fresh date fruit.

    Science.gov (United States)

    Belbahi, A; Leguerinel, I; Méot, J-M; Loiseau, G; Madani, K; Bohuon, P

    2016-12-01

    To quantify and model the combined effects of temperature (T) (10-40°C), water activity (a w ) (0·993-0·818) and CO 2 concentration (9·4-55·1%, v/v) on the growth rate of Aspergillus niger and Alternaria alternata that cause spoilage during the storage and packaging of dates. The effects of environmental factors were studied using the γ-concept. Cardinal models were used to quantify the effect of studied environmental factors on the growth rates. Firstly, the cardinal parameters were estimated independently from experiments carried out on potato dextrose agar using a monofactorial design. Secondly, model performance evaluation was conducted on pasteurized date paste. The boundary between growth and no-growth was predicted using a deterministic approach. Aspergillus niger displayed a faster growth rate and higher tolerance to low a w than Al. alternata, which in turn proved more resistant to CO 2 concentration. Minimal cardinal parameters of T and a w were lower than those reported in the literature. The combination of the a w and CO 2 effects significantly affected As. niger and Al. alternata growth. The γ-concept model overestimated growth rates, however, it is optimistic and provides somewhat conservative predictions. The developed model provides a decision support tool for the choice of the date fruit conservation mode (refrigeration, drying, modified atmospheric packaging or their combination) using T, a w and CO 2 as environmental factors. © 2016 The Society for Applied Microbiology.

  8. EFIKASI ASAP CAIR DARI TANDAN KOSONG KELAPA SAWIT (TKKS DALAM PENEKANAN PERKEMBANGAN JAMUR ASPERGILLUS NIGER

    Directory of Open Access Journals (Sweden)

    Hasan Ashari Oramahi, Farah Diba, & Wahdina .

    2011-11-01

    Full Text Available The efficacy of liquid smoke from oilpalm empty fruit bunch in suppressing the development of fungus. Fungi that have been grown on maize seed were Aspergillus niger, A. flavus and Aspergillus sp. From those species, A. niger is important species because of its toxigenic characteristic on agricultural product. The objective of this research was to evaluate the efficacy of oilpalm empty fruit bunch liquid smoke in suppressing the development of the fungus. This research was conducted in several steps i.e. pyrolisis of liquid smoke, analysis of liquid smoke content, and efficacy test of liquid smoke as antifungal. Agar media used was PDA (potato dextrose agar and concentration of liquid smoke was 0, 1, 2, and 3% (v/v. The results indicated that the liquid smoke inhibited the fungal growth. The highest result was on liquid smoke with temperature pyrolisis of 400 and 450oC and concentration 3% with average value of 100%. The contents of organic fraction of liquid smoke, such as acid and phenol might be responsible for the difference in antifungal activities among this liquid smoke.

  9. 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.

  10. The Indoor Fungus Cladosporium halotolerans Survives Humidity Dynamics Markedly Better than Aspergillus niger and Penicillium rubens despite Less Growth at Lowered Steady-State Water Activity.

    Science.gov (United States)

    Segers, Frank J J; van Laarhoven, Karel A; Huinink, Hendrik P; Adan, Olaf C G; Wösten, Han A B; Dijksterhuis, Jan

    2016-09-01

    Indoor fungi cause damage in houses and are a potential threat to human health. Indoor fungal growth requires water, for which the terms water activity (aw) and relative humidity (RH) are used. The ability of the fungi Aspergillus niger, Cladosporium halotolerans, and Penicillium rubens at different developmental stages to survive changes in aw dynamics was studied. Fungi grown on media with high aw were transferred to a controlled environment with low RH and incubated for 1 week. Growth of all developmental stages was halted during incubation at RHs below 75%, while growth continued at 84% RH. Swollen conidia, germlings, and microcolonies of A. niger and P. rubens could not reinitiate growth when retransferred from an RH below 75% to a medium with high aw All developmental stages of C. halotolerans showed growth after retransfer from 75% RH. Dormant conidia survived retransfer to medium with high aw in all cases. In addition, retransfer from 84% RH to medium with high aw resulted in burst hyphal tips for Aspergillus and Penicillium Cell damage of hyphae of these fungi after incubation at 75% RH was already visible after 2 h, as observed by staining with the fluorescent dye TOTO-1. Thus, C. halotolerans is more resistant to aw dynamics than A. niger and P. rubens, despite its limited growth compared to that of these fungi at a lowered steady-state aw The survival strategy of this phylloplane fungus in response to the dynamics of aw is discussed in relation to its morphology as studied by cryo-scanning electron microscopy (cryo-SEM). Indoor fungi cause structural and cosmetic damage in houses and are a potential threat to human health. Growth depends on water, which is available only at certain periods of the day (e.g., during cooking or showering). Knowing why fungi can or cannot survive indoors is important for finding novel ways of prevention. Until now, the ability of fungi to grow on media with little available water at steady state (unchanging conditions) has

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

    Science.gov (United States)

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

  12. Bioleaching of serpentine group mineral by fungus Talaromyces flavus: application for mineral carbonation

    Science.gov (United States)

    Li, Z.; Lianwen, L.; Zhao, L.; Teng, H.

    2011-12-01

    Many studies of serpentine group mineral dissolution for mineral carbonation have been published in recent years. However, most of them focus mainly on either physical and chemical processes or on bacterial function, rather than fungal involvement in the bioleaching of serpentine group mineral. Due to the excessive costs of the magnesium dissolution process, finding a lower energy consumption method will be meaningful. A fungal strain Talaromyces flavus was isolated from serpentinic rock of Donghai (China). No study of its bioleaching ability is currently available. It is thus of great significance to explore the impact of T. flavus on the dissolution of serpentine group mineral. Serpentine rock-inhabiting fungi belonging to Acremonium, Alternaria, Aspergillus, Botryotinia, Cladosporium, Clavicipitaceae, Cosmospora, Fusarium, Monascus, Paecilomyces, Penicillium, Talaromyces, Trichoderma were isolated. These strains were chosen on the basis of resistance to magnesium and nickel characterized in terms of minimum inhibiting concentration (MIC). Specifically, the strain Talaromyces flavus has a high tolerance to both magnesium (1 mol/L) and nickel (10 mM/L), and we examine its bioleaching ability on serpentine group mineral. Contact and separation experiments (cut-off 8 000-14 000 Da), as well as three control experiments, were set up for 30 days. At least three repeated tests were performed for each individual experiment. The results of our experiments demonstrate that the bioleaching ability of T. flavus towards serpentine group mineral is evident. 39.39 wt% of magnesium was extracted from lizardite during the bioleaching period in the contact experiment, which showed a dissolution rate at about a constant 0.126 mM/d before reaching equilibrium in 13 days. The amount of solubilized Mg from chrysotile and antigorite were respectively 37.79 wt% and 29.78 wt% in the contact experiment. These results make clear the influence of mineral structure on mineral bioleaching

  13. 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.

  14. 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.

  15. Aspergillus contaminans

    Science.gov (United States)

    Aspergillus contaminans is described as a new species from the fingernail of a patient with an infected nail. Phylogenetic analysis of four loci (ITS, calmodulin, beta tubulin and RNA polymerase beta, second largest subunit) showed that this species is most closely related to A. carlsbadensis from A...

  16. Influence of temperature on growth rate and lag phase of fungi isolated from Argentine corn.

    Science.gov (United States)

    González, H H; Resnik, S L; Vaamonde, G

    1988-03-01

    The influence of temperature on the growth of nine strains of fungi belonging to the genera Eurotium, Aspergillus, Penicillium and Fusarium has been investigated for the temperature range 15-35 degrees C. The lag phase and the growth rate were evaluated by using a laboratory medium. The maximum growth rate for E. repens, A. wentii and P. chrysogenum was observed at about 25 degrees C, for P. citrinum near 30 degrees C and for F. semitectum and F. moniliforme between 20 and 25 degrees C. The growth rate of A. niger, A. flavus and A. parasiticus increased with increasing temperatures in the range studied. For all strains studied it appeared that the higher the growth rate the lower the lag phase was.

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

    Science.gov (United States)

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

    2017-06-28

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

  18. Effect of powdered spice treatments on mycelial growth, sporulation and production of aflatoxins by toxigenic fungi Efeito de tratamentos com condimentos em pó sobre o crescimento micelial, esporulação e produção de aflatoxinas por fungos toxigênicos

    Directory of Open Access Journals (Sweden)

    Sára Maria Chalfoun

    2004-08-01

    Full Text Available The effect of ten powdered spice plants was evaluated at the concentration of 1, 2, 3 and 4% to observe the mycelial growth and sporulation of Aspergillus niger and Eurotium repens. The spices were added to the culture media PDA and CYA20S. Clove completely inhibited the mycelial growth of the tested fungi. The other spices: cinnamon, garlic, thyme, mint, anis, oregano and onion were, in a decreasing order, promising antifungals. Bay leaf and basil did not show a pronounced fungistatic effect. The antitoxigenic potential of the spices was tested against one aflatoxin-producing strain of AspergiIIus flavus. The spices were tested at the same concentrations previously mentioned and were added to the culture medium YES, appropriate for the production of those metabolites. Clove completely inhibited the mycelial growth of Aspergillus flavus. Cinnamon and anis totally inhibited the production of Bl and B2 aflatoxin. Both bay leaf and basil inhibited the synthesis of aflatoxin starting from the concentration of 2%. The other spices did not have a pronounced antiaflatoxigenic effect.O efeito de dez plantas condimentares em pó foi avaliado nas concentrações de 1, 2, 3 e 4%, para observar o desenvolvimento micelial e esporulação de Aspergillus niger e Eurotium repens. Os condimentos foram adicionados aos meios de cultura BDA e CYA 20S. O cravo inibiu completamente o desenvolvimento micelial dos fungos testados. Os outros condimentos: canela, alho, tomilho, menta, erva-doce, orégano e cebola foram, em ordem decrescente, antifúngicos promissores. Louro e manjericão não apresentaram um efeito fungistático pronunciado. O potencial antitoxigênico dos condimentos foi testado contra uma cepa de Aspergillus flavus, produtora de aflatoxina. Os condimentos foram testados nas mesmas concentrações previamente mencionadas e foram adicionados ao meio de cultura YES, apropriado para a produção daqueles metabólitos. O cravo inibiu completamente o

  19. Fumigant Antifungal Activity of Myrtaceae Essential Oils and Constituents from Leptospermum petersonii against Three Aspergillus Species

    Directory of Open Access Journals (Sweden)

    Il-Kwon Park

    2012-09-01

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

  20. 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.

  1. Impact of non-selective fungicides on the growth and production of ochratoxin A by Aspergillus ochraceus and A. carbonarius in barley-based medium.

    Science.gov (United States)

    Mateo, Eva M; Valle-Algarra, F M; Mateo-Castro, R; Jimenez, M

    2011-01-01

    The aim of this study was to assess the influence of the non-selective fungicides mancozeb, copper oxychloride, and sulfur on the growth and capability for producing ochratoxin A (OTA) of ochratoxigenic isolates of Aspergillus carbonarius and A. ochraceus in barley-based medium. Lag phases and growth rates were determined for each fungicide at different doses, at 15°C and 25°C and at 0.97 a(w). Mancozeb at 40 mg l(-1 )inhibited fungal growth and provided lag phases >24 days at 10-20 mg l(-1) and 15°C. OTA was observed only at 25°C and doses Sulfur was inhibitory or provided large lag phases at 5-8 g l(-1) (at 15°C) while at 25°C growth took place even at 8 g l(-1), although OTA levels were low or undetectable. The antifungal activity decreased in the order mancozeb > copper oxychloride > sulfur, and was lower at 25°C than at 15°C. OTA accumulation was affected by the type of fungicide, dose, temperature and time. The efficacy of these fungicides on the growth of A. carbonarius and A. ochraceus and OTA production in barley-based medium is assessed for the first time.

  2. Heterologous expression of Gaeumannomyces graminis lipoxygenase in Aspergillus nidulans.

    Science.gov (United States)

    Heshof, Ruud; van Schayck, J Paul; Tamayo-Ramos, Juan Antonio; de Graaff, Leo H

    2014-01-01

    Aspergillus sp. contain ppo genes coding for Ppo enzymes that produce oxylipins from polyunsaturated fatty acids. These oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of Aspergillus sp. Fungi like Aspergillus nidulans and Aspergillus niger contain just ppo genes where the human pathogenic Aspergillus flavus and Aspergillus fumigatus contain ppo genes as well as lipoxygenases. Lipoxygenases catalyze the synthesis of oxylipins and are hypothesized to be involved in quorum-sensing abilities and invading plant tissue. In this study we used A. nidulans WG505 as an expression host to heterologously express Gaeumannomyces graminis lipoxygenase. The presence of the recombinant LOX induced phenotypic changes in A. nidulans transformants. Also, a proteomic analysis of an A. nidulans LOX producing strain indicated that the heterologous protein was degraded before its glycosylation in the secretory pathway. We observed that the presence of LOX induced the specific production of aminopeptidase Y that possibly degrades the G. graminis lipoxygenase intercellularly. Also the presence of the protein thioredoxin reductase suggests that the G. graminis lipoxygenase is actively repressed in A. nidulans.

  3. 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

  4. 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

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

    Science.gov (United States)

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

    2015-11-01

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

  6. 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

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

    Science.gov (United States)

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

    2010-01-01

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

  8. Highly active promoters and native secretion signals for protein production during extremely low growth rates in Aspergillus niger.

    Science.gov (United States)

    Wanka, Franziska; Arentshorst, Mark; Cairns, Timothy C; Jørgensen, Thomas; Ram, Arthur F J; Meyer, Vera

    2016-08-20

    The filamentous ascomycete Aspergillus niger is used in many industrial processes for the production of enzymes and organic acids by batch and fed-batch cultivation. An alternative technique is continuous cultivation, which promises improved yield and optimized pipeline efficiency. In this work, we have used perfusion (retentostat) cultivation to validate two promoters that are suitable for A. niger continuous cultivation of industrially relevant products. Firstly, promoters of genes encoding either an antifungal protein (Panafp) or putative hydrophobin (PhfbD) were confirmed as active throughout retentostat culture by assessing mRNA and protein levels using a luciferase (mluc) reporter system. This demonstrated the anafp promoter mediates a high but temporally variable expression profile, whereas the hfbD promoter mediates a semi-constant, moderate-to-high protein expression during retentostat culture. In order to assess whether these promoters were suitable to produce heterologous proteins during retentostat cultivation, the secreted antifungal protein (AFP) from Aspergillus giganteus, which has many potential biotechnological applications, was expressed in A. niger during retentostat cultivation. Additionally, this assay was used to concomitantly validate that native secretion signals encoded in anafp and hfbD genes can be harnessed for secretion of heterologous proteins. Afp mRNA and protein abundance were comparable to luciferase measurements throughout retentostat cultivation, validating the use of Panafp and PhfbD for perfusion cultivation. Finally, a gene encoding the highly commercially relevant thermal hysteresis protein (THP) was expressed in this system, which did not yield detectable protein. Both hfbD and anafp promoters are suitable for production of useful products in A. niger during perfusion cultivation. These findings provide a platform for further optimisations for high production of heterologous proteins with industrial relevance.

  9. Growth of aspergillus terreus and the production of itaconic acid in batch and continuous cultures. The influence of pH

    Energy Technology Data Exchange (ETDEWEB)

    Rychtera, M.; Wase, J.D.A.

    1981-01-01

    Aspergillus terreus (NRRL 1960) was cultivated in batch and in continuous single-stage culture. The influence of pH on the growth of the organism, on the formation of itaconic acid and on the kinetics of fermentation was studied under phosphate limitation, both at controlled ph values and also when the pH was allowed to decrease in a natural way. In the pH range 1.7-3.5, the ratio of undissociated:half-dissociated acid varied from 190:1 to 1.5:1. The amount of completely dissociated acid may be regarded as negligible. In batch systems operated without pH control, an initial pH of 3.1 proved to be the most effective. Product formation under such conditions started at a point where the exponential growth phase commenced and was described by a zero-order equation. The maximum itaconic acid production rate was shifted behind maximum growth rate. The continuous single-stage system was first order with respect to product formation. At pH greater than 3.1, a number of aberrant and pellet forms of the mould occurred, resulting in decreased acid production. (Refs. 41).

  10. Microtubule plus end-tracking proteins play critical roles in directional growth of hyphae by regulating the dynamics of cytoplasmic microtubules in Aspergillus nidulans.

    Science.gov (United States)

    Zeng, Cui J Tracy; Kim, Hye-Ryun; Vargas Arispuro, Irasema; Kim, Jung-Mi; Huang, An-Chi; Liu, Bo

    2014-11-01

    Cytoplasmic microtubules (MTs) serve as a rate-limiting factor for hyphal tip growth in the filamentous fungus Aspergillus nidulans. We hypothesized that this function depended on the MT plus end-tracking proteins (+TIPs) including the EB1 family protein EBA that decorated the MT plus ends undergoing polymerization. The ebAΔ mutation reduced colony growth and the mutant hyphae appeared in an undulating pattern instead of exhibiting unidirectional growth in the control. These phenotypes were enhanced by a mutation in another +TIP gene clipA. EBA was required for plus end-tracking of CLIPA, the Kinesin-7 motor KipA, and the XMAP215 homologue AlpA. In addition, cytoplasmic dynein also depended on EBA to track on most polymerizing MT plus ends, but not for its conspicuous appearance at the MT ends near the hyphal apex. The loss of EBA reduced the number of cytoplasmic MTs and prolonged dwelling times for MTs after reaching the hyphal apex. Finally, we found that colonies were formed in the absence of EBA, CLIPA, and NUDA together, suggesting that they were dispensable for fundamental functions of MTs. This study provided a comprehensive delineation of the relationship among different +TIPs and their contributions to MT dynamics and unidirectional hyphal expansion in filamentous fungi. © 2014 John Wiley & Sons Ltd.

  11. Impact of alg3 gene deletion on growth, development, pigment production, protein secretion, and functions of recombinant Trichoderma reesei cellobiohydrolases in Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Ziyu; Aryal, Uma K.; Shukla, Anil; Qian, Wei-Jun; Smith, Richard D.; Magnuson, Jon K.; Adney, William S.; Beckham, Gregg T.; Brunecky, Roman; Himmel, Michael E.; Decker, Stephen R.; Ju, Xiaohui; Zhang, Xiao; Baker, Scott E.

    2013-12-01

    ALG3 is a Family 58 glycosyltransferase enzyme involved in early N-linked glycan synthesis. Here, we investigated the effect of the alg3 gene disruption on growth, development, metabolism, and protein secretion in Aspergillus niger. The alg3 gene deletion resulted in a significant reduction of growth on complete (CM) and potato dextrose agar (PDA) media and a substantial reduction of spore production on CM. It also delayed spore germination in the liquid cultures of both CM and PDA media, but led to a significant accumulation of red pigment on both CM and liquid modified minimal medium (MM) supplemented with yeast extract. The relative abundance of 55 proteins of the total 190 proteins identified in the secretome was significantly different as a result of alg3 gene deletion. Comparison of a Trichoderma reesei cellobiohydrolase (Cel7A) heterologously expressed in A. niger parental and Δalg3 strains showed that the recombinant Cel7A expressed in the mutant background was smaller in size than that from the parental strains. This study suggests that ALG3 is critical for growth and development, pigment production, and protein secretion in A. niger. Functional analysis of recombinant Cel7A with aberrant glycosylation demonstrates the feasibility of this alternative approach to evaluate the role of N-linked glycosylation in glycoprotein secretion and function.

  12. Effects of onion (Allium cepa L.) and garlic (Allium sativum L.) essential oils on the Aspergillus versicolor growth and sterigmatocystin production.

    Science.gov (United States)

    Kocić-Tanackov, Sunčica; Dimić, Gordana; Lević, Jelena; Tanackov, Ilija; Tepić, Aleksandra; Vujičić, Biserka; Gvozdanović-Varga, Jelica

    2012-05-01

    In the present study the effects of individual and combined essential oils (EOs) extracted from onion (Allium cepa L.) bulb and garlic (Allium sativum L.) clove on the growth of Aspergillus versicolor and sterigmatocystin (STC) production were investigated. The EOs obtained by hydrodistillation were analyzed by GC/MS. Twenty one compounds were identified in onion EO. The major components were: dimethyl-trisulfide (16.64%), methyl-propyl-trisulfide (14.21%), dietil-1,2,4-tritiolan (3R,5S-, 3S,5S- and 3R,5R- isomers) (13.71%), methyl-(1-propenyl)-disulfide (13.14%), and methyl-(1-propenyl)-trisulfide (13.02%). The major components of garlic EO were diallyl-trisulfide (33.55%), and diallyl-disulfide (28.05%). The mycelial growth and the STC production were recorded after 7, 14, and 21 d of the A. versicolor growth in Yeast extract sucrose (YES) broth containing different EOs concentrations. Compared to the garlic EO, the onion EO showed a stronger inhibitory effect on the A. versicolor mycelial growth and STC production. After a 21-d incubation of fungi 0.05 and 0.11 μg/mL of onion EO and 0.11 μg/mL of garlic EO completely inhibited the A. versicolor mycelial growth and mycotoxins biosynthesis. The combination of EOs of onion (75%) and garlic (25%) had a synergistic effect on growth inhibition of A. versicolor and STC production. © 2012 Institute of Food Technologists®

  13. Polyphasic identification of Aspergillus isolates belonging to section Nigri with clinical relevance

    OpenAIRE

    Maciel, Marília; Santos, Cledir; Lima, Nelson; Souza-Motta, Cristina Maria

    2012-01-01

    Aspergillosis is the name of a group of diseases in humans and animals caused by opportunist moulds of the genus Aspergillus. The vast majority of infections are caused by A. fumigatus, followed by other species such as A. flavus, A. terreus and A. niger. Among the pulmonary infection, aspergillosis is gaining prominent position not only in immunocompromised patients, but also in immunosuppressed. The absence of a reliable fungal identification system affects the control of ...

  14. [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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-12-15

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

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

    Science.gov (United States)

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

    2005-01-01

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

  17. Effect of Antioxidant Mixtures on Growth and Ochratoxin A Production of Aspergillus Section Nigri Species under Different Water Activity Conditions on Peanut Meal Extract Agar

    Directory of Open Access Journals (Sweden)

    Carla Barberis

    2010-06-01

    Full Text Available The effect of mixtures of antioxidants butylated hydroxyanisol (BHA and propyl paraben (PP on lag phase, growth rate and ochratoxin A (OTA production by four Aspergillus section Nigri strains was evaluated on peanut meal extract agar (PMEA under different water activities (aw. The antioxidant mixtures used were: BHA + PP (mM, M1 (0.5 + 0.5, M2 (1.0 + 0.5, M3 (2.5 + 0.5, M4 (0.5 + 1.0, M5 (1.0 + 1.0, M6 (2.5 + 1.0, M7 (5.0 + 2.5 and M8 (10 + 2.5. The mixture M8 completely suppressed mycelial growth for all strains. A significant stimulation in OTA production was observed with mixtures M1 to M5 mainly at the highest aw; whereas M6, M7 and M8 completely inhibited OTA production in all strains assayed; except M6 in A. carbonarius strain (RCP G. These results could enable a future intervention strategy to minimize OTA contamination.

  18. Effects of diet and Aspergillus oryzae extract or Saccharomyces cervisiae on growth and carcass characteristics of lambs and steers fed to meet requirements of natural markets.

    Science.gov (United States)

    Zerby, H N; Bard, J L; Loerch, S C; Kuber, P S; Radunz, A E; Fluharty, F L

    2011-07-01

    Two studies were conducted to determine the effects of diet and feed additive on growth and carcass characteristics of lambs and cattle destined for all natural markets. In Exp. 1, 48 Dorset × Hampshire lambs (initial BW 29.4 ± 0.1 kg) were used in a randomized complete block experiment to determine the effects of Aspergillus oryzae extract, Amaferm (AMF) supplementation (1 g/d) in an 85% concentrate diet on growth and carcass characteristics. Lambs were allotted to 12 pens (4 lambs per pen), and blocked by sex and BW. Lambs were fed until the average BW of each pen reached a target BW (55.4 kg for wethers and 50.0 kg for ewes), at which time the entire pen of lambs was slaughtered. Amaferm resulted in a greater (P=0.07) G:F. In Exp. 2, 168 crossbred steers (initial BW 300 ± 0.7 kg) were used in a trial with a 3 × 2 factorial arrangement of treatments to examine the effects of 0.5 g/d of Saccaromyces cervisiae boulardii CNCM 1079-Levucell SB (LEV), or 3 g/d of AMF with 2 corn sources, dry whole-shelled corn or high moisture corn, on growth and carcass characteristics. Neither LEV nor AMF improved (P>0.10) carcass characteristics compared with control or non-feed-supplemented steers. Addition of LEV to high-concentrate, corn-based diets did not improve (P>0.10) growth performance of feedlot steers. However, addition of AMF to a diet composed of dry whole-shelled corn resulted in an improvement (P<0.05) in G:F (0.208 vs. 0.194). Results indicate that at the amounts fed, AMF may improve G:F for lambs and steers fed dry corn-based finishing diets. © 2011 American Society of Animal Science. All rights reserved.

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

    Science.gov (United States)

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

    2017-01-01

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

  20. Growth Modeling of Aspergillus niger Strains Isolated from Citrus Fruit as a Function of Temperature on a Synthetic Medium from Lime (Citrus latifolia T.) Pericarp.

    Science.gov (United States)

    Sandoval-Contreras, T; Marín, S; Villarruel-López, A; Gschaedler, A; Garrido-Sánchez, L; Ascencio, F

    2017-07-01

    Molds are responsible for postharvest spoilage of citrus fruits. The objective of this study was to evaluate the effect of temperature on growth rate and the time to visible growth of Aspergillus niger strains isolated from citrus fruits. The growth of these strains was studied on agar lime medium (AL) at different temperatures, and growth rate was estimated using the Baranyi and Roberts model (Int. J. Food Microbiol. 23:277-294, 1994). The Rosso et al. cardinal model with inflexion (L. Rosso, J. R. Lobry, S. Bajard, and J. P. Flandrois, J. Theor. Biol. 162:447-463, 1993) was used as a secondary model to describe the effect of temperature on growth rate and the lag phase. We hypothesized that the same model could be used to calculate the time for the mycelium to become visible (t v ) by substituting the lag phase (1/λ and 1/λ opt ) with the time to visible colony (1/t v -opt and 1/t v ), respectively, in the Rosso et al. High variability was observed at suboptimal conditions. Extremes of temperature of growth for A. niger seem to have a normal variability. For the growth rate and time t v , the model was satisfactorily compared with results of previous studies. An external validation was performed in lime fruits; the bias and accuracy factors were 1.3 and 1.5, respectively, for growth rate and 0.24 and 3.72, respectively, for the appearance time. The discrepancy may be due to the influence of external factors. A. niger grows significantly more slowly on lime fruit than in culture medium, probably because the nutrients are more easily available in medium than in fruits, where the peel consistency may be a physical barrier. These findings will help researchers understand the postharvest behavior of mold on lime fruits, host-pathogen interactions, and environmental conditions infecting fruit and also help them develop guidelines for future work in the field of predictive mycology to improve models for control of postharvest fungi.

  1. On-line monitoring of Aspergillus niger GH1 growth in a bioprocess for the production of ellagic acid and ellagitannase by solid-state fermentation.

    Science.gov (United States)

    Aguilar-Zárate, Pedro; Wong-Paz, Jorge E; Rodríguez-Duran, Luis V; Buenrostro-Figueroa, Juan; Michel, Mariela; Saucedo-Castañeda, Gerardo; Favela-Torres, Ernesto; Ascacio-Valdés, Juan A; Contreras-Esquivel, Juan C; Aguilar, Cristóbal N

    2018-01-01

    The present work describes the monitoring of CO 2 production by Aspergillus niger GH1 in a bioprocess for the production of ellagitannase (EAH) and ellagic acid by solid state fermentation. Pomegranate ellagitannins, mainly punicalagin, were used as carbon source and EAH inducer. A second condition, using ellagitannins and maltose as growth promoting carbon source, was tested. The ellagic acid production was quantified and the EAH activity was assayed. The accumulated metabolites were identified by HPLC-ESI-MS/MS. Higher CO 2 production (7.79mg/grams of dry material) was reached in media supplemented with maltose. Short-time lag phase (7.79h) and exponential phase (10.42h) were obtained using only ellagitannins, despite its lower CO 2 production (3.79mg/grams of dry material). Without the use of maltose lower ellagic acid (11.85mg/L/h) and EAH (21.80U/L/h) productivities were reached. The use of maltose enhances the productivity of EA (33.18mg/L/h) and EAH (33.70U/L/h). Besides of punicalin and ellagic acid, two unknown compounds with mass weight of 702 and 290g/mol (ions 701 and 289m/z in negative mode, respectively) were identified and characterized by HPLC-ESI-MS/MS analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Development and application of a predictive model of Aspergillus candidus growth as a tool to improve shelf life of bakery products.

    Science.gov (United States)

    Huchet, V; Pavan, S; Lochardet, A; Divanac'h, M L; Postollec, F; Thuault, D

    2013-12-01

    Molds are responsible for spoilage of bakery products during storage. A modeling approach to predict the effect of water activity (aw) and temperature on the appearance time of Aspergillus candidus was developed and validated on cakes. The gamma concept of Zwietering was adapted to model fungal growth, taking into account the impact of temperature and aw. We hypothesized that the same model could be used to calculate the time for mycelium to become visible (tv), by substituting the matrix parameter by tv. Cardinal values of A. candidus were determined on potato dextrose agar, and predicted tv were further validated by challenge-tests run on 51 pastries. Taking into account the aw dynamics recorded in pastries during reasonable conditions of storage, high correlation was shown between predicted and observed tv when the aw at equilibrium (after 14 days of storage) was used for modeling (Af = 1.072, Bf = 0.979). Validation studies on industrial cakes confirmed the experimental results and demonstrated the suitability of the model to predict tv in food as a function of aw and temperature. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Improved growth of Lactobacillus bulgaricus and Streptococcus thermophilus as well as Increased antioxidant activity by biotransforming litchi pericarp polysaccharide with Aspergillus awamori.

    Science.gov (United States)

    Lin, Sen; Wen, Lingrong; Yang, Bao; Jiang, Guoxiang; Shi, John; Chen, Feng; Jiang, Yueming

    2013-01-01

    This study was conducted to increase the bioactivity of litchi pericarp polysaccharides (LPPs) biotransformed by Aspergillus awamori. Compared to the non-A. awamori-fermented LPP, the growth effects of A. awamori-fermented LPP on Lactobacillus bulgaricus and Streptococcus thermophilus were four and two times higher after 3 days of fermentation, respectively. Increased 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and DNA protection activity of litchi pericarp polysaccharides were also achieved after A. awamori fermentation. Moreover, the relative content of glucose and arabinose in LPP after fermentation decreased from 58.82% to 22.60% and from 18.82% to 10.09%, respectively, with a concomitant increase in the relative contents of galactose, rhamnose, xylose, and mannose. Furthermore, lower molecular weight polysaccharides were obtained after A. awamori fermentation. It can be concluded that A. awamori was effective in biotransforming LPP into a bioactive mixture with lower molecular weight polysaccharides and higher antioxidant activity and relative galactose content.

  4. Improved Growth of Lactobacillus bulgaricus and Streptococcus thermophilus as well as Increased Antioxidant Activity by Biotransforming Litchi Pericarp Polysaccharide with Aspergillus awamori

    Directory of Open Access Journals (Sweden)

    Sen Lin

    2013-01-01

    Full Text Available This study was conducted to increase the bioactivity of litchi pericarp polysaccharides (LPPs biotransformed by Aspergillus awamori. Compared to the non-A. awamori-fermented LPP, the growth effects of A. awamori-fermented LPP on Lactobacillus bulgaricus and Streptococcus thermophilus were four and two times higher after 3 days of fermentation, respectively. Increased 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and DNA protection activity of litchi pericarp polysaccharides were also achieved after A. awamori fermentation. Moreover, the relative content of glucose and arabinose in LPP after fermentation decreased from 58.82% to 22.60% and from 18.82% to 10.09%, respectively, with a concomitant increase in the relative contents of galactose, rhamnose, xylose, and mannose. Furthermore, lower molecular weight polysaccharides were obtained after A. awamori fermentation. It can be concluded that A. awamori was effective in biotransforming LPP into a bioactive mixture with lower molecular weight polysaccharides and higher antioxidant activity and relative galactose content.

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

    Directory of Open Access Journals (Sweden)

    Amaranta Carvajal-Campos

    2017-10-01

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

  6. Evidence for synergistic activity of plant-derived volatile essential oils against fungal pathogens of food

    Science.gov (United States)

    The antifungal activities of eight essential oils (EOs) namely basil, cinnamon, eucalyptus, mandarin, oregano, peppermint, tea tree and thyme were evaluated for their ability to inhibit growth of Aspergillus niger, Aspergillus flavus, Aspergillus paraciticus and Penicillium chrysogenum. The antifung...

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

    Science.gov (United States)

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

    2017-11-16

    Aflatoxins are cancer-causing, immuno-suppressive mycotoxins that frequently contaminate important staples in Zambia including maize and groundnut. Several species within Aspergillus section Flavi have been implicated as causal agents of aflatoxin contamination in Africa. However, Aspergillus populations associated with aflatoxin contamination in Zambia have not been adequately detailed. Most of Zambia's arable land is non-cultivated and Aspergillus communities in crops may originate in non-cultivated soil. However, relationships between Aspergillus populations on crops and those resident in non-cultivated soils have not been explored. Because characterization of similar fungal populations outside of Zambia have resulted in strategies to prevent aflatoxins, the current study sought to improve understanding of fungal communities in cultivated and non-cultivated soils and in crops. Crops (n=412) and soils from cultivated (n=160) and non-cultivated land (n=60) were assayed for Aspergillus section Flavi from 2012 to 2016. The L-strain morphotype of Aspergillus flavus and A. parasiticus were dominant on maize and groundnut (60% and 42% of Aspergillus section Flavi, respectively). Incidences of A. flavus L-morphotype were negatively correlated with aflatoxin in groundnut (log y=2.4990935-0.09966x, R 2 =0.79, P=0.001) but not in maize. Incidences of A. parasiticus partially explained groundnut aflatoxin concentrations in all agroecologies and maize aflatoxin in agroecology III (log y=0.1956034+0.510379x, R 2 =0.57, Pagroecologies across Zambia gives support for modifying fungal community structure to reduce the aflatoxin-producing potential. Published by Elsevier B.V.

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

    Science.gov (United States)

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

    2015-01-28

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

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

    Science.gov (United States)

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

    2014-11-13

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

  10. Sunflower seed for human consumption as a substrate for the growth of mycopopulations

    Directory of Open Access Journals (Sweden)

    Škrinjar Marija M.

    2012-01-01

    Full Text Available These mycological investigations are implicating samples of protein sunflower seed from regular cultivation in the Vojvodina Province. Samples are examined in different stages of production: reception in the silo, separation of massive fraction on peeler and then peeling, kernel after peeling, hull, final product, i.e. kernels separated from visible impurities on conveyor bel, that are later manually divided in two fractions - a seemingly whole, undamaged kernels, without change of colour, and b seemingly damaged kernels, broken, with change of colour. For the determination of viable count of moulds and their isolation, two different media are used in parallel: Sabouraud maltose agar (SMA and malt/yeast extract with 50% of glucose (MY50G, favourable for growth of xerophilic moulds. All samples tested were contaminated with fungi. Total viable mould count per seed varied from 1.6 (SMA respecting 1.3 (MY50G on reception, to 5.6 (SMA and 7.5 (MY50G cfu/seed in visually damaged sunflower kernels (final product. From seeds, kernels and hull, numerous moulds were isolated, belonging to 8 genera and 13 species (Alternaria alternata, Arthrinium phaeospermum, Aspergillus candidus, A. flavus, A. niger, A. ochraceus, A. versicolor, A. wentii, Cladosporium cladosporioides, Eurotium herbariorum, Penicillium aurantiogriseum, Rhizopus stolonifer and Trichoderma harzianum. Alternaria alternata, Aspergillus flavus, A.ochraceus, A. versicolor and Eurotium herbariorum were isolated on both media. Aspergillus candidus, A. versicolor, C. Cladosporioides, P. aurantiogriseum and T. harzianum were isolated only on SMA, while A. niger, A. wentii and R. stolonifer were exclusively isolated on MY50G. Most ubiquitous species is A. alternata, which is isolated from all tested samples, while A. candidus, C. cladosporioides and T. harzianum were isolated from sunflower seed on reception in silo, using SMA medium.

  11. BASAL MEDIA FORMULATION USING CANAVALIA ENSIFORMIS AS CARBON AND NITROGEN SOURCE FOR THE GROWTH OF SOME FUNGI SPECIES

    Directory of Open Access Journals (Sweden)

    B.J. Akinyele2

    2012-02-01

    Full Text Available The possibility of developing alternative media to commercial potato dextrose agar was assessed using, Canavalia ensiformis (Linn (jack beans as carbon and nitrogen source. Six leguminous meal media were used as substitute for either carbon or nitrogen or both, while potato dextrose broth (PDB was used as a positive control and basal medium as a negative control. Six species of fungi Aspergillus flavus, A. niger, Meria coniospora, Mucor sp, Neurospora crassa and Rhizopus oryzae were aseptically inoculated into the formulated media and allowed to grow. Their mycelia dry weights were taken after 24, 48, 72, 96 and 120 hours. Growth of all fungal species was observed to be slightly lower, about the same or better in the formulated media relative to the control. Aspergillus flavus had its highest biomass of 1.70g in the media formulated with Canavalia ensiformis as the carbon source relative to 1.42g as the standard at the 120 hour. A. niger had a growth of 0.62g relative to 0.61g at 120 hours of the control. Meria coniospora had a growth of 0.27g relative to 0.38g at 120 hours. Mucor sp had a growth of 0.54g relative to 0.44g at 120 hours. Neurospora crassa had a growth of 1.05g relative to 0.24g at 120 hours. Rhizopus oryzae had a growth of 0.14g relative to 0.25g at 120 hours. The study revealed that Canavalia ensiformis contains minerals and nutrients that is able to provide the nutritional requirements of these fungi. Thus, it can be used as an alternative material in the preparation of culture media for in vitro cultivation of these fungi for teaching and research purposes.

  12. Bioimpact of application of pesticides with plant growth hormone (gibberellic acid on target and non-target microorganisms

    Directory of Open Access Journals (Sweden)

    Mohamed Abdullah Al Abboud

    2014-12-01

    Full Text Available The objective of this investigation was to determine the impacts of fungicide, insecticide, plant growth hormone (gibberellic acid on soil microbiota, and the growth characteristics of Aspergillus flavus. In the fungicide or insecticide mixed with plant growth hormone treated soil sample, the total viable number of soil microbiota was found to be higher than that of the soil treated with fungicide or insecticide alone. Moderate effect of insecticide used on the total number of fungi was observed. On the other hand the effect of insecticide on soil bacteria was more than effect of fungicide, and the negative effect of fungicide on soil bacteria was observed particularly at latent periods (15 and 20 days of application. A great sensitivity to fungicide and insecticide was observed in the case of nitrogen fixing bacteria. At 15 days after fungicide and insecticide application the adverse effect was found. Morphological deformations were clear in A. flavus cultivated on medium containing fungicide, the fungus failed to form conidiospores, conidiophores and vesicles. Intermediate and terminal outgrowths like blisters and terminal vesicle originate from hyphae. The addition of plant growth hormone reduced the effect of fungicide on fungus.

  13. Nitrogen Metabolism and Growth Enhancement in Tomato Plants Challenged with Trichoderma harzianum Expressing the Aspergillus nidulans Acetamidase amdS Gene

    Science.gov (United States)

    Domínguez, Sara; Rubio, M. Belén; Cardoza, Rosa E.; Gutiérrez, Santiago; Nicolás, Carlos; Bettiol, Wagner; Hermosa, Rosa; Monte, Enrique

    2016-01-01

    Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in Trichoderma harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea, and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by (i) enhanced growth, (ii) increased carbon and nitrogen levels, and (iii) a

  14. Nitrogen metabolism and growth enhancement in tomato plants challenged with Trichoderma harzianum expressing the Aspergillus nidulans acetamidase amdS gene

    Directory of Open Access Journals (Sweden)

    Sara Domínguez

    2016-08-01

    Full Text Available Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in T. harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by i enhanced growth, ii increased carbon and nitrogen levels and iii a

  15. Nitrogen Metabolism and Growth Enhancement in Tomato Plants Challenged with Trichoderma harzianum Expressing the Aspergillus nidulans Acetamidase amdS Gene.

    Science.gov (United States)

    Domínguez, Sara; Rubio, M Belén; Cardoza, Rosa E; Gutiérrez, Santiago; Nicolás, Carlos; Bettiol, Wagner; Hermosa, Rosa; Monte, Enrique

    2016-01-01

    Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in Trichoderma harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea, and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by (i) enhanced growth, (ii) increased carbon and nitrogen levels, and (iii) a

  16. Aflatoxin B1-producing Aspergillus in sun-dried medicinal plant materials

    Directory of Open Access Journals (Sweden)

    Chinaputi, A.

    2001-10-01

    Full Text Available Fifty sun-dried medicinal plants were obtained from fraditional drug stores in Songkhla Province, Thailand, and examined for Aspergillus and aflatoxin B1. 288 isolates of Aspergillus were obtaines by standard blotter plate and 25 species were identified. The most common species were A. niger with 99 isolates, A. Flavus 84 isolates, A. terreus 33 isolates, A. oryzae 25 isolates, A.nidulans (Emericella nidulans 10 isolates, A fumigatus 9 isolates and A. chevalieri (Eurotium chevalieri 8 isolates. The other species[A. alliaceus, A.auricomus, A. carbonarius, A. carneus, A. clavatus, A. fisheri(Sartorya fumigata, A. janus, A. melleus,A. ochraceus, A. phoencis, A. sparsus, A. terricola, A. thomii, A. versicolor, A. wentii and Aspergillus sp.1-3] each had 1-2 siolates. Ofthe 50 different plants examined,9 had no trace of Aspergillus, namely Cinnamomum zeylanicum, Illicium verum, Andrographis paniculate, Carthamus tinctorius, Eugenia caryophyllus, Elettaria cardomomum, Coriandrum sativum, Curcuma longa and Cassia garrettiana. The highest number of species(9 of Aspergillus was found on Rauvolfia serpentina.The ability of Aspergillus to form aflatoxin was determined in coconut milk agar by observing the intensity of blue fluorescence in agar surrounding the colonies under ultraviolet light and the yellow pigment under the colonies. The results showed the production of aflatoxin was limited to the one species, A. flavus, from which 84 isolates produced aflatoxin in 57 isolates(67.8%.Aflatoxin B1. production was confirmed by culturing fluorescencing isolates of A. flavus in coconut nilk broth and detecting by ELISA technique. Aflatoxin B1. showed increasing production after 2 days, stabilizing at 3-4 days, and the decreasing after 5-6 days. Aflatoxin B1. could not be detected from nonfluorescencing isolates.The morphological characteristics of the aflatoxin B1. -producing and non-producing strains of A. flavus were similar under light microscope and

  17. Submerged Conidiation and Product Formation by Aspergillus niger at Low Specific Growth Rates Are Affected in Aerial Developmental Mutants

    DEFF Research Database (Denmark)

    Jørgensen, Thomas R.; Nielsen, Kristian Fog; Arentshorst, Mark

    2011-01-01

    as associated with conidium formation, while fumonisins B2, B4, and B6 were characteristic of early response to nutrient limitation by the vegetative mycelium. The developmental mutants responded differently to the severe substrate limitation, which resulted in distinct profiles of growth and product formation...

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

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    S M Rudramurthy

    2016-01-01

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

  19. Species identification of Aspergillus section Flavi isolates from Portuguese almonds using phenotypic, including MALDI-TOF ICMS, and molecular approaches.

    Science.gov (United States)

    Rodrigues, P; Santos, C; Venâncio, A; Lima, N

    2011-10-01

    Section Flavi is one of the most significant sections in the genus Aspergillus. Taxonomy of this section currently depends on multivariate approaches, entailing phenotypic and molecular traits. This work aimed to identify isolates from section Flavi by combining various classic phenotypic and genotypic methods as well as the novel approach based on spectral analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF ICMS) and to evaluate the discriminatory power of the various approaches in species identification.   Aspergillus section Flavi isolates obtained from Portuguese almonds were characterized in terms of macro- and micromorphology, mycotoxin pattern, calmodulin gene sequence and MALDI-TOF protein fingerprint spectra. For each approach, dendrograms were created and results were compared. All data sets divided the isolates into three groups, corresponding to taxa closely related to Aspergillus flavus, Aspergillus parasiticus and Aspergillus tamarii. In the A. flavus clade, molecular and spectral analyses were not able to resolve between aflatoxigenic and nonaflatoxigenic isolates. In the A. parasiticus cluster, two well-resolved clades corresponded to unidentified taxa, corresponding to those isolates with mycotoxin profile different from that expected for A. parasiticus. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  20. Influence of the mycelium growth conditions on the production of amylolytic, proteolytic and pectinolytic enzymes by Aspergillus niger C

    Energy Technology Data Exchange (ETDEWEB)

    Fiedurek, J.; Ilczuk, Z.; Lobarzewski, J. (Uniwersytet Marii Curie-Sklodowskiej, Lublin (Poland). Inst. Mikrobiologii i Biochemii)

    1989-01-01

    Various nitrogen and carbon sources, as well as natural products, were examined as inducers of the production of amylases, proteases and pectinases by A. niger C. A. niger C grown on wheat bran extract medium provided culture supernatants with the highest enzymatic activities. Some culture conditions, e.g. pH, medium temperature and time period of cultivation, were optimalized to improve the growth and enzyme biosynthesis by A. niger C. (orig.).

  1. Impact of alg3 gene deletion on growth, development, pigment production, protein secretion, and functions of recombinant Trichoderma reesei cellobiohydrolases in Aspergillus niger.

    Science.gov (United States)

    Dai, Ziyu; Aryal, Uma K; Shukla, Anil; Qian, Wei-Jun; Smith, Richard D; Magnuson, Jon K; Adney, William S; Beckham, Gregg T; Brunecky, Roman; Himmel, Michael E; Decker, Stephen R; Ju, Xiaohui; Zhang, Xiao; Baker, Scott E

    2013-12-01

    Dolichyl-P-Man:Man(5)GlcNAc(2)-PP-dolichyl α-1,3-mannosyltransferase (also known as "asparagine-linked glycosylation 3", or ALG3) is involved in early N-linked glycan synthesis and thus is essential for formation of N-linked protein glycosylation. In this study, we examined the effects of alg3 gene deletion (alg3Δ) on growth, development, pigment production, protein secretion and recombinant Trichoderma reesei cellobiohydrolase (rCel7A) expressed in Aspergillus niger. The alg3Δ delayed spore germination in liquid cultures of complete medium (CM), potato dextrose (PD), minimal medium (MM) and CM with addition of cAMP (CM+cAMP), and resulted in significant reduction of hyphal growth on CM, potato dextrose agar (PDA), and CM+cAMP and spore production on CM. The alg3Δ also led to a significant accumulation of red pigment on both liquid and solid CM cultures. The relative abundances of 54 of the total 215 proteins identified in the secretome were significantly altered as a result of alg3Δ, 63% of which were secreted at higher levels in alg3Δ strain than the parent. The rCel7A expressed in the alg3Δ mutant was smaller in size than that expressed in both wild-type and parental strains, but still larger than T. reesei Cel7A. The circular dichroism (CD)-melt scans indicated that change in glycosylation of rCel7A does not appear to impact the secondary structure or folding. Enzyme assays of Cel7A and rCel7A on nanocrystalline cellulose and bleached kraft pulp demonstrated that the rCel7As have improved activities on hydrolyzing the nanocrystalline cellulose. Overall, the results suggest that alg3 is critical for growth, sporulation, pigment production, and protein secretion in A. niger, and demonstrate the feasibility of this alternative approach to evaluate the roles of N-linked glycosylation in glycoprotein secretion and function. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. The LysR-type transcriptional regulator CbbR controlling autotrophic CO2 fixation by Xanthobacter flavus is an NADPH sensor

    NARCIS (Netherlands)

    van Keulen, G; Girbal, L; van den Bergh, E.R E; Dijkhuizen, L.; Meijer, W.G

    Autotrophic growth of Xanthobacter flavus is dependent on the fixation of carbon dioxide via the Calvin cycle and on the oxidation of simple organic and inorganic compounds to provide the cell with energy. Maximal induction of the cbb and gap-pgk operons encoding enzymes of the Calvin cycle occurs

  3. THE CALVIN CYCLE ENZYME PHOSPHOGLYCERATE KINASE OF XANTHOBACTER-FLAVUS REQUIRED FOR AUTOTROPHIC CO2 FIXATION IS NOT ENCODED BY THE CBB OPERON

    NARCIS (Netherlands)

    MEIJER, WG

    1994-01-01

    During autotrophic growth of Xanthobacter flavus, energy derived from the oxidation of hydrogen methanol or formate is used to drive the assimilation of CO2 via the Calvin cycle. The genes encoding the Calvin cycle enzymes are organized in the cbb operon, which is expressed only during autotrophic

  4. Unique antimicrobial spectrum of ophiobolin K produced by Aspergillus ustus.

    Science.gov (United States)

    Sohsomboon, Natthapat; Kanzaki, Hiroshi; Nitoda, Teruhiko

    2018-03-01

    A co-cultivation study of two fungal strains showed that Aspergillus ustus could inhibit Aspergillus repens growth. The bioactive compound responsible for the observed activity was purified and identified as a sesterterpene, ophiobolin K. Ophiobolin K exhibited marked inhibition against both fungi and bacteria, especially A. repens, A. glaucus and gram-positive bacteria including Bacillus subtilis, Staphylococcus aureus, and Micrococcus luteus.

  5. Ecophysiological characterization of Aspergillus carbonarius, Aspergillus tubingensis and Aspergillus niger isolated from grapes in Spanish vineyards.

    Science.gov (United States)

    García-Cela, E; Crespo-Sempere, A; Ramos, A J; Sanchis, V; Marin, S

    2014-03-03

    The aim of this study was to evaluate the diversity of black aspergilli isolated from berries from different agroclimatic regions of Spain. Growth characterization (in terms of temperature and water activity requirements) of Aspergillus carbonarius, Aspergillus tubingensis and Aspergillus niger was carried out on synthetic grape medium. A. tubingensis and A. niger showed higher maximum temperatures for growth (>45 °C versus 40-42 °C), and lower minimum aw requirements (0.83 aw versus 0.87 aw) than A. carbonarius. No differences in growth boundaries due to their geographical origin were found within A. niger aggregate isolates. Conversely, A. carbonarius isolates from the hotter and drier region grew and produced OTA at lower aw than other isolates. However, little genetic diversity in A. carbonarius was observed for the microsatellites tested and the same sequence of β-tubulin gene was observed; therefore intraspecific variability did not correlate with the geographical origin of the isolates or with their ability to produce OTA. Climatic change prediction points to drier and hotter climatic scenarios where A. tubingensis and A. niger could be even more prevalent over A. carbonarius, since they are better adapted to extreme high temperature and drier conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Effect of cinnamomum zeylanicum blume essential oil on the rowth and morphogenesis of some potentially pathogenic Aspergillus species Efeito do óleo essencial de Cinnamomum zeylanicum Blume sobre o crescimento e morfogênese de algumas espécies de Aspergillus potencialmente patogênicas

    Directory of Open Access Journals (Sweden)

    Egberto Santos Carmo

    2008-03-01

    Full Text Available Cinnamomum zeylanicum Blume is known for a wide range of medicinal properties. This study aimed to assess the interference of C. zeylanicum essential oil on the growth and morphogenesis of some potentially pathogenic Aspergillus species. The essential oil presented strong antifungal effect causing the growth inhibition of the assayed strains and development of large growth inhibition zones. MIC50 and MIC90 values were 40 and 80 µL/mL, respectively. 80, 40 and 20 µL/mL of the oil strongly inhibited the radial mycelial growth of A. niger, A. flavus and A. fumigatus along 14 days. 80 and 40 µL/mL of the oil caused a 100% inhibition of the fungal spore germination. Main morphological changes observed under light microscopy provided by the essential oil in the fungal strains were decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure indicating fungal wall degeneration. It is concluded that C. zeylanicum essential oil could be known as potential antifungal compound, particularly, to protect against the growth of Aspergillus species.Cinnamomum zeylanicum Blume é uma planta conhecida por apresentar ampla variedade de propriedades medicinais. Portanto, este estudo teve por objetivo avaliar a interferência do óleo essencial C. zeylanicum sobre o crescimento e morfogênese de algumas espécies de Aspergillus potencialmente patogênicas. O óleo essencial testado apresentou potente efeito antifúngico demonstrado pela visualização de grandes zonas de inibição de crescimento de todas as linhagens testadas. Os valores de CIM50 e de CIM90 foram 40 e 80 µL/mL, respectivamente. Nas concentrações de 80, 40 e 20 µL/mL o óleo demonstrou um potente efeito fumigante, inibindo o crescimento micelial radial de A. niger, A. flavus e A. fumigatus ao longo de 14 dias de exposição. A 80 e 40 µL/mL o óleo essencial promoveu inibição de 100% da germinação de esporos, das três espécies de Aspergillus citadas

  7. Phosphate solubilization and promotion of maize growth in a calcareous soil by penicillium oxalicum P4 and aspergillus niger P85

    Science.gov (United States)

    Alternative tactics for improving phosphorus nutrition in crop production are needed in China and elsewhere as the over-application of phosphatic fertilizers can adversely impact agricultural sustainability. Penicillium oxalicum P4 and Aspergillus niger P85 were isolated from a calcareous soil in C...

  8. Inhibitory effect of gamma radiation and Nigella sativa seeds oil on growth, spore germination and toxin production of fungi

    International Nuclear Information System (INIS)

    El-Bazza, Z.E.; Hala, A.F.; El-Fouly, M.E.Z.; El-Tablawy, S.Y.M.

    2001-01-01

    Twenty samples of Nigella sativa seeds (Black cumin) were purchased from different localities in Egypt. The mold viable count ranged from 1.7x10 1 to 9.8x10 3 c.f.u. Sixty six molds were isolated belonging to six genera Aspergillus, Penicillium, Rhizopus, Mucor, Alternaria and Fusarium. Exposure of seeds samples to different radiation doses showed that a dose level of 6.0 kGy could be considered as a sufficient dose for decontamination of the tested samples. Seven radioresistant isolates were identified as Rhizopus oryzae, Rhizopus stolonifer, Penicillium chrysogenum and Penicillium corylophillum. All the herb samples were found to be free from aflatoxins B 1 , B 2 , G 1 , G 2 and ochratoxin A. One mold isolate was identified as Aspergillus flavus could produce aflatoxin B 1 and G 1 . None of the isolated radioresistant strains could produce mycotoxins. The water activities of seeds were slightly decreased by the storage time and the seeds needed to be stored at relative humidity not more than 85%. The addition of extract volatile and fixed oil from tested seeds to the medium stimulated the growth of isolated Aspergillus sp. (author)

  9. Inhibitory effect of gamma radiation and Nigella sativa seeds oil on growth, spore germination and toxin production of fungi

    Science.gov (United States)

    Zeinab, E. M. EL-Bazza; Hala, A. Farrag; Mohie, E. D. Z. EL-Fouly; Seham, Y. M. EL-Tablawy

    2001-02-01

    Twenty samples of Nigella sativa seeds (Black cumin) were purchased from different localities in Egypt. The mold viable count ranged from 1.7×10 1 to 9.8×10 3 c.f.u. Sixty six molds were isolated belonging to six genera Aspergillus, Penicillium, Rhizopus, Mucor, Alternaria and Fusarium. Exposure of seeds samples to different radiation doses showed that a dose level of 6.0 kGy could be considered as a sufficient dose for decontamination of the tested samples. Seven radioresistant isolates were identified as Rhizopus oryzae, Rhizopus stolonifer, Penicillium chrysogenum and Penicillium corylophillum. All the herb samples were found to be free from aflatoxins B 1, B 2, G 1, G 2 and ochratoxin A. One mold isolate was identified as Aspergillus flavus could produce aflatoxin B 1 and G 1. None of the isolated radioresistant strains could produce mycotoxins. The water activities of seeds were slightly decreased by the storage time and the seeds needed to be stored at relative humidity not more than 85%. The addition of extract volatile and fixed oil from tested seeds to the medium stimulated the growth of isolated Aspergillus sp.

  10. Inhibitory effect of gamma radiation and Nigella sativa seeds oil on growth, spore germination and toxin production of fungi

    Energy Technology Data Exchange (ETDEWEB)

    El-Bazza, Z.E.; Hala, A.F. E-mail: hfarragmassoud@hotmail.com; El-Fouly, M.E.Z.; El-Tablawy, S.Y.M

    2001-02-01

    Twenty samples of Nigella sativa seeds (Black cumin) were purchased from different localities in Egypt. The mold viable count ranged from 1.7x10{sup 1} to 9.8x10{sup 3} c.f.u. Sixty six molds were isolated belonging to six genera Aspergillus, Penicillium, Rhizopus, Mucor, Alternaria and Fusarium. Exposure of seeds samples to different radiation doses showed that a dose level of 6.0 kGy could be considered as a sufficient dose for decontamination of the tested samples. Seven radioresistant isolates were identified as Rhizopus oryzae, Rhizopus stolonifer, Penicillium chrysogenum and Penicillium corylophillum. All the herb samples were found to be free from aflatoxins B{sub 1}, B{sub 2}, G{sub 1}, G{sub 2} and ochratoxin A. One mold isolate was identified as Aspergillus flavus could produce aflatoxin B{sub 1} and G{sub 1}. None of the isolated radioresistant strains could produce mycotoxins. The water activities of seeds were slightly decreased by the storage time and the seeds needed to be stored at relative humidity not more than 85%. The addition of extract volatile and fixed oil from tested seeds to the medium stimulated the growth of isolated Aspergillus sp. (author)

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

    Science.gov (United States)

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

  12. Detection of aflatoxigenic aspergillus flavus contamination of coconut (cocos nucifera) nutmeat (copra) using ammonia treatment

    Science.gov (United States)

    For many crops government regulations define mycotoxin contamination levels that represent the primary determinants of quality, value and possible uses of crops. Quality can be raised in some crops by lowering the mycotoxin level through removal of infected products. In the case of copra, the drie...

  13. Differential role of gpaB and sidA gene expressions in relation to virulence in Aspergillus species from patients with invasive aspergillosis.

    Science.gov (United States)

    Ghods, Nayereh; Falahati, Mehraban; Roudbary, Maryam; Farahyar, Shirin; Shamaei, Masoud; Pourabdollah, Mahin; Seif, Farhad

    2018-02-03

    The virulence genes in invasive aspergillosis (IA) have not been analyzed adequately. The present study was designed to evaluate the expression of gpaB and sidA genes, which are important virulence genes in Aspergillus spp. from bronchoalveolar lavage (BAL) samples. Direct examination and culture on Czapek Agar and Sabouraud Dextrose Agar media were performed for 600 BAL specimens isolated from patients with possible aspergillosis. A Galactomannan ELISA assay was also carried out. The expression levels of the gpaB and sidA genes in isolates were analyzed using quantitative real-time PCR (qRT-PCR). We identified 2 species, including Aspergillus flavus (A. flavus) and Aspergillus fumigatus (A. fumigatus) in 25 positive samples for invasive aspergillosis as validated using GM-ELISA. A. flavus is the main pathogen threatening transplant recipients and cancer patients worldwide. In this study, A. flavus had low levels of the gpaB gene expression compared to A. fumigatus (p=0.006). The highest sidA expression was detected in transplant recipients (p=0.05). There was no significant correlation between sidA expression and underlying disease (p=0.15). The sidA and gpaB gene expression patterns may provide evidence that these virulence genes play important roles in the pathogenicity of Aspergillus isolates; however, there are several regulatory genes responsible for the unexpressed sidA and gpaB genes in the isolates. Copyright © 2018 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  14. Evaluation of the control ability of five essential oils against Aspergillus section Nigri growth and ochratoxin A accumulation in peanut meal extract agar conditioned at different water activities levels.

    Science.gov (United States)

    Passone, María A; Girardi, Natalia S; Etcheverry, Miriam

    2012-10-15

    Essential oils (EOs) from boldo [Pëumus boldus Mol.], poleo [Lippia turbinata var. integrifolia (Griseb.)], clove [Syzygium aromaticum L.], anise [Pimpinella anisum] and thyme [Thymus vulgaris]) obtained by hydrodistillation were evaluated for their effectiveness against the growth of Aspergillus niger aggregate and A. carbonarius and accumulation of ochratoxin A (OTA). The evaluation was performed by compound dissolution at the doses of 0, 500, 1500 and 2500μL/L in peanut meal extract agar (PMEA) and exposure to volatiles of boldo, poleo (0, 1000, 2000 and 3000μL/L) and clove oils (0, 1000, 3000 and 5000μL/L), taking into account the levels of the water activity of the medium (a(W) 0.98, 0.95, 0.93). Statistical analyses on growth of Aspergillus strains indicated that the major effect was produced by oil concentrations followed by substrate a(W), and that reductions in antifungal efficiency of the oils tested were observed in vapor exposure assay. At all a(W) levels, complete fungal growth inhibition was achieved with boldo EO at doses of 1500 and 2000μL/L by contact and volatile assays, respectively. Contact exposure by poleo and clove EOs showed total fungal inhibition at the middle level tested of 1500μL/L, regardless of a(W), while their antifungal effects in headspace volatile assay were closely dependent on medium a(W). The fumigant activity of poleo (2000μL/L) and clove oils (3000μL/L) inhibited growth rate by 66.0% and 80.6% at a(W) 0.98 and 0.93, respectively. OTA accumulation was closely dependent on a(W) conditions. The antiochratoxigenic property of the volatile fractions of boldo, poleo and clove EOs (1000μL/L) was more significant at low a(W) levels, inhibition percentages were estimated at 14.7, 41.7 and 78.5% at a(W) 0.98, 0.95 and 0.93, respectively. Our results suggest that boldo, poleo and clove oils affect the OTA biosynthesis pathway of both Aspergillus species. This finding leaves open the possibility of their use by vapor exposure

  15. Effects of N2-O2 and CO2-O2 tensions on growth of fungi isolated from damaged flue-cured tobacco.

    Science.gov (United States)

    Yang, H; Lucas, G B

    1970-02-01

    Ten fungi, Aspergillus niger, A. flavus, A. ochraceus, A. ruber, A. repens, A. amstelodami, Alternaria tenuis, Penicillium brevi-compactum, Cladosporium herbarum, and Chaetomium dolicotrichum, were isolated from moldy flue-cured tobacco and grown in various mixtures of N(2)-O(2) or CO(2)-O(2). A 1 to 5% concentration of O(2) in an N(2) atmosphere caused the greatest change in growth of the nine species, and a 10 to 20% concentration of O(2) for A. flavus. All species, except A. amstelodami and A. ruber, grew faster in air than in mixtures containing 10% O(2). High O(2) concentrations generally inhibited furrow production in the mycelial mats. In an atmosphere of 5 to 40% O(2) in the N(2) atmosphere, furrows formed in mycelial mats between 5 and 40% O(2) in the species except for A. ruber, A. repens, and A. amstelodami, which produced none in any concentration. As O(2) decreased below 20%, spore production was progressively decreased, colony color faded to white, and cleistothecia formation was suppressed. In CO(2)-O(2) mixtures radial growth of all species increased with each quantitative decrease of CO(2). All species except A. niger grew faster in air than in 10% CO(2). In contrast to N(2)-O(2) mixtures, the fungi formed furrows, sporulation and cleistothecial formation were suppressed, and colony color changed to white in higher O(2) concentrations.

  16. Effects of N2-O2 and CO2-O2 Tensions on Growth of Fungi Isolated from Damaged Flue-Cured Tobacco 1

    Science.gov (United States)

    Yang, H.; Lucas, G. B.

    1970-01-01

    Ten fungi, Aspergillus niger, A. flavus, A. ochraceus, A. ruber, A. repens, A. amstelodami, Alternaria tenuis, Penicillium brevi-compactum, Cladosporium herbarum, and Chaetomium dolicotrichum, were isolated from moldy flue-cured tobacco and grown in various mixtures of N2-O2 or CO2-O2. A 1 to 5% concentration of O2 in an N2 atmosphere caused the greatest change in growth of the nine species, and a 10 to 20% concentration of O2 for A. flavus. All species, except A. amstelodami and A. ruber, grew faster in air than in mixtures containing 10% O2. High O2 concentrations generally inhibited furrow production in the mycelial mats. In an atmosphere of 5 to 40% O2 in the N2 atmosphere, furrows formed in mycelial mats between 5 and 40% O2 in the species except for A. ruber, A. repens, and A. amstelodami, which produced none in any concentration. As O2 decreased below 20%, spore production was progressively decreased, colony color faded to white, and cleistothecia formation was suppressed. In CO2-O2 mixtures radial growth of all species increased with each quantitative decrease of CO2. All species except A. niger grew faster in air than in 10% CO2. In contrast to N2-O2 mixtures, the fungi formed furrows, sporulation and cleistothecial formation were suppressed, and colony color changed to white in higher O2 concentrations. PMID:5461786

  17. 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 ...

  18. An attempt to optimize potassium sorbate use to preserve low pH (4.5-5.5) intermediate moisture bakery products by modelling Eurotium spp., Aspergillus spp. and Penicillium corylophilum growth.

    Science.gov (United States)

    Guynot, M Elena; Marín, Sonia; Sanchis, Vicente; Ramos, Antonio J

    2005-05-25

    Mould growth was modelled on fermented bakery product analogues (FBPA) of two different pH (4.5 and 5.5), different water activity (a(w)) levels (0.80-0.90) and potassium sorbate concentrations (0-0.3%) by using seven moulds commonly causing spoilage of bakery products (Eurotium spp., Aspergillus spp. and Penicillium corylophilum). For the description of fungal growth (growth rates) as a function of a(w), potassium sorbate concentration and pH, 10-terms polynomial models were developed. Modelling enables prediction of spoilage during storage as a function of the factors affecting fungal growth. At pH 4.5 the concentration of potassium sorbate could be reduced to some extent only at low levels of a(w), whereas at pH 5.5 fungal growth was observed even by adding 0.3% of potassium sorbate. However, this preservative could be a valuable alternative as antifungal in such bakery product, of slightly acidic pH, if a long shelf life has not to be achieved.

  19. A rare case of bilateral aspergillus endophthalmitis

    Directory of Open Access Journals (Sweden)

    Saurabh Gupta

    2015-12-01

    Full Text Available Aspergillus endophthalmitis is a devastating inflammatory condition of the intraocular cavities that may result in irreparable loss of vision and rapid destruction of the eye. Almost all cases in the literature have shown an identified source causing aspergillus endophthalmitis as a result of direct extension of disease. We present a rare case of bilateral aspergillus endophthalmitis. A 72-year-old woman with a history of diabetes mellitus, congenital Hirschsprung disease, and recent culture-positive candida pyelonephritis with hydronephrosis status post-surgical stent placement presented with difficulty opening her eyes. She complained of decreased vision (20/200 with pain and redness in both eyes – right worse then left. Examination demonstrated multiple white fungal balls in both retinas consistent with bilateral fungal endophthalmitis. Bilateral vitreous taps for cultures and staining were performed. Patient was given intravitreal injections of amphotericin B, vancomycin, ceftazidime, and started on oral fluconazole. Patient was scheduled for vitrectomy to decrease organism burden and to remove loculated areas of infection that would not respond to systemic antifungal agents. Four weeks after initial presentation, the fungal cultures revealed mold growth consistent with aspergillus. Patient was subsequently started on voriconazole and fluconazole was discontinued due to poor efficacy against aspergillus. Further workup was conducted to evaluate for the source of infection and seeding. Transthoracic cardiogram was unremarkable for any vegetation or valvular abnormalities. MRI of the orbits and sinuses did not reveal any mass lesions or bony destruction. CT of the chest was unremarkable for infection. Aspergillus endophthalmitis may occur because of one of these several mechanisms: hematogenous dissemination, direct inoculation by trauma, and contamination during surgery. Our patient's cause of bilateral endophthalmitis was through an

  20. Biocidal synthetic coatings based on high-molecular metaloorganic compounds. [Aspergillus flavus; Aspergillus niger; Aspergillus terreus; Penicillium funiculosum; penicillium cyclopium; Penicillium chrysogenum; Paecilomyces varioti; Chaetomium globosum; trichoderma viride

    Energy Technology Data Exchange (ETDEWEB)

    Mishchenko, V.F.; Zubov, V.A.; Eremenko, Yu.G.

    Long-term stays of man and animals in closed life-support systems lead to contamination of the space-craft by various microorganisms. Organotin compounds are considered promising biocidal agents for paints and varnishes with a broad spectrum of action against a variety of microorganisms. Several organotin polymers of the acrylate type were prepared and were found to be effective fungicides.

  1. In vitro susceptibility testing of Aspergillus spp. against voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin.

    Science.gov (United States)

    Shi, Jun-yan; Xu, Ying-chun; Shi, Yi; Lü, Huo-xiang; Liu, Yong; Zhao, Wang-sheng; Chen, Dong-mei; Xi, Li-yan; Zhou, Xin; Wang, He; Guo, Li-na

    2010-10-01

    During recent years, the incidence of serious infections caused by opportunistic fungi has increased dramatically due to alterations of the immune status of patients with hematological diseases, malignant tumors, transplantations and so forth. Unfortunately, the wide use of triazole antifungal agents to treat these infections has lead to the emergence of Aspergillus spp. resistant to triazoles. The present study was to assess the in vitro activities of five antifungal agents (voriconazole, itraconazole, posaconazole, amphotericin B and caspofungin) against different kinds of Aspergillus spp. that are commonly encountered in the clinical setting. The agar-based Etest MIC method was employed. One hundred and seven strains of Aspergillus spp. (5 species) were collected and prepared according to Etest Technique Manuel. Etest MICs were determined with RPMI agar containing 2% glucose and were read after incubation for 48 hours at 35°C. MIC(50), MIC(90) and MIC range were acquired by Whonet 5.4 software. The MIC(90) of caspofungin against A. fumigatus, A. flavus and A. nidulans was 0.094 µg/ml whereas the MIC(90) against A. niger was 0.19 µg/ml. For these four species, the MIC(90) of caspofungin was the lowest among the five antifungal agents. For A. terrus, the MIC(90) of posaconazole was the lowest. For A. fumigatus and A. flavus, the MIC(90) in order of increasing was caspofungin, posaconazole, voriconazole, itraconazole, and amphotericin B. The MIC of amphotericin B against A. terrus was higher than 32 µg/ml in all 7 strains tested. The in vitro antifungal susceptibility test shows the new drug caspofungin, which is a kind of echinocandins, has good activity against the five species of Aspergillus spp. and all the triazoles tested have better in vitro activity than traditional amphotericin B.

  2. 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.

  3. 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.

  4. Identification by Molecular Methods and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry and Antifungal Susceptibility Profiles of Clinically Significant Rare Aspergillus Species in a Referral Chest Hospital in Delhi, India.

    Science.gov (United States)

    Masih, Aradhana; Singh, Pradeep K; Kathuria, Shallu; Agarwal, Kshitij; Meis, Jacques F; Chowdhary, Anuradha

    2016-09-01

    Aspergillus species cause a wide spectrum of clinical infections. Although Aspergillus fumigatus and Aspergillus flavus remain the most commonly isolated species in aspergillosis, in the last decade, rare and cryptic Aspergillus species have emerged in diverse clinical settings. The present study analyzed the distribution and in vitro antifungal susceptibility profiles of rare Aspergillus species in clinical samples from patients with suspected aspergillosis in 8 medical centers in India. Further, a matrix-assisted laser desorption ionization-time of flight mass spectrometry in-house database was developed to identify these clinically relevant Aspergillus species. β-Tubulin and calmodulin gene sequencing identified 45 rare Aspergillus isolates to the species level, except for a solitary isolate. They included 23 less common Aspergillus species belonging to 12 sections, mainly in Circumdati, Nidulantes, Flavi, Terrei, Versicolores, Aspergillus, and Nigri Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) identified only 8 (38%) of the 23 rare Aspergillus isolates to the species level. Following the creation of an in-house database with the remaining 14 species not available in the Bruker database, the MALDI-TOF MS identification rate increased to 95%. Overall, high MICs of ≥2 μg/ml were noted for amphotericin B in 29% of the rare Aspergillus species, followed by voriconazole in 20% and isavuconazole in 7%, whereas MICs of >0.5 μg/ml for posaconazole were observed in 15% of the isolates. Regarding the clinical diagnoses in 45 patients with positive rare Aspergillus species cultures, 19 (42%) were regarded to represent colonization. In the remaining 26 patients, rare Aspergillus species were the etiologic agent of invasive, chronic, and allergic bronchopulmonary aspergillosis, allergic fungal rhinosinusitis, keratitis, and mycetoma. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  5. Identification by Molecular Methods and Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry and Antifungal Susceptibility Profiles of Clinically Significant Rare Aspergillus Species in a Referral Chest Hospital in Delhi, India

    Science.gov (United States)

    Masih, Aradhana; Singh, Pradeep K.; Kathuria, Shallu; Agarwal, Kshitij

    2016-01-01

    Aspergillus species cause a wide spectrum of clinical infections. Although Aspergillus fumigatus and Aspergillus flavus remain the most commonly isolated species in aspergillosis, in the last decade, rare and cryptic Aspergillus species have emerged in diverse clinical settings. The present study analyzed the distribution and in vitro antifungal susceptibility profiles of rare Aspergillus species in clinical samples from patients with suspected aspergillosis in 8 medical centers in India. Further, a matrix-assisted laser desorption ionization–time of flight mass spectrometry in-house database was developed to identify these clinically relevant Aspergillus species. β-Tubulin and calmodulin gene sequencing identified 45 rare Aspergillus isolates to the species level, except for a solitary isolate. They included 23 less common Aspergillus species belonging to 12 sections, mainly in Circumdati, Nidulantes, Flavi, Terrei, Versicolores, Aspergillus, and Nigri. Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) identified only 8 (38%) of the 23 rare Aspergillus isolates to the species level. Following the creation of an in-house database with the remaining 14 species not available in the Bruker database, the MALDI-TOF MS identification rate increased to 95%. Overall, high MICs of ≥2 μg/ml were noted for amphotericin B in 29% of the rare Aspergillus species, followed by voriconazole in 20% and isavuconazole in 7%, whereas MICs of >0.5 μg/ml for posaconazole were observed in 15% of the isolates. Regarding the clinical diagnoses in 45 patients with positive rare Aspergillus species cultures, 19 (42%) were regarded to represent colonization. In the remaining 26 patients, rare Aspergillus species were the etiologic agent of invasive, chronic, and allergic bronchopulmonary aspergillosis, allergic fungal rhinosinusitis, keratitis, and mycetoma. PMID:27413188

  6. In vitro analysis of the role of glucose oxidase from Talaromyces flavus in biocontrol of the plant pathogen Verticillium dahliae.

    OpenAIRE

    Stosz, S K; Fravel, D R; Roberts, D P

    1996-01-01

    Culture filtrates from Talaromyces flavus grown on glucose contained high levels of glucose oxidase activity, while culture filtrates from T. flavus grown on xylan contained negligible glucose oxidase activity. Culture filtrates from T-flavus grown on both media contained complex protein profiles. However, only culture filtrates from T. flavus grown on glucose inhibited germination of microsclerotia of Verticillium dahliae in in vitro inhibition assays. A polyclonal antiserum preparation, pAB...

  7. Induction of the gap-pgk operon encoding glyceraldehyde-3-phosphate dehydrogenase and 3-phosphoglycerate kinase of Xanthobacter flavus requires the LysR-type transcriptional activator CbbR

    NARCIS (Netherlands)

    Meijer, W.G; van den Bergh, E.R E; Smith, L.M

    In a previous study, a gene (pgk) encoding phosphoglycerate kinase was isolated from a genomic labrid of Xanthobacter flavus. Although this gene is essential for autotrophic growth, it is not located within the cbb operon encoding other Calvin cycle enzymes. An analysis of the nucleotide sequence

  8. Early detection of fungal growth in bakery products by use of an electronic nose based on mass spectrometry.

    Science.gov (United States)

    Vinaixa, Maria; Marín, Sonia; Brezmes, Jesús; Llobet, Eduard; Vilanova, Xavier; Correig, Xavier; Ramos, Antonio; Sanchis, Vicent

    2004-10-06

    This paper presents the design, optimization, and evaluation of a mass spectrometry-based electronic nose (MS e-nose) for early detection of unwanted fungal growth in bakery products. Seven fungal species (Aspergillus flavus, Aspergillus niger, Eurotium amstelodami, Eurotium herbariorum, Eurotium rubrum, Eurotium repens, and Penicillium corylophillum) were isolated from bakery products and used for the study. Two sampling headspace techniques were tested: static headspace (SH) and solid-phase microextraction (SPME). Cross-validated models based on principal component analysis (PCA), coupled to discriminant function analysis (DFA) and fuzzy ARTMAP, were used as data treatment. When attempting to discriminate between inoculated and blank control vials or between genera or species of in vitro growing cultures, sampling based on SPME showed better results than those based on static headspace. The SPME-MS-based e-nose was able to predict fungal growth with 88% success after 24 h of inoculation and 98% success after 48 h when changes were monitored in the headspace of fungal cultures growing on bakery product analogues. Prediction of the right fungal genus reached 78% and 88% after 24 and 96 h, respectively.

  9. In vitro activity of the novel antifungal compound F901318 against difficult-to-treat Aspergillus isolates.

    Science.gov (United States)

    Buil, J B; Rijs, A J M M; Meis, J F; Birch, M; Law, D; Melchers, W J G; Verweij, P E

    2017-09-01

    F901318 is a new antifungal agent with a novel mechanism of action with activity against Aspergillus species. We investigated the in vitro activity of F901318 against a collection of Aspergillus isolates. A total of 213 Aspergillus isolates were used in this study. A total of 143 Aspergillus fumigatus sensu stricto isolates were used, of which 133 were azole resistant [25 TR34/L98H; 25 TR46/Y121F/T289A; 33 A. fumigatus with cyp51A-associated point mutations (25 G54, 1 G432 and 7 M220); and 50 azole-resistant A. fumigatus without known resistance mechanisms]. Ten azole-susceptible A. fumigatus isolates were used as WT controls. The in vitro activity was also determined against Aspergillus calidoustus (25 isolates), Aspergillus flavus (10), Aspergillus nidulans (10) and Aspergillus tubingensis (25). F901318 activity was compared with that of itraconazole, voriconazole, posaconazole, isavuconazole, amphotericin B and anidulafungin. Minimum effective concentrations and MICs were determined using the EUCAST broth microdilution method. F901318 was active against all tested isolates: A. fumigatus WT, MIC90 0.125 mg/L (range 0.031-0.125); TR34/L98H,TR46/Y121F/T289A and azole resistant without known resistance mechanisms, MIC90 0.125 mg/L (range 0.031-0.25); A. fumigatus with cyp51A-associated point mutations, MIC90 0.062 mg/L (range 0.015-0.125); and other species, A. calidoustus MIC90 0.5 mg/L (range 0.125-0.5), A. flavus MIC90 0.062 mg/L (range 0.015-0.62), A. nidulans MIC90 0.125 mg/L (range 0.062-0.25) and A. tubingensis MIC90 0.062 mg/L (range 0.015-0.25). F901318 showed potent and consistent in vitro activity against difficult-to-treat Aspergillus spp. with intrinsic and acquired antifungal resistance due to known and unknown resistance mechanisms, suggesting no significant implications of azole resistance mechanisms for the mode of action of F901318. © The Author 2017. Published by Oxford University Press on behalf of the British Society for

  10. 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...

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

    Science.gov (United States)

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

    2018-02-02

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

  12. 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.

  13. Glucose uptake and growth of glucose-limited chemostat cultures of Aspergillus niger and a disruptant lacking MstA, a high-affinity glucose transporter

    DEFF Research Database (Denmark)

    Jørgensen, Thomas R; vanKuyk, Patricia A; Poulsen, Bjarne R

    2007-01-01

    This is a study of high-affinity glucose uptake in Aspergillus niger and the effect of disruption of a high-affinity monosaccharide-transporter gene, mstA. The substrate saturation constant (K(s)) of a reference strain was about 15 microM in glucose-limited chemostat culture. Disruption of mst......-affinity uptake system of A. niger. The mstA disruptant and a reference strain were cultivated in glucose-limited chemostat cultures at low, intermediate and high dilution rate (D=0.07 h(-1), 0.14 h(-1) and 0.20 h(-1)). Mycelium harvested from steady-state cultures was subjected to glucose uptake assays...

  14. PRODUCTION AND OPTIMIZATION OF GROWTH CONDITIONS FOR INVERTASE ENZYME BY ASPERGILLUS SP., IN SOLID STATE FERMENTATION (SSF USING PAPAYA PEEL AS SUBSTRATE

    Directory of Open Access Journals (Sweden)

    Brindha Chelliappan

    2013-12-01

    Full Text Available Invertase enzymes are produced mainly by plants, some filamentous fungi, yeast and many other microorganisms which finds applications in food industries, confectionaries, pharmaceuticals, etc., The present work deals with the production of Invertase by Aspergillus sp., isolated from various soil samples in solid state fermentation using papaya peel waste as substrate. Enzyme activity was checked using Fehling’s reagent and assay was carried out by DNSA method. The results of optimized conditions showed that the invertase activity was high in the SSF using papaya peel as substrate, incubated for 6 days at temperature of 35°C, pH 7, with 2.25gms/100ml of Ammonium nitrate as nitrogen source and 10gms/100ml of sucrose as carbon source. Hence the agro wastes from industries can be recycled by using it as substrate in SSF for high invertase enzyme production which finds applications in many fields.

  15. Enantioselective degradation and unidirectional chiral inversion of 2-phenylbutyric acid, an intermediate from linear alkylbenzene, by Xanthobacter flavus PA1

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yishan; Han, Ping [School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Li, Xiao-yan; Shih, Kaimin [Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Gu, Ji-Dong, E-mail: jdgu@hkucc.hku.hk [School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong (China); The Swire Institute of Marine Science, The University of Hong Kong, Shek O, Cape d' Aguilar, Hong Kong (China)

    2011-09-15

    Highlights: {yields} We isolated a Xanthobacter flavus strain PA1 utilizing the racemic 2-PBA and the single enantiomers as the sole source of carbon and energy. {yields} Both (R) and (S) forms of enantiomers can be degraded in a sequential manner in which the (S) disappeared before the (R) form. {yields} The biochemical degradation pathway involves an initial oxidation of the alkyl side chain before aromatic ring cleavage. - Abstract: Microbial degradation of the chiral 2-phenylbutyric acid (2-PBA), a metabolite of surfactant linear alkylbenzene sulfonates (LAS), was investigated using both racemic and enantiomer-pure compounds together with quantitative stereoselective analyses. A pure culture of bacteria, identified as Xanthobacter flavus strain PA1 isolated from the mangrove sediment of Hong Kong Mai Po Nature Reserve, was able to utilize the racemic 2-PBA as well as the single enantiomers as the sole source of carbon and energy. In the presence of the racemic compounds, X. flavus PA1 degraded both (R) and (S) forms of enantiomers to completion in a sequential manner in which the (S) enantiomer disappeared much faster than the (R) enantiomer. When the single pure enantiomer was supplied as the sole substrate, a unidirectional chiral inversion involving (S) enantiomer to (R) enantiomer was evident. No major difference was observed in the degradation intermediates with either of the individual enantiomers when used as the growth substrate. Two major degradation intermediates were detected and identified as 3-hydroxy-2-phenylbutanoic acid and 4-methyl-3-phenyloxetan-2-one, using a combination of liquid chromatography-mass spectrometry (LC-MS), and {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR) spectroscopy. The biochemical degradation pathway follows an initial oxidation of the alkyl side chain before aromatic ring cleavage. This study reveals new evidence for enantiomeric inversion catalyzed by pure culture of environmental bacteria and emphasizes the

  16. Tannase Production by Aspergillus niger

    Directory of Open Access Journals (Sweden)

    N. Lokeswari

    2007-01-01

    Full Text Available A method for assay of microbial tannase (Tannin acyl hydrolase based on the formation of chromogen between gallic acid and rhodanine is reported. Maximum Tannase production occurred in the culture broth containing 1-2% (w/v tannic acid and 0.05 – 0.1% (w/v glucose. The pH, incubation period, temperature and Glucose concentration optima of Tannase production was found at 5.5, 36 h, 35°C and 0.5% respectively. These properties make the enzyme suitable for pollution control and bioprocess industry. This assay is very simple, reproducible, and very convenient, and with it Tannase activity can be measured in relation to the growth of the organism. Aspergillus niger exhibited higher enzyme activity showing about 65 mole percent conversion respectively after a 36 h incubation period. The assay is complete in a short time, very convenient and reproducible.

  17. Response to Pitt and Taylor 2016: Conservation of Aspergillus with A. niger as the conserved type is unnecessary and potentially disruptive

    DEFF Research Database (Denmark)

    Samson, Robert A.; Hubka, Vit; Varga, János

    2017-01-01

    Aspergillus is a diverse fungal genus containing many species of great agricultural, biotechnological and medical relevance. Because of the broad use of the genus name in diverse disciplines, and the importance of individual species names in these areas, the taxonomy and nomenclature of Aspergillus...... should remain stable. A formal proposal to change the generic type from A. glaucus to A. niger was recently published. Here we present arguments against this proposal. We assert that it should be rejected because it will not ensure nomenclatural stability for Aspergillus, and will put the names...... of several important species, such as A. flavus, A. fumigatus and A. oryzae at risk of being classified in different genera and being lost....

  18. Albumin Enhances Caspofungin Activity against Aspergillus Species by Facilitating Drug Delivery to Germinating Hyphae

    Science.gov (United States)

    Ioannou, Petros; Andrianaki, Aggeliki; Akoumianaki, Tonia; Kyrmizi, Irene; Albert, Nathaniel; Perlin, David; Samonis, George

    2015-01-01

    The modest in vitro activity of echinocandins against Aspergillus implies that host-related factors augment the action of these antifungal agents in vivo. We found that, in contrast to the other antifungal agents (voriconazole, amphotericin B) tested, caspofungin exhibited a profound increase in activity against various Aspergillus species under conditions of cell culture growth, as evidenced by a ≥4-fold decrease in minimum effective concentrations (MECs) (P = 0. 0005). Importantly, the enhanced activity of caspofungin against Aspergillus spp. under cell culture conditions was strictly dependent on serum albumin and was not observed with the other two echinocandins, micafungin and anidulafungin. Of interest, fluorescently labeled albumin bound preferentially on the surface of germinating Aspergillus hyphae, and this interaction was further enhanced upon treatment with caspofungin. In addition, supplementation of cell culture medium with albumin resulted in a significant, 5-fold increase in association of fluorescently labeled caspofungin with Aspergillus hyphae (P Aspergillus hyphae. PMID:26643329

  19. (+)-Geodin from Aspergillus terreus

    DEFF Research Database (Denmark)

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

    2011-01-01

    The fungal metabolite (+)-geodin [systematic name: (2R)-methyl 5,7-dichloro-4-hydroxy-6'-methoxy-6-methyl-3,4'-dioxospiro[benzofuran-2,1'-cyclohexa-2',5'-diene]-2'-carboxylate], C(17)H(12)Cl(2)O(7), was isolated from Aspergillus terreus. The crystal structure contains two independent molecules...

  20. D-Galactose uptake is nonfunctional in the conidiospores of Aspergillus niger

    NARCIS (Netherlands)

    Fekete, E.; de Vries, R.P.; Seiboth, B.; vanKuyk, P.A.; Sandor, E.; Metz, B.; Kubicek, C.P.; Karaffa, L.

    2012-01-01

    The majority of black Aspergilli (Aspergillus section Nigri), including Aspergillus niger, as well as many other Ascomycetes fail to germinate on d-galactose as a sole carbon source. Here, we provide evidence that the ability of A. niger to transport d-galactose is growth stage dependent, being

  1. 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...

  2. 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.

  3. Fungi in cake production chain: Occurrence and evaluation of growth potential in different cake formulations during storage.

    Science.gov (United States)

    Morassi, Letícia L P; Bernardi, Angélica O; Amaral, Alexandra L P M; Chaves, Rafael D; Santos, Juliana L P; Copetti, Marina V; Sant'Ana, Anderson S

    2018-04-01

    This study aimed to determine the prevalence and populations of fungi in cake production chain. Besides, the growth potential of twelve fungal strains in different cake formulations was evaluated. Raw materials from two different batches (n=143), chocolate cakes (n=30), orange cakes (n=20), and processing environment air samples (n=147) were analyzed. Among the raw materials, wheat flour (3.2±0.3 log CFU per g) and corn meal (3.8±0.8 log CFU per g) belonging to batch #1 showed significant higher fungal counts (pcakes were Aspergillus flavus (28.15%), Penicillium citrinum (18.45%), Penicillium paxilli (14.56%), and Aspergillus niger (6.8%), which were also detected in the raw materials and processing environment air. Only Penicillium glabrum and Penicillium citrinum showed visible mycelium (>3mm) in the free of preservative cake formulation at 19th and 44th days of storage at 25°C, respectively. Revealing the biodiversity of fungi in ingredients, air and final products, as well as challenging final products with representative fungal strains may assist to implement effective controlling measures as well as to gather data for the development of more robust cake formulations. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Jiujiang Yu

    2011-08-01

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

  5. The effectiveness of arbuscular-mycorrhizal fungi and Aspergillus niger or Phanerochaete chrysosporium treated organic amendments from olive residues upon plant growth in a semi-arid degraded soil.

    Science.gov (United States)

    Medina, A; Roldán, A; Azcón, R

    2010-12-01

    Arbuscular mycorrhizal (AM) fungi and a residue from dry olive cake (DOC) supplemented with rock phosphate (RP) and treated with either Aspergillus niger (DOC-A) or Phanerochaete chrysosporium (DOC-P), were assayed in a natural, semi-arid soil using Trifolium repens or Dorycnium pentaphyllum plants. The effects of the AM fungi and/or DOC-A were compared with P-fertilisation (P) over eleven successive harvests to evaluate the persistence of the effectiveness of the treatments. The biomass of dually-treated plants after four successive harvests was greater than that obtained for non-treated plants or those receiving the AM inoculum or DOC-A treatments after eleven yields. The AM inoculation was critical for obtaining plant growth benefit from the application of fermented DOC-A residue. The abilities of the treatments to prevent plant drought stress were also assayed. Drought-alleviating effects were evaluated in terms of plant growth, proline and total sugars concentration under alternative drought and re-watering conditions (8th and 9th harvests). The concentrations of both compounds in plant biomass increased under drought when DOC-A amendment and AM inoculation were employed together: they reinforced the plant drought-avoidance capabilities and anti-oxidative defence. Water stress was less compensated in P-fertilised than in DOC-A-treated plants. DOC-P increased D. pentaphyllum biomass, shoot P content, nodule number and AM colonisation, indicating the greater DOC-transforming ability of P. chrysosporium compared to A. niger. The lack of AM colonisation and nodulation in this soil was compensated by the application of DOC-P, particularly with AM inoculum. The management of natural resources (organic amendments and soil microorganisms) represents an important strategy that assured the growth, nutrition and plant establishment in arid, degraded soils, preventing the damage that arises from limited water and nutrient supply. Copyright © 2010 Elsevier Ltd. All rights

  6. Proteomics as a Tool to Identify New Targets Against Aspergillus and Scedosporium in the Context of Cystic Fibrosis.

    Science.gov (United States)

    Ramirez-Garcia, Andoni; Pellon, Aize; Buldain, Idoia; Antoran, Aitziber; Arbizu-Delgado, Aitana; Guruceaga, Xabier; Rementeria, Aitor; Hernando, Fernando L

    2018-02-01

    Cystic fibrosis (CF) is a genetic disorder that increases the risk of suffering microbial, including fungal, infections. In this paper, proteomics-based information was collated relating to secreted and cell wall proteins with potential medical applications from the most common filamentous fungi in CF, i.e., Aspergillus and Scedosporium/Lomentospora species. Among the Aspergillus fumigatus secreted allergens, β-1,3-endoglucanase, the alkaline protease 1 (Alp1/oryzin), Asp f 2, Asp f 13/15, chitinase, chitosanase, dipeptidyl-peptidase V (DppV), the metalloprotease Asp f 5, mitogillin/Asp f 1, and thioredoxin reductase receive a special mention. In addition, the antigens β-glucosidase 1, catalase, glucan endo-1,3-β-glucosidase EglC, β-1,3-glucanosyltransferases Gel1 and Gel2, and glutaminase A were also identified in secretomes of other Aspergillus species associated with CF: Aspergillus flavus, Aspergillus niger, Aspergillus nidulans, and Aspergillus terreus. Regarding cell wall proteins, cytochrome P450 and eEF-3 were proposed as diagnostic targets, and alkaline protease 2 (Alp2), Asp f 3 (putative peroxiredoxin pmp20), probable glycosidases Asp f 9/Crf1 and Crf2, GPI-anchored protein Ecm33, β-1,3-glucanosyltransferase Gel4, conidial hydrophobin Hyp1/RodA, and secreted aspartyl protease Pep2 as protective vaccines in A. fumigatus. On the other hand, for Scedosporium/Lomentospora species, the heat shock protein Hsp70 stands out as a relevant secreted and cell wall antigen. Additionally, the secreted aspartyl proteinase and an ortholog of Asp f 13, as well as the cell wall endo-1,3-β-D-glucosidase and 1,3-β-glucanosyl transferase, were also found to be significant proteins. In conclusion, proteins mentioned in this review may be promising candidates for developing innovative diagnostic and therapeutic tools for fungal infections in CF patients.

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

    Science.gov (United States)

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

    2017-06-01

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

  8. Chemodiversity in the genus Aspergillus

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Larsen, Thomas Ostenfeld

    2015-01-01

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

  9. Biomarkers of Aspergillus spores

    Science.gov (United States)

    Sulc, Miroslav; Peslova, Katerina; Zabka, Martin; Hajduch, Marian; Havlicek, Vladimir

    2009-02-01

    We applied both matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometric and 1D sodium dodecylsulfate polyacrylamide gel electrophoretic (1D-PAGE) approaches for direct analysis of intact fungal spores of twenty four Aspergillus species. In parallel, we optimized various protocols for protein extraction from Aspergillus spores using acidic conditions, step organic gradient and variable sonication treatment. The MALDI-TOF mass spectra obtained from optimally prepared samples provided a reproducible fingerprint demonstrating the capability of the MALDI-TOF approach to type and characterize different fungal strains within the Aspergillus genus. Mass spectra of intact fungal spores provided signals mostly below 20 kDa. The minimum material amount represented 0.3 [mu]g (10,000 spores). Proteins with higher molecular weight were detected by 1D-PAGEE Eleven proteins were identified from three selected strains in the range 5-25 kDa by the proteomic approach. Hemolysin and hydrophobin have the highest relevance in host-pathogen interactions.

  10. Effect of simulated microgravity on Aspergillus niger

    Science.gov (United States)

    Pratap, Jeffrey J.

    2005-08-01

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

  11. 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.

  12. 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...

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

    Science.gov (United States)

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

    2017-04-01

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

  14. Discrimination of Aspergillus isolates at the species and strain level by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry fingerprinting.

    Science.gov (United States)

    Hettick, Justin M; Green, Brett J; Buskirk, Amanda D; Kashon, Michael L; Slaven, James E; Janotka, Erika; Blachere, Francoise M; Schmechel, Detlef; Beezhold, Donald H

    2008-09-15

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to generate highly reproducible mass spectral fingerprints for 12 species of fungi of the genus Aspergillus and 5 different strains of Aspergillus flavus. Prior to MALDI-TOF MS analysis, the fungi were subjected to three 1-min bead beating cycles in an acetonitrile/trifluoroacetic acid solvent. The mass spectra contain abundant peaks in the range of 5 to 20kDa and may be used to discriminate between species unambiguously. A discriminant analysis using all peaks from the MALDI-TOF MS data yielded error rates for classification of 0 and 18.75% for resubstitution and cross-validation methods, respectively. If a subset of 28 significant peaks is chosen, resubstitution and cross-validation error rates are 0%. Discriminant analysis of the MALDI-TOF MS data for 5 strains of A. flavus using all peaks yielded error rates for classification of 0 and 5% for resubstitution and cross-validation methods, respectively. These data indicate that MALDI-TOF MS data may be used for unambiguous identification of members of the genus Aspergillus at both the species and strain levels.

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

    Science.gov (United States)

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

    2016-12-01

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

  16. 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.

  17. Contaminação do ar por Aspergillus em ambiente de reabilitação de animais marinhos

    Directory of Open Access Journals (Sweden)

    Melissa Orzechowski Xavier

    2008-06-01

    Full Text Available Aspergillosis in captivity seabirds is often associated with elevated rates of mortality. The infection is usually acquired by inhalation of airborne fungal conidia. The aim of this study was to evaluate the presence of Aspergillus species in the indoor environment of a rehabilitation centre for marine animals in Southern Brazil. This centre continuously receives injured penguins, seagulls, albatrosses and petrels. Petri dishes plates with Agar Sabouraud dextrose and chloramphenicol were left open for 15 minutes in 3 distinct points in the rehabilitation centre and then incubated at 25ºC. During a period of two years the indoor air was sampled in 81 occasions. A total of 43 isolates belonging to 7 different Aspergillus species were recovered. Aspegillus fumigatus was the predominant species (27.9%, followed by A. niger (25.6%, and A. flavus (16.3%. Four other Aspergillus species were isolated. This study demonstrates that seabirds were exposed to pathogenic Aspergillus species in our rehabilitation centre, reinforcing the need for a strict microbiology control of the indoor air in the captivity environment.

  18. Identification of morphological and molecular Aspergillus species isolated from patients based on beta-tubulin gene sequencing

    Directory of Open Access Journals (Sweden)

    Mahnaz Kheirkhah

    2017-06-01

    Full Text Available Background: Aspergillus species are opportunistic pathogens among immunocompromised patients. In terms of pathogenesis and mycotoxin production, they are in great value. The aim of the this study was to evaluate of beta-tubulin gene for identification of clinical Aspergillus species by PCR-sequencing method compared to morphological features of clinical isolates (such as conidial shape in direct microscopic examination, colony shape in culture, and physiological tests. Materials and Methods: In this study, 465 patients referred to the Shefa laboratory of Isfahan were evaluated. Morphological and molecular identification of clinical samples were performed using culture on sabouraud agar, malt extract agar, czapekdox agar, direct microscopy, and PCR-sequencing of beta tubulin gene, respectively. Sequences were analyzed in comparison with gene bank data. Results: Thirty nine out of 465 suspected cases (8.4% had aspergillosis. The most prevalent species were Aspergillus flavus (56.4%, A. oryzae (20.5%, and A. fumigatus (10.2%, respectively. Fifty nine percent of patients were females and 49% were males. Conclusion: In comparison with phenotypic tests, sequencing of beta-tubulin gene for identification of Aspergillus species is at great value. Replacement of molecular techniques with conventional tests is recommended for precise identification of microorganism for better management of infection.

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

    OpenAIRE

    DHANASEKARAN, Dharumadurai; PANNEERSELVAM, Annamalai; THAJUDDIN, Noorudin

    2014-01-01

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

  20. Albumin Enhances Caspofungin Activity against Aspergillus Species by Facilitating Drug Delivery to Germinating Hyphae.

    Science.gov (United States)

    Ioannou, Petros; Andrianaki, Aggeliki; Akoumianaki, Tonia; Kyrmizi, Irene; Albert, Nathaniel; Perlin, David; Samonis, George; Kontoyiannis, Dimitrios P; Chamilos, Georgios

    2015-12-07

    The modest in vitro activity of echinocandins against Aspergillus implies that host-related factors augment the action of these antifungal agents in vivo. We found that, in contrast to the other antifungal agents (voriconazole, amphotericin B) tested, caspofungin exhibited a profound increase in activity against various Aspergillus species under conditions of cell culture growth, as evidenced by a ≥4-fold decrease in minimum effective concentrations (MECs) (P = 0. 0005). Importantly, the enhanced activity of caspofungin against Aspergillus spp. under cell culture conditions was strictly dependent on serum albumin and was not observed with the other two echinocandins, micafungin and anidulafungin. Of interest, fluorescently labeled albumin bound preferentially on the surface of germinating Aspergillus hyphae, and this interaction was further enhanced upon treatment with caspofungin. In addition, supplementation of cell culture medium with albumin resulted in a significant, 5-fold increase in association of fluorescently labeled caspofungin with Aspergillus hyphae (P hyphae. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  1. Application of Aspergillus niger-treated agrowaste residue and Glomus mosseae for improving growth and nutrition of Trifolium repens in a Cd-contaminated soil.

    Science.gov (United States)

    Medina, A; Vassilev, N; Barea, J M; Azcón, R

    2005-04-06

    The microbial transformation of sugar beet (SB) agrowaste with or without rock-phosphate (RP) has utility for the improvement of plant growth in a Cd (5 microg g-1) artificially contaminated soil, particularly when the soil is co-inoculated with arbuscular mycorrhizal (AM) fungus Glomus mosseae isolated from a Cd-polluted area. Under such Cd-polluted conditions, the limited growth, mineral nutrition, symbiotic developments (nodulation and AM-colonization) and soil enzymatic activities were stimulated using SB or SB+RP as soil amendments and G. mosseae as inoculant. G. mosseae enhanced plant establishment in a higher extent in amended soil; it is probably due to the interactive effect increasing the potential fertility of such compounds and its ability for decreasing Cd transfer from soil to plant. The amount of Cd transferred from soil solution to biomass of AM-colonized plants ranged from 0.09 microg Cd g-1 (in SB+RP-amended soil) to 0.6 microg Cd g-1 (in non-amended soil). Nodule formation was more sensitive to Cd than AM-colonization, and both symbioses were stimulated in amended soils. Not only AM-colonization but also amendments were critical for plant growth and nutrition in Cd-polluted soil. The high effectiveness of AM inoculum increasing nutrients and decreasing Cd in amended soil indicated the positive interaction of these treatments in increasing plant tolerance to Cd contamination.

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

    Science.gov (United States)

    Verweij, Paul E.

    2016-01-01

    Aspergillus fungi are the cause of an array of diseases affecting humans, animals and plants. The triazole antifungal agents itraconazole, voriconazole, isavuconazole and posaconazole are treatment options against diseases caused by Aspergillus. However, resistance to azoles has recently emerged as a new therapeutic challenge in six continents. Although de novo azole resistance occurs occasionally in patients during azole therapy, the main burden is the aquisition of resistance through the environment. In this setting, the evolution of resistance is attributed to the widespread use of azole-based fungicides. Although ubiquitously distributed, A. fumigatus is not a phytopathogen. However, agricultural fungicides deployed against plant pathogenic moulds such as Fusarium, Mycospaerella and A. flavus also show activity against A. fumigatus in the environment and exposure of non-target fungi is inevitable. Further, similarity in molecule structure between azole fungicides and antifungal drugs results in cross-resistance of A. fumigatus to medical azoles. Clinical studies have shown that two-thirds of patients with azole-resistant infections had no previous history of azole therapy and high mortality rates between 50% and 100% are reported in azole-resistant invasive aspergillosis. The resistance phenotype is associated with key mutations in the cyp51A gene, including TR34/L98H, TR53 and TR46/Y121F/T289A resistance mechanisms. Early detection of resistance is of paramount importance and if demonstrated, either with susceptibility testing or through molecular analysis, azole monotherapy should be avoided. Liposomal amphotericin B or a combination of voriconazole and an echinocandin are recomended for azole-resistant aspergillosis. This article is part of the themed issue ‘Tackling emerging fungal threats to animal health, food security and ecosystem resilience’. PMID:28080986

  3. 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)....

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

    OpenAIRE

    Moreira, Fabiana G.; Lenartovicz, Veridiana; Souza, Cristina G.M. de; Ramos, Edivan P.; Peralta, Rosane M.

    2001-01-01

    The use of a methyl-D-glucoside (alphaMG), a synthetic analogue of maltose, as carbon source and inducer of amylase synthesis to several species of Aspergillus was studied in submerged and solid-state fermentations. Among a group of ten species, A. tamarii, A. fumigatus and A. flavus were able to produce biomass and high specific amylolytic activity in submerged cultures containing alphaMG as the only carbon source. In solid state fermentation, the enrichment of basal wheat bran or corn cob m...

  5. Identification and analysis of Ku70 and Ku80 homologs in the koji molds Aspergillus sojae and Aspergillus oryzae.

    Science.gov (United States)

    Takahashi, Tadashi; Masuda, Tsutomu; Koyama, Yasuji

    2006-01-01

    Ku genes play a key role in the non-homologous end-joining pathway. We have identified Ku70 and Ku80 homologs in the koji molds Aspergillus sojae and Aspergillus oryzae, and have constructed the disruption mutants of Ku70, Ku80, and Ku70-80 to characterize the phenotypic change in these mutants. Neither Ku70- nor Ku80-disrupted strains show hypersensitivity to the DNA damaging agents methylmethane sulfonate (MMS) and phleomycin. Moreover, undesirable phenotypes, such as poor growth or repressed conidiospore formation, were not observed in the Ku-disrupted A. sojae and A. oryzae.

  6. Evaluation of the Bruker Biotyper Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry System for Identification of Aspergillus Species Directly from Growth on Solid Agar Media

    Directory of Open Access Journals (Sweden)

    Ying Li

    2017-06-01

    Full Text Available We evaluated the accuracy of the Bruker Biotyper matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS system at identifying clinical isolates of Aspergillus species that were grown on agar media. A total of 381 non-duplicate Aspergillus isolates representing 21 different Aspergillus species identified by molecular analysis were included in this study. The Bruker Biotyper MALDI-TOF MS system was able to identify 30.2% (115/381 of the isolates to the species level (score values of ≥2.000 and 49.3% to the genus level (score values of 1.700–1.999. When the identification cutoff value was lowered from ≥2.000 to ≥1.700, the species-level identification rate increased to 79.5% with a slight rise of false identification from 2.6 to 5.0%. From another aspect, a correct species-level identification rate of 89% could be reached by the Bruker Biotyper MALDI-TOF MS system regardless of the score values obtained. The Bruker Biotyper MALDI-TOF MS system had a moderate performance in identification of Aspergillus directly inoculated on solid agar media. Continued expansion of the Bruker Biotyper MALDI-TOF MS database and adoption of alternative cutoff values for interpretation are required to improve the performance of the system for identifying highly diverse species of clinically encountered Aspergillus isolates.

  7. Evaluation of the Bruker Biotyper Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry System for Identification of Aspergillus Species Directly from Growth on Solid Agar Media.

    Science.gov (United States)

    Li, Ying; Wang, He; Zhao, Yu-Pei; Xu, Ying-Chun; Hsueh, Po-Ren

    2017-01-01

    We evaluated the accuracy of the Bruker Biotyper matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) system at identifying clinical isolates of Aspergillus species that were grown on agar media. A total of 381 non-duplicate Aspergillus isolates representing 21 different Aspergillus species identified by molecular analysis were included in this study. The Bruker Biotyper MALDI-TOF MS system was able to identify 30.2% (115/381) of the isolates to the species level (score values of ≥2.000) and 49.3% to the genus level (score values of 1.700-1.999). When the identification cutoff value was lowered from ≥2.000 to ≥1.700, the species-level identification rate increased to 79.5% with a slight rise of false identification from 2.6 to 5.0%. From another aspect, a correct species-level identification rate of 89% could be reached by the Bruker Biotyper MALDI-TOF MS system regardless of the score values obtained. The Bruker Biotyper MALDI-TOF MS system had a moderate performance in identification of Aspergillus directly inoculated on solid agar media. Continued expansion of the Bruker Biotyper MALDI-TOF MS database and adoption of alternative cutoff values for interpretation are required to improve the performance of the system for identifying highly diverse species of clinically encountered Aspergillus isolates.

  8. Previously unknown species of Aspergillus.

    Science.gov (United States)

    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

  9. Deletion of creB in Aspergillus oryzae increases secreted hydrolytic enzyme activity.

    Science.gov (United States)

    Hunter, A J; Morris, T A; Jin, B; Saint, C P; Kelly, J M

    2013-09-01

    Aspergillus oryzae has been used in the food and beverage industry for centuries, and industrial strains have been produced by multiple rounds of selection. Targeted gene deletion technology is particularly useful for strain improvement in such strains, particularly when they do not have a well-characterized meiotic cycle. Phenotypes of an Aspergillus nidulans strain null for the CreB deubiquitinating enzyme include effects on growth and repression, including increased activity levels of various enzymes. We show that Aspergillus oryzae contains a functional homologue of the CreB deubiquitinating enzyme and that a null strain shows increased activity levels of industrially important secreted enzymes, including cellulases, xylanases, amylases, and proteases, as well as alleviated inhibition of spore germination on glucose medium. Reverse transcription-quantitative PCR (RT-qPCR) analysis showed that the increased levels of enzyme activity in both Aspergillus nidulans and Aspergillus oryzae are mirrored at the transcript level, indicating transcriptional regulation. We report that Aspergillus oryzae DAR3699, originally isolated from soy fermentation, has a similar phenotype to that of a creB deletion mutant of the RIB40 strain, and it contains a mutation in the creB gene. Collectively, the results for Aspergillus oryzae, Aspergillus nidulans, Trichoderma reesei, and Penicillium decumbens show that deletion of creB may be broadly useful in diverse fungi for increasing production of a variety of enzymes.

  10. 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®

  11. Epidemiological and Genomic Landscape of Azole Resistance Mechanisms in Aspergillus Fungi

    Science.gov (United States)

    Hagiwara, Daisuke; Watanabe, Akira; Kamei, Katsuhiko; Goldman, Gustavo H.

    2016-01-01

    Invasive aspergillosis is a life-threatening mycosis caused by the pathogenic fungus Aspergillus. The predominant causal species is Aspergillus fumigatus, and azole drugs are the treatment of choice. Azole drugs approved for clinical use include itraconazole, voriconazole, posaconazole, and the recently added isavuconazole. However, epidemiological research has indicated that the prevalence of azole-resistant A. fumigatus isolates has increased significantly over the last decade. What is worse is that azole-resistant strains are likely to have emerged not only in response to long-term drug treatment but also because of exposure to azole fungicides in the environment. Resistance mechanisms include amino acid substitutions in the target Cyp51A protein, tandem repeat sequence insertions at the cyp51A promoter, and overexpression of the ABC transporter Cdr1B. Environmental azole-resistant strains harboring the association of a tandem repeat sequence and punctual mutation of the Cyp51A gene (TR34/L98H and TR46/Y121F/T289A) have become widely disseminated across the world within a short time period. The epidemiological data also suggests that the number of Aspergillus spp. other than A. fumigatus isolated has risen. Some non-fumigatus species intrinsically show low susceptibility to azole drugs, imposing the need for accurate identification, and drug susceptibility testing in most clinical cases. Currently, our knowledge of azole resistance mechanisms in non-fumigatus Aspergillus species such as A. flavus, A. niger, A. tubingensis, A. terreus, A. fischeri, A. lentulus, A. udagawae, and A. calidoustus is limited. In this review, we present recent advances in our understanding of azole resistance mechanisms particularly in A. fumigatus. We then provide an overview of the genome sequences of non-fumigatus species, focusing on the proteins related to azole resistance mechanisms. PMID:27708619

  12. Efficiency of four currently used decontamination conditionings in Romania against Aspergillus and Candida strains.

    Science.gov (United States)

    Lorin, D; Cristina, R T; Teusdea, V; Mitrănescu, E; Muselin, F; Butnariu, M; David, G; Dumitrescu, E

    2017-09-01

    Efficacy of four commercial biocidal products (noted A to D), using manufacturers' recommendations, and a contact time of 30minutes, were evaluated in the purpose of standard SR EN1657: 2006 adapted. Were used four strains, two as reference: Aspergillus brasiliensis (niger) (ATCC 16404) and Candida albicans (ATCC 10231), and two isolates: Aspergillus flavus and respectively Aspergillus fumigatus. The inoculum plates containing Malt Extract Agar (MEA) were incubated 48h for C. albicans and 72hours for Aspergillus spp. The standard SR EN1657: 2006 adapted was conducted in two phases: the test cultures preparation and the method validation. Method validation included: the control of experimental conditions and of neutralizant solution, and the method verification. Results revealed that three from the four tested products (A, B and D) had exerted biocidal effect on the studied strains at the recommended concentrations, the registered CFU values being reduced by more than 4 log 10 , conversely in the case of the product (C), applied against A. fumigatus at the recommended concentration of 2%, the biocidal effect was not detected, fact confirmed also by the CFU's value (3.59 log 10 ). The biocide retested at a greater concentration (of 5%), showed a biocidal effect against A. fumigatus after 30minutes, the CFU value being reduced, by more than 5.29 log 10 , evidencing the resistance emergence of A. fumigatus under the repeated pressure of biocides. It is re-confirming that merely the "chemical" defense measures to defuse the fungi's strategies become unproductive. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

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

    Science.gov (United States)

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

    2013-01-15

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

  14. History of treated pulmonary tuberculosis will also be an underlying symptom of opportunistic aspergillosis by Aspergillus flavus: A case report

    Directory of Open Access Journals (Sweden)

    Akbar Hossein Nejad

    2015-01-01

    Conclusion: The importance of tuberculosis (TB in the development of aspergillosis, even after treatment, has been highlighted by multiple studies. Microbiological and molecular evaluation are needed to detect PA quickly and accurately. The WHO reported about 8.8 million new cases of TB in 2010. Therefore, it is essential to focus more on monitoring of diagnosis and treatment of PA.

  15. 77 FR 14287 - Aspergillus flavus AF36; Amendment to an Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2012-03-09

    ... to in such systems or facilities, including chlorination, pH adjustments, and filtration (Refs. 6 and... Mandates Reform Act of 1995 (UMRA) (Pub. L. 104-4). This action does not involve any technical standards...

  16. Aspergillus fumigatus in Poultry

    Directory of Open Access Journals (Sweden)

    Pascal Arné

    2011-01-01

    Full Text Available Aspergillus fumigatus remains a major respiratory pathogen in birds. In poultry, infection by A. fumigatus may induce significant economic losses particularly in turkey production. A. fumigatus develops and sporulates easily in poor quality bedding or contaminated feedstuffs in indoor farm environments. Inadequate ventilation and dusty conditions increase the risk of bird exposure to aerosolized spores. Acute cases are seen in young animals following inhalation of spores, causing high morbidity and mortality. The chronic form affects older birds and looks more sporadic. The respiratory tract is the primary site of A. fumigatus development leading to severe respiratory distress and associated granulomatous airsacculitis and pneumonia. Treatments for infected poultry are nonexistent; therefore, prevention is the only way to protect poultry. Development of avian models of aspergillosis may improve our understanding of its pathogenesis, which remains poorly understood.

  17. Aspergillus terreus endogenous endophthalmitis: Report of a case and review of literature

    Directory of Open Access Journals (Sweden)

    Pradeep Kumar Panigrahi

    2014-01-01

    Full Text Available We report a rare case of Aspergillus terreus endogenous endophthalmitis in an immunocompetent patient with subretinal abscess and also review the reported cases. A 50-year-old healthy male presented with sudden painful loss of vision in right eye. He was diagnosed with endogenous endophthalmitis and underwent urgent vitrectomy. Aspergillus terreus growth was obtained in culture. At final follow-up, there was complete resolution of the infection but visual acuity was poor due to macular scar. Aspergillus terreus is a rare cause of endophthalmitis with usually poor outcomes. Newer antifungals like Voriconazole can be sometimes associated with better prognosis.

  18. Application of a modified culture medium for the simultaneous counting of molds and yeasts and detection of aflatoxigenic strains of Aspergillus flavus and Aspergillus parasiticus.

    Science.gov (United States)

    Jaimez, J; Fente, C A; Franco, C M; Cepeda, A; Vázquez, B I

    2003-02-01

    Molds and yeasts from 91 samples of feed and raw materials used in feed formulation were enumerated on a new culture medium to which a beta cyclodextrin (beta-W7M 1.8-cyclodextrin) had been added. This medium was compared with other media normally used in laboratories for the routine analysis of fungi, such as Sabouraud agar, malt agar supplemented with 2% dextrose, and potato dextrose agar. When a t test for paired data (0.05 significance level, 95% confidence interval) was applied, no statistically significant differences between the results obtained with the new culture medium and those obtained with the other media used to enumerate molds and yeasts were found. For the evaluation of contamination due to aflatoxin for all of the samples, Sabouraud agar and yeast extract agar, both supplemented with 0.3% beta-W7M 1.8-cyclodextrin, and APA (aflatoxin-producing ability) medium were used. Aflatoxin was detected in 21% of the feed samples and in 23% of the raw-material samples analyzed, with maximal amounts of 2.8 and 6.0 microg of aflatoxin B1 per kg, respectively, being detected. In any case, the aflatoxin contents found exceeded the legally stipulated limits. The t test for paired data (0.05 significance level, 95% confidence interval) did not show statistically significant differences between the results obtained with the different culture media used for the detection of aflatoxins. The advantage of the new medium developed (Sabouraud agar with 0.3% beta-W7M 1.8-cyclodextrin) is that it allows simultaneous fungal enumeration and determination (under UV light) of the presence of aflatoxin-producing strains without prior isolation and culture procedures involving expensive and/or complex specific media and thus saves work, time, and money.

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

    Science.gov (United States)

    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.

  20. 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.