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David Garon

Publications and source records attributed to David Garon.

3 recordsLinked to original sources

Mycoflora and multimycotoxin detection in corn silage: experimental study.

Agricultural activities involve the use of crop preservation such as "trench-type" silo, which can sometimes be contaminated by fungi. To investigate the exposure of livestock and farm workers to fungal spores and mycotoxins, a multimycotoxin analysis method has been developed. Six mycotoxins (aflatoxin B1, citrinin, deoxynivalenol, gliotoxin, ochratoxin A, and zearalenone) were quantified by high-performance liquid chromatography coupled to mass spectrometry after solid-phase extraction. An experimental study of fungal species and mycotoxins was conducted in corn silage (Normandy, France) during 9 months of monitoring. The results indicated the recurrence of around 20 different species, with some of them being potentially toxigenic fungi such as Aspergillus fumigatus, Aspergillus parasiticus, Fusarium verticillioides, and Monascus ruber, and the detection of aflatoxin B1 (4-34 ppb), citrinin (4-25 ppb), zearalenone (23-41 ppb), and deoxynivalenol (100-213 ppb). This suggested a possible chronic exposure to low levels of mycotoxins.

Aspergillus↗

Fungal microflora and ochratoxin a risk in French vineyards.

To evaluate the ochratoxin A risk in French vineyards, five winemaking regions were investigated. An exhaustive survey of the fungal microflora of 60 grape samples was carried out at two development stages of the berries: end of veraison and harvest time. Potentially toxinogenic fungi isolated from grapes were assessed in vitro for ochratoxin A production. Ochratoxin A was also quantified in musts by high-performance liquid chromatography after cleanup on immunoaffinity columns. Among the 90 species identified, almost half are listed as mycotoxin producers, but only 2 are potentially ochratoxinogenic: Aspergillus carbonarius and Aspergillus niger. Among these strains, only A. carbonarius, isolated from the Languedoc region at harvest time, was found to produce ochratoxin A. These results were in accordance with the presence of ochratoxin A in French southern region musts (0.01-0.43 microg/L) and confirmed the major implication of A. carbonarius in ochratoxin A contamination.

Aspergillus↗

Effects of fungal bioaugmentation and cyclodextrin amendment on fluorene degradation in soil slurry.

This study assesses the potential of fungal bioaugmentation and the effect of maltosyl-cyclodextrin amendment, as an approach to accelerate fluorene biodegradation in soil slurries. 47 fungal strains isolated from a contaminated site were tested in the biodegradation of fluorene. Results showed the greater efficiency of "adaptated" fungi isolated from contaminated soil vs. reference strains belonging to the collection of the laboratory. These assays allowed us to select the most efficient strain, Absidia cylindrospora, which was used in a bioaugmentation process. In the presence of Absidia cylindrospora, more than 90% of the fluorene was removed in 288 h while 576 h were necessary in the absence of fungal bioaugmentation. Maltosyl-cyclodextrin, a branched-cyclodextrin was chosen in order to optimize fluorene bioavailability and biodegradation in soil slurries. The results of this study indicate that Absidia cylindrospora and maltosyl-cyclodextrin could be used successfully in bioremediation systems.

Absidia↗