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6. Lichenicolous (parasitic) fungi. (a) Pertusaria pertusa (Weigel) Tuck. (Pp; Pertusariales) invaded and partially killed by Marchandiomyces corallinus (Roberge) Diederich et D. Hawksw. (Mc; Corticiales, Agaricomycetes). (b) Mazaediate fruiting bodies of Sphinctrina turbinata (Pers. ex Fr.) De Not. (Mycocaliciales, Eurotiomycetes) on the surface of Pertusaria pertusa. (c) Beard lichen Usnea ceratina Ach. with fruiting body (arrow) of Biatoropsis usnearum Räsänen (Tremellales, Basidiomycota). (d, e) thallus squamule of Cladonia macrophylla (Schaer.) Stenh. invaded by Phaeopyxis punctum (A. Massal.) Rambold, Triebel et Coppins (Parmeliaceae, Lecanorales). Black dots in (d) are fruting bodies of P. punctum, whitish dots are adhering soredia of C. macrophylla. (e) Stained semithin section of C. macrophylla with cortex (c), photobiont layer (ph) and medullary layer (m) of the lichen-forming ascomycete; also primordium (left arrow) and mature fruiting body (right arrow; ac) of P. punctum. Arrows point to trichogynes of the ascomal primordium of the parasite growing through the cortex of the host
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Lichens are the symbiotic phenotype of nutritionally specialized fungi, ecologically obligate biotrophs which acquire fixed
carbon from a population of minute photobiont cells (Honegger 1991). Lichenforming fungi (also referred to as lichen mycobionts)
are, like plant or animal pathogens or mycorrhizal fungi, a polyphyletic, taxonomically diverse g...
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Most climate and environmental change models predict significant increases in temperature and precipitation by the end of the 21st Century, for which the current functional output of certain symbioses may also be altered. In this context we address the following questions: 1) How the expected changes in abiotic factors (temperature, and water) diff...
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... The so established symbiosis is determined by the presence of the different partners and their specialization in different environmental conditions (Rosenberg et al., 2010;Rosenberg and Zilber-Rosenberg, 2011;Rafferty et al., 2015;Douglas and Werren, 2016;Chomicki and Renner, 2017). The term symbiosis was originally introduced to study lichens (Frank, 1877) which are, among the terrestrial symbioses, iconic examples of the living together of a main fungus (the mycobiont) and populations of photosynthetic green algae or cyanobacteria (the photobionts; Hawksworth and Honegger, 1994;Honegger, 2009). These two partners shape the phenotypic outcome of the lichen symbioses, i.e., the lichen thallus. ...
... Lichens are, by definition, symbiotic organisms typically composed of a fungus (the mycobiont) and one or more photosynthetic organisms (the photobionts), which may be green algae and/or cyanobacteria [1][2][3]. Historically, it was widely believed that these organisms had broad distribution ranges, and the presence of endemic species was considered rare [4]. This is probably a result of the long-standing application of the paradigm "everything small is everywhere", as traditionally asserted for these life forms [5]. ...
... The photobionts tended to be located very close to the hyphae within the photobiont layer. The interactions between the photobiont cells and the fungal hyphae exhibited characteristics of the "simple" type described by [2], without invaginations or haustoria. No auxospores or sexual reproduction were observed. ...
It has long been assumed that lichen-forming fungi have very large distribution ranges, and that endemic species are rare in this group of organisms. This is likely a consequence of the "everything small is everywhere" paradigm that has been traditionally applied to cryptogams. However, the description of numerous endemic species over the last decades, many of them in oceanic islands, is challenging this view. In this study, we provide another example, Xanthoparmelia ramosae, a species that is described here as new to science on the basis of morphological, chemical, and macroclimatic data, and three molecular markers (ITS rDNA, nuLSU rDNA, and mtSSU). The new species is endemic to the island of Gran Canaria but clusters into a clade composed exclusively of specimens collected in Eastern Africa, a disjunction that is here reported for the first time in lichen-forming fungi. Through the use of dating analysis, we have found that Xanthoparmelia ramosae diverged from its closely related African taxa in the Pliocene. This result, together with the reproductive strategy of the species, points to the Relict theory as a likely mechanism behind the disjunction, although the large gap in lichenological knowledge in Africa makes this possibility hard to explore any further.
... Lichen-forming fungi are adapted to obtain their carbon source from the algae and/or the cyanobacteria with which they associate, thus becoming obligate symbionts [1]. About 17% of all fungi and 27% of known Ascomycota are lichen-forming fungi [2], indicating the evolutionary success of this life strategy, which appears in most terrestrial ecosystems. ...
... Despite recent advances based on DNA sequencing studies, the diversity of algae associated with lichen-forming fungi, the photobionts, is still far from being well known. The identity of photobionts has only been studied in approximately 5% of lichens up to now [1,4,5]. Significant progress has been made in recent years with the description of several new genera and species of photobionts [6][7][8][9][10][11], suggesting that the true diversity of photobionts may be much greater than previously thought [4,5]. ...
This study explores the diversity of photobionts associated with the Mediterranean lichen-forming fungus Cladonia subturgida. For this purpose, we sequenced the whole ITS rDNA region by Sanger using a metabarcoding method for ITS2. A total of 41 specimens from Greece, Italy, France, Portugal, and Spain were studied. Additionally, two specimens from Spain were used to generate four cultures. Our molecular studies showed that the genus Myrmecia is the main photobiont of C. subturgida throughout its geographic distribution. This result contrasts with previous studies, which indicated that the main photobiont for most Cladonia species is Asterochloris. The identity of Myrmecia was also confirmed by ultrastructural studies of photobionts within the lichen thalli and cultures. Photobiont cells showed a parietal chloroplast lacking a pyrenoid, which characterizes the species in this genus. Phylogenetic analyses indicate hidden diversity within this genus. The results of amplicon sequencing showed the presence of multiple ASVs in 58.3% of the specimens studied.
... Recent DNA-based metabarcoding work has shown that the L. pygmaea photobiont community on southern UK shores contains two major cyanobacterial lineages: the filamentous diazotroph Rivularia (Nostocales) (Ortiz-Alvarez et al., 2015;Chrismas et al., 2021) and Pleurocapsa (Pleurocapsales) (Chrismas et al., 2021), which appear intermingled in the lichen thallus (Fig. 1aiii). Pleurocapsales are not well known from terrestrial lichen symbioses (Jung et al., 2021) but are associated with other marine lichens (Honegger, 2009). ...
Lichens are exemplar symbioses based upon carbon exchange between photobionts and their mycobiont hosts. Historically considered a two‐way relationship, some lichen symbioses have been shown to contain multiple photobiont partners; however, the way in which these photobiont communities react to environmental change is poorly understood.
Lichina pygmaea is a marine cyanolichen that inhabits rocky seashores where it is submerged in seawater during every tidal cycle. Recent work has indicated that L. pygmaea has a complex photobiont community including the cyanobionts Rivularia and Pleurocapsa. We performed rRNA‐based metabarcoding and mRNA metatranscriptomics of the L. pygmaea holobiont at high and low tide to investigate community response to immersion in seawater.
Carbon exchange in L. pygmaea is a dynamic process, influenced by both tidal cycle and the biology of the individual symbiotic components. The mycobiont and two cyanobiont partners exhibit distinct transcriptional responses to seawater hydration.
Sugar‐based compatible solutes produced by Rivularia and Pleurocapsa in response to seawater are a potential source of carbon to the mycobiont. We propose that extracellular processing of photobiont‐derived polysaccharides is a fundamental step in carbon acquisition by L. pygmaea and is analogous to uptake of plant‐derived carbon in ectomycorrhizal symbioses.
... Many of the mold genera identified in the ETICS stains have been detected as common colonizers and biodeteriogens of building surfaces, for instance (i) in cementitious building materials (e.g., Cladosporium, Alternaria, Penicillium) (Ferrari et al., 2015;Campana et al., 2020); (ii) in (sand) stone surfaces (e.g., Cladosporium, Epicoccum, Penicillium, Knufia) (Rosado et al., 2020;Wu et al., 2022); and (iii) in external painted surfaces (e.g., Cladosporium, Epicoccum, Aureobasidium) (Gaylarde and Gaylarde, 2005;Gaylarde et al., 2011;Ferrari et al., 2015). In general, these molds are ubiquitous in soil, rocks, decaying vegetation, trees, pollen, and dust (Honegger, 2009;van Nieuwenhuijzen et al., 2016;Chen et al., 2017;Abdollahzadeh et al., 2020;Liu et al., 2022) and their spores and mycelium fragments can undergo airborne dispersal, either outdoor or indoor (Karlsson et al., 2020;Savković et al., 2021). The high prevalence of the class Lecanoromycetes (orders Lecanorales, Teloschistales, and Caliciales) in the fungal microbiota of almost all the ETICS stains is noteworthy since these taxa have a widespread distribution and contain around 78% of the known lichen-forming fungi (Honegger, 2009;Lücking and Nelsen, 2018). ...
... In general, these molds are ubiquitous in soil, rocks, decaying vegetation, trees, pollen, and dust (Honegger, 2009;van Nieuwenhuijzen et al., 2016;Chen et al., 2017;Abdollahzadeh et al., 2020;Liu et al., 2022) and their spores and mycelium fragments can undergo airborne dispersal, either outdoor or indoor (Karlsson et al., 2020;Savković et al., 2021). The high prevalence of the class Lecanoromycetes (orders Lecanorales, Teloschistales, and Caliciales) in the fungal microbiota of almost all the ETICS stains is noteworthy since these taxa have a widespread distribution and contain around 78% of the known lichen-forming fungi (Honegger, 2009;Lücking and Nelsen, 2018). In turn, green microalgae chlorophytes, also detected within the stains' microbiota, are photobiont partners in many lichenized ascomycete fungi (Honegger, 2009). ...
... The high prevalence of the class Lecanoromycetes (orders Lecanorales, Teloschistales, and Caliciales) in the fungal microbiota of almost all the ETICS stains is noteworthy since these taxa have a widespread distribution and contain around 78% of the known lichen-forming fungi (Honegger, 2009;Lücking and Nelsen, 2018). In turn, green microalgae chlorophytes, also detected within the stains' microbiota, are photobiont partners in many lichenized ascomycete fungi (Honegger, 2009). ...
External Thermal Insulation Composite Systems (ETICS) are frequently used to enhance the energy efficiency of the built environment. However, stains of presumable biological nature are often detected shortly after application , causing cladding defacement and altering the building aesthetics. To address which microbiota could contribute to these biodeterioration related color/aesthetic anomalies, samples collected from stains detected on the surface of building facades with ETICS in three residential sites in Lisbon, Portugal, were analyzed through microbiological culture-dependent technique and culture-independent amplicon DNA high throughput sequencing taxonomic profiling. The obtained data provided a comprehensive description of microbial communities assigned to diverse taxa of the major microbial groups of heterotrophic bacteria, fungi, cyanobacteria, and microalgae (through DNA plastid detection) in the sampled stains. Based on that, we propose that new microorganisms could be added to the list of bio-susceptibility testing organisms in ETICS. Furthermore, microbiota diversity depended more on facade location and cardinal orientation than on ETICS material composition. Overall, this study reveals the unique microbial communities of color/aesthetic biodeterioration stains in ETICS facades, unlike those of other surfaces, and the associated environmental dynamics.
... However, one of the metabolites frequently tested, atranorin, is known to have an unstable chemical structure when immersed in methanol; in acetone, acetonitrile and a solvent pH close to neutral, the structure of the compound is found to be more stabilised (Vos et al., 2018). The potential of water as an effective solvent for secondary metabolites is enhanced by a higher temperature [(+)-usnic acid: Jin et al., 2013], pH (Honegger, 2009) and a greater number of polar functional groups, including mainly hydroxyl groups (Iskandar and Syers, 1971;Rundel, 1978), but its effect on maintaining the chemical structure of the compounds has not been understood to date. Like primary metabolites, the relative concentrations of secondary ones in lichens are a result of external environmental stress factors, including altitude (usnic acid : Cansaran Duman et al., 2008;Neupane et al., 2017), insolation and moisture of thallus (Armaleo et al., 2008) and exposure to radiation in the UV range (Al-Amoody et al., 2020;UV-A: Kov a cik et al., 2011). ...
... Its higher concentration can support the search for the best fractionation of the extract. In contrast, belonging to the orcinol depsides, the other two secondary compounds may be more easily extractable with ethanol or methanol (Cowan, 1999), at a pH above neutral (Honegger, 2009) and potentially at higher temperatures as metabolites belonging to the phenols (Zagoskina et al., 2013), in view of which the presence of water should also be effective by forming hydrogen bonds with the hydroxyl groups of these compounds (Iskandar and Syers, 1971;Rundel, 1978). Scrobiculin can be extracted from the as-yet-untested epiphytic Lobaria scrobiculata (Asplund et al., 2010;Culberson, 1967), while 4-[(2-hydroxy-4-methoxy-6-propylbenzoyl)oxy]-2-methoxy-6-propylbenzoic acid can be extracted from Ramalina leiodea (Bharadwaj and Sastry, 2019). ...
A meta-analysis of literature data with statistical analysis concerning the effect of lichen substances on the inhibition of 10 yeast species (Candida albicans, C. dubliniensis, C. glabrata, C. parapsilosis, C. sake, C. tropicalis, Colacogloea diffluens, Cryptococcus neoformans, Issatchenkia orientalis and Saccharomyces cerevisiae) is provided. Lichen extracts were obtained using 16 solvents from 100 epiphytic, 51 epigeic and 37 epilithic lichen species. The most studied lichen taxa at the generic level belonged to the family Parmeliaceae. 67 individual secondary metabolites belonging to 12 biochemical classes were subjected to experiments. The MIC was used most frequently. Candida albicans was the most commonly tested species; other fungal species remain relatively less or very poorly tested. Against C. albicans, a stronger antifungal potential is demonstrated by extracts from numerous lichen species, including Evernia prunastri, Hypotrachyna vexans, Pseudevernia furfur-acea, Ramalina pollinaria, R. polymorpha, Cladonia foliacea, C. pocillum, C. rangiformis and Umbilicaria cylin-drica, which generated secondary compounds such as atranorin, a-collatolic acid, ethyl everninate, lecanoric acid, methyl 2,6-dihydroxy-4-methylbenzoate, protolichesterinic acid, retigeric acid A and B, scrobiculin and usnic acid. The potential of the extracts and secondary metabolites makes it possible to replace several commercial antibiotics in the future, in particular clotrimazole and fenticonazole. For the purpose of future experiments, this review stresses the need to standardizse research methodology, especially for the simultaneous determination of MIC and IZ and, if possible, MFC. There is a need for greater use of water as a solvent to extract lichen substances as a safe and feasible method for phytopharmaceutical and cosmetic purposes. The conclusions drawn highlight the prospective use of lichen extracts and secondary metabolites against yeast in the medical, phytopharmaceutical and cosmetic fields and as preservatives.
... Lichens are a diverse group of symbiotic organisms found in nearly every terrestrial ecosystem from the poles (Kappen 2000;Sancho and Pintado 2004) to the tropics (Sipman and Harris 1989) and grow on diverse substrates, commonly found on rocks, soil, and tree bark (Nash 2008). In summary, lichens consist of the partnership between a mycobiont (fungus) and a photobiont [cyanobacteria (Büdel 1992), eukaryotic algae (Tschermak-Woess 1988;Gärtner 1992), or both; (Nash 2008;Honegger 2009)], along with numerous other microorganisms (Hawksworth and Grube 2020) such as bacteria (e.g. Cardinale et al. 2008;Bates et al. 2011), other fungi [e.g. ...
Acarospora socialis, the bright cobblestone lichen, is commonly found in southwestern North America. This charismatic yellow lichen is a species of key ecological significance as it is often a pioneer species in new environments. Despite their ecological importance virtually no research has been conducted on the genomics of A. socialis. To address this, we used long-read sequencing to generate the first high-quality draft genome of A. socialis. Lichen thallus tissue was collected from Pinkham Canyon in Joshua Tree National Park, California and deposited in the UC Riverside herbarium under accession #295874. The de novo assembly of the mycobiont partner of the lichen was generated from Pacific Biosciences HiFi long reads and Dovetail Omni-C chromatin capture data. After removing algal and bacterial contigs, the fungal genome was approximately 31.2 Mb consisting of 38 scaffolds with contig and scaffold N50 of 2.4 Mb. The BUSCO completeness score of the assembled genome was 97.5% using the Ascomycota gene set. Information on the genome of A. socialis is important for California conservation purposes given that this lichen is threatened in some places locally by wildfires due to climate change. This reference genome will be used for understanding the genetic diversity, population genomics, and comparative genomics of A. socialis species. Genomic resources for this species will support population and landscape genomics investigations, exploring the use of A. socialis as a bioindicator species for climate change, and in studies of adaptation by comparing populations that occur across aridity gradients in California.
... In the search for unique bioactive phytomolecules, most of the researchers draw their attention to lower groups of plants and fungus such as lichens. Lichens are a marvelous group of the fungi kingdom and are naturally assembled by the consortium of fungi and algae (Honegger 2009). Lichens are endowed with unique bioactive metabolites and have been used as important traditional medicine in many cultures. ...
Catheter-associated urinary tract infections (CAUTI) are the most common healthcare problem in hospitals. In this study, we isolated the Daldinia starbaeckii (An endolichenic fungus from Roccella montagnie) and its biomass extract were used to simultaneously synthesize and deposit DSFAgNPs on the inner and outer surfaces of the catheter tube using chitosan biopolymer via In-situ deposition method. Perfectly designed D. starbaeckii extract functionalized DSFAgNPs were characterized by UV spectroscopy, FTIR, SEM, EDS, TEM, and XRD. The microbial efficacy of DSFAgNPs & DSFAgNPs coated catheter (CTH3) was evaluated against eight human pathogenic gram (+ / −) ive strains and Candida albicans. Results indicated DSFAgNPs showed significant biological activity against both gram (+ / −) ive bacteria with an average MIC90 of 4 µl/ml. The most promising activity was observed against Helicobacter pylori. When bacteria strains allow to grow with CTH3 we reported significant reduction in colony formation unit (CFU/ml) in broth culture assay with an average 70% inhibition. Further, antibiofilm activity of CTH3 against P. aeruginosa showed strong inhibition of biofilm formation (85%). The study explored an alternate approach for significantly prevent CAUTI among hospital patients.
Graphical abstract
We isolated an endolichenic fungus from lichen Roccella montagnei. The molecular characterization of fungus identified as Daldinia starbaeckii (DSF). The DSF was cultured and its fungal biomass exudes were used to simultaneously construct DSF-AgNPs and its deposition on the catheter surface using biopolymer chitosan via In-situ deposition method. Further, antimicrobial and antibiofilm efficacy of DSF-AgNPs was checked against urinary catheter contaminating and human pathogenic bacterial strains. Based on our research, we determined that DSF-AgNPs coating on a urinary catheter through this method is a cost-effective, eco-friendly approach to prevent catheter contamination.
... This is because nutrient exchange can also happen through physical contact between organisms (without penetrating the algal cells), as seen in Mortierella elongata and Nannochloropsis oceanica (Du et al. 2019). Similarly, some lichenized fungi also adopt this mechanism for withdrawing nutrients from the photobiont, such as Coenogonium subvirescens (Honegger 2009). More in-depth studies are needed to demystify whether C. fibrosae is nutritionally dependent on Trebouxia sp. and what its mode of nutrient acquisition is. ...
Lichens produce diverse secondary metabolites. A diversity of these compounds is synthesized by fungal polyketide synthases (PKSs). In this study, we catalogued the PKS genes from Xanthoparmelia taractica, a lichen with global distribution. To accomplish this, we isolated the symbionts to sequence the whole genome of the mycobiont and established an in vitro co-culture system for this lichen. We also added an endolichenic fungus, Coniochaeta fibrosae, to this co-culture to evaluate its effect on lichen symbiosis. The genome of the mycobiont X. taractica was around 43.1 Mb with 10,730 ORFs. Twenty-eight PKS genes were identified in the genome. These included 27 Type I and one Type III gene. Except for three PKS genes, XTPKS12, XTPKS18, and XTPKS22, the function of the majority of PKS genes remained unknown. We selected these genes for the expression analyses using a co-culture system. The co-culture system that included the mycobiont and the photobiont showed an early stage of lichenization because the fungi produced a hyphal network connecting and penetrating the algal cells. Also, XTPKS12 was down-regulated and XTPKS18 and XTPKS22 were modestly up-regulated. As predicted, C. fibrosae did not participate in the symbiosis. This study reconfirms that Type I is the most dominant PKS gene in lichenized fungi and the function of these genes might be influenced by symbiosis.
... Aspergillus pseudoglaucus was not previously mentioned as a lichen forming fungus (Honegger, 2009); however, some Aspergillus sp. were reported as endolichenic species having antimicrobial properties (Dou et al., 2014;Padhi et al., 2020;Prateeksha et al., 2020). ...
The comprehension of microbial interactions is one of the key challenges in marine microbial ecology. This study focused on exploring chemical interactions between the toxic dinoflagellate Prorocentrum lima and a filamentous fungal species, Aspergillus pseudoglaucus, which has been isolated from the microalgal culture. Such interspecies interactions are expected to occur even though they were rarely studied. Here, a co‐culture system was designed in a dedicated microscale marine‐like condition. This system allowed to explore microalgal‐fungal physical and metabolic interactions in presence and absence of the bacterial consortium. Microscopic observation showed an unusual physical contact between the fungal mycelium and dinoflagellate cells. To delineate specialized metabolome alterations during microalgal‐fungal co‐culture metabolomes were monitored by high‐performance liquid chromatography coupled to high‐resolution mass spectrometry. In‐depth multivariate statistical analysis using dedicated approaches highlighted (1) the metabolic alterations associated with microalgal‐fungal co‐culture, and (2) the impact of associated bacteria in microalgal metabolome response to fungal interaction. Unfortunately, only a very low number of highlighted features were fully characterised. However, an up‐regulation of the dinoflagellate toxins okadaic acid and dinophysistoxin 1 was observed during co‐culture in supernatants. Such results highlight the importance to consider microalgal‐fungal interactions in the study of parameters regulating toxin production. This article is protected by copyright. All rights reserved.
