18 research outputs found
Secondary metabolite profiling, growth profiles and other tools for species recognition and important Aspergillus mycotoxins
Species in the genus Aspergillus have been classified primarily
based on morphological features. Sequencing of house-hold genes has also been
used in Aspergillus taxonomy and phylogeny, while extrolites and
physiological features have been used less frequently. Three independent ways
of classifying and identifying aspergilli appear to be applicable: Morphology
combined with physiology and nutritional features, secondary metabolite
profiling and DNA sequencing. These three ways of identifying
Aspergillus species often point to the same species. This consensus
approach can be used initially, but if consensus is achieved it is recommended
to combine at least two of these independent ways of characterising aspergilli
in a polyphasic taxonomy. The chemical combination of secondary metabolites
and DNA sequence features has not been explored in taxonomy yet, however.
Examples of these different taxonomic approaches will be given for
Aspergillus section Nigri
Phylogeny of chrysosporia infecting reptiles: proposal of the new family Nannizziopsiaceae and five new species
We have performed a phenotypic and phylogenetic study of a set of fungi, mostly of veterinary origin, morphologically similar to the Chrysosporium asexual morph of Nannizziopsis vriesii (Onygenales, Eurotiomycetidae, Eurotiomycetes, Ascomycota). The analysis of sequences of the D1-D2 domains of the 28S rDNA, including representatives of the different families of the Onygenales, revealed that N. vriesii and relatives form a distinct lineage within that order, which is proposed as the new family Nannizziopsiaceae. The members of this family show the particular characteristic of causing skin infections in reptiles and producing hyaline, thin- and smooth-walled, small, mostly sessile 1-celled conidia and colonies with a pungent skunk-like odour. The phenotypic and multigene study results, based on ribosomal ITS region, actin and β-tubulin sequences, demonstrated that some of the fungi included in this study were different from the known species of Nannizziopsis and Chrysosporium and are described here as new. They are N. chlamydospora, N. draconii, N. arthrosporioides, N. pluriseptata and Chrysosporium longisporum.
Nannizziopsis chlamydospora is distinguished by producing chlamydospores and by its ability to grow at 5 °C.
Nannizziopsis draconii is able to grow on bromocresol purple-milk solids-glucose (BCP-MS-G) agar alkalinizing the medium, is resistant to 0.2 % cycloheximide but does not grow on Sabouraud dextrose agar (SDA) with 3 % NaCl. Nannizziopsis arthrosporioides is characterised by the production of very long arthroconidia. Nannizziopsis pluriseptata produces 1- to 5-celled sessile conidia, alkalinizes the BCP-MS-G agar and grows on SDA supplemented with 5 % NaCl. Chrysosporium longisporum shows long sessile conidia (up to 13 ÎĽm) and does not produce lipase