Search results for "USA"
showing 10 items of 3178 documents
Isolation, purification, LC–MS/MS characterization and reactive oxygen species induced by fumonisin B1 in VERO cells
2010
Fumonisins are mycotoxins produced by Fusarium verticillioides that commonly contaminate maize and maize products. The present work shows the results of a comparative study of three different fermentation's techniques (solid and liquid medium of corn and a solid agarized medium) for the production of fumonisins B-1, B-2 and B-3 with strains of F. verticillioides. The solid medium of corn was the most effective in the production of fumonisins, being Fumonisin B-1 the one produced with higher concentration, so the extract obtained by solid fermentation process was used for FB1 purification. Fumonisins characterization and quantification were performed with reversed-phase high-performance liqu…
Production, purification, and mass spectrometry characterization of the cyclohexadepsipeptide enniatin J3and study of the cytoxicity on differentiate…
2011
The enniatins (EN) are bioactive compounds of hexadepsipeptidic structure produced by several strains of Fusarium spp. The enniatin J3 (EN J3) was purified from extracts of Fusarium solani growth on solid medium of kamut, using semipreparative liquid chromatography (LC) followed by an analytical LC. The purity and the structure of the isolated compound were confirmed by electrospray ionization-mass spectrometry study-linear ion trap (ESI-MS-LIT). The pure fraction of EN J3 was utilized to study the cytotoxicity on differentiated and undifferentiated Caco-2 cells. The use of both chromatographic techniques allowed us to produce and purify 50 mg of EN J3 completely characterized with the tech…
Identification and Quantification of Enniatins and Beauvericin in Animal Feeds and Their Ingredients by LC-QTRAP/MS/MS
2019
Emerging fusariotoxins, mainly enniatins (ENNs) and beauvericin (BEA), are secondary toxic metabolites produced by Fusarium spp. and are widely distributed contaminants of cereals and by-products. Mycotoxin contamination in these products supposes an important risk to feed supply security in the feed industry due to the common use of cereals in feed formulations. Hence, continuous monitoring of both raw materials and feed mixtures is highly recommended as stated by sanitary authorities. Therefore, an analytical procedure based on liquid chromatography tandem mass spectrometry and an acetonitrile-based extraction followed by a d-SPE (QuEChERS) step for the simultaneous determination of emerg…
Implications of cysteine metabolism in the heavy metal response in Trichoderma harzianum and in three Fusarium species
2009
We studied the ability of four different fungal species, Trichoderma harzianum, Fusarium antophyllum, Fusarium compactum and Fusarium phyllophilum, to grow in the presence of heavy metals, and monitored their cysteine and glutathione content and the activity of O-acetylserine(thiol)lyase (OASTL), which is involved in cysteine biosynthesis. Zn and Pb did not affect fungal growth or sporulation at the concentrations used, whereas Cd and Hg did. In most cases, cysteine and glutathione content was higher when fungi were grown in the presence of toxic metals. As T. harzianum and F. phyllophilum presented the best growth rate on Cd and Hg, they were selected to further analyse the accumulation of…
Interactions between glyphosate and autochthonous soil fungi surviving in aqueous solution of glyphosate
2007
The survival of autochthonous fungi in soil treated with 1mM aqueous solution of glyphosate was investigated. Significant differences in the total number of fungi in the studied objects were observed, and additionally significant qualitative changes were encountered. The dominating group of fungi belonged to genus Fusarium: Fusarium solani H30, Fusarium solani H50 and Fusarium oxysporum H80. Interactions between the isolated strains of fungi and varying concentrations of glyphosate were determined. The studied strains possessed high tolerance against the applied doses of glyphosate (0.5-2.0 mM). In the presence of glyphosate (as a sole source of phosphorus) applied in concentrations of 1.0-…
The use of glyphosate as the sole source of phosphorus or carbon for the selection of soil-borne fungal strains capable to degrade this herbicide
1997
Abstract The herbicide glyphosate was used as a selection agent for isolation of fungal strains capable to degrade phosphorus-to-carbon bond from standard sandy-clay soil. The studies have shown that the herbicide used in Martin medium as a sole source of phosphorus br carbon caused the decrease of the fungal population and substantially changed strain composition, thus selecting those which are able to degrade glyphosate.
Emerging Fusarium mycotoxins in organic and conventional pasta collected in Spain
2012
Abstract One of the main sources of emerging Fusarium mycotoxins in human nutrition is the cereals and cereal products. In this study, an analytical method to determine enniatins A, A1, B and B1 (ENs), beauvericin (BEA) and fusaproliferin (FUS) based on Ultra-Turrax extraction followed by liquid chromatography coupled to triple quadrupole mass spectrometer detector (MS/MS QqQ), was applied for the analysis of pasta. For this purpose, 114 commercial samples of pasta were acquired from supermarkets located in Valencia. The results showed higher frequencies of contamination in organic pasta than in conventional pasta, while the concentration levels were variable for both types of pasta. In pos…
First study on trichothecene and zearalenone exposure of the Romanian population through wheat-based products consumption
2018
Abstract In this study, a dietary exposure assessment of mycotoxins was conducted for the Romanian population using the contamination data of a various categories of wheat-based products for direct human consumption. Wheat-based foods (n = 181) commercialized in Romania, including flour, bread, biscuits, breakfast cereals and pasta, were evaluated by GC-QqQ-MS/MS for the occurrence of deoxynivalenol (DON), 3-acetyldeoxynivalenol (3AcDON), 15-acetyldeoxynivalenol (15AcDON), fusarenon-X, nivalenol, HT-2 and T-2 toxins, diacetoxyscirpenol, neosolaniol and zearalenone (ZEA). DON and 15AcDON were detected in 63 and 5% of all the analyzed samples, whereas 13-AcDON, HT-2, T-2, NIV and ZEA were not…
Evaluation of gaseous allyl isothiocyanate against the growth of mycotoxigenic fungi and mycotoxin production in corn stored for 6 months
2018
Brazil produces approximately 63 million tons of corn kernels annually, which is commonly contaminated with fungi and mycotoxins. The objective of this study was to evaluate the efficacy of gaseous allyl isothiocyanate (AITC) to inhibit the growth of Aspergillus parasiticus and Fusarium verticillioides, and mycotoxin production (aflatoxins B1 , B2 , G1 and G2 , fumonisins B1 and B2 ) in corn during 180 days of storage.; Results: AITC at 50 µL L-1 resulted in a significant reduction of the fungal population (P < 0.05) after 180 days, decreasing 3.17 log(CFU g-1 ) and 3.9 log(CFU g-1 ) of A. parasiticus and F. verticillioides respectively in comparison with the control. In addition, 10 and 50…
Trichothecenes and fumonisins produced in autoclaved tiger nuts by strains of Fusarium sporotrichioides andFusarium moniliforme
2000
This work describes for the first time the production of trichothecenes and fumonisins in autoclaved tiger nuts by strains of Fusarium sporotrichioides and F. moniliforme respectively. The study was carried out using a high performance liquid chromatograph with fluorescence detector. The results obtained show that the strains studied are capable of producing these mycotoxins in tiger nuts and that the concentrations of toxin found depend on the variety of tiger nut used as substrate. The amount of type A trichothecenes produced in tiger nuts by the different strains of F. sporotrichioides is smaller than that produced by the same strains in other substrates. However, the strains of F. monil…