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The process of supercritical fluid extraction (SCFE) of the thallus of the lichen species Hypogymnia physodes with carbon dioxide in the presence of acetone as a cosolvent is studied. The extraction conditions (temperature, pressure, and duration) on the yields of the extract (EX), phenolic compounds, including low molecular weight phenols (LPs), atranorin (AT), and flavonoids (FVs) are assessed. It is shown that the main amount of extractives (up to 90%) is extracted within 40 min of extraction. The EX yield reaches 156.5 mg/g with a phenolic compound (PC) content of up to 87.3%. The obtained EXs have high antiradical activity (ARA) (up to 225 μmol Trolox-equiv/g). A positive correlation is established between the ARA of the EXs and the content of PCs in them, including AT. The antibacterial activity of the EXs against the gram-positive (Bacillus subtilis) and gram-negative (Escherichia coli, Proteus mirabilis) strains of microorganisms is revealed. [ABSTRACT FROM AUTHOR]

An experiment was conducted on the development of Hypogymnia physodes (L.) Nyl. from soredia to branched lobes near the copper smelter in the Middle Urals 10 years after emission cessation. Soredia were cultivated in fir-spruce forests in heavily polluted and unpolluted areas. In both areas, soredia development was examined on fir bark collected from both the heavily polluted and unpolluted areas. The probability of lobe formation was lower in the polluted area even when soredia were cultivated on bark from the unpolluted area. Bark from the polluted area negatively impacted the success of soredia development, irrespective of the cultivation area. The lowest success of early development occurred when soredia were cultivated on polluted bark in the heavily polluted area, where the already low probability of lobe formation was accompanied by high mortality of the developed lobes. This study underscores the enduring impact of industrial pollution on H. physodes development, highlighting the need for ongoing environmental restoration and monitoring efforts in post-industrial areas to support biodiversity conservation. [ABSTRACT FROM AUTHOR]

Aerogel composites were synthesized on the basis of the sodium alginate-chitosan interpolymer complex with the inclusion of calcium carbonate microparticles and supercritical drying. It is shown that the textural characteristics of materials did not depend on the morphology of calcium carbonate particles: the specific surface area of aerogels was almost the same for all materials, 380–400 m2/g. The developed porous structure of composites along with the polyelectrolyte nature determined their high water absorption (up to 110 g/g). To impart antimicrobial properties, the materials were impregnated with atranorin isolated from the lichen Hypogymnia physodes, which has a pronounced inhibitory effect on the bacterium P. mirabilis, the main causative agent of wound infections. The minimum suppressive concentration of atranorine was 1 mg/mL. The release of the main amount of atranorine aerosol material included in the matrix occurred within 4 hours, 50%. [ABSTRACT FROM AUTHOR]

The main physiological and biochemical characteristics and elemental composition of three lichen species of the genus Hypogymnia (Nyl.) Nyl. in one habitat were studied using spectroscopic methods. The model species were placed in the following order of decreasing degree of anthropotolerance: H. physodes (L.) Nyl. → H. tubulosa (Schaer.) Hav. → H. vittata (Ach.) Parrique. The contents of chlorophylls a and b, phenolic compounds, pheophytinization quotient, and antiradical activity were determined by a spectrophotometric method. The antioxidant activity was determined by an amperometric method. The physiological and biochemical parameters for each of the three species corresponded to those for background ecotopes. These parameters and the integrity of the system of correlations between the parameters were lower in species with a low degree of anthropotolerance. Twenty-three elements were found in thalli of the model species using atomic emission spectroscopy with inductively coupled plasma. They included macro- and microelements, heavy metals, and metalloids. The maximum concentrations of most elements were found in H. vittata; the minimum concentrations, in H. physodes. An analysis of the interaction between the physiological and biochemical characteristics and the contents of the elements indicated the presence of a complex system of correlations in each species. Differences in this system of correlations may have been due to the specific composition of secondary metabolites, which determine the features of adaptive reactions. The use of various optical spectroscopy methods enabled an evaluation of not only the functional specificity of the studied species but also its connection to their anthropotolerance level. Low resistance to anthropogenic influences was combined with lower coordination of physiological and biochemical characteristics and low integrity of the system of correlations. The most vulnerable species H. vittata had the minimal values of the main functional parameters, a poorer correlation of them with the elemental composition, and higher concentrations of some toxic elements. The use of a complex analysis of the physiological and biochemical characteristics and elemental compositions using various spectral methods was crucial for the bioindication and ecological physiology of lichens. [ABSTRACT FROM AUTHOR]

The goal of this study was to give comparative evaluation of applicability of different species of mosses and lichens for radiation monitoring of 137Cs contamination of pine forest biogeocenoses in Ukrainian Polissia in different forest-ecological conditions (FEC). Objects of research were: species composition of mosses and lichens on stationary experimental plots (SEP), their occurrence in FEC–В3 and FEC–А1, sufficiency for multiyear monitoring, values of 137Сs specific activity in investigated indicator species, and concentration ratio (CR) in the system «indicator biomass – substratum». Research was carried out in 2020 in Ukrainian Polissia, Zhytomyr Region, on 4 stationary experimental plots: SEP-1 – in forest-ecological conditions FEC–В3, SEP-2, 3, 4 – in FEC–А1. For these forest-ecological conditions occurrence of indicator species of mosses and lichens as well as their sufficiency for sampling at multiyear monitoring was studied by route method on 20 forest sites. On each SEP, samples of moss and lichen species were collected in sets of 3-5 repetitions. The substratum was sampled directly below them: for epigeous species – soil at the depth of 20 cm, for epiphytic ones – pine bark. 137Сs specific activity was measured on spectrum analyser SЕG-001 «АKP-S»-150 with scintillation detector BDЕG-20-R1. Relative error of measurement – < 15 %. A concentration ratio (CR) was chosen as an index of intensity of 137Cs accumulation by biota. The occurrence of the following species-indicators of radioactive contamination of a pine forest were shown to prevail in FEC–В3: Dicranum polysetum, Pleurozium schreberi, Hypogymnia physodes; in FEC–А1: Cladonia mitis, Cladonia rangiferina, Hypogymnia physodes, Dicranum polysetum. It was found that in FEC–В3, the average values of CR in Dicranum polysetum (2.31±0.127) significantly exceeded the corresponding values in Pleurozium schreberi (1.64±0.06). The difference of the average CR values was essential at a confidence level of 95 %. In FEC–В3, epiphytic lichen Hypogymnia physodes was characterized by the highest average CR value (8.45±0.33), i.e. the difference with mosses was statistically reliable. In FEC–A1, epigeous mosses accumulated 137Cs more intensively than epigeous lichens of genus Cladonia, the average CR values were 4.78±0.28 and 2.51±0.15, respectively, the difference was essential. In FEC–A1, the group of epiphytic lichens was characterized by the maximum CR, with average value 6.84±0.36, which was essentially and reliably different from the corresponding values of the group of epigeous lichens and the group of epigeous mosses. It was found that among the indicator species of mosses and lichens, Hypogymnia physodes was characterized by the highest values of radiocontamination in investigated forest ecological conditions.

Lichens are symbiotic associations consisting of a photobiont (algae or cyanobacteria) and a mycobiont (fungus). They are known to produce a variety of unique secondary metabolites. To access this biosynthetic potential for biotechnological applications, deeper insights into the biosynthetic pathways and corresponding gene clusters are necessary. Here we provide a comprehensive view of the biosynthetic gene clusters of all organisms comprising a lichen thallus: fungi, green algae, and bacteria. We present two high-quality PacBio metagenomes, in which we identified a total of 460 biosynthetic gene clusters. Lichen mycobionts yielded 73–114 clusters, other lichen associated ascomycetes 8–40, green algae of the genus Trebouxia 14–19, and lichen-associated bacteria 101–105 clusters. The mycobionts contained mainly T1PKSs, followed by NRPSs, and terpenes; Trebouxia reads harbored mainly clusters linked to terpenes, followed by NRPSs and T3PKSs. Other lichen-associated ascomycetes and bacteria contained a mix of diverse biosynthetic gene clusters. In this study, we identified for the first time the biosynthetic gene clusters of entire lichen holobionts. The yet untapped biosynthetic potential of two species of the genus Hypogymnia is made accessible for further research. [ABSTRACT FROM AUTHOR]