Abstract The mat-forming fruticose lichens Cladonia stellaris and Cetraria islandica frequently co-occur on soils in sun-exposed boreal, subarctic, and alpine ecosystems. While the dominant reindeer lichen Cladonia lacks a cortex but produces the light-reflecting pale pigment usnic acid on its surface, the common but patchier Cetraria has a firm cortex sealed by the light-absorbing pigment melanin. By measuring reflectance spectra, high-light tolerance, photosynthetic responses, and chlorophyll fluorescence in sympatric populations of these lichens differing in fungal pigments, we aimed to study how they cope with high light while hydrated. Specimens of the two species tolerated high light equally well but with different protective mechanisms. The mycobiont of the melanic species efficiently absorbed excess light, consistent with a lower need for its photobiont to protect itself by non-photochemical quenching (NPQ). By contrast, usnic acid screened light at 450–700 nm by reflectance and absorbed shorter wavelengths. The ecorticate usnic species with less efficient fungal light screening exhibited a consistently lower light compensation point and higher CO 2 uptake rates than the melanic lichen. In both species, steady state NPQ rapidly increased at increasing light with no signs of light saturation. To compensate for less internal shading causing light fluctuations with a larger amplitude, the usnic lichen photobiont adjusted to changing light by faster induction and faster relaxation of NPQ rapidly transforming excess excitation energy to less damaging heat. The high and flexible NPQ tracking fluctuations in solar radiation probably contributes to the strong dominance of the usnic mat-forming Cladonia in open lichen-dominated heaths. 

Non-photochemical quenching may contribute to the dominance of the pale mat-forming lichen Cladonia stellaris over the sympatric melanic Cetraria islandica.

The mangosteen peel contains phenol compounds that have antifungal activity. The study aimed to find out the antifungal activity in the dosage form of toothpaste against Candida albicans. The research methods used include the extraction of mangosteen peel (Garcinia mangostana L.) by maceration using 96% ethanol. The toothpaste formula was composed with an extract concentration of 1.25% (F1); 2.5% (F2); 5% (F3); and base (B). Antifungal testing was carried out by diffusion method using Potato Dextrose Agar (PDA) media. The results showed that the toothpaste formula with a concentration of F1; F2; F3; and base (B) has an average value of successive inhibition zone diameters of 11.86 mm; 12.03mm; 12.54mm; and 7.78 mm. The conclusion of the study showed that the toothpaste preparation of the ethanol extract of mangosteen fruit peel (Garcinia mangostana L.) concentration was 1.25%; 2.5%; 5% which performs antifungal activity.

/pdf/toothpaste-formulation-ethanol-extract-mangosteen-peel-1togcuh1.pdf

Toothpaste Formulation Ethanol Extract Mangosteen Peel (Garcinia mangostana L.) and Test Activity Against Candida Albicans

Abstract Aegerolysin proteins are involved in various interactions by recognising a molecular receptor in the target organism. The formation of pores in combination with larger, non‐aegerolysin‐like protein partners (such as membrane attack complex/perforin proteins [MACPFs]) is one of the possible responses in the presumed competitive exclusion of other organisms from the ecological niche. Bicomponent pairs are already observed at the gene level. Fungi growing under extreme conditions can be divided into ubiquitous and extremotolerant generalists which can compete with mesophilic species and rare, isolated extremophilic and extremotolerant specialists with narrow ecological amplitude that cannot compete. Under extreme conditions, there are fewer competitors, so fungal specialists generally produce less diverse and complicated profiles of specialised molecules. Since extremotolerant and extremophilic fungi have evolved in numerous branches of the fungal tree of life and aegerolysins are unevenly distributed across fungal genomes, we investigated whether aegerolysins, together with their partner proteins, contribute to the extreme survival ecology of generalists and specialists. We compiled a list of 109 thermo‐, psihro‐, acido‐, alkali‐, halo‐, metallo‐ and polyextremo‐tolerant/‐philic fungal species. Several challenges were identified that affected the outcome: renaming fungal species, defining extremotolerant/extremophilic traits, identifying extremotolerant/extremophilic traits as metadata in databases and linking fungal isolates to fungal genomes. The yield of genomes coding aegerolysins or MACPFs appears to be lower in extremotolerant/extremophilic fungi compared to all fungal genomes. No candidates for pore‐forming gene pairs were identified in the genomes of extremophilic fungi. Aegerolysin and MACPFs partner pairs were identified in only two of 69 species with sequenced genomes, namely in the ubiquitous metallotolerant generalists Aspergillus niger and A. foetidus . These results support the hypothesised role of these pore‐forming proteins in competitive exclusion. 

Pore‐forming aegerolysin and <scp>MACPF</scp> proteins in extremotolerant or extremophilic fungi

The genus Exophiala is polymorphic, able to transition between yeast, hyphal and pseudohyphal forms. Species of the genus Exophiala are ubiquitous fungi that are distributed in various environments around the world. During a survey of fungal diversity in the gut of amphipods (Floresorchestia amphawaensis and undescribed Dogielinotid amphipods) from the Amphawa estuary, Samut Songkhram province, Thailand, five black yeast strains (DMKU-MG01, DMKU-MG07, DMKU-MG08, DMKU-HG10 and DMKU-FG04) were identified as representing a novel taxon on the basis of a combination of morphological and molecular phylogenetic features. The five strains did not produce filamentous hyphae or pseudohyphae. Only budding yeast cells were observed. On the basis of the phenotypic characteristics and the results of molecular analyses of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, the five strains were identified as representing a novel species via applied nucleotide pairwise analysis. They differed from the most closely related species Exophiala alcalophiala by 3.54 % nucleotide substitutions (20 nucleotide substitutions in 572 bp) in the D1/D2 domains of the LSU rRNA gene. Moreover, the sequences of the ITS region of the five strains differed from those of the most closely related species E. alcalophiala, by 7.44-9.62 % nucleotide substitutions, and Exophiala halophiala, by 7.2-7.53 % nucleotide substitutions. The results of phylogenetic analyses based on the concatenated sequences of the ITS regions and the D1/D2 domains of the LSU rRNA gene confirmed that the five black yeast strains represented a single novel species of the genus Exophiala. In this study, Exophiala amphawaensis sp. nov. is proposed to accommodate these strains. The holotype is TBRC 15626T and the isotype is PYCC9020. The MycoBank accession number of the novel species is MB 851477.

Exophiala amphawaensis sp. nov., a novel black yeast isolated from the gut of amphipods in Thailand.

Exophiala is a black fungi of the family Herpotrichiellaceae that can be found in a wide range of environments like soil, water and the human body as potential opportunistic pathogen. Some species are known to be extremophiles, thriving in harsh conditions such as deserts, glaciers, and polluted habitats. The identification of novel Exophiala species across diverse environments underlines the remarkable biodiversity within the genus. However, its classification using traditional phenotypic and phylogenetic analyses has posed a challenges. Here we describe a novel taxon, Exophiala chapopotensis sp. nov., strain LBMH1013, isolated from oil-polluted soil in Mexico, delimited according to combined morphological, molecular, evolutionary and statistics criteria. This species possesses the characteristic dark mycelia growing on PDA and tends to be darker in the presence of hydrocarbons. Its growth is dual with both yeast-like and hyphal forms. LBMH1013 differs from closely related species such as E. nidicola due to its larger aseptate conidia and could be distinguished from E. dermatitidis and E. heteromorpha by its inability to thrive above 37°C or 10% of NaCl. A comprehensive genomic analyses using up-to-date overall genome relatedness indices, several multigene phylogenies and molecular evolutionary analyzes using Bayesian speciation models, further validate its species-specific transition from all current Exophiala/Capronia species. Additionally, we applied the phylophenetic conceptual framework to delineate the species-specific hypothesis in order to incorporate this proposal within an integrative taxonomic framework. We believe that this approach to delimit fungal species will also be useful to our peers.

Exophiala chapopotensis sp. nov., an extremotolerant black yeast from an oil-polluted soil in Mexico; phylophenetic approach to species hypothesis in the Herpotrichiellaceae family

Black yeasts are polyextremotolerant fungi that contain high amounts of melanin in their cell wall and maintain a primarily yeast form. These fungi grow in xeric, nutrient deplete environments which implies that they require highly flexible metabolisms and have been suggested to contain the ability to form lichen-like mutualisms with nearby algae and bacteria. However, the exact ecological niche and interactions between these fungi and their surrounding community is not well understood. We have isolated two novel black yeasts from the genus Exophiala that were recovered from dryland biological soil crusts. Despite notable differences in colony and cellular morphology, both fungi appear to be members of the same species, which has been named Exophiala viscosa (i.e., E. viscosa JF 03-3 Goopy and E. viscosa JF 03-4F Slimy). A combination of whole genome sequencing, phenotypic experiments, and melanin regulation experiments have been performed on these isolates to fully characterize these fungi and help decipher their fundamental niches within the biological soil crust consortium. Our results reveal that E. viscosa is capable of utilizing a wide variety of carbon and nitrogen sources potentially derived from symbiotic microbes, can withstand many forms of abiotic stresses, and excrete melanin that can potentially provide UV resistance to the biological soil crust community. Besides the identification of a novel species within the genus Exophiala, our study also provides new insight into the regulation of melanin production in polyextremotolerant fungi.

Characterization of a novel polyextremotolerant fungus, Exophiala viscosa, with insights into its melanin regulation and ecological niche

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Characterization of a novel polyextremotolerant fungus, Exophiala viscosa, with insights into its melanin regulation and ecological niche