Highly acidic soils (pH < 3) represent an environment which might potentially offer new biotechnologically interesting fungi. Nevertheless, only little data on fungal communities in highly acidic habitats are available. Here, we focused on the diversity of cultivable filamentous microfungi in highly acidic soils (pH < 3) in the Czech Republic. Altogether, 16 soil samples were collected from four sampling sites and were processed by various approaches. In total, 54 fungal taxa were isolated and identified using classical as well as molecular markers. All dominant species were found both as living mycelia and as resistant stages. Numerous recently described or unknown taxa were isolated. The core of the fungal assemblage under study consisted of phylogenetically unrelated and often globally distributed fungi exclusively inhabiting highly acidic habitats like Acidiella bohemica, Acidomyces acidophilus, and unidentified helotialean fungus, as well as taxa known from less acidic and often extreme environments like Acidea extrema, Penicillium simplicissimum s.l., and Penicillium spinulosum. The large number of identified specialized species indicates that highly acidic environments provide suitable conditions for the evolution of specialist species. The occurrence of ubiquitous fungi in highly acidic substrates points to the principal role of competition in the colonization of such environments. The detected taxa did not require low pH to survive, because they can grow in a broad range of pH.

• Keywords
• Acidea, Acidiella, Acidohtrix, Acidomyces, Diversity, Microscopic fungi,
• MeSH
• Ascomycota classification   isolation & purification   MeSH
• Biodiversity * MeSH
• DNA, Fungal analysis   MeSH
• Species Specificity MeSH
• Ecosystem MeSH
• Phylogeny * MeSH
• Fungi classification   genetics   growth & development   isolation & purification   MeSH
• Classification MeSH
• Hydrogen-Ion Concentration MeSH
• Acids MeSH
• Penicillium classification   isolation & purification   MeSH
• Soil chemistry   MeSH
• Soil Microbiology * MeSH
• Base Sequence MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Czech Republic MeSH
• Names of Substances
• DNA, Fungal MeSH
• Acids MeSH
• Soil MeSH

A strain of Biatriospora sp. CCF 4378 was tested for the production of secondary metabolites under submerged fermentation conditions. Eleven compounds were isolated from the culture broth, and the structures of these compounds were determined using HRMS, NMR and X-ray analysis. In addition to six known naphthoquinone derivatives, i.e. ascomycone A, ascomycone B, 6-deoxyfusarubine, 6-deoxyanhydrofusarubine, herbarine and balticol A, one derivative of 2-azaanthraquinone, 6-deoxybostrycoidine, was also identified. Four new natural pyranonaphthoquinones were found, and these natural products were pleorubrin A, pleorubrin B, pleorubrin C and pleorubrin D. The toxicity on human cell lines of the crude naphthoquinone fraction and pure 6-deoxybostrycoidin, ascomycone B, pleorubrin B and 6-deoxyfusarubin was tested. Ascomycone B and 6-deoxyfusarubin elicited rapid cytotoxicity at micromolar concentrations.

• MeSH
• Ascomycota classification   genetics   isolation & purification   metabolism   MeSH
• Cell Line MeSH
• Endophytes classification   genetics   isolation & purification   metabolism   MeSH
• Humans MeSH
• Molecular Structure MeSH
• Naphthoquinones chemistry   metabolism   pharmacology   MeSH
• Ulmus microbiology   MeSH
• Cell Survival drug effects   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Naphthoquinones MeSH