The presence of orellanine in spores and basidiocarp from Cortinarius orellanus and Cortinarius rubellus.

This is the first report quantifying the orellanine content in basidiospores. The toxin content and tissue distribution of orellanine were determined from Cortinarius orellanus (Fr.) Fr. and Cortinarius rubellus Cooke. Basidiospores, the basidiocarp, divided into cap and stem, and mycorrhiza roots were analyzed to determine the amount of orellanine by reversed phase high performance liquid chromatography and thin layer chromatography. The orellanine contents in spores were 0.31% (C. orellanus) and 0.09% (C. rubellus). In caps, we found the toxin content to be 0.94% (C. orellanus) and 0.78% (C. rubellus), in stems 0.48% (C. orellanus) and 0.42% (C. rubellus) and in mycorrhiza roots from C. rubellus we determined the orellanine contents to 0.03%. In addition, extracts from the different structures of the basidiocarp of C. orellanus and C. rubellus, with an orellanine content corresponding to 25 nmol, inhibited the growth of Bacillus subtilis.

Molecular characterization and evaluation of plant litter-associated fungi from the spring 'grazing corridor' of a sheep herd vulnerable to alveld disease.

This study sample and identify species of fungi on withered vegetation in the spring 'grazing corridor' from infields to Narthecium bogs for a sheep herd almost chronically vulnerable to phototoxic disease. Hepatogen photosensitizing disorders like alveld attack grazing sheep, especially lambs, in various parts of the world. It has been hypothesized that saponin metabolites in the monocotyledonous plant Narthecium ossifragum causes the disorder in Norway, however, this has not been verified. Thus, the search for other causal agents or saponin cofactors (the cofactor hypothesis) has been intensified, and endophytic poisonous fungi associated with dead N. ossifragum leaves and grasses are among the prime suspects. The fungal diversity was targeted by obtaining axenic cultures from surface-sterilized plant material, with subsequent DNA isolation, PCR, and sequencing of the ITS nrDNA region. The taxonomic affinities of the obtained sequences were thereafter explored by similarity searches against the public access sequence database EMBL/GenBank/DDBJ. Among the spectrum of identified taxa were representatives of Cladosporium, Fusarium, Penicillium, and Trichoderma, all of which are well known as potential producers of toxins. A possible involvement of these toxic species in the etiology of alveld is evaluated and discussed.