Lack of aflatoxin production by Aspergillus flavus is associated with reduced fungal growth and delayed expression of aflatoxin pathway genes
Aflatoxins, produced by Aspergillus flavus and Aspergillus parasiticus, are the most toxic fungal secondary metabolites that contaminate agricultural commodities such as peanuts, cotton and maize. Understanding the underlying mechanisms of crop resistance to fungal infection is an important step for plant breeders to develop better and improved crop varieties for safe production of human food and animal feed. Infection studies have identified a resistant (R) peanut line, GT-C20, which is able to decrease aflatoxin contamination. The mycelial growth of A. flavus NRRL3357 on the R peanut line was much lower than that on the ...
Source: World Mycotoxin Journal - November 12, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Determination of the amount of bioaccessible fumonisin B1 in different matrices after in vitro digestion
Conventional analytical methods used for the analysis of fumonisin content in animal feeds fail to take into account the fumonisin content bound to the matrix, which is otherwise bioaccessible and can be absorbed from the gastrointestinal tract. Moreover, underestimation of fumonisin content using routine analytical methods can affect animal experiments using cereals contaminated by fungi. In the present study, hidden fumonisin B1 was analysed in two cereal substrates (maize and wheat) which were inoculated with Fusarium verticillioides (MRC 826). The study compared a routine extraction procedure with an in vitro digestion...
Source: World Mycotoxin Journal - November 6, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
By-products of grain cleaning: an opportunity for rapid sampling and screening of wheat for mycotoxins
By-products of cereal grain cleaning were analysed for a number of mycotoxins. Deoxynivalenol (DON) was the most frequently detected in by-products from commercial-scale cleaning procedures (maximum 2.94 mg/kg), followed by zearalenone (ZEA; maximum 0.045 mg/kg) and ochratoxin A (OTA; maximum 0.019 mg/kg). These three mycotoxins were also the most frequently detected in four different fractions collected from wheat run through a dockage tester, a piece of equipment used in the Canadian inspection process to separate material other than grain from wheat. Concentrations of mycotoxins were highest in the ‘light dockage’ f...
Source: World Mycotoxin Journal - November 6, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Mycotoxins as antagonistic or supporting agents in the interaction between phytopathogenic Fusarium and Alternaria fungi
The role of mycotoxins in the microbial competition in an ecosystem or on the same host plant is still unclear. Therefore, a laboratory study was conducted to evaluate the influence of mycotoxins on growth and mycotoxin production of Fusarium and Alternaria fungi. Fusarium culmorum Fc13, Fusarium graminearum Fg23 and two Alternaria tenuissima isolates (At18 and At220) were incubated on wheat kernels supplemented with alternariol (AOH), tetramic acid derivates (TeA), deoxynivalenol (DON) and zearalenone (ZEA) in an in vitro test system. Fungal biomass was quantified by determining ergosterol content. Three Fusarium toxins (...
Source: World Mycotoxin Journal - October 1, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Heritability study of eGFP-transformed Aspergillus flavus strains
Field inoculation with non-aflatoxigenic Aspergillus flavus is a preferred method for pre-harvest biocontrol of aflatoxin contamination of maize, cottonseed, and groundnut. Rationale for using these A. flavus strains is that they (1) maintain persistent control of aflatoxigenic fungi in the field, and (2) are incapable of out-crossing. Trackable field-released biocontrol strains will be beneficial to study the movement and longevity of non-aflatoxigenic A. flavus strains. Incorporating a naturally-occurring compound such as enhanced green fluorescent protein (eGFP) into a biocontrol strain might allow observation of its be...
Source: World Mycotoxin Journal - October 1, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
The awareness about mycotoxin contamination of food and feed: a survey in the Flemish population
The objective of this quantitative survey (n=520) was to determine the awareness of the risks of mycotoxin contaminated food and feed throughout the Flemish population. The study highlighted gaps in food and feed safety knowledge regarding mould growth and consequently the presence of mycotoxins. Most people were aware of the negative effects of mould species in food or feed. Around 60% of the people picked out moulds as the producers of mycotoxins, but the majority did not have an idea about the toxicity of these toxins, especially towards plants. Respondents were also asked about possible food products where mould growth...
Source: World Mycotoxin Journal - October 1, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Solid-phase extraction using molecularly imprinted polymer for determination of ochratoxin A in human urine
A rapid, selective and reliable sample preparation technique employing solid-phase extraction (SPE) based on molecularly imprinted polymer (MIP) for the determination of ochratoxin A (OTA) in human urine was described. After sample adjustment to pH 2.5 with 0.1 M HCl, the urine sample was loaded onto the MIP-SPE column, and after a wash step, OTA was eluted for measurement by ultra-high performance liquid chromatography coupled with fluorescence detection. Key parameters which affected the MIP-SPE extraction efficiency were optimized as was the detection method. Under the optimised conditions, the limits of detection and q...
Source: World Mycotoxin Journal - October 1, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Simultaneous determination of zearalenone, deoxynivalenol and their metabolites in bovine urine as biomarkers of exposure
In conclusion, increased urine toxin concentrations may hint on toxin exposure through the diets and thus the mycotoxins ZEA and DON and their detected metabolites could be used as biomarkers of exposure.
Content Type Journal ArticleCategory Research-ArticlePages 1-12DOI 10.3920/WMJ2014.1745Authors
J. Winkler, Institute of Animal Nutrition, Friedrich-Loeffler-Institute (FLI), Federal Research Institute for Animal Health, Bundesallee 50, 38116 Braunschweig, GermanyS. Kersten, Institute of Animal Nutrition, Friedrich-Loeffler-Institute (FLI), Federal Research Institute for Animal Health, Bundesallee 50, 38116 Braunschweig...
Source: World Mycotoxin Journal - October 1, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Foreword: rapid methods for mycotoxin detection
Content Type Journal ArticleCategory ForewordPages 401-405DOI 10.3920/WMJ2014.x003
Journal World Mycotoxin JournalOnline ISSN 1875-0796Print ISSN 1875-0710
Journal Volume Volume 7
Journal Issue Volume 7, Number 4 / 2014 (Source: World Mycotoxin Journal)
Source: World Mycotoxin Journal - September 30, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Cross-reactivity of rapid immunochemical methods for mycotoxins detection towards metabolites and masked mycotoxins: the current state of knowledge
The cross-reactivity of antibodies employed within immunochemistry-based analytical methods may lead to overestimation of the results. Under certain conditions, specifically when controlling mycotoxin maximum limits serious problems can be encountered. Not only the structurally related mycotoxins, such as their masked (conjugated) forms, but also the unidentified matrix components are responsible for concentration overestimation of respective target analytes. The cross-reactivity phenomenon may also pose a risk of miss-interpretation of the proficiency tests results, when the assigned value becomes influenced by over-estim...
Source: World Mycotoxin Journal - September 30, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Recent advances in the rapid acoustic screening of deoxynivalenol in wheat grains
Deoxynivalenol (DON) is a natural and ubiquitous toxic metabolite produced by filamentous fungi of the genus Fusarium. Approximately one quarter of the world's food crops (mainly cereals) are affected by mycotoxins such as DON. A rapid and non-destructive method to evaluate the quality and safety of grains is therefore required to eliminate these toxins from the food chain. The first portable acoustic device that predicts the concentration of DON in cereal grains has been developed using a broadband capacitive ultrasonic transducer. An acoustic method was optimised for the rapid prediction of DON in wheat. To measure the p...
Source: World Mycotoxin Journal - September 30, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Inhibition of ochratoxin A production in Aspergillus carbonarius by hydroxycinnamic acids from grapes
This study sought to determine the potential of HCAs, such as caffeic, p-coumaric and ferulic acids, as antifungal natural compounds for the control of A. carbonarius growth and OTA production. The HCAs were tested at the increasing concentrations of 0.30, 0.65 and 1.10 mg/ml in minimal medium (MM) and grape juice. Germination of conidia was not affected in neither of the two media in presence of HCAs. At all the concentrations tested, OTA biosynthesis in MM was reduced and the dose effect was more evident for p-coumaric and ferulic acids; in grape juice the reduction trend was confirmed, and ferulic acid showed the highes...
Source: World Mycotoxin Journal - September 22, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Atoxigenic Aspergillus flavus biological control of aflatoxin contamination: what is the mechanism?
The term ‘competitive exclusion’ involving physical blockage of growth or access of the toxigenic strain to the seed target has been used to describe the mechanism of biological control of aflatoxin contamination. However, recent evidence suggests that a form of intraspecific aflatoxin inhibition requiring growth of the competing strains together during the infection process in such a way that hyphae physically interact or touch is the trigger for preventing induction of aflatoxin synthesis. This direct touch-based inhibition of aflatoxin synthesis is posited to be the mechanistic basis of biological control in this sy...
Source: World Mycotoxin Journal - September 22, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Growth and gliotoxin production by feed-borne Aspergillus fumigatus sensu stricto strains under different interacting environmental conditions
In this study the effects of temperature, oxygen tension, water activity (aW), pH, incubation time and their interactions on (1) the lag phase prior to growth, (2) growth rate and (3) gliotoxin production of two feed-borne Aspergillus fumigatus sensu stricto strains, isolated from fermented maize silage and brewer's grains, were evaluated on an agar medium based on these substrates. Regardless of oxygen tension, the growth rate of the two strains decreased significantly as temperature and aW decreased (P (Source: World Mycotoxin Journal)
Source: World Mycotoxin Journal - September 22, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
Development and inter-laboratory study of a method for quantification of fumonisin B1, B2 and B3 in pet foods
An analytical method to determine fumonisin B1 (FB1), B2 (FB2) and B3 (FB3) in pet foods using a liquid chromatography-electrospray ionization-mass spectrometer (LC-ESI-MS) was developed, and an inter-laboratory study was conducted in eleven laboratories. FB1, FB2 and FB3 were extracted with aqueous acetonitrile. The extract was purified by a multifunctional column, MultiSep 211 Fum, and analysed by LC-ESI-MS. The limit of quantification of fumonisins was estimated to be 0.2 mg/kg for dry and semi-dry pet foods, and 0.1 mg/kg for wet pet food. The calibration curve showed linearity in the range of 0.1-5 ng of fumonisins (0...
Source: World Mycotoxin Journal - September 11, 2014 Category: Toxicology Tags: World Mycotoxin Journal Source Type: research
