Screening fungi isolated from historic Discovery Hut on Ross Island, Antarctica for cellulose degradation

To survive in Antarctica, early explorers of Antarctica's Heroic Age erected wooden buildings and brought in large quantities of supplies. The introduction of wood and other organic materials may have provided new nutrient sources for fungi that were indigenous to Antarctica or were brought in with the materials. From 30 samples taken from Discovery Hut, 156 filamentous fungi were isolated on selective media. Of these, 108 were screened for hydrolytic activity on carboxymethyl cellulose, of which 29 demonstrated activities. Endo-1, 4-β-glucanase activity was confirmed in the extracellular supernatant from seven isolates when grown at 4°C, and also when they were grown at 15°C. Cladosporium oxysporum and Geomyces sp. were shown to grow on a variety of synthetic cellulose substrates and to use cellulose as a nutrient source at temperate and cold temperatures. The research findings from the present study demonstrate that Antarctic filamentous fungi isolated from a variety of substrates (wood, straw, and food stuffs) are capable of cellulose degradation and can grow well at low temperatures

Multi-Level Characterization of Microbial Consortia Involved in the Biodeterioration of Wooden and Stone Romanian Heritage Churches

The 17th to 19th century wooden and stone churches are an iconic symbol of Romanian national heritage. The present study investigates by qualitative and quantitative methods the microbial communities from the biodeteriorated surfaces of wooden and stone monument churches included in the cultural heritage list of local or national importance. From a total of twelve monuments, samples were taken with cotton sterile swabs, inoculated on specific culture and identified by classical, automated and molecular methods. A total of 133 strains belonging to Ascomycota phylum were identified and confirmed at species level from the wooden churches, amongst which, Penicillium spp. strains (mostly P. corylophylum, P. chrysogenum) were the most frequent, followed by Alternaria alternata and species of Trichoderma, Aspergillus, Rhizopus, Mucor, and Fusarium genera. From the stone churches a total of 100 strains belonging to Aspergillus, Alternaria, Mucor, Penicillium, Aspergillus, Trichoderma, Fusarium and Rhizopus genera were isolated. A total of 55 bacterial strains were isolated and identified as Bacillus, Artrobacter and Pseudomonas species. The microbial load of the samples ranged between 2.18x107 and 3x105 CFU/mL. A very small number of fungal strains (6/77) isolated from wooden churches (mostly A. alternata, followed by P. corylophilum and one Cladosporium spp. strain) and from stone churches (5/55) (mostly A. alternata, followed by A. versicolor, A. nidulans strain) were involved in biofilm formation. The results of this study can help to improve understanding of the microbial deterioration of Romanian heritage churches and allow more reliable decontamination, conservation and preservation tools to be defined.Le chiese in legno e pietra dal XVII al XIX secolo sono un simbolo iconico del patrimonio nazionale rumeno. Il presente studio indaga con metodi qualitativi e quantitativi le comunità microbiche provenienti dalle superfici biodeteriorate di chiese monumentali in legno e pietra incluse nell'elenco dei beni culturali di importanza locale o nazionale. Da un totale di dodici monumenti, sono stati prelevati campioni con tamponi di cotone sterili, inoculati su colture specifiche e identificati con metodi classici, automatizzati e molecolari. Un totale di 133 ceppi appartenenti ad Ascomycota phylum sono stati identificati e confermati a livello di specie dalle chiese di legno, tra cui Penicillium spp. I ceppi (principalmente P. corylophylum, P. chrysogenum) sono i più frequenti, seguiti da Alternaria alternata e dalle specie dei generi Trichoderma, Aspergillus, Rhizopus, Mucor e Fusarium. Dalle chiese in pietra sono stati isolati in totale 100 ceppi appartenenti ai generi Aspergillus, Alternaria, Mucor, Penicillium, Aspergillus, Trichoderma, Fusarium e Rhizopus. Un totale di 55 ceppi batterici è stato isolato e identificato come specie Bacillus, Artrobacter e Pseudomonas. La carica microbica dei campioni varia tra 2,18x107 e 3x105 CFU / mL. Un numero molto piccolo di ceppi fungini (6/77) isolati da chiese in legno (principalmente A. alternata, seguito da P. corylophilum e un ceppo Cladosporium spp.) e da chiese in pietra (5/55) (principalmente A. alternata, seguito di A. versicolor, ceppo di A. nidulans) sono stati coinvolti nella formazione del biofilm. I risultati di questo studio possono aiutare a migliorare la comprensione del deterioramento microbico delle chiese del patrimonio rumeno e consentire la definizione di strumenti di decontaminazione, conservazione e conservazione più affidabili

Microfungi associated with withering willow wood in ground contact near Syowa Station, East Antarctica for 40 years

Data are rather lacking on the diversity of microfungi associated with exotic plant substrates transported to continental Antarctica. We examined the diversity and species composition of microfungi associated with withering woody shoots of saplings of Salix spp. (willows) transplanted and in ground contact near Syowa Station, East Antarctica for more than 40 years. The willow saplings originated from Hokkaido, Northern Japan, and were experimentally transplanted in 1967–1968, but died within a few years. Dead willow shoots, unbranched and standing on bare ground for approximately 50 years, were used for the isolation of fungi with the surface disinfection method. A total of 43 isolates were retrieved from 32 (78 %) of the 41 shoots tested. The fungal isolates were classified into 18 molecular operational taxonomic units (MOTUs) based on the similarity of rDNA ITS sequences at the 97 % criterion. Leotiomycetes was the most common class in terms of the number of isolates and MOTUs, followed by Dothideomycetes, Sordariomycetes, and Eurotiomycetes. Molecular phylogenetic affinities suggested that the closest relatives of the MOTUs were saprobic and root-associated fungi. The result of the present study suggested that Cadophora luteo-olivacea is widespread in soils throughout Antarctica and likely indigenous

Characterization of Cadophora luteo-olivacea and C. melinii isolates obtained from grapevines and environmental samples from grapevine nurseries in Spain

[EN] Fifty-eight Cadophora luteo-olivacea and three C. melinii isolates were recovered from grapevines showing black vascular streaking and decline symptoms characteristic of Petri disease, and from different stages of the grapevine nursery process in Spain. The isolates were studied by means of phenotypical characterization, DNA analysis and pathogenicity tests. The morphological characters studied included conidiophore, phialide and conidial morphology. Colony characters and pigment production on MEA, PDA and OA were also examined. Phenotypical data were subjected to cluster analysis, which clearly separated C. luteo-olivacea isolates into four groups. Mating tests were performed on all possible combinations for each Cadophora species but no sexual fruiting bodies were produced. Partial sequences of the nuclear ribosomal internal transcribed spacer (ITS), beta-tubulin (BT) and the elongation factor 1¿ (EF) were analysed, but no genetic variation occurred within the C. luteo-olivacea isolates or within the C. melinii isolates in any of the regions studied. Pathogenicity tests were conducted on 1-year-old grapevine cuttings of four different rootstocks using four C. luteo-olivacea isolates and one isolate of C. melinii. All Cadophora isolates except the C. melinii isolate caused significantly longer lesions in the xylem of grapevine rootstocks than in the controls.This research was financially supported by the Projects AGL2006-11884-C04-01 (Ministerio de Educación y Ciencia, Spain), RTA2007-00023-C04-03 and RTA2010-00009-C03-03 (Programa Nacional de Recursos y Tecnologías Agrarias, Ministerio de Educación y Ciencia, Spain), and the European Regional Development Fund (ERDF). We thank V. Garrigues for technical assistance.Gramaje, D.; Mostert, L.; Armengol Fortí, J. (2011). Characterization of Cadophora luteo-olivacea and C. melinii isolates obtained from grapevines and environmental samples from grapevine nurseries in Spain. Phytopathologia Mediterranea. 50(Supplement):112-126. https://doi.org/10.14601/Phytopathol_Mediterr-8723S11212650Supplemen

Ecology of members of the genus Cadophora (Helotiales) and similar species

Katedra botanikyDepartment of BotanyFaculty of SciencePřírodovědecká fakult

Low-diversity fungal assemblage in an Antarctic Dry Valleys soil

The McMurdo Dry Valleys of Antarctica present extreme environmental challenges. Life is restricted to patchy occurrence of lichens, mosses and invertebrates, plus soil microbial communities. Fungi have been described in lichen symbioses but relatively little is known about the occurrence of free-living soil fungi in the Dry Valleys. A challenge in estimating fungal species richness has been the extent to which estimates based on either cultivation or environmental DNA reflect the active assemblage in cold-arid soils. Here, we describe analysis for inland Dry Valleys soil of environmental DNA and RNA (cDNA) to infer total and putative metabolically active assemblages, respectively, plus cultivation approaches using a variety of laboratory growth conditions. Environmental sequences indicated a highly restricted assemblage of just seven phylotypes that affiliated phylogenetically within two known genera, Helicodendron and Zalerion, plus previously unidentified fungal phylotypes. None of the commonly encountered molds and mitosporic genera recorded from maritime Antarctic locations were encountered. A striking difference was observed in the frequency of recovery for phylotypes between libraries. This suggests that both species richness and beta diversity estimates based on DNA libraries have the potential to misinform putatively active assemblages. Cultivation yielded a cold-tolerant Zalerion strain that affiliated with DNA and RNA library clones, and a psychrotrophic yeast (Debaryomyces hansenii), which was not detected using either culture-independent approach. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

Three new genera of fungi from extremely acidic soils

Extremely acidic soils (pH<3) harbour poorly diversified mycobiota that are very different from less acidic habitats. During investigations of the mycobiota from several highly acidic soils in the Czech Republic and a coastal site in the Antarctic Peninsula, a group of hyaline fungal isolates was obtained. Based on phenotype and nuclear ribosomal DNA sequences (ITS region, SSU, LSU), the isolates belonged to three phylogenetic lineages within two different classes, Sordariomycetes and Leotiomycetes (Pezizomycotina, Ascomycota). The first lineage is described here as a new genus and species Acidothrix acidophila gen. nov. et sp. nov. (Amplistromataceae, Sordariomycetes, Ascomycota). The most closely related species to this new clade are woodinhabiting fungi. The isolates belonging to the second and the third lineages are also described as two new genera and species Acidea extrema gen. nov. et sp. nov. and Soosiella minima gen. nov. et sp. nov. (Helotiales, Leotiomycetes, Ascomycota). Their position and the relationships within Helotiales are discussed. Soosiella minima was acidotolerant, Acidothrix acidophila and Acidea extrema exhibited both acidotolerant and acidophilic characteristics. All the species were slightly halophilic. The adaptation of hyaline fungi from mesophilic lineages to highly acidic environments has been revealed. The association between highly acidic and Antarctic habitats is discussed.http://link.springer.com/journal/11557hb201

Modeling geographic distribution of arbuscular mycorrhizal fungi from molecular evidence in soils of Argentinean Puna using a maximum entropy approach

The biogeographic region of Argentinean Puna mainly extends at elevations higher than 3,000 m within the Andean Plateau and hosts diverse ecological communities highly adapted to extreme aridity and low temperatures. Soils of Puna are typically poorly evolved and geomorphology is shaped by drainage networks, resulting in highly vegetated endorheic basins and hypersaline basins known as salar or salt flats. Local communities rely on soil fertility for agricultural practices and on pastures for livestock rearing. From this perspective, investigating the scarcely explored microbiological diversity of these soils as indicators of ecosystems functioning might help to predict the fragility of these harsh environments. In this study we collected soil samples from 28 points, following a nested design within three different macro-habitats, i.e., Puna grassland, hypersaline salar and family-run crop fields. Total fungi and arbuscular mycorrhizal fungi (AMF) occurrence were analyzed using eDNA sequencing. In addition, the significance of soil salinity and organic matter content as significant predictors of AMF occurrence, was assessed through Generalized Linear Mixed Modeling. We also investigated whether intensive grazing by cattle and lama in Puna grasslands may reduce the presence of AMF in these highly disturbed soils, driving or not major ecological changes, but no consistent results were found, suggesting that more specific experiments and further investigations may address the question more specifically. Finally, to predict the suitability for AMF in the different macro-habitats, Species Distribution Modeling (SDM) was performed within an environmental coherent area comprising both the phytogeographic regions of Puna and Altoandino. We modeled AMF distribution with a maximum entropy approach, including bioclimatic and edaphic predictors and obtaining maps of environmental suitability for AMF within the predicted areas. To assess the impact of farming on AMF occurrence, we set a new series of models excluding the cultivated Chaupi Rodeo samples. Overall, SDM predicted a lower suitability for AMF in hypersaline salar areas, while grassland habitats and a wider temperature seasonality range appear to be factors significantly related to AMF enrichment, suggesting a main role of seasonal dynamics in shaping AMF communities. The highest abundance of AMF was observed in Vicia faba crop fields, while potato fields yielded a very low AMF occurrence. The models excluding the cultivated Chaupi Rodeo samples highlighted that if these cultivated areas had theoretically remained unmanaged habitats of Puna and Altoandino, then large-scale soil features and local bioclimatic constraints would likely support a lower suitability for AMF. Using SDM we evidenced the influence of bioclimatic, edaphic and anthropic predictors in shaping AMF occurrence and highlighted the relevance of considering human activities to accurately predict AMF distribution.Fil: Nepote Valentin, Davide. University Of Turin. Life Sciences And Systems Biology; ItaliaFil: Voyron, Samuele. University Of Turin. Life Sciences And Systems Biology; Italia. National Research Council; ItaliaFil: Soteras, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Iriarte, Hebe Jorgelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis; ArgentinaFil: Giovannini, Andrea. University of Turin. Life Sciences And Systems Biology; ItaliaFil: Lumini, Erica. Institute For Sustainable Plant Protection ; Italia. National Research Council; ItaliaFil: Lugo, Mónica Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis; Argentin