1,721,150 research outputs found
The mycotoxin Beauvericin induces a new dehydroascorbate reducing protein in tomato plants
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Synergystic and/or antagonistic actions of beauvericin and T-2 mycotoxins on antioxidant systems in tomato seedlings
No full textAspergillus-Derived Mycotoxins In The Feed And Food Chain.
Full text linkAspergillus-produced mycotoxins can enter the feed and food chain at many points in both preharvest
and post-harvest. Although current climate changes seem to speed up the world-wide
spread of mycotoxigenic fungi including the Aspergilli and also facilitate the production of these
harmful secondary metabolites the factors governing these disadvantageous global processes are
only partly understood or even have remained completely hidden until now. This Research Topic
summarizes our knowledge on Aspergillus-derived mycotoxins especially focusing on three major
areas of on-going research: (i) toxicological, medical, veterinary aspects, prevalence, detection,
risk assessment, control strategies, (ii) ecology and biological control of mycotoxigenic Aspergilli
in the fields, and (iii) pre-harvest and post-harvest management of mycotoxigenic Aspergilli and
their mycotoxin production. We hope that the wealth of information generously provided by the
Aspergillus mycotoxin research community will help the hard work of all those experts, who are
active in this important field, and the papers collected here will be instructive and illuminating
readings for students and the public as well
FIELD EVALUATION OF FUSARIUM LARVARUM FORMULATIONS IN THE BIOCONTROL OF SAISSETIA OLEAE ON OLIVE IN APULIA
No full textSaissetia oleae is a well known olive pest that causes direct damage to the
crop and favoursthe development of sooty mold. The efficacy of two fields strains of Fusarium larvarum (ITEM 2135 and ITEM 2139) isolated from adults of the almond scale insect Suturaspis archangelskyae, was tested in Apulia (southern Italy) as biocontrol agents against populations of Saissetia oleae with field trials in 1997 and 1998. Assays were done using a solid formulation, obtained by growing fungal cultures on rice at 25 °C for 4 weeks. Suspensions of the fungal formulations were spread on olive branches infested by S. oleae, using different levels of CFU/g (Colony Forming Unit per gram). An encouraging insecticidal effect was observed. In particular, 7 days after treatment, a significant activity of the formulations was recorded (from 65% to 70% reduction of S. oleae populations as compared with the control) regardless of the different CFU used. After 30 days a generalized significant control of crawlers and second instar larvae was still observed except for ITEM 2135 with the lowest CFU, which showed a much reduced insecticidal activity. Finally, the data collected after 80 days, confirmed the insecticidal activity of both formulations
Occurrence of fusaproliferin and beauvericin in Fusarium contaminated livestock feed in Iowa
No full textAdvances on the toxicity of the cereal contaminant Fusarium esadepsipeptides
No full textFusarium head blight (FHB) of cereals is a well known disease caused by a complex of several
toxigenic species of Fusarium. FHB can reduce grain yield and quality, because of the accumulation of
mycotoxins in cereal grains and derived foods and feeds. The pathogen mainly reported as causal agent of
FHB is F. graminearum, that produces Deoxynivalenol (DON), the mycotoxin mostly associated to the
disease. However in the last decade, in Europe, in addition to DON, the esadepsipeptides Enniatins (ENs) and
Beauvericin (BEA) have been often reported as cereal contaminants, in association with different species such
as F. avenaceum, F. poae, and F. tricinctum. The natural occurrence of high amounts of BEA and ENs in
FHB small grains, evaluated with the phytotoxic and zootoxic properties of these metabolites, compel to an
examination of their potential role in contributing to the severity of FHB. On the other hand, the recent studies
that have provided further data on the biological role of the esadepsipeptide in plants and their toxicity toward
plants, animal and humans, make it worthwhile to expand the knowledge on the significance and the toxicity
of these frequent contaminants of cereals
Molecular and biochemical diversity of Oenococcus oeni strains isolated during spontaneous malolactic fermentation of Malvasia Nera wine
No full textThe diversity of indigenous Oenococcus oeni strains was investigated by molecular and biochemical characterization of isolates from Malvasia Nera wine, an economically important red wine of the Salento Region (Apulia, Italy), during spontaneous malolactic fermentation (MLF). A total of 82 isolates of this species, identified by species-specific PCR and 16S rDNA sequence analysis, was molecularly characterized by the amplified fragment length polymorphism (AFLP) technique. Three main groups resulted from cluster analysis and showed intraspecific homology higher than 50%, and a total of seven subgroups, with similarity values ranged from 80% to 98%, were obtained within these groups. Enzymatic activities, such as esterase, β-glucosidase, protease, and the consumption rate of l-malic acid, citric acid, acetaldehyde and arginine were assessed in the representative strains, according to AFLP analysis. The results showed different enzymatic activities and consumption rates of the tested metabolites among the strains. No correlation between molecular and biochemical data was observed. The evidence of biochemical variability observed among Malvasia Nera strains demonstrated that the wine aroma can be modulated depending on the strains involved in MLF. Hence, the heterogeneity existing within natural O. oeni populations represents an interesting ecological source that can be useful for technological purposes
Bio-molecular characterisation of indigenous Oenococcus oeni strains from Negroamaro wine
No full textThe variation in the coding capacity within Oenococcus oeni can have a significant impact on wine quality. The detection of several genes involved in important metabolic pathways (i.e. citrate, sulphur and arginine metabolisms) was performed on 10 indigenous O.oeni strains from Negroamaro wine, a red table wine (Apulia, Italy). These strains were selected from 95 isolates, collected during spontaneous malolactic fermentation, according to the results of an Amplified Fragment Length Polymorphism (AFLP) analysis. A total of 16 genes were screened, most (11) of which had never previously been assayed on O.oeni. All strains possessed 10 genes encoding enzymes such as malolactic enzyme (mleA), esterase (estA), citrate lyase (citD, citE and citF), citrate transporter (maeP), α-acetolactate decarboxylase (alsD), α- acetolactate synthase (alsS), S-adenosylmethionine synthase (metK) and cystathionine β-lyase (metC) and resulted negative in the detection of genes encoding cystathionine γ-lyase (metB), ornithine transcarbamylase (arcB) and carbamate kinase (arcC). The sequence of PCR fragments of 11 genes of a representative strain (ITEM 15929) was compared to those of three reference O.oeni strains. The indigenous strain was phylogenetically more similar to PSU-1 and ATCC BAA1163 than AWRI B429. This study describes new genetic markers useful for detecting the genetic potential of O.oeni strains to contribute to aroma production and for investigating the population structure of the species. © 2014 Elsevier Ltd
Identification of toxigenic fungal species associated with maize ear rot: Calmodulin as single informative gene
No full textAccurate identification of fungi occurring on agrofood products is the key aspect of any prevention and pest management program, offering valuable information in leading crop health and food safety. Fungal species misidentification can dramatically impact biodiversity assessment, ecological studies, management decisions, and, concerning toxigenic fungi, health risk assessment, since they can produce a wide range of toxic secondary metabolites, referred to as mycotoxins. Since each toxigenic fungal species can have its own mycotoxin profile, a correct species identification, hereby attempted with universal DNA barcoding approach, could have a key role in mycotoxins prevention strategies. Currently, identification of single marker for species resolution in fungi has not been achieved and the analysis of multiple genes is used, with the advantage of an accurate species identification and disadvantage of difficult setting up of PCR-based diagnostic assays. In the present paper, we describe our strategy to set up a DNA-based species identification of fungal species associated with maize ear rot, combining DNA barcoding approach and species-specific primers design for PCR based assays. We have (i) investigated the appropriate molecular marker for species identification, limited to mycobiota possibly occurring on maize, identifying calmodulin gene as single taxonomically informative entity; (ii) designed 17 sets of primers for rapid identification of 14 Fusarium, 10 Aspergillus, 2 Penicillium, and 2 Talaromyces species or species groups, and finally (iii) tested specificity of the 17 set of primers, in combination with 3 additional sets previously developed
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