Combination of Isotope Labeling and Molecular Networking of Tandem Mass Spectrometry Data To Reveal 69 Unknown Metabolites Produced by .

The secondary metabolome of is poorly documented despite its frequent detection on contaminated food and its capacity to produce toxic metabolites such as ochratoxin A. To characterize metabolites produced by this fungi, we combined a full stable isotopes labeling with the dereplication of tandem mass spectrometry (MS/MS) data by molecular networking. First, the untargeted metabolomic analysis by high-resolution mass spectrometry of a double stable isotope labeling of enabled the specific detection of its metabolites and the unambiguous determination of their elemental composition.

Impact of veA on the development, aggressiveness, dissemination and secondary metabolism of Penicillium expansum.

Penicillium expansum, the causal agent of blue mould disease, produces the mycotoxins patulin and citrinin amongst other secondary metabolites. Secondary metabolism is associated with fungal development, which responds to numerous biotic and abiotic external triggers. The global transcription factor VeA plays a key role in the coordination of secondary metabolism and differentiation processes in many fungal species.

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

Several strains of a new aflatoxigenic species of , , were isolated in the course of a screening study involving species from section found contaminating peanuts () 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 (, , , , , , , and ) was subjected to phylogenetic analysis, and resulted in all four strains being inferred as a distinct clade.

Evidencing 98 secondary metabolites of Penicillium verrucosum using substrate isotopic labeling and high-resolution mass spectrometry.

Industrial applications of fungal compounds, coupled with the emergence of fungal threats to natural ecosystems and public health, have increased interest in filamentous fungi. Among all pathogenic fungi, Penicillium verrucosum is one of the most common mold-infecting stored cereals in temperate regions. However, it is estimated that 80% of fungal secondary metabolites remain unknown.

The gene PatG involved in the biosynthesis pathway of patulin, a food-borne mycotoxin, encodes a 6-methylsalicylic acid decarboxylase.

Patulin is a mycotoxin produced by fungal genera such as Aspergillus, Penicillium and Byssochlamys. It induces neurological, gastrointestinal and immunological effects, which is why patulin belongs to a short list of mycotoxins whose level in food is regulated in many countries around the world. Recently, a cluster gathering 15 genes involved in the biosynthesis of patulin has been identified in Aspergillus clavatus, but so far, only 4 genes encoding 6-methylsalicylic acid synthase, m-cresol hydroxylase, m-hydroxybenzyl alcohol hydroxylase and isoepoxydon dehydrogenase have been characterized.

New untargeted metabolic profiling combining mass spectrometry and isotopic labeling: application on Aspergillus fumigatus grown on wheat.

Characterization of fungal secondary metabolomes has become a challenge due to the industrial applications of many of these molecules, and also due to the emergence of fungal threats to public health and natural ecosystems. Given that, the aim of the present study was to develop an untargeted method to analyze fungal secondary metabolomes by combining high-accuracy mass spectrometry and double isotopic labeling of fungal metabolomes. The strain NRRL 35693 of Aspergillus fumigatus , an important fungal pathogen, was grown on three wheat grain substrates: (1) naturally enriched grains (99% (12)C), (2) grains enriched 96.

Trypacidin, a spore-borne toxin from Aspergillus fumigatus, is cytotoxic to lung cells.

Inhalation of Aspergillus fumigatus conidia can cause severe aspergillosis in immunosuppressed people. A. fumigatus produces a large number of secondary metabolites, some of which are airborne by conidia and whose toxicity to the respiratory tract has not been investigated.

Molecular cloning and functional characterization of two CYP619 cytochrome P450s involved in biosynthesis of patulin in Aspergillus clavatus.

Patulin is an acetate-derived tetraketide mycotoxin produced by several fungal species, especially Aspergillus, Penicillium and Byssochlamys species. The health risks due to patulin consumption by humans have led many countries to regulate it in human food. Previous studies have shown the involvement of cytochrome P450 monooxygenases in the hydroxylation of two precursors of patulin, m-cresol and m-hydroxybenzylalcohol.

The inability of Byssochlamys fulva to produce patulin is related to absence of 6-methylsalicylic acid synthase and isoepoxydon dehydrogenase genes.

Byssochlamys species are responsible for spoilage and degradation of fruits and silages. Under specific conditions they are able to produce mycotoxins. The aim of this study was to evaluate the potential of 19 different strains of Byssochlamys nivea and Byssochlamys fulva to produce patulin in relation with the presence of two genes involved in the patulin biosynthesis pathways in the genome of these fungal strains.

Byssochlamys nivea as a source of mycophenolic acid.

Byssochlamys species are responsible for spoilage and degradation of fruits and silages and can also produce the mycotoxin patulin. We analyzed secondary metabolite production by Byssochlamys nivea. Mycophenolic acid and its precursors, 5-methylorsellinic acid and 5,7-dihydroxy-4-methylphthalide, were identified in all of the B.