Extreme environments such as the Antarctic can lead to the discovery of new microbial taxa, as well as to new microbial-derived natural products. Considering that little is known yet about the diversity and the genetic resources present in these habitats, the main objective of this study was to evaluate the fungal communities from extreme environments collected at Aldmiralty Bay (Antarctica). A total of 891 and 226 isolates was obtained from soil and marine sediment samples, respectively. The most abundant isolates from soil samples were representatives of the genera Leucosporidium, Pseudogymnoascus, and a non-identified Ascomycota NIA6. Metschnikowia sp. was the most abundant taxon from marine samples, followed by isolates from the genera Penicillium and Pseudogymnoascus. Many of the genera were exclusive in marine sediment or terrestrial samples. However, representatives of eight genera were found in both types of samples. Data from non-metric multidimensional scaling showed that each sampling site is unique in their physical-chemical composition and fungal community. Biotechnological potential in relation to enzymatic production at low/moderate temperatures was also investigated. Ligninolytic enzymes were produced by few isolates from root-associated soil. Among the fungi isolated from marine sediments, 16 yeasts and nine fungi showed lipase activity and three yeasts and six filamentous fungi protease activity. The present study permitted increasing our knowledge on the diversity of fungi that inhabit the Antarctic, finding genera that have never been reported in this environment before and discovering putative new species of fungi.

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Subterranean environments are oligotrophic. However, few studies have investigated the composition and function of their terrestrial mycobiota. This study examined the functional role of filamentous cave fungi in cellulose degradation. Soil samples and dry sediment were collected in the surface epigean environment and two sites in the entrance and twilight zones inside Gruta do Catão in the São Desidério karst area, state of Bahia, Brazil. Fungi were cultured from the samples, and the total organic carbon, culturable microorganisms, and carbon and nitrogen microbial biomasses were estimated. All fungal strains were evaluated for cellulase production in carboxymethylcellulose synthetic medium, and the enzymatic indices were estimated. We observed a significant difference (p 0.05) in physical, chemical, and biological parameters between epigean soil and cave sediments by Tukey's test. We recovered a total of 20 isolates comprising the genera Aspergillus (50.0%), Penicillium (25.0%), Talaromyces (10.0%), Trichoderma (5.0%), Purpureocillium (5.0%) and Scopulariopsis (5.0%). The majority of the isolates (90%) showed cellulolytic activity, which is a higher percentage compared to that normally reported in the literature for sediments. Thus there is a high probability that the filamentous fungi act in nutrient cycling, thereby contributing to the quality and maintenance of the cave ecosystem. These results indicate that parameters such as total organic carbon, biomass, and relative humidity that tend to differ between caves and epigean environments, provide selective pressures for microorganisms that use alternative sources of energy and nutrients.

Since the formal description of fungi in the genus Escovopsis in 1990, only a few studies have focused on the systematics of this group. For more than two decades, only two Escovopsis species were described; however, in 2013, three additional Escovopsis species were formally described along with the genus Escovopsioides, both found exclusively in attine ant gardens. During a survey for Escovopsis species in gardens of the lower attine ant Mycetophylax morschi in Brazil, we found four strains belonging to the pink-colored Escovopsis clade. Careful examination of these strains revealed significant morphological differences when compared to previously described species of Escovopsis and Escovopsioides. Based on the type of conidiogenesis (sympodial), as well as morphology of conidiogenous cells (percurrent), non-vesiculated conidiophores, and DNA sequences, we describe the four new strains as a new species, Escovopsis kreiselii sp. nov. Phylogenetic analyses using three nuclear markers (Large subunit RNA; translation elongation factor 1-alpha; and internal transcribed spacer) from the new strains as well as available sequences in public databases confirmed that all known fungi infecting attine ant gardens comprise a monophyletic group within the Hypocreaceae family, with very diverse morphological characteristics. Specifically, Escovopsis kreiselii is likely associated with gardens of lower-attine ants and its pathogenicity remains uncertain.

Anthracnose is a crop disease usually caused by fungi in the genus Colletotrichum or Gloeosporium. These are considered one of the main pathogens, causing significant economic losses, such as in peppers and guarana. The current forms of control include the use of resistant cultivars, sanitary pruning and fungicides. However, even with the use of some methods of controlling these cultures, the crops are not free of anthracnose. Additionally, excessive application of fungicides increases the resistance of pathogens to agrochemicals and cause harm to human health and the environment. In order to find natural antifungal agents against guarana anthracnose, endophytic fungi were isolated from Amazon guarana. The compounds piliformic acid and cytochalasin D were isolated by chromatographic techniques from two Xylaria spp., guided by assays with Colletotrichum gloeosporioides. The isolated compounds were identified by spectrometric techniques, as NMR and mass spectrometry. This is the first report that piliformic acid and cytochalasin D have antifungal activity against C. gloeosporioides with MIC 2.92 and 2.46 μmol mL−1 respectively. Captan and difenoconazole were included as positive controls (MIC 16.63 and 0.02 μmol mL−1, respectively). Thus, Xylaria species presented a biotechnological potential and production of different active compounds which might be promising against anthracnose disease.