Project description:The strain Aspergillus chevalieri TM2-S6 was isolated from the sponge Axinella and identified according to internal transcribed spacer (ITS) molecular sequence homology with Aspergillus species from the section Restricti. The strain was cultivated 9 days on potato dextrose broth (PDB), and the medium evaluated as antioxidant on primary normal human dermal fibroblasts (NHDF). The cultivation broth was submitted to sterile filtration, lyophilized and used without any further processing to give the Aspergillus chevalieri TM2-S6 cultivation broth ingredient named ACBB. ACCB contains two main compounds: tetrahydroauroglaucin and flavoglaucin. Under oxidative stress, ACCB showed a significant promotion of cell viability. To elucidate the mechanism of action, the impact on a panel of hundreds of genes involved in fibroblast physiology was evaluated. Thus, ACCB stimulates cell proliferation (VEGFA, TGFB3), antioxidant response (GPX1, SOD1, NRF2), and extracellular matrix organization (COL1A1, COL3A1, CD44, MMP14). ACCD also reduced aging (SIRT1, SIRT2, FOXO3). These findings indicate that Aspergillus chevalieri TM2-S6 cultivation broth exhibits significant in vitro skin protection of human fibroblasts under oxidative stress, making it a potential cosmetic ingredient.
Project description:Molecular approaches are now being developed to provide a more rapid and objective identification of fungi compared to traditional phenotypic methods. Ribosomal targets, especially the large-subunit RNA gene (D1-D2 region) and internal transcribed spacers 1 and 2 (ITS1 and ITS2 regions), have shown particular promise for the molecular identification of some fungi. We therefore conducted an assessment of these regions for the identification of 13 medically important Aspergillus species: Aspergillus candidus, Aspergillus (Eurotium) chevalieri, Aspergillus (Fennellia) flavipes, Aspergillus flavus, Aspergillus fumigatus, Aspergillus granulosus, Aspergillus (Emericella) nidulans, Aspergillus niger, Aspergillus restrictus, Aspergillus sydowii, Aspergillus terreus, Aspergillus ustus, and Aspergillus versicolor. The length of ribosomal regions could not be reliably used to differentiate among all Aspergillus species examined. DNA alignment and pairwise nucleotide comparisons demonstrated 91.9 to 99.6% interspecies sequence identities in the D1-D2 region, 57.4 to 98.1% in the ITS1 region, and 75.6 to 98.3% in the ITS2 region. Comparative analysis using GenBank reference data showed that 10 of the 13 species examined exhibited a < or = 1-nucleotide divergence in the D1-D2 region from closely related but different species. In contrast, only 5 of the species examined exhibited a < or = 1-nucleotide divergence from sibling species in their ITS1 or ITS2 sequences. Although the GenBank database currently lacks ITS sequence entries for some species, and major improvement in the quality and accuracy of GenBank entries is needed, current identification of medically important Aspergillus species using GenBank reference data seems more reliable using ITS query sequences than D1-D2 sequences, especially for the identification of closely related species.
Project description:In the last few years, increasing numbers of viruses infecting fungi have been identified. In this study, we used an in silico approach for the analysis of deep RNA sequencing data in order to discover and characterize putative genomic ssRNA or dsRNA mycovirus sequences in Aspergillus fumigatus. RNA sequencing reads of A. fumigatus strains were mapped against the A. fumigatus Af293 reference genome. Unmapped reads were collected for de novo assembly. Contigs were analyzed by Blastx comparison with a mycovirus protein database. Assembled viral genomes were used as template for remapping of RNA sequencing reads. In total, deep RNA sequencing results from 11 A. fumigatus strains were analyzed for the presence of mycoviral genomic RNAs. In 9 out of 11 strains, putative mycoviral RNA genomes were identified. Three strains were infected with two different mycovirus species. Two strains were infected with Aspergillus fumigatus polymycovirus type-1 (AfuPmV-1). Four strains contained fully recovered genomic RNA of unknown narna-like viruses designated as Aspergillus fumigatus narnavirus-1 and Aspergillus fumigatus narnavirus-2 (AfuNV-1 and AfuNV-2). Both viruses showed 38% amino acid sequence identity to Beihai narna-like virus-21. Three strains contained partially recovered genomic RNA of an unknown narna-like virus. Two strains contained fully recovered genomic RNAs of an unknown partitivirus designated as Aspergillus fumigatus partitivirus-2 (AfuPV-2) which showed 50% amino acid sequence identity to Alternaria alternata partitivirus-1. Finally, one strain contained fully recovered genomic RNA of an unknown mitovirus designated as Aspergillus fumigatus mitovirus-1 (AfuMV-1) which showed 34% amino acid sequence identity to Sclerotina sclerotiorum mitovirus. In silico analysis of deep RNA sequencing results showed that a majority of the A. fumigatus strains used here were infected with mycoviruses. Four novel A. fumigatus RNA mycoviruses could be identified: two different Aspergillus fumigatus narna-like viruses, one Aspergillus fumigatus partitivirus, and one Aspergillus fumigatus mitovirus.
Project description:This study records a severe outbreak of a disease on Zizyphus mucronata (Rhamnaceae) in Greater Kruger National Park, South Africa. The causal agent of the disease was found to be Coniodictyum chevalieri, a fungus previously believed to be very rare. Detailed illustrations of the symptoms and fungus are presented in order to facilitate future studies. The known geographical distribution of Coniodictyum is presented in relation to the distribution of its host, and a short review of its systematic history is also given. This also treats an invalidly published species name in South Africa, which has confused the literature. A DNA-based phylogeny is presented for the pathogen and this reflects the unique nature of its geographical distribution and biology.