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Mosses and lichens are often used to assess atmospheric deposition of 210Pb. The most widely used method for determining this isotope is gamma spectrometric analysis. There is often a need to enhance the sensitivity of the method, which can be achieved by pre-concentrating 210Pb. The simplest method in this case is direct dry ashing according to commonly accepted standardized procedures. However, the question of potential losses of 210Pb during the combustion of mosses and lichens remains unclear. The main objective of this study is to investigate the effect of the dry ashing procedure on the accuracy of determining 210Pb concentrations in the studied samples. The conducted experiment showed that ashing samples with low (< 8%) ash content, which includes all mosses and lichens, at a temperature of 450 °C leads to significant losses of 210Pb (up to 40%). For samples with an ash content > 14% (litter), the losses of this isotope do not exceed 3–4%. For both groups, the value of ashing losses has a nearly linear dependence, inversely proportional to the ash content in the studied material. The obtained relationships allowed us to calculate the corrections necessary to account for 210Pb losses during ashing of both low and high ash materials. The application of several statistical tests demonstrated good convergence and consistency of the results of 210Pb determination obtained by direct measurement in unashed samples and those calculated through the measured activity of this isotope in ashes, corrected for ashing losses. [ABSTRACT FROM AUTHOR]

There are few detailed surveys of lichens in the Canadian Arctic Archipelago (CAA) and only one from Victoria Island, which previously recorded 108 species. We surveyed a further 31 sites near Cambridge Bay and another eight sites from the Wellington Inlier, an area of Precambrian Era rocks, about 70 km to the northwest of Cambridge Bay. Based on these surveys and existing records, a total of 237 species are now reported that include 186 from our sampling sites and another 51 from various previous collections. Thirty-five species were previously unreported from the Archipelago. The 39 surveyed sites surveyed were from six geographic locations and 40% of 237 the lichen species occurred at only one location. Only three species occurred at all six locations. To date, no endemic species have been recorded for Victoria Island and only one is known for the CAA; likely a consequence of the recently deglaciated landscape (ca. 5000 years). [ABSTRACT FROM AUTHOR]

Lichen photomorphs refer to distinct symbiotic structures formed by conspecific fungi associated with different photosynthetic partners, either a green alga or a cyanobacterium. Thus, a single fungal species can engage in symbiotic relationships with different photobionts, resulting in independent, often morphologically distinct, lichen thalli. Historically, the morphological dissimilarity between photomorphs has often led to their classification as separate fungal species, which could even have been accommodated in different genera. However, molecular data have played a crucial role in revealing the genetic similarity and conspecific nature of the fungi composing these photomorphs. In this study, we employed a phylogenetic framework to validate the conspecificity of photomorph pairs within three species indigenous to the Americas: Nephroma kuehnemannii, Ricasolia quercizans and Sticta ainoae. Consequently, Nephroma microphyllum is considered a synonym of N. kuehnemannii, Dendriscocaulon intricatulum a synonym of R. quercizans, and free-living Chilean dendriscocauloid lichens are shown to be cyanomorphs of S. ainoae. A species distribution modeling approach to investigate the geographical distribution and niche characteristics of photomorphs within R. quercizans in eastern North America revealed that its two photomorphs exhibit distinct distributions and ecological niches, suggesting potential adaptations to different environmental conditions. The confirmed conspecificity and niche variation among the considered photomorphs provide insights into the ecological and evolutionary dynamics of these symbiotic associations. [ABSTRACT FROM AUTHOR]

A lichenicolous species, Calicium ramboldiicola , growing on Ramboldia elabens is described. In phylogenetic analyses with 22 Calicium taxa, based on 121 sequences from five DNA regions (mtSSU, Mcm7 , nuITS, nuLSU, β-tubulin), the new species formed a strongly supported clade with C. abietinum and C. verrucosum. Although the ascomata of the new species resemble miniatures of those of C. abietinum , no morphological synapomorphies for this clade were found. Calicium ramboldiicola is known from boreal and hemiboreal areas of northern Europe and north-eastern North America. It is the second known lichenicolous species of Calicium and the first found on a lichen in the Lecanorales. [ABSTRACT FROM AUTHOR]

Umbilicaria ahtii sp. nov. is described based on morphological and molecular characters. The new species resembles Umbilicaria vellea but the former has larger and submuriform ascospores, a darker lower surface, longer dark brown to black rhizinomorphs, and lacks thalloconidia directly on the lower surface and basal part of the rhizinomorphs. Phylogenetic analyses (ITS, mtLSU and RPB 2) confirmed the distinctness of U. ahtii and indicated its sister relationship to U. meizospora. Umbilicaria ahtii is described from Finland and is currently known from several localities in Northern Europe (Svalbard, Norway, Finland, Kola Peninsula in Russia), Asia (Kodar Range, Siberia) and North America (Alaska). Within the U. vellea group, new molecular data confirmed U. koidzumii as a widespread, separate species sister to U. cinereorufescens. Diagnostic traits and variability of species, as well as their distribution patterns and nomenclature, are discussed. [ABSTRACT FROM AUTHOR]

The pale yellowish tint of usnic acid in a lichen thallus itself is a commonly used character in identification keys, particularly in the genus Cladonia. Furthermore, the presence of usnic acid is phylogenetically significant in numerous groups of lichens. While the distinctive colour of usnic acid is readily visible when present in high concentrations, it is commonly problematic to discern when in low to moderate concentrations. We explored the use of an anisaldehyde reagent for visualizing usnic acid. Using both usnic acid-containing Cladonia samples and pure usnic acid, this reaction quickly yields a bright magenta colour on HPTLC and TLC plates after heating and directly with crude acetone extracts on glass slides heated with a lighter. The same magenta product was observed whether or not the usnic acid was accompanied by barbatic, fumarprotocetraric, psoromic, squamatic or thamnolic acids, each of which alone did not produce any colour with anisaldehyde reagent. However, the merochlorophaeic acids in C. albonigra also produced a red reaction. Analysis by high resolution LC-MS of the reaction mixture between anisaldehyde and usnic acid revealed several ions at m/z 477.1586 ([M+H]+, C27H25O8) and 463.1385 ([M+H]+, C26H23O8), respectively, consistent with aldol condensation of usnic acid and p -anisaldehyde. [ABSTRACT FROM AUTHOR]

Simple Summary: This paper reports on three new species and a new record of the lichen genus Peltula Nyl., highlighting research progress on lichen diversity in Helan Mountain. In this study, species were identified through a combination of morpho-anatomy, molecular systematics, and chemical substance detection. The results of the study enrich the data of Peltula and the study of lichens in Helan Mountain. In this study, a systematic taxonomic analysis was carried out on the lichen genus Peltula, collected from Helan Mountain in China; three new species (Peltula helanense, P. overlappine, and P. reticulata) and a new record (P. crispatula (Nyl.) Egea) for China were identified. Four species were identified by morph-anatomical, chemical, and phylogenetic analyses by combining two gene loci (ITS and LSU). Peltula helanense is with tiny individual thalli up to 1mm, attached by creamy-white cylindrical rhizoids and apothecia filling the whole squamule. Peltula overlappine is characterized by thallus squamulose forming rosette-shaped patches and squamules with distinctive thickened margins. Peltula reticulata is characterized by brownish brown thallus and squamules with densely reticulate upper surface. P. crispatula is characterized by irregular squamules attached to a tuft of hyphae. The four species are described in detail, compared, and discussed with similar species, and images of morpho-anatomical structures of the four species are also provided. Moreover, a key to the species of Peltula from Helan Mountain is provided. The results enrich the data of the genus Peltula and also indicate that the rich diversity of lichen species in Helan Mountain is worthy of in-depth study. [ABSTRACT FROM AUTHOR]

Background: Lichens, traditionally considered as a simple partnership primarily between mycobiont and photobiont, are, in reality, complex holobionts comprised of a multitude of microorganisms. Lichen mycobiome represents fungal community residing within lichen thalli. While it is acknowledged that factors like the host lichen species and environmental conditions influence the structure of the lichen mycobiome, the existing research remains insufficient. To investigate which factor, host genus or location, has a greater impact on the lichen mycobiome, we conducted a comparative analysis of mycobiomes within Parmelia and Peltigera collected from both Turkey and South Korea, using high-throughput sequencing based on internal transcribed spacer region amplification. Results: Overall, the lichen mycobiome was dominated by Capnodiales (Dothideomycetes), regardless of host or location. At the order level, the taxonomic composition was not significantly different according to lichen genus host or geographical distance. Hierarchical clustering of the top 100 abundant ASVs did not clearly indicate whether the lichen mycobiome was more influenced by host genus or location. Analyses of community similarity and partitioning variables revealed that the structure of the lichen mycobiome is more significantly influenced by location than by host genus. When analyzing the core mycobiome by host genus, the Peltigera mycobiome contained more ASV members than the Parmelia mycobiome. These two core mycobiomes also share common fungal strains, including basidiomycete yeast. Additionally, we used chi-squared tests to identify host genus-specialists and location-specialists. Conclusions: By comparing lichen mycobiomes of the same genera across different countries, our study advances our comprehension of these microbial communities. Our study elucidates that, although host species play a contributory role, geographic distance exerts a more pronounced impact on the structure of lichen mycobiome. We have made foundational contributions to understanding the lichen mycobiome occupying ecologically crucial niches. We anticipate that broader global-scale investigations into the fungal community structures will provide more detailed insights into fungal residents within lichens. [ABSTRACT FROM AUTHOR]

Background and Aims There is growing interest in the functional ecology of poikilohydric non-vascular photoautotrophs (NVPs), including 'cryptogamic' bryophytes and lichens. These organisms are structurally important in many ecosystems, contributing substantially to ecosystem function and services, while also being sensitive to climate change. Previous research has quantified the climate change response of poikilohydric NVPs using predictive bioclimatic models with standard climate variables including precipitation totals and temperature averages. This study aimed for an improved functional understanding of their climate change response based on their growth rate sensitivity to moisture and light. Methods We conducted a 24-month experiment to monitor lichen hydration and growth. We accounted for two well-known features in the ecology of poikilohydric NVPs, and exemplified here for a structurally dominant lichen epiphyte, Lobaria pulmonaria : (1) sensitivity to multiple sources of atmospheric moisture including rain, condensed dew-formation and water vapour; and (2) growth determined by the amount of time hydrated in the light, driving photosynthesis, referred to as the I wet hypothesis. Key Results First, we found that even within an oceanic high-rainfall environment, lichen hydration was better explained by vapour pressure deficit than precipitation totals. Second, growth at a monthly resolution was positively related to the amount of time spent hydrated in the light, and negatively related to the amount of time spent hydrated in the dark. Conclusions Using multimodel averaging to project growth models for an ensemble of future climate change scenarios, we demonstrated reduced net growth for L. pulmonaria by the late 21st century, explained by extended climate dryness and lichen desiccation for periods when there is otherwise sufficient light to drive photosynthesis. The results further emphasize a key issue of photoperiodism when constructing functionally relevant models to understand the risk of climate change, especially for poikilohydric NVPs. [ABSTRACT FROM AUTHOR]

During a recent expedition of the Eurasian Dry Grassland Group in the steppes of southern Ukraine, we discovered on sand dunes a new sterile crustose aspicilioid lichen with rhizomorphs. It is described here as new to science under the name Circinaria ucrainica (Megasporaceae). The new combination Circinaria reptans (Looman) Khodos. & Darmostuk is also proposed. Circinaria ucrainica is characterized by small grey areoles with a net of dark grey to brownish spicate prothalline tips and pale rhizomorphs. According to the phylogenetic analysis, the new species is closely related to the terricolous Circinaria reptans , but the latter has thicker rhizomorphs of 200–400 μm diameter, finely developed areoles and lacks spicate prothalline tips. Furthermore, we discuss the differences between the new species and other morphologically similar species with rhizomorphs, such as Aspicilia spicata , Circinaria crespiana and C. reptans. The ecological characters of soil and vegetation, including vascular plants, bryophytes and lichens, are provided for the habitat of C. ucrainica. [ABSTRACT FROM AUTHOR]

This research presents the contents of K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Rb, Sr, and Pb in lichen and moss samples used as biomonitors of air pollution collected in Ulaanbaatar city. X‐ray fluorescence (XRF) methods were used, employing for excitation a Pd X‐ray tube with a molybdenum secondary target. Matrix effects were corrected by the use of normalization for the coherent and incoherent scattered peak, in this way the determination is more efficient. For quality control of the results, comparisons were made with results from other certified laboratories. No significant differences were found between the different techniques. The elemental distribution patterns obtained for each metal were associated with different pollution sources, thus contributing to the assessment of air pollution in Ulaanbaatar. [ABSTRACT FROM AUTHOR]

Oceanic islands have been recognized as natural laboratories in which to study a great variety of evolutionary processes. One such process is evolutionary radiations, the diversification of a single ancestor into a number of species that inhabit different environments and differ in the traits that allow them to exploit those environments. The factors that drive evolutionary radiations have been studied for decades in charismatic organisms such as birds or lizards, but are lacking in lichen-forming fungi, despite recent reports of some lineages showing diversification patterns congruent with radiation. Here we propose the Ramalina decipiens group as a model system in which to carry out such studies. This group is currently thought to be comprised of five saxicolous species, all of them endemic to the Macaronesian region (the Azores, Madeira, Selvagens, Canary and Cape Verde islands). Three species are single-island endemics (a rare geographic distribution pattern in lichens), whereas two are widespread and show extreme morphological variation. The latter are suspected to harbor unrecognized species-level lineages. In order to use the Ramalina decipiens group as a model system it is necessary to resolve the group's phylogeny and to clarify its species boundaries. In this study we attempt to do so following an integrative taxonomy approach. We constructed a phylogenetic tree based on six molecular markers, four of which are newly developed and generated competing species hypotheses based on molecular (species discovery strategies based on both single locus and multilocus datasets) and phenotypic data (unsupervised clustering algorithms based on morphology, secondary chemistry and geographic origin). We found that taxonomic diversity in the Ramalina decipiens group has been highly underestimated in previous studies. In consequence, we describe six new species, most of them single-island endemics and provide a key to the group. Phylogenetic relationships among species have been reconstructed with almost full support which, coupled with the endemic character of the group, makes it an excellent system for the study of island radiations in lichen-forming fungi. [ABSTRACT FROM AUTHOR]

Lichens, a diverse group of organisms, have a unique structure consisting of fungal filaments and photosynthetic partner cells. This research conducted a comprehensive chemical analysis and evaluation of the anti-inflammatory and antioxidant properties of methanolic and acetone extracts from Umbilicaria crustulosa lichen, along with its isolated metabolites. The process involved separating atranorin and chloratranorin fractions, physodic acid, and gyrophoric acid. Secondary metabolites were identified using chromatographic and spectroscopic data. The total polyphenols content was determined spectrophotometrically. This study examined the antioxidant activity of extracts of the lichen U. crustulosa and the isolated fractions using three methods: DPPH scavenging activity, ABTS scavenging activity, and reducing power. This study also evaluated the acute oral toxicity and the anti-inflammatory activity of the extracts in Wistar albino rats. A higher content of the total phenolic compounds was found in the acetone extract, but antioxidant and anti-inflammatory activities were more prominent in the methanolic extract. The isolated atranorin and chloratranorin fractions and compound physodic acid showed the highest antioxidant activity. No toxic effects were noted in the acute oral toxicity study. This study highlights the potential of the investigated lichen as a valuable source of novel biological agents. [ABSTRACT FROM AUTHOR]

Parmotrema perlatum, a lichen belonging to the family Parmeliaceae, is well known for its culinary benefits and aroma used as a condiment in Indian homes is also known as the "black stone flower" or "kalpasi" in India. This research intends to analyze the antioxidant power of the crude extracts using four pH‐based buffers solubilized proteins/peptides and RP‐HPLC fractions of P. perlatum obtained by purification. The proteins that were extracted from the four different buffers were examined using LC‐MS/MS‐based peptide mass fingerprinting. When compared to the other buffers, the 0.1 M of Tris‐HCl buffer pH 8.0 solubilized proteins/peptides had the strongest antioxidant capacity. The sequential purification of the peptide was carried out by using a 3‐kDa cut‐off membrane filter and semipreparative RP‐HPLC. Additionally, the purified fractions of the peptide's antioxidant activity were assessed, and effects were compared with those of the crude and 3 kDa cut‐‐off membrane filtrates. The peptide fractions were sequenced by LC‐MS/MS, which reveals that fraction 2 from RP‐HPLC with the sequence LSWFMVVAP has shown the highest antioxidant potential in comparison with other fractions which can serve as the potential natural antioxidant drug. Further, fraction 2 also showed antibacterial activity against the selected microorganisms. [ABSTRACT FROM AUTHOR]

Dirinaria picta is a lichen species known for its tolerance to air pollution and its ability to accumulate pollutants in its thallus, making it a suitable bioindicator in urban areas. This study aims to assess the response of lichens to air pollution by examining their morphological characteristics, analyzing the presence of magnetic grains, and identifying the origin of elements in their tissues. Samples were collected from three locations in Bandung area which represent polluted areas, namely Juanda Street (JD) and Kebon Kawung (KK), and Padalarang Street (PD) and one location which represent as a control area with low pollution levels, namely Curug Cimahi (CC). Lichen microstructure scanning was performed using a Scanning Electron Microscope (SEM), and the presence of elements was detected through Energy Dispersive X-ray Spectroscopy (EDS). The SEM analysis revealed that samples from areas with higher air pollution levels exhibited obvious damage to their thallus, characterized by a more porous structure and the presence of cuboidal particles. Conversely, samples from control area showed a more compact structure. The EDS observations identified 14 elements present in the lichen tissues, ranked in descending order of abundance: C>Ca>O>Pb>Cu>Mn>Zn>Fe>Cr>Al>Cl>Se>Cd>K. The composition and quantity of these elements in lichen tissues were influenced by the level of air pollution generated by the number of vehicles passing through the area. The more vehicles, the higher the level of air pollution, resulting in greater stress for the D. picta population. [ABSTRACT FROM AUTHOR]

Environmental filtering and competition are two fundamental processes that shape plant community assembly in terms of functional composition, that is, the distribution of trait values. Understanding the role of these two processes in the assembly of non‐vascular vegetation, such as bryophytes and lichens, is important since these communities provide essential ecosystem services in many regions around the world, and these depend on functional composition. Responses of non‐vascular communities to environmental selection pressures have been explored in a range of experimental and modelling studies. However, it is still largely unknown to what extent competition affects the distribution of functional traits of non‐vascular communities. Moreover, it remains poorly explored which traits that are associated with competition are key for shaping community functional assembly.Here, we integrated a field transplantation experiment with a process‐based model to disentangle the effects of environmental filtering and competition on the assembly of non‐vascular communities. Following the validation of environmental selection in the model using field observations, we performed a simulation experiment to understand the impacts of competition on trait distributions in non‐vascular communities growing in two temperate locations that differ in microclimatic conditions (a shaded and an open location).Our results suggest that the functional composition is likely a result of weak competition or may not depend on competitive exclusion at all while environmental filtering plays an essential role. Plant height seems to be a key trait for competition. However, no single‐trait competition scheme could consistently explain the observed functional composition of the studied non‐vascular communities.Synthesis. The presented model provides a new trait‐based approach for simulating the functional assembly of non‐vascular communities. Environmental filtering appears to be more essential than competition for predicting trait distributions of non‐vascular communities under temperate climatic conditions and we recommend caution in associating competition to a single trait while analysing community functional assembly. [ABSTRACT FROM AUTHOR]

The foliicolous lichen Gallaicolichen pacificus exhibits unique goniocystangia-like structures named peltidiangia and peltidia. Its taxonomic classification within the Ascomycota has been unclear due to the absence of ascomata and lack of molecular data. Here we clarify the phylogenetic affinities of Gallaicolichen pacificus by analyzing mitochondrial small subunit ribosomal RNA (mtSSU) sequences obtained from specimens collected in New Caledonia. Ascomata and ascospores of G. pacificus , previously unknown, are described and illustrated for the first time. The results from the molecular and morphological analyses clearly indicate that Gallaicolichen pacificus belongs to the Porinaceae and is closely related to Porina guianensis. This is a remarkable extension of the already known, wide morphological diversity of thalli and diaspores produced within this family. [ABSTRACT FROM AUTHOR]

This research explores an environmentally friendly alternative: lichens, which produce natural compounds with antioxidant effects. This study focuses on the inhibition of corrosion by lichens, which has not been previously explored for this purpose. The anti‐corrosion potential of methanol extracts of Parmotrema hypoleucinum, Roccella phycopsis, and Xanthoria parietina was examined. The electrochemical impedance and weight loss methods were used to examine the corrosion inhibition process of mild steel XC48 in 1 M HCl by three lichen extracts. [ABSTRACT FROM AUTHOR]

Arthopyrenia parolinii Beltr. is one of the few species of the lichen genus Arthopyrenia A. Massal. described by Italian authors of the XIX century, lacking type formal association. In this regard, the name Arthopyrenia parolinii is hereby lectotypified using a specimen stored in the lichen herbarium of A.B. Massalongo at VER. Additional original material was found only at M, while another specimen at MSNVE , labelled as Spermatodium parolinii, although referable to this species, should not be considered as original material. Arthopyrenia parolinii is among the least well-known species in the genus. Given the genus Arthopyrenia is still very poorly known, it is important to clarify the original material of the species and propose the lectotyping. The selected lectotype is the only sample among the analyzed ones reporting complete data on the locus classicus; it conforms to the characters described in the protologue and comes from the Herbarium Beltramini. [ABSTRACT FROM AUTHOR]

Question: What are the extent and the possible causes of imperfect detection in lichens? Because lichens are sessile and lack seasonality, they should be easier to survey than animals that can move or plants and fungi with seasonal morphology, and one could therefore expect relatively high detection probabilities. Location: 826 standardised sampling plots across Switzerland. Methods: Using repeated detection/non‐detection data from a national lichen survey conducted by professional lichenologists, we estimated the mean and variation in detectability for 373 tree‐living species with a multi‐species occupancy model. We also quantified the effect of species conspicuousness, identifiability and observer experience on detection probability. Results: The average detection probability for a single survey was unexpectedly low with an average of 0.49 (range across species: 0.25–0.74). Conspicuous species showed higher average detectability (0.56) than inconspicuous species (0.41), and identifiability as well as previous experience with a species substantially increased the probability of a person detecting it. Accounting for experience, the mean detection probabilities of observers ranged from 0.32 to 0.69. Conclusions: Our study confirms that detection probability per survey is often far below 1 also in sessile organisms, even when a standardised survey is conducted by experts. When species are seasonal (plants, fungi, etc.), survey areas are larger, or field personnel are less experienced, as is the case for many surveys and monitoring programs, detectabilities are likely to be substantially lower. We therefore argue that imperfect detection should systematically be considered in the survey design and data analysis also for sessile organisms. [ABSTRACT FROM AUTHOR]

Lichens are combinations of two symbiotic organisms, a green alga or cyanobacterium and a fungus. They grow in nearly all terrestrial ecosystems and survive in habitats, which are very dry or cold, or too poor in nutrients to maintain vegetation growth. Because lichens grow on visible surfaces and exhibit spectral properties, which are clearly different from, for example, vegetation, it is possible to distinguish them in remote sensing data. In this first systematic review article on remote sensing of lichens, we analyze and summarize which lichen species or genera, and in which habitats and geographical regions, have been remotely sensed, and which remote sensing or spectroscopic technologies have been used. We found that laboratory or in situ measured spectra of over 70 lichen species have been reported to date. We show that studies on remote sensing of lichens fall under seven broad themes: (1) collection of lichen spectra for quantification of lichen species or characteristics, (2) pollution monitoring with lichens as ecological indicators, (3) geological and lithological mapping, (4) desert and dryland monitoring, (5) animal habitat monitoring, (6) land cover or vegetation mapping, and (7) surface energy budget modeling. [ABSTRACT FROM AUTHOR]

In traditional medicine, people commonly consume Bryoria capillaris (BC) as flour and tea, particularly in Northeast Anatolia, where it is one of the most prevalent lichen species. This study aimed to obtain an acetone extract of BC and investigate its inhibitory effects on carbonic anhydrase (CA) I, CA II, acetylcholine esterase (AChE), and butyrylcholine esterase (BChE) enzymes. We determined IC50 values of BC for each enzyme to measure the level of inhibition. The IC50 values for CA I and CA II were 8.77 µg/mL and 7.56 µg/mL, respectively. Acetazolamide, a specific CA I and II inhibitor, had IC50 values of 1.65 and 0.016 µg/mL, respectively. The IC50 values of BC for AChE and BChE were 7.96 and 8.58 µg/mL, respectively. Galantamine had IC50 values of 4.68 and 16.07 µg/mL for AChE and BChE, respectively. These results indicate that BC extract has a high potential to provide new drug candidates for all the tested enzymes, particularly for BChE. [ABSTRACT FROM AUTHOR]

The present study aims to explore the inhibitory action of lichen metabolites against important protein targets of marine fouling organisms using computational methods. Lichens with their unique ability to produce various secondary metabolites find versatile applications in Biotechnology and allied fields. The 3D structure of target proteins associated with fouling activity of marine organism were collected from the protein data bank (PDB) and the computational docking analysis was performed using the PyRx software with 40 lichen compounds that are collected from PubChem. The lichen compounds were docked against the following protein targets—mannose‐specific lectin CGL1 of Crassostrea gigas, Proximal thread matrix protein 1 PTMP 1 of Mytilus galloprovincialis, and G protein‐coupled receptor (GPCR) of Balanus amphitrite. As there was no experimentally determined structure available for GPCR of B. amphitrite, homology modeling was performed to predict the protein structure. The docking study showed effective binding of lichen compounds to various fouling targets with the binding energies in the range of −10.1 to −5 kcal/mol. Among the lichen compounds studied, roccanin showed the least binding energy for CGL1, PTMP1 and GPCR. The correlation assessments predict a positive relationship between binding energy, molecular weight and retention time. MD Simulation studies were performed using LARMD online tool and the RMSD and radius of gyration (Rg) values was recorded. This study proves that the compounds produced by lichens have high antifouling effect against marine foulers under in silico conditions. [ABSTRACT FROM AUTHOR]

Lichens represent a complex life form characterized by a symbiotic partnership between at least two organisms: a fungus and an alga. In this unique relationship, the fungus offers a protective habitat for the alga, which, in turn, harnesses energy from sunshine, water and air to provide sustenance for the fungus. They fulfill ecological roles as a food source for many invertebrates and serve as the basal trophic level for a variety of animals, being considered micro-ecosystems which can host a rich and diverse biota. Nematodes are among the most widespread and abundant of all metazoans, inhabit moist interstitial environments in all habitats and are abundant in marine and freshwater benthic habitats and in the soil. They were also reported from accumulations of detritus in leaf axils, in the angles of tree branches and in mosses and lichens. In this case study, the trophic role and diversity of free-living nematodes associated with lichens were examined in an area of Buenos Aires province, Argentina, revealing seven genera of nematodes linked to Heterodermia diademata, representing all trophic levels of free-living nematodes: bacteriophages (Plectus and Acrobeles), fungivores (Aphelenchus), herbivores (Helicotylenchus), omnivores (Eudorylaimus and Mesodorylaimus) and a predator (Prionchulus). [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the chemical composition of methanol extracts of the lichens Pleurosticta acetabulum and Cladonia subulata and their antioxidant, and anticancer activities. The phytochemical analysis of the extracts of lichens was determined by HPLC-UV method. The predominant phenolic compounds in these extracts were norstictic acid and salazinic acids in P. acetabulum, while hypoprotocetraric acid and fumarprotocetraric acid were the major metabolites detected in C. subulata. Total phenolics and flavonoids in the extracts were determined spectrophotometrically, with the varied amount from 21.31 to 73.45 mg GA/g and from 8.48 to 15.42 mg RU/g, respectively. The lichen extracts showed comparable and strong antioxidant activity, exhibited higher DPPH and hydroxyl radical scavengings, inhibitory activity towards lipid peroxidation and reducing power. Cytotoxic effects of lichens were tested against HeLa S3 and LS174 cell lines using MTT method.The cytotoxic effects of P. acetabulum and C. subulata extracts toward two cancer cell lines were in the range from 39.17 to >200 μg/mL IC50 value. The present study showed that the tested extracts of lichens demonstrated important antioxidant and anticancer effects. That suggests that these lichens can be used as new sources of the natural antioxidants and anti-cancer compounds. [ABSTRACT FROM AUTHOR]

Snow is the largest component of the cryosphere, with its cover and distribution rapidly decreasing over the last decade due to climate warming. It is imperative to characterize the snow (nival) microbial communities to better understand the role of microorganisms inhabiting these rapidly changing environments. Here, we investigated the core nival microbiome, the cultivable microbial members, and the microbial functional diversity of the remote Uapishka mountain range, a massif of alpine sub-arctic tundra and boreal forest. Snow samples were taken over a two-month interval along an altitude gradient with varying degree of anthropogenic traffic and vegetation cover. The core snow alpine tundra/boreal microbiome, which was present across all samples, constituted of Acetobacterales, Rhizobiales and Acidobacteriales bacterial orders, and of Mycosphaerellales and Lecanorales fungal orders, with the dominant fungal taxa being associated with lichens. The snow samples had low active functional diversity, with Richness values ranging from 0 to 19.5. The culture-based viable microbial enumeration ranged from 0 to 8.05 × 103 CFUs/mL. We isolated and whole-genome sequenced five microorganisms which included three fungi, one alga, and one potentially novel bacterium of the Lichenihabitans genus; all of which appear to be part of lichen-associated taxonomic clades. [ABSTRACT FROM AUTHOR]

The genus Parvoplaca is extended with four new species: P. candanii from Antarctica, P. lamprocarpa from Alaska, and P. macroborealis and P. tenebrosa from Oregon. Collections identified as P. tiroliensis are shown to form two independent clades when DNA was analyzed, but it is currently not clear which clade represents the species in a strict sense. Parvoplaca athallina has been considered an Antarctic species, but according to our analyses, the species is shown to be bipolar occurring also in northern Europe, Greenland, Alaska and in California. [ABSTRACT FROM AUTHOR]

Clove essential oil with eugenol as the major compound was used to develop a biopesticide formulation for lichens. Due to the suboptimal effectiveness and high volatility, the present research aimed to prepare a stable and effective deliverable nano biopesticide formulation by adding AgNO3 powder to clove essential oil. The analysis was carried out with several variations: Storage time, AgNO3 concentration, and the effect of adding emulsifiers like Tween 80 and PEG 400. Biopesticide formulations were characterized using a ultraviolet-visible spectrophotometer, Fourier transform infrared, pore size analyzer, and scanning electron microscope-energy dispersive X-ray. The effectiveness of inhibiting lichen growth was determined through an inhibition test. The results showed that the effective biopesticide formulation with AgNO3 was obtained at 429-475 nm wavelength, with a particle size of 217 nm and a PI value below 0.5. To reduce the particle size further, the addition of Tween 80 and PEG 400 in the process showed that the particle size achieved was 111.8-172.2 nm with round and irregular morphology, close to the nanoparticle size, and a suitable nanoemulsion formulation. Clove essential oil biopesticide modified with AgNO3, Tween 80, and PEG 400 effectively inhibited lichen growth with an average inhibition zone diameter of 33-37 mm compared to 36.4 mm in positive control and no inhibition in negative controls. [ABSTRACT FROM AUTHOR]

Lichens are poikilohydric organisms and an important part of the ecosystem. They show high desiccation tolerance, but the mechanism of dehydration resistance still needs to be studied. The photosynthesis recovery of the photobiont in rehydrated lichen Cladonia stellaris after 11-year desiccation was investigated by simultaneously monitoring both photosystem I and II (PSI and PSII) activities. The responses of the photochemical efficiency and relative electron transport rate (rETR) of PSI and PSII, and the quantum yield of the cyclic electron flow (CEF) were measured using a Dual-PAM-100 system. PSI recovered rapidly, but PSII hardly recovered in C. stellaris during rehydration. The maximal photochemical efficiency of PSII (Fv/Fm) was generally very low and reached about just 0.4 during the rehydration. These results indicated that PSII had restored little and was largely inactivated during rehydration. The quantum yield of PSI recovered quickly to almost 0.9 within 4 h and remained constant at nearly 1 thereafter. The results showed that the activation of the CEF in the early stages of rehydration helped the rapid recovery of PSI. The quantum yield of the CEF made up a considerable fraction of the quantum yield of PSI during rehydration. A regulated excess energy dissipation mechanism and non-photochemical quenching (NPQ) also recovered. However, the small extent of the recovery of the NPQ was not enough to dissipate the excess energy during rehydration, which may be responsible for the weak activity of PSII during rehydration. The results indicated that both CEF and NPQ were essential during the rehydration of the photobiont in C. stellaris. The methods used in the measurements of chlorophyll a fluorescence and P700+ absorbance changes in this study provided a speedy and simple way to detect the physiological characteristics of the photobionts of lichen during rehydration. This work improves our understanding of the mechanism behind lichen's desiccation tolerance. [ABSTRACT FROM AUTHOR]

Background: Lichens are symbiotic organisms composed of a fungus and a photosynthetic partner, which are key ecological bioindicators due to their sensitivity to environmental changes. The endolichenic fungi (ELF) living inside lichen thalli, are an important but understudied component of playing crucial ecological roles such as nutrient cycling and protection against environmental stressors. Therefore ELF community investigation is vital for fostering sustainable ecosystems and leveraging their ecological benefits. Deciphering the intricate relationships between ELF and their lichen hosts, alongside the influence of environmental factors on these communities, presents a significant challenge in pinpointing the underlying drivers of community structure and diversity. Results: Our research demonstrated that locational factors were the main drivers of the ELF community structure, rather than host haplotype. Several climatic factors affected the diversity of the ELF community and contributed to the prevalence of different types of fungal residents within the ELF community. A decrease in isothermality was associated with a greater prevalence of pathotrophic and saprotrophic fungi within the ELF community, resulting in an overall increase in community diversity. By conducting a structural equation modeling analysis, we identified a robust link between climatic variables, fungal trophic mode abundance, and the species diversity of the ELF community. Conclusion: This study's discoveries emphasize the significance of examining climate-related factors when investigating ELF's structure and function. The connection between fungi and climate is intricate and complex, and can be influenced by various other factors. Investigating the potential for ELF to adapt to changing climatic conditions, as well as the potential effects of changes in ELF communities on lichen function, would be valuable research areas. We anticipate that our research results will establish a basis for numerous future ELF research projects and have a significant impact on the field. [ABSTRACT FROM AUTHOR]

Background: Lichens represent not only the mutualism of fungal and photosynthetic partners but also are composed of microbial consortium harboring diverse fungi known as endolichenic fungi. While endolichenic fungi are known to exert a remarkable influence on lichen ecology through their crucial roles in nutrient cycling, bioprospecting and biodiversity, the enigmatic community structures of these fungal inhabitants remain shrouded in mystery, awaiting further exploration and discovery. To address knowledge gap, we conducted metabarcoding on two lichens using 18S gene amplification, Dirinara applanta and Parmotrema tinctorum, and compared their microbial communities to those found in the pine bark to which the lichens were attached. Our hypothesis was that the endolichenic communities would exhibit distinct diversity patterns, community structures, network structures, and specialist composition compared to the surrounding epiphytic community. Results: Our investigation has shed light on the clear demarcation between the endolichenic and epiphytic fungal communities, as they exhibit markedly different characteristics that set them apart from each other. This research demonstrated that the endolichenic communities are less diverse as compared to the epiphytic communities. Through community similarity analysis, we observed that two endolichenic communities are more similar to each other in terms of community composition than with the adjacent epiphytic communities. Moreover, we unveiled a striking contrast in the network structures between the endolichenic and epiphytic communities, as the former displayed a more modular and less nested features that is evocative of a potent host-filtration mechanism. Conclusions: Through our investigation, we have discovered that lichens harbor less intricate and interconnected fungal communities compared to the neighboring epiphytic environment. These observations provide valuable insights into the metagenomic architecture of lichens and offer a tantalizing glimpse into the unique mycobiome. [ABSTRACT FROM AUTHOR]

Lichens play crucial roles in the ecosystems, contributing to soil formation and nutrient cycling, and being used in biomonitoring efforts to assess the sustainability of ecosystems including air quality. Previous studies on heavy metal accumulation in lichens have mostly relied on manipulated environments, such as transplanted lichens, leaving us with a dearth of research on how lichens physiologically respond to heavy metal exposure in their natural habitats. To fill this knowledge gap, we investigated lichens from two of South Korea's geographically distant regions, Gangwon Province and Jeju Island, and examined whether difference in ambient heavy metal concentrations could be detected through physiological variables, including chlorophyll damage, lipid oxidation, and protein content. The physiological variables of lichens in response to heavy metals differed according to the collection area: Arsenic exerted a significant impact on chlorophyll degradation and protein content. The degree of fatty acid oxidation in lichens was associated with increased Cu concentrations. Our research highlights the value of lichens as a bioindicator, as we found that even small variations in ambient heavy metal concentrations can be detected in natural lichens. Furthermore, our study sheds light on which physiology variables that can be used as indicators of specific heavy metals, underscoring the potential of lichens for future ecology studies. [ABSTRACT FROM AUTHOR]

A species of the genus Ramalea, R. coilophylla, was recollected at the type locality and an additional large population was found in another state, Espírito Santo, in Brazil. This enabled a morphological study showing that the podetia arise from the margins of primary squamules. Sequencing showed the species and, because it is very similar to the type species, the genus, which was lastly cited as incertae sedis, to belong to the Ramalinaceae. A new species from the Amazon was also shown to belong to the Ramalinaceae and the new genus Appressodiscus is erected to accommodate this species, as well as a species that was recently described in the genus Ramboldia. New lichen species are Appressodiscus isidiobadius and Lecania variocolorata, and Appressodiscus badius is a new combination. [ABSTRACT FROM AUTHOR]

Biofouling is a significant problem in various industries, including marine, medical, and water treatment. It occurs when microorganisms, such as bacteria, fungi, and algae, attach to surfaces and form biofilms, which can lead to material degradation, decreased performance, and increased maintenance costs. Traditional approaches to mitigate biofouling include the use of biocides, physical cleaning, and chemical treatments. However, these methods have limitations, such as environmental concerns, short-term effectiveness, and development of resistant organisms. One alternative approach is the use of lichenassociated symbionts, which have been found to produce compounds that inhibit biofilm formation and growth. These compounds could be used to develop eco-friendly and sustainable antifouling coatings. Another promising approach is the use of nanotechnology to develop novel coatings that prevent biofouling. Nanomaterials can be engineered to have hydrophobic structures, which deter microorganisms from attaching to surfaces. They can also be designed to contain nano biocides, which can kill organisms that come into contact with the surfaces. Overall, the use of lichen-associated symbionts and nanotechnology holds great potential for developing effective and sustainable solutions to mitigate biofouling. However, further research is needed to optimize these approaches and ensure their safety and efficacy in various applications. This review offers a brief overview on the mechanisms of biofouling and evaluate the potential of using lichen-associated symbionts and nanotechnology to prevent or reduce biofouling. [ABSTRACT FROM AUTHOR]

Biotic and abiotic factors influence the formation of fungal–algal pairings in lichen symbiosis. However, the specific determinants of these associations, particularly when distantly related fungi are involved, remain poorly understood. In this study, we investigated the impact of different drivers on the association patterns between taxonomically diverse lichenized fungi and their trebouxioid symbiotic partners. We collected 200 samples from four biomes and identified 41 species of lichenized fungi, associating them with 16 species of trebouxioid green algae, of which 62% were previously unreported. The species identity of both the fungal and algal partners had the most significant effect on the outcome of the symbiosis, compared to abiotic factors like climatic variables and geographic distance. Some obviously specific associations were observed in the temperate zone; however, the nestedness value was lower in arid regions than in cold, polar, and temperate regions according to interaction network analysis. Cophylogenetic analyses revealed congruent phylogenies between trebouxioid algae and associated fungi, indicating a tendency to reject random associations. The main evolutionary mechanisms contributing to the observed phylogenetic patterns were "loss" and "failure to diverge" of the algal partners. This study broadens our knowledge of fungal–algal symbiotic patterns in view of Trebouxia-associated fungi. [ABSTRACT FROM AUTHOR]

Some trace elements in various lichens as biomonitors of pollution were investigated. Also, the pollution status was assessed by enrichment factor, contamination factor, and pollution load index. Investigated elements were Ta, Bi, Hf, Nb, Ga, Sc, Li, Y, Ce, and Sr. The lichen species were Rhizoplaca chrysoleuca, Umbilicaria vellea, Aspicilia calcarea, Pseudevernia furfuracea, and Cetraria islandica. According to the results, lichen species accumulate Sr element well. The highest trace element accumulated by Pseudevernia furfuracea (21.7±1.0 mg/kg; 75%), Rhizoplaca chrysoleuca (31.9±1.6 mg/kg; 61%), Umbilicaria vellea (16.3±0.8 mg/kg; 59%), Aspicilia calcarea (77.9±3.8 mg/kg; 88%), and Cetraria islandica (22.7±1.1 mg/kg; 75%) was determined as Sr. The highest CFs in lichens investigated were calculated for Sr, Ta, and Li. PLI values for Cetraria islandica, Aspicilia calcarea, and Umbilicaria vellea were greater than 1. As a result, it has been proven that these lichen species can be used as good biomonitors of pollution. [ABSTRACT FROM AUTHOR]

Lichens, a symbiotic association of fungi and algae, are suitable to serve as a bio-indicator of air pollution due to their ability to absorb toxic materials into their thallus. The photobiont performs photosynthesis; it belongs to blue-green algae, i.e. cyanobacteria and/or green algae; a mycobiont is a fungus from the Ascomycetes, Basidiomycetes or Deuteromycetes group. Biodiversity Index (LBI) which was used to determine the effect of phytotoxic gases released from pollutants on the diversity of lichens, especially on Level II Sample Plots with conifers. One of the goals of the study is to determine which species of lichen are the most tolerant and the most sensitive to air pollution. This is one of several different methods that have been developed to monitor the environmental quality. One of them, which was used as basis for obtaining the basic statistical parameters, with the subsequently used T-test that confirmed some of the basic initial assumptions, is the significance of sample surface coverage by lichens. The percentages of lichen coverage of the recordings were obtained with basic photo processing programs, most simply viewed in black and white technique. The results are represented graphically through maps. Different aspects of the current biomonitoring should be compared to the results obtained in practice to date, in order to increase the number of the related studies in the years to come. Lastly, the current studies, progress, and challenges of biomonitoring using lichen as a biological indicator were discussed, and relevant recommendations were formulated. [ABSTRACT FROM AUTHOR]

In the exploration of Sumatran lichen, phytochemical investigations were conducted on the lichen Cladonia crispata (Ach.) Flot. The working process started with maceration, non-polar, semi-polar, and polar solvents. For the purification process, column chromatography was used to obtain squamatic acid (1) and barbatic acid (2). These compounds were identified spectroscopically (UV-vis-IR-MS-NMR). Furthermore, antibacterial activity from the extract and isolated compounds against seven pathogenic bacteria were evaluated. The ethyl acetate extract significantly inhibited all tested bacteria in the concentration range of 250-2000 μg/disc. Regarding the isolated compound, barbatic acid had the potential as an antibacterial agent at a concentration of 12.5-50 μg/disc, followed by squamatic acid. In the in silico study, the absorption, distribution, metabolism, excretion, and toxicity (ADMET) prediction and molecular docking simulation were conducted for both compounds to understand the action mechanism of the two compounds as antibacterial agents. [ABSTRACT FROM AUTHOR]

Lecanora caledonica is described as new to science. Molecular analyses show that it belongs to the L. intumescens group. It is also rather similar in appearance to L. intumescens , but differs mainly chemically in containing only atranorin and an unknown UV+ ice blue substance. There are also anatomical and morphological differences to the other species of the group. The new species has a pronounced oceanic distribution and is so far known only from western Norway and Scotland. [ABSTRACT FROM AUTHOR]

Background and aims: Low productivity open lichen (Cladonia spp.) woodlands have been rapidly expanding in the closed-crown feather moss (Pleurozium schreberi (Brid.) Mitt.) boreal forest of eastern Canada. While open-woodland areas are progressing, there is little information on the recoverability of open lichen woodlands back to closed-canopy forests. Methods: An experimental set-up using moss transplantation was installed on a poor jack pine (Pinus banksiana Lamb.) stand with a lichen ground cover in 2011. Treatments included: 1) lichen cover removed, 2) lichen cover removed and transplantation of a feather moss cover, 3) lichen control, and 4) a natural jack pine site with feather moss cover (moss control). We extracted tree stem increment cores and collected needles and soil samples for nutrient analysis. Results: The transplanted-moss treatment can counteract the adverse effects of lichen on jack pine growth. This treatment enhanced foliar nutrition and soil nutrients, especially ammonium (N-NH4+) and nitrate (N-NO3−). With this treatment, the soil conditions (e.g., soil nutrients, soil moisture) and foliar nutrition were closer to that of moss control. Surprisingly, lichen removal treatment did not improve growth and resulted in poorer jack pine growth and harsher soil conditions. Conclusion: Feather moss can establish, survive, and remain healthy in an environment previously occupied by lichen. The replacement of lichen by feather moss establishes soil conditions that appear conducive to better tree growth and have the potential of restoring the productivity of boreal forests in open-canopy lichen woodlands. [ABSTRACT FROM AUTHOR]

Specialization, contextualized in a resource axis of an organism niche, is a core concept in ecology. In biotic interactions, specialization can be determined by the range of interacting partners. Evolutionary and ecological factors, in combination with the surveyed scale (spatial, temporal, biological, and/or taxonomic), influence the conception of specialization. This study aimed to assess the specialization patterns and drivers in the lichen symbiosis, considering the interaction between the principal fungus (mycobiont) and the associated Nostoc (cyanobiont), from a community perspective considering different spatial scales. Thus, we determined Nostoc phylogroup richness and composition of lichen communities in 11 Nothofagus pumilio forests across a wide latitudinal gradient in Chile. To measure specialization, cyanobiont richness, Simpson's and d′ indices were estimated for 37 mycobiont species in these communities. Potential drivers that might shape Nostoc composition and specialization measures along the environmental gradient were analysed. Limitations in lichen distributional ranges due to the availability of their cyanobionts were studied. Turnover patterns of cyanobionts were identified at multiple spatial scales. The results showed that environmental factors shaped the Nostoc composition of these communities, thus limiting cyanobiont availability to establish the symbiotic association. Besides, specialization changed with the spatial scale and with the metric considered. Cyanolichens were more specialized than cephalolichens when considering partner richness and Simpson's index, whereas the d′ index was mostly explained by mycobiont identity. Little evidence of lichen distributional ranges due to the distribution of their cyanobionts was found. Thus, lichens with broad distributional ranges either associated with several cyanobionts or with widely distributed cyanobionts. Comparisons between local and regional scales showed a decreasing degree of specialization at larger scales due to an increase in cyanobiont richness. The results support the context dependency of specialization and how its consideration changes with the metric and the spatial scale considered. Subsequently, we suggest considering the entire community and widening the spatial scale studied as it is crucial to understand factors determining specialization. [ABSTRACT FROM AUTHOR]

Individuals of Usnea fulvoreagens (Parmeliaceae, lichenised Ascomycota), a shrubby corticolous species that is widespread in Europe, East Asia and North America, produce medullary lichen acids in several distinct chemotypic patterns. One such chemotype reportedly contains an unidentified substance as the major secondary metabolite. We isolated this compound from Californian specimens of U. fulvoreagens and identified it as the rare depsidone neotricone. A co-occurring compound, conneotricone, was identified as 4,10-dihydroxy-5-(hydroxymethyl)-8-methyl-3,7-dioxo-1,3-dihydro-7H-isobenzofuro[4,5-b][1,4]benzodioxepine-11-carboxylic acid by NMR and HPLC-UV-MSn comparison with the material synthesised from salazinic acid. [ABSTRACT FROM AUTHOR]

Objectives: The aims of our study were to investigate the clinical and audiometric outcome of the surgical treatment of postinflammatory medial meatal fibrosis (PIMMF) and to review the histopathologic changes in the specimens of the fibrotic plug, in order to try to shed light on the pathogenesis of the disease. Materials and Methods: The clinical records and the histopathologic specimens of all patients who underwent tympanomeatoplasty for PIMMF at the ENT Clinic of the University of Erlangen between 2006 and 2020 were evaluated retrospectively. Results: Thirty-four patients (41 primary surgical procedures) made up our study cohort. Of this, 28 cases were managed by means of meatoplasty and 13 cases with tympanomeatoplasty. The mean preoperative air–bone gap (ABG) was 27.8 dB (10-44 dB). Postoperative ABG was significantly improved compared to preoperative values at both short- and long-term follow-ups (P <.001 for both). No significant difference was noted between short-term and long-term ABG (P =.240). An ABG ≤20 dB was achieved in 65.8% of patients (short term) and 50% (long term). The overall rate of revision surgery for restenosis was 29.3% (12/41). Histopathologic reevaluation of the fibrotic plugs revealed a mosaic of patterns with frequent occurrence of secondary cholesteatoma-like lesions and keloid-like tissue changes. Lichenoid submucosal inflammation and increased ectopic ceruminous gland lobules were seen less frequently. Discussion: The moderate long-term outcome of surgical management and the identification of histologic changes with therapeutic implications might pave the way for alternative nonsurgical treatment options. [ABSTRACT FROM AUTHOR]

The atmosphere is an important pathway for microplastic (MP) transport; however, observations are limited, as traditional sampling methods are generally labor-intensive. Biological monitors (biomonitors) have been widely used as a simple alternative to determine the abundance or presence of anthropogenic pollutants. Here, we compared the effectiveness of co-located lichen and moss species as biomonitors of the atmospheric deposition of microplastics. Samples of the epiphytic lichen Evernia prunastri and the epigeic moss Pseudoscleropodium purum were collected from five remote areas of central Italy. A total of 154 MPs were found across all samples, 93.5% of which were fibers and 6.5% were fragments. The accumulation of MPs for lichens (range of 8–12 MP/g) was significantly lower than for mosses (12–17 MP/g), which might be related to their structural characteristics or habitat positions (epiphytic versus epigeic). Nonetheless, higher accumulation facilitates analytical determination and provides greater separation from the limit of detection, suggesting that mosses are preferred over lichens for studying the deposition of airborne MPs. This study further suggests that biomonitoring may be an effective tool to assess the spatial distribution of atmospheric microplastics, which is a key requirement for the development of waste mitigation policies. [ABSTRACT FROM AUTHOR]

Endolichenic fungi are considered a promising source of new materials. For further evaluation of some biological activities of the Trichoderma strains isolated from lichens Dirinaria spp. and Cryptothecia spp., their antifungal and antibacterial activities were screened by the methods of dual culture and environmental toxicity. Substrate degradation was evaluated using the qualitative enzyme assays. Fourteen strains of Trichoderma spp. were isolated from 60 lichen samples. All the isolates were able to inhibit the radial growth of tested fungal strains (Bipolaris spp., Colletotrichum spp., Corynespora cassiicola, and Fusarium spp.). Otherwise, only 12/14 isolates were found capable of competing for substrates with Ralstonia solanacearum. The cell-free supernatant obtained from the cultures possessed both antifungal and antibacterial activities. The antagonistic activity of the isolates was selective. Most of the isolates were able to degrade at least one of the investigated substrates, namely cellulose, pectin, and starch. All strains could produce peroxidase; none of the isolates possessed laccase and tyrosinase. A potential antagonistic fungal strain VDT6 has been identified as Trichoderma harzianum. The assessment results indicated that the Trichoderma isolates could be used in agriculture as biological control agents. [ABSTRACT FROM AUTHOR]

Lichens are symbiotic organisms that are composed of fungal partners and photosynthetic algal partners. During the symbiotic process in lichen thallus, the fungus synthesizes certain secondary metabolites in which lecanoric acid is very important in terms of antibiotic properties. Considering the vital importance of lecanoric acid, the present study aimed to produce lecanoric acid from the thallus of Parmotrema austrosinense lichen using Modified Bold's basal salt medium and evaluate the bio-efficacy against tea fungal pathogens. Lecanoric acid was purified and confirmed by micro-crystallization method and subsequently bioassayed against tea fungal pathogens. The results revealed that lecanoric acid registered a significant antifungal activity in terms of the growth inhibition of test pathogens. Companion systemic and botanical fungicides were found to be inferior to lecanoric acid in the percentage of growth inhibition. The inhibition rate varied among tea pathogens. Of the tea pathogens tested, tea leaf disease-causing pathogens including Cercospora theae (C. theae), Glomerella cingulata (G. cingulate), and Phomopsis theae (P. theae) showed the highest percentage of growth inhibition followed by stem and root rot diseases. The present study suggests that lecanoric acid showed an inhibitory effect against tea pathogens, which might be due to antibiotic properties and fungicidal action of lecanoric acid. [ABSTRACT FROM AUTHOR]

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]

Optimizing growth chamber conditions for Arctic lichen biocrusts will create new opportunities to assess and prioritize reclamation techniques given the challenges associated with conducting arctic field work. Our study is the first to examine growth chamber conditions for optimizing survival and growth of Arctic lichen biocrusts, as measured by changes in lichen cover. We assessed effects of substrate crossed with substrate depth, substrate sterilization, lichen inoculation and community composition, and watering frequency in four concurrent experiments over 6 weeks on survival of arctic biocrusts collected from Diavik Diamond Mine Inc., Northwest Territories, Canada. Mixed species declined less than Flavocetraria cucullata, and substrate affected F. cucullata survival over time. Live lichen cover declined least with a 3‐day watering frequency and substrate depth of 1 cm. Sterilization did not affect lichen survival, and no contamination was observed over 6 weeks. Our results highlight the challenges of maintaining and growing lichens under controlled conditions, as only a few treatments showed increases in cover. Our research shows that even short‐term growth chamber experiments have potential to screen reclamation treatments prior to field assessments, permitting reclamation scientists to optimize limited time and resources while in the field. [ABSTRACT FROM AUTHOR]

Lichen-forming fungi are a diverse and ecologically important group of obligate mutualistic symbionts. Due to difficulties with maintaining them in culture and their extremely slow growth, lichenologists are increasingly opting for metagenomic sequencing followed by symbiont genome separation using bioinformatic pipelines. However, without knowing the true genome size of the lichen-forming fungus, we cannot quantify the completeness of the genome assembly and the efficacy of the bioinformatic filtering. To address this issue, we report here the first whole-genome assembly for the lichen-forming fungus Ramalina farinacea (L.) Ach. sequenced with Oxford Nanopore long-read technology alongside direct measurements of its genome size using flow cytometry. The assembly showed high contiguity (N50 = 1.55 Mb) and gene set completeness (BUSCO = 95.8%). The highly robust genome size of 33.61 Mb/1C (coefficients of variation = 2.98) that was obtained showed our assembly covered 97% of the entire genome. Our results demonstrate that accurate genome size measurements can be obtained directly from lichen thalli and used to provide a benchmark for assessing true cytometric completeness of metagenome-derived assemblies. [ABSTRACT FROM AUTHOR]

The lichen Usnea baileyi is a fruticose lichen belonging to the Usnea genus. It is well known as a rich source of natural xanthone dimers and possesses various bioactivities. Nevertheless, the chemical investigation on this type of lichen is still rare as most of researches reported its components without structural elucidation. Herein, in the continuous study on this type of lichen, we further isolate xanthone dimers from the dichloromethane extract and explore three new xanthone dimers, eumitrins F − H (1 − 3). Their structures were elucidated unambiguously by spectroscopic analyses, including high resolution electrospray ionisation mass spectrometry (HRESIMS), 1 D and 2 D nuclear magnetic resonance spectroscopy (1 D and 2 D NMR), and DP4 probability. All compounds were evaluated for their enzyme inhibition against α-glucosidase, tyrosinase, and antibacterial activity. They revealed moderate antimicrobial and weak tyrosinase inhibition. For α-glucosidase inhibition, compound 3 displayed the most significant inhibitory against α-glucosidase possessing an IC50 value of 64.2 µM. [ABSTRACT FROM AUTHOR]