Occurrence of mycotoxins and mycotoxigenic fungi in silage from the north of Portugal at feed-out.

Maize and grass silages are important dietary components for ruminant livestock that influence the quality of animal products for human consumption, such as milk, in many parts of the world. Infection of plants by fungi able to produce mycotoxins, either in the field or post-harvest, can result in a decrease of silage nutritional quality and, consequently, in milk quality. In this study, 45 maize and grass silage samples were collected from 25 dairy farms located in the north of Portugal. The occurrence of fungi was evaluated in samples, the most frequently isolated species being Aspergillus fumigatus, Dipodascus geotrichum, Mucor circinelloides, Penicillium paneum, and Aspergillus flavus. The mycotoxigenic profile of the fungal species was studied using the ultra-high-performance liquid chromatography coupled to mass spectrometry-ion trap-time-of-flight (UHPLC-MS-IT-TOF) detection. In addition, a new method based on a QuEChERS extraction followed by the UHPLC- tandem mass spectrometry (UHPLC-MS/MS) detection was developed for simultaneous analysis of 39 mycotoxins in silage. A high co-occurrence of Fusarium mycotoxins was found, although at low levels of contamination. Deoxynivalenol and beauvericin were found in more than 82% of maize silage samples. It can be highlighted the low occurrence of Penicillium and Aspergillus toxins in the maize and grass silages studied despite the frequent detection of species of both genera.

First report of Fusarium foetens as a mycotoxin producer.

Fusarium foetens, a pathogen of Begonia plants, has been recently described as a new fungal species. This Fusarium species causes a destructive vascular wilt disease which leads to the death of the plant. Moreover, Fusarium species are known to produce a huge variety of secondary metabolites such as mycotoxins and phytotoxins. Here, we studied the toxicogenic profile of one F. foetens strain, isolated from maize, employing two methods based on the use of ultra-performance liquid chromatography coupled to mass spectrometry-ion trap-time of flight detection. The mycotoxins beauvericin and fusaric acid were detected in a pure culture of F. foetens. In addition, four fusaric acid analogs (10,11-dihidroxyfusaric acid, hydroxyfusaric acid, dehydrofusaric acid, and a hydroxylated unsaturated fusaric acid analog) were tentatively identified on the basis of their accurate mass and fragmentation patterns. Therefore, these preliminary data indicate that F. foetens isolated from maize is able to produce Fusarium mycotoxins including beauvericin and fusaric acid.

[Incidence and distribution of the genus Armillaria in vineyards of the five protected designation of origin wines in Galicia (Northwestern Spain)]. / Incidencia y distribución del género Armillaria en viñedos de las cinco denominaciones de origen de vino de Galicia (noroeste de España).

BLACKGROUND: The genus Armillaria, specifically Armillaria mellea, is an important phytopathological problem in the wine sector in Galicia (NW Spain), having caused yield reductions in vineyards for the last 15 years. The fungus attacks the root system, resulting in a decrease in vigour, and eventually in the death of the plant. Up to now, there is no chemical or biological method really effective against the pathogen once it has infected the plant. AIMS: The main objective of this work was to study the incidence and distribution of the genus Armillaria across the five Galician protected designation of origin (DO) wines (namely Rías Baixas, Ribeiro, Ribeira Sacra, Valdeorras and Monterrei) through the application of molecular techniques. METHODS: A total of 624 samples (483 soils and 141 symptomatic vines) were analyzed by nested-PCR/RFLP, PCR-RFLP and phylogeny. RESULTS: Armillaria mellea is widely distributed in vineyards of the five DO wines, with the highest incidence in the Ribeiro DO. CONCLUSIONS: Preventive control measures against Armillaria mellea must be established in the five DO wines of Galicia, in order to reduce the advance of white root rot.