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Background: Phylogeographic studies have gained prominence in linking past geological events to the distribution patterns of biodiversity, primarily in mountainous regions. However, such studies often focus on plant taxa, neglecting the intricate biogeographical patterns of microbes, particularly soil microbial communities. This article explores the spatial distribution of the nematode-trapping fungus Arthrobotrys oligospora, a widespread microorganism, in a tectonically active region at the southeastern edge of the Qinghai-Tibetan Plateau. By analysing the genetic variation of this fungus alongside the historical structure of major river watersheds, we sought to uncover potential connections between the two. Our study involved sampling 149 strains from 116 sites across six major watersheds in the region., Results: The resulting haplotype network revealed five distinct clusters, each corresponding closely to a specific watershed. These clusters exhibited high haplotype diversity and low nucleotide diversity, supporting the notion of watershed-based segregation. Further analysis of haplotypes shared across watersheds provided evidence for three proposed past river connections. In particular, we found numerous shared haplotypes between the Yangtze and Mekong basins, as well as between the Yangtze and the Red basins. Evidence for a Irrawaddy-Salween-Red and a Yangtze-Pearl-Red river connections were also portrayed in our mapping exercise., Conclusions: These findings emphasize the crucial role of historical geomorphological events in shaping the biogeography of microbial biodiversity, alongside contemporary biotic and abiotic factors. Watershed perimeters emerged as effective predictors of such patterns, suggesting their suitability as analytical units for regional-scale studies. Our study also demonstrates the potential of microorganisms and phylogeographic approaches to complement traditional geological analyses, providing a more comprehensive understanding of past landscape structure and its evolution., (© 2024. The Author(s).)

Background: Rhizosphere and endophytic fungi play important roles in plant health and crop productivity. However, their community dynamics during the continuous cropping of Knoxia valerianoides have rarely been reported. K. valerianoides is a perennial herb of the family Rubiaceae and has been used in herbal medicines for ages. Here, we used high-throughput sequencing technology Illumina MiSeq to study the structural and functional dynamics of the rhizosphere and endophytic fungi of K. valerianoides., Results: The findings indicate that continuous planting has led to an increase in the richness and diversity of rhizosphere fungi, while concomitantly resulting in a decrease in the richness and diversity of root fungi. The diversity of endophytic fungal communities in roots was lower than that of the rhizosphere fungi. Ascomycota and Basidiomycota were the dominant phyla detected during the continuous cropping of K. valerianoides. In addition, we found that root rot directly affected the structure and diversity of fungal communities in the rhizosphere and the roots of K. valerianoides. Consequently, both the rhizosphere and endophyte fungal communities of root rot-infected plants showed higher richness than the healthy plants. The relative abundance of Fusarium in two and three years old root rot-infected plants was significantly higher than the control, indicating that continuous planting negatively affected the health of K. valerianoides plants. Decision Curve Analysis showed that soil pH, organic matter (OM), available K, total K, soil sucrase (S&#95;SC), soil catalase (S&#95;CAT), and soil cellulase (S&#95;CL) were significantly related (p < 0.05) to the fungal community dynamics., Conclusions: The diversity of fungal species in the rhizosphere and root of K. valerianoides was reported for the first time. The fungal diversity of rhizosphere soil was higher than that of root endophytic fungi. The fungal diversity of root rot plants was higher than that of healthy plants. Soil pH, OM, available K, total K, S&#95;CAT, S&#95;SC, and S&#95;CL were significantly related to the fungal diversity. The occurrence of root rot had an effect on the community structure and diversity of rhizosphere and root endophytic fungi., (© 2024. The Author(s).)

Background: Fusarium wilt of banana (Musa spp.) caused by the fungal pathogen Fusarium oxysporum f. sp. cubense (Foc) is a typical soilborne disease, that severely devastates the banana industry worldwide, and soil microbial diversity is closely related to the spread of Fusarium wilt. To understand the relationship between microbial species and Fusarium wilt, it is important to understand the microbial diversity of the Fusarium wilt-diseased and disease-free soils from banana fields., Results: Based on sequencing analysis of the bacterial 16S rRNA genes and fungal internal transcribed spacer (ITS) sequences, Foc abundance, fungal or bacterial richness and diversity were higher in the diseased soils than in the disease-free soils. Although Ascomycota and Zygomycota were the most abundant fungi phyla in all soil samples, Ascomycota abundance was significantly reduced in the disease-free soils. Mortierella (36.64%) was predominant in the disease-free soils. Regarding bacterial phyla, Proteobacteria, Acidobacteria, Chloroflexi, Firmicutes, Actinobacteria, Gemmatimonadetes, Bacteroidetes, Nitrospirae, Verrucomicrobia and Planctomycetes were dominant phyla in all soil samples. In particular, Firmicutes contributed 16.20% of the total abundance of disease-free soils. At the bacterial genus level, Bacillus, Lactococcus and Pseudomonas were abundant in disease-free soils with abundances of 8.20, 5.81 and 2.71%, respectively; lower abundances, of 4.12, 2.35 and 1.36%, respectively, were found in diseased soils. The distribution characteristics of fungal and bacterial genera may contribute to the abundance decrease of Foc in the disease-free soils., Conclusion: Unique distributions of bacteria and fungi were observed in the diseased and disease-free soil samples from banana fields. These specific genera are useful for constructing a healthy microbial community structure of soil.

A Citizen Science initiative by the Westerdijk Fungal Biodiversity Institute and the Utrecht University Museum gave rise to a project where fungal and yeast isolates were obtained and identified from Dutch soil samples. During the current study, 386 yeast strains were isolated from 157 different locations in the Netherlands. These strains were identified using sequence data of the large-subunit rRNA gene (D1/D2 region) and the internal transcribed spacer 1 and 2 regions. A total of 53 different yeast species were found as well as 15 potentially novel species. Six novel ascomycetous species are described during this study that include Hanseniaspora mollemarum sp. nov., Ogataea degrootiae sp. nov., Pichia gijzeniarum sp. nov., Saccharomycopsis oosterbeekiorum sp. nov., Trichomonascus vanleenenius sp. nov. and Zygoascus flipseniorum sp. nov. This study made it possible to incorporate numerous yeast isolates into the CBS collection without any restrictions, which make these isolates readily available for use by others. Many of the isolates represented species of which only a few isolates or even only a single ex-type strain were available. Therefore, it is a clear indication that such biodiversity-orientated Citizen Science projects can enrich the pool of available yeasts for future research projects.

Although sugarcane-soybean intercropping has been widely used to control disease and improve productivity in the field, the response of soil fungal communities to intercropping has not been fully understood. In this study, the rhizosphere fungal communities of sugarcane and soybean under monoculture and intercropping systems were investigated using Illumina MiSeq sequencing of ITS gene. Intercropping decreased the alpha-diversity and changed fungal community composition compared to monocultures. Taxonomic analyses showed that the dominant phyla were Ascomycota, Zygomycota and Basidiomycota. The abundance of Ascomycota decreased in intercropping sugarcane-grown soil compared to monoculture, while it increased in soybean-grown soil in the intercropping system. In addition, intercropping increased the abundance of important fungal genera, such as Trichoderma, Hypocreales and Fusarium but decreased the relative abundance of Gibberella and Chaetomium. The results of canonical correspondence analysis and automatic linear modelling indicated that fungal community compositions were closely associated with soil parameters such as total nitrogen (TN), soil organic matter (SOC), pH and NO 3 - , which suggests that the impacts of intercropping on the soil fungal community are linked to the alteration of soil chemical properties.

Endocarpon species are key components of biological soil crusts. Phenotypic and systematic molecular analyses were carried out to identify samples of Endocarpon collected from the southeast edge of the Tengger Desert in China. These morphological and molecular analyses revealed two previously undescribed species that form highly supported independent monophyletic clades within Endocarpon. The new taxa were named Endocarpon deserticola sp. nov. and E. unifoliatum sp. nov. Furthermore, our results indicated that the newly developed protein coding markers adenylate kinase (ADK) and ubiquitin-conjugating enzyme h (UCEH) are useful for assessing species boundaries in phylogenic analyses.

The aim of this study was to investigate the effect of an ectomycorrhizal fungus (Tuber indicum) on the diversity of microbial communities associated with an indigenous tree, Pinus armandii, and the microbial communities in the surrounding ectomycorhizosphere soil. High-throughput sequencing was used to analyze the richness of microbial communities in the roots or rhizosphere of treatments with or without ectomycorrhizae. The results indicated that the bacterial diversity of ectomycorhizosphere soil was significantly lower compared with the control soil. Presumably, the dominance of truffle mycelia in ectomycorhizosphere soil (80.91%) and ectomycorrhizae (97.64%) was the main factor that resulted in lower diversity and abundance of endophytic pathogenic fungi, including Fusarium, Monographella, Ustilago and Rhizopus and other competitive mycorrhizal fungi, such as Amanita, Lactarius and Boletus. Bacterial genera Reyranena, Rhizomicrobium, Nordella, Pseudomonas and fungal genera, Cuphophyllus, Leucangium, Histoplasma were significantly more abundant in ectomycorrhizosphere soil and ectomycorrhizae. Hierarchical cluster analysis of the similarities between rhizosphere and ectomycorrhizosphere soil based on the soil properties differed significantly, indicating the mycorrhizal synthesis may have a feedback effect on soil properties. Meanwhile, some soil properties were significantly correlated with bacterial and fungal diversity in the rhizosphere or root tips. Overall, this work illustrates the interactive network that exists among ectomycorrhizal fungi, soil properties and microbial communities associated with the host plant and furthers our understanding of the ecology and cultivation of T. indicum.

A novel species of Cladophialophora is herein described from the natural environment of secondary forest soil in Japan, which was able to be colonized by the host plant root. Morphological observations indicated that the isolate is distinct from previously identified species, and, thus, is described as the new species, C. inabaensis sp. nov.

With an aim to develop a highly efficient method for the recovery of rare earth elements (REEs) by using microorganisms, we attempted to isolate dysprosium (Dy)-accumulating microorganisms that grow under acidic conditions from environmental samples containing high concentrations of heavy metals. One acidophilic strain, T9, which was isolated from an abandoned mine, decreased the concentration of Dy in medium that contained 100 mg/liter Dy to 53 mg/liter Dy after 3 days of cultivation at pH 2.5. The Dy content in the cell pellet of the T9 strain was 910 μg/mg of dry cells. The T9 strain also accumulated other REEs. Based on the results of 28S-D1/D2 rRNA gene sequencing and morphological characterization, we designated this fungal strain Penidiella sp. T9. Bioaccumulation of Dy was observed on the cell surface of the T9 strain by elemental mapping using scanning electron microscopy-energy dispersive X-ray spectroscopy. Our results indicate that Penidiella sp. T9 has the potential to recover REEs such as Dy from mine drainage and industrial liquid waste under acidic conditions., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Fungi play fundamental ecological roles in terrestrial ecosystems. However, their distribution and diversity remain poorly described in natural communities, particularly in arid and semi-arid ecosystems. In order to identify environmental factors determining fungal community structure in these systems, we assessed their diversity in conjunction with soil physicochemical characteristics in a semi-arid ecosystem in Baja California, Mexico, endemic for Coccidioidomycosis (Valley Fever). Two different microhabitats, burrows (influenced by rodent activity) and topsoil, were compared in winter and summer. Using a metagenomic approach, the ITS1 region of nuclear ribosomal DNA was used as barcode. A total of 1940 Operational Taxonomic Units (OTUs) were identified from 362 332 ITS1 sequences obtained by 454 pyrosequencing. Differences in fungal composition between seasons were clearly identified. Moreover, differences in composition between microhabitats were mainly correlated to significant differences in environmental factors, such as moisture and clay content in topsoil samples, and temperature and electrical conductivity in burrow samples. Overall, the fungal community structure (dominated by Ascomycota and Basidiomycota) was less variable between seasons in burrow than in topsoil samples. Coccidioides spp. went undetected by pyrosequencing. However, a nested PCR approach revealed its higher prevalence in burrows., (© FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Ulleungdo and Dokdo are volcanic islands that experience a characteristic marine climate, influenced by warm currents. The richness and diversity of the plant species, particularly vascular plants, are higher on Ulleungdo than on Dokdo. In contrast to the native plant life, little is known about the diversity of soil fungi living in the rhizosphere of these two islands. In this study, we utilized the barcoded pyrosequencing method to analyze rhizosphere soil fungi on Ulleungdo and Dokdo. In total, 768 operational taxonomic units (OTUs) were analyzed from the Ulleungdo samples, while 640 OTUs and 382 OTUs were analyzed from the Dongdo and Seodo (islets of Dokdo) samples, respectively. Species richness was considerably higher in the Ulleungdo samples than in the Dongdo and Seodo samples, while there was little difference in species diversity between the samples. The taxonomic composition analyses demonstrated that members of the phylum Basidiomycota dominated the Ulleungdo samples, whereas members of the phylum Ascomycota were predominant in the Dokdo samples. Ectomycorrhizal fungi belonging to the phylum Basidiomycota, in particular, were more abundant in the Ulleungdo samples. This finding suggests that the difference in the abundance of the ectomycorrhizal fungi in the rhizospheres of Ulleungdo and Dokdo may have been affected by species richness and diversity of the vascular plants. Our study is the first detailed report of the composition of soil fungal communities on the Ulleungdo and Dokdo islands. In addition, our findings provide a basis for understanding the ecological interactions between plants and fungi.

The ectomycorrhizal fungus Cenococcum geophilum (Ascomycota, Dothideomycetes) forms black, round to irregular sclerotia in forest soils. Fungi that colonize the sclerotia appear to affect sclerotia viability and may play an important role in the life history of Cenococcum. Some of the fungi could also affect nutrient cycling by decomposing Cenococcum sclerotia, which are melanized and recalcitrant to decay. We used a culture-based method to document the fungal communities growing inside surface-sterilized sclerotia that were collected from forest soils. Cenococcum was successfully isolated from 297 of 971 sclerotia whereas 427 sclerotia hosted fungi other than Cenococcum. DNA barcoding of the internal transcribed spacer rDNA followed by grouping at 97% sequence similarity yielded 85 operational taxonomic units (OTUs) that consisted primarily of Ascomycota (e.g. Chaetothyriales, Eurotiales, Helotiales, Pleosporales) and a few Basidiomycota and Mucoromycotina. Although most fungal OTUs were infrequently cultured, several OTUs such as members of Asterostroma, Cladophialophora, Oidiodendron, and Pleosporales were common and found across many sites. Our results suggest that Cenococcum sclerotia act as a substrate for diverse fungi. The occurrence of several OTUs in sclerotia across many sites suggests that these fungi may be active parasites of Cenococcum sclerotia or may preferentially use sclerotia as a nutrient source., (© 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.)

The Mediterranean basin has been identified as a biodiversity hotspot, about whose soil microbial diversity little is known. Intensive land use and aggressive management practices are degrading the soil, with a consequent loss of fertility. The use of organic amendments such as dry olive residue (DOR), a waste produced by a two-phase olive-oil extraction system, has been proposed as an effective way to improve soil properties. However, before its application to soil, DOR needs a pre-treatment, such as by a ligninolytic fungal transformation, e.g. Coriolopsis floccosa. The present study aimed to describe the bacterial and fungal diversity in a Mediterranean soil and to assess the impact of raw DOR (DOR) and C. floccosa-transformed DOR (CORDOR) on function and phylogeny of soil microbial communities after 0, 30 and 60 days. Pyrosequencing of the 16S rRNA gene demonstrated that bacterial diversity was dominated by the phyla Proteobacteria, Acidobacteria, and Actinobacteria, while 28S-rRNA gene data revealed that Ascomycota and Basidiomycota accounted for the majority of phyla in the fungal community. A Biolog EcoPlate experiment showed that DOR and CORDOR amendments decreased functional diversity and altered microbial functional structures. These changes in soil functionality occurred in parallel with those in phylogenetic bacterial and fungal community structures. Some bacterial and fungal groups increased while others decreased depending on the relative abundance of beneficial and toxic substances incorporated with each amendment. In general, DOR was observed to be more disruptive than CORDOR.

Western European coastal sand dunes are highly important for nature conservation. Communities of the creeping willow (Salix repens) represent one of the most characteristic and diverse vegetation types in the dunes. We report here the results of the first kingdom-wide fungal diversity assessment in S. repens coastal dune vegetation. We carried out massively parallel pyrosequencing of ITS rDNA from soil samples taken at ten sites in an extended area of joined nature reserves located along the North Sea coast of the Netherlands, representing habitats with varying soil pH and moisture levels. Fungal communities in Salix repens beds are highly diverse and we detected 1211 non-singleton fungal 97% sequence similarity OTUs after analyzing 688,434 ITS2 rDNA sequences. Our comparison along a north-south transect indicated strong correlation between soil pH and fungal community composition. The total fungal richness and the number OTUs of most fungal taxonomic groups negatively correlated with higher soil pH, with some exceptions. With regard to ecological groups, dark-septate endophytic fungi were more diverse in acidic soils, ectomycorrhizal fungi were represented by more OTUs in calcareous sites, while detected arbuscular mycorrhizal genera fungi showed opposing trends regarding pH. Furthermore, we detected numerous red listed species in our samples often from previously unknown locations, indicating that some of the fungal species currently considered rare may be more abundant in Dutch S. repens communities than previously thought.

Soil fungi play a major role in terrestrial ecosystem functioning through interactions with soil structure, plants, micro- and mesofauna, and nutrient cycling through predation, pathogenesis, mutualistic, and saprotrophic roles. The diversity of soil fungi was assessed by sequencing their 28S rRNA gene in Alaskan permafrost and Oklahoma tallgrass prairie soils at experimental sites where the effect of climate warming is under investigation. A total of 226,695 reads were classified into 1,063 genera, covering 62% of the reference data set. Using the Bayesian Classifier offered by the Ribosomal Database Project (RDP) with 50% bootstrapping classification confidence, approximately 70% of sequences were returned as "unclassified" at the genus level, although the majority (∼65%) were classified at the class level, which provided insight into these lesser-known fungal lineages. Those unclassified at the genus level were subjected to BLAST analysis against the ARB-SILVA database, where ∼50% most closely matched nonfungal taxa. Compared to the more abundant sequences, a higher proportion of rare operational taxonomic units (OTU) were successfully classified to genera at 50% bootstrap confidence, indicating that the fungal rare biosphere in these sites is not composed of sequencing artifacts. There was no significant effect after 1 year of warming on the fungal community structure at both sites, except perhaps for a few minor members, but there was a significant effect of sample depth in the permafrost soils. Despite overall significant community structure differences driven by variations in OTU dominance, the prairie and permafrost soils shared 90% and 63% of all fungal sequences, respectively, indicating a fungal "seed bank" common between both sites.

Soil fungi are key players in the degradation of recalcitrant organic matter in terrestrial ecosystems. To examine the organisms and genes responsible for complex organic matter degradation in soil, we tracked changes in fungal community composition and expressed genes in soil adjacent to mesh bags containing maize leaves undergoing decomposition. Using high-throughput sequencing approaches, changes in fungal community composition were determined by targeting 18S rRNA gene sequences, whereas community gene expression was examined via a metatranscriptomic approach. The majority of the 93 000 partial 18S rRNA gene sequences generated, were affiliated with the Ascomycota and Basidiomycota. Fungal diversity was at least 224 operational taxonomic units at the 97% similarity cutoff level. During litter degradation, the relative proportion of Basidiomycota increased, with a decrease in Ascomycota : Basidiomycota ratios over time. The most commonly detected decomposition-associated fungi included Agaricomycetes and Tremellales as well as unclassified Mucoromycotina. The majority of protein families found in the metatranscriptomic data were affiliated to fungal groups described to degrade plant-derived cellulose, such as Mucoraceae, Chaetomiaceae, Sordariaceae, Sebacinaceae, Tremellaceae, Psathyrellaceae and Schizophyllaceae. The combination of high-throughput rRNA gene-based and metatranscriptomic approaches provided perspectives into the organisms and genes involved in complex organic matter in soil., (© 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.)

The recent emergence of white-nose syndrome (WNS), a fungal disease causing unprecedented mortality among hibernating bats of eastern North America, has revealed a knowledge gap regarding fungal communities associated with bats and their hibernacula. We used culture-based techniques to investigate the diversity of fungi in soil samples collected from 24 bat hibernacula in the eastern United States. Ribosomal RNA regions (internal transcribed spacer and partial intergenic spacer) were sequenced to preliminarily characterize isolates. Geomyces species were one of the most abundant and diverse groups cultured, representing approximately 33% of all isolates. Geomyces destructans was isolated from soil samples from three hibernacula in states where WNS is known to occur, and many of the other cultured Geomyces isolates likely represent undescribed taxa. Further characterization of the diversity of fungi that occur in hibernacula both will facilitate an improved understanding of the ecology of G. destructans within this complex fungal community and provide an opportunity to identify characteristics that differentiate G. destructans from non-pathogenic relatives.

Structure of fungal communities is known to be influenced by host plants and environmental conditions. However, in most cases, the dynamics of these variation patterns are poorly understood. In this work, we compared richness, diversity, and composition between assemblages of endophytic and rhizospheric fungi associated to roots of two plants with different lifestyles: the halophyte Inula crithmoides and the non-halophyte I. viscosa (syn. Dittrichia viscosa L.), along a spatially short salinity gradient. Roots and rhizospheric soil from these plants were collected at three points between a salt marsh and a sand dune, and fungi were isolated and characterized by ITS rDNA sequencing. Isolates were classified in a total of 90 operational taxonomic units (OTUs), belonging to 17 fungal orders within Ascomycota and Basidiomycota. Species composition of endophytic and soil communities significantly differed across samples. Endophyte communities of I. crithmoides and I. viscosa were only similar in the intermediate zone between the salt marsh and the dune, and while the latter displayed a single, generalist association of endophytes, I. crithmoides harbored different assemblages along the gradient, adapted to the specific soil conditions. In the lower salt marsh, root assemblages were strongly dominated by a single dark septate sterile fungus, also prevalent in other neighboring salt marshes. Interestingly, although its occurrence was positively correlated to soil salinity, in vitro assays revealed a strong inhibition of its growth by salts. Our results suggest that host lifestyle and soil characteristics have a strong effect on endophytic fungi and that environmental stress may entail tight plant-fungus relationships for adaptation to unfavorable conditions.

Truffles are hypogeous ectomycorrhizal (EM) fungi belonging to the genus Tuber. Although outplanting of truffle-inoculated host plants has enabled the realization of productive orchards, truffle cultivation is not yet standardized. Therefore, monitoring the distribution of fungal species in different truffle fields may help us to elucidate the factors that shape microbial communities and influence the propagation and fruiting of Tuber spp. In this study, we compared the fungal biodiversity in cultivated and natural Tuber melanosporum truffle fields located in Central Italy. To this end, ectomycorrhizas (ECM) and soil samples were molecularly analyzed, and an inventory of the fungi associated with Quercus pubescens plants colonized by T. melanosporum, Tuber aestivum or Tuber brumale was compiled. T. melanosporum and T. aestivum were dominant on the cultivated plants, and the number of EM species was markedly lower in the cultivated sites than in the natural sites. However, in the same site, EM biodiversity was higher in T. brumale-colonized plants than in T. melanosporum-colonized plants. These results suggest that different Tuber spp. may have different competitive effects on the other mycobionts. Additionally, in keeping with our previous findings, we found that the number of T. melanosporum genotypes recovered from the soil samples was higher than that of the underlying ECM., (© 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.)

New collections of T. gennadii, T. oligospermum and T. asa (Tuberaceae, Pezizales) from the Mediterranean basin were compared on the basis of morphology and DNA sequences. Phylogenetic inference based on the internal transcribed spacer region (ITS) and the 28S nuclear large ribosomal subunit (nrLSU) indicates that T. gennadii includes at least two lineages with characteristic morphological traits. T. gennadii s. str. has small subglobose ascomata with conspicuous glebal locules that form a continuous labyrinth when mature and has a prosenchymatic peridium. T. lacunosum has medium to large, deeply lobed ascomata with small to very small isolated locules when mature and has a pseudoparenchymatic peridium. Two major clades were identified within the T. oligospermum group. On the basis of morphological, ecological and biogeographical data, these are identified with the taxa T. oligospermum (= T. asa) and T. sphaerospermum. Tuber oligospermum forms small to medium globose or subglobose, whitish ascomata, with globose to broadly ellipsoidal ascospores and is found in alkaline, sandy soils. Tuber sphaerospermum forms medium to large, irregularly globose or deeply lobed, yellowish ascomata, with regularly globose ascospores and is found in acidic soils. Finally, a new truffle species with a prosenchymatic peridium and globose to ellipsoid reticulate spores, collected in acidic argillaceous soils of Spain under Cistus ladanifer is proposed here as the new species T. cistophilum.

Molecular methodologies were used to investigate fungal assemblages of biological soil crusts (BSCs) from arid lands in the southwestern United States. Fungal diversity of BSCs was assessed in a broad survey that included the Chihuahuan and Sonoran deserts as well as the Colorado Plateau. At selected sites samples were collected along kilometer-scale transects, and fungal community diversity and composition were assessed based on community rRNA gene fingerprinting using PCR-denaturing gradient gel electrophoresis (DGGE). Individual phylotypes were characterized through band sequencing. The results indicate that a considerable diversity of fungi is present within crusted soils, with higher diversity being recovered from more successionally mature BSCs. The overwhelming majority of crust fungi belong to the Ascomycota, with the Pleosporales being widespread and frequently dominant. Beta diversity patterns of phylotypes putatively representing dominant members of BSC fungal communities suggest that these assemblages are specific to their respective geographic regions of origin.

A new endoconidial taxon, Endophoma elongata gen. et sp. nov., isolated from bat-cave soil, is reported from Alberta, Canada. It is morphologically unique in producing two forms of unilocular, endoconidial conidiomata (i.e. a superficially Phoma-like spherical, often ostiolate form and a cylindrical, non-ostiolate, often setose cleistopycnidial form). Locules of both forms are pseudoparenchymatous, filled with hyaline, thin-walled, endoconidial conidiogenous cells. Endoconidia are hyaline and unicellular. One- or two-celled chlamydospores are abundant in culture. Phylogenetic analysis of the LSU, ITS and β-tubulin regions indicates Endophoma is a member of the Didymellaceae and remote from all other endoconidial genera. Endoconidiogenesis has not been reported previously within the Didymellaceae, and Endophoma represents the first report of a coelomycetous, endoconidial genus in the Pleosporales.

Estimates suggest that only one-tenth of the true fungal diversity has been described. Among numerous fungal lineages known only from environmental DNA sequences, Soil Clone Group 1 is the most ubiquitous. These globally distributed fungi may dominate below-ground fungal communities, but their placement in the fungal tree of life has been uncertain. Here, we report cultures of this group and describe the class, Archaeorhizomycetes, phylogenetically placed within subphylum Taphrinomycotina in the Ascomycota. Archaeorhizomycetes comprises hundreds of cryptically reproducing filamentous species that do not form recognizable mycorrhizal structures and have saprotrophic potential, yet are omnipresent in roots and rhizosphere soil and show ecosystem and host root habitat specificity.

White-nose syndrome (WNS) is an emerging disease causing unprecedented morbidity and mortality among bats in eastern North America. The disease is characterized by cutaneous infection of hibernating bats by the psychrophilic fungus Geomyces destructans. Detection of G. destructans in environments occupied by bats will be critical for WNS surveillance, management and characterization of the fungal lifecycle. We initiated an rRNA gene region-based molecular survey to characterize the distribution of G. destructans in soil samples collected from bat hibernacula in the eastern United States with an existing PCR test. Although this test did not specifically detect G. destructans in soil samples based on a presence/absence metric, it did favor amplification of DNA from putative Geomyces species. Cloning and sequencing of PCR products amplified from 24 soil samples revealed 74 unique sequence variants representing 12 clades. Clones with exact sequence matches to G. destructans were identified in three of 19 soil samples from hibernacula in states where WNS is known to occur. Geomyces destructans was not identified in an additional five samples collected outside the region where WNS has been documented. This study highlights the diversity of putative Geomyces spp. in soil from bat hibernacula and indicates that further research is needed to better define the taxonomy of this genus and to develop enhanced diagnostic tests for rapid and specific detection of G. destructans in environmental samples.

Thielaviopsis basicola is a soil-borne fungus with a wide host range and a cosmopolitan distribution. It causes disease on many agricultural crops and in China it is the causal agent of black root rot on tobacco plant. Early diagnosis and detection of the pathogen in soil are critical to control this disease in field. The objective of this study was to develop sensitive and effective methods suitable for large-scale detection and quantification of T. basicola. Based on the nucleotide sequences of the internal transcribed spacer (ITS) regions of rDNA genes of Thielaviopsis spp, primers and TaqMan probe were designed specifically to amplify DNA from T. basicola and real-time, quantitative PCR (qPCR) assays were developed for rapid, specific and sensitive detection and quantification of T. basicola. It was sensitive with the detection limit of 100 fg microl(-1) genomic DNA of T. basicola in qPCR assays. By combining the qPCR assays with the efficient protocol to extract DNA from soil, it was possible to achieve real-time detection of T. basicola in soil in 4-5 h and the detection limit of 3 conidia per reaction in qPCR was recorded. The assays were applied to survey soils from tobacco fields in China for the presence of T. basicola and the analyses of naturally infested soil showed the reliability of the qPCR assays., (Copyright 2009 Elsevier GmbH. All rights reserved.)

A total of 4 strains (DR2-4, DW2-1, DS2-1 and DS3-1) of undescribed ascomycetous yeast, isolated from Nam Nao forest soil, were identified as a novel species in the genus Millerozyma. The D1/D2 sequences of the strains differed from the closely related species Millerozyma acaciae and Pichia koratensis by 1.2% (7 nucleotide substitutions) and 1.4% (8 nucleotide substitutions). Phenotypically, all the novel strains were identical, but differed from M. acaciae and P. koratensis by a variety of phenotypic characteristics. Based on phenotypic and phylogenetic data, these four yeast strains were assigned to a single novel species in the genus Millerozyma and the name Millerozyma phetchabunensis sp. nov. is proposed. In addition, we also propose the transfer of P. koratensis, which was placed in the Millerozyma clade based on the analysis of the D1/D2 and ITS sequences, to the genus Millerozyma as M. koratensis comb. nov.

The fruiting bodies of the ectomycorrhizal (ECM) fungus Tuber melanosporum are usually collected in an area devoid of vegetation which is defined as a 'burnt area' (brulé in French). Here, the soil fungal populations of inside and outside brulé were compared in order to understand whether the scanty plant cover was related to a change in fungal biodiversity. Both denaturing gradient gel electrophoresis (DGGE) and molecular cloning of the internal transcribed spacer (ITS) marker were employed on soil DNA to obtain profiles from nine truffle grounds and fungal sequences from one selected truffle ground sampled in two years. Denaturant gradient gel electrophoresis profiles from the two areas formed two distinct clusters while molecular cloning allowed 417 fungal sequences to be identified. T. melanosporum was the dominant fungus within the brulé. There were nine new haplotypes, which had never been detected in fruiting bodies. The Basidiomycota ECM fungi decreased within the brulé, indicating a competitive effect of T. melanosporum on the other ECM fungi. Among other factors, the dynamics of fungal populations seems to be correlated to brulé formation.

Nematode-trapping fungi, a monophyletic lineage within the Orbiliales (Ascomycota), use specialized structures to capture and consume nematodes in soil, leaf litter, and other substrates. These fungi have been studied both because of their unique predatory life history and because they are potential control agents of important plant- and animal-parasitic nematodes. Ecological studies of nematode-trapping fungi have primarily used culture-based methods, but molecular detection techniques are now available and should be useful for studying this group. We developed Orbiliales-specific PCR primers for the ITS and 28s rDNA to directly detect nematode-trapping fungi without culturing and also to screen fungal isolates for phylogenetic placement in the Orbiliales. We used these primers to selectively amplify, clone, and sequence Orbiliales DNA extracted from soil, litter, and wood, and we compared the results of molecular detection with those obtained using a culture-based method. Of the eight species of nematode-trapping Orbiliales detected with the culture-based assay, only three were detected with PCR. The molecular assay, however, detected 18 species of uncultured Orbiliales, many of which are closely related to nematode-trapping fungi and fungal parasites of nematode eggs. Our results suggest that the combined use of Orbiliales-specific primers and culture-based techniques may benefit future studies of nematophagous fungi.

Common occurrence of testate amoebae (TA) in the rhizosphere of mycorrhizal plants indicates existence of yet undocumented ecological interactions, involving three distinct groups of organisms: soil protists, mycorrhizal fungi, and their host plants. This tripartite relationship was to date investigated only to a limited extent, despite its probable importance for processes taking place in the mycorrhizosphere. In this study, we (1) explored spectra of different TA genera naturally associated with the rhizoplane of three autochthonous European Rhododendron species, (2) screened natural fungal colonization of the TA shells occupying the rhizoplane of selected rhododendrons, and (3) carried out two in vitro experiments addressing the question whether TA shells may serve as a nutrient source for ericoid mycorrhizal fungi (ErMF) and dark septate endophytes (DSE). Our field observations indicated that TA regularly associated with the rhizoplane of all screened rhododendrons and that ErMF and/or DSE associated with their roots possibly exploited the TA shells as a nutrient source. We were unable to detect any major differences among the TA spectra from the rhizoplanes with respect to the three Rhododendron species. The spectra were dominated by Diplochlamys, Centropyxis, Cyclopyxis, Euglypha, Trinema, and Assulina. Positive, neutral, and negative associations were found for various TA genera x Rhododendron species combinations. The highest fungal colonization was observed in Centropyxidae and Trigonopyxidae, reaching up to 45% of the shells in the case of Trigonopyxis. In the in vitro experiments, both ErMF Rhizoscyphus ericae and DSE Phialocephala fortinii regularly colonized TA shells, utilizing them as a source of nutrients. We hypothesize a complex relationship between ErMF-DSE and TA. If corroborated, it would represent an interesting nutrient loop in the mycorrhizosphere of ericaceous plants.

The fungal species involved in the decomposition of needle litter and their response to intraspecific genetic variation of trees are poorly known. First, we compared the needle decomposition and fungal decomposers underneath eight different Norway spruce clones in situ. This experiment revealed 60-70% loss of needle mass in two years. Although spruce clones differed considerably in growth (twofold height difference) and their needles differed in chemical composition, no significant difference was found for loss of needle mass under the spruce clones. Furthermore, the spruce clones did not affect the community structure of the fungal decomposers. Fungi inhabiting needle litter were identified by extracting ribosomal RNA (rRNA) and sequencing complementary DNA (cDNA) of internal trascribed spacer 1 (ITS1) region. The most frequent identifications were Lophodermium, Pezizales, Mycena, and Marasmius, suggesting that endophytic fungi were involved in the decomposition process. Second, we evaluated the potential of endophytes to decompose needle material in a microcosm experiment in which all other fungi than endophytes were excluded. Within 2 years, the endophytes had decomposed 35-45% of the needle mass. Sequences of Mollisia, Lophodermium, Lachnum, and Phialocephala were most frequently found in rRNA and rDNA extracted from the needles at the end of the microcosm experiment. The dominant needle endophyte in fresh, green needles was Lophodermium piceae, and this species was also found frequently in the needle material after 2 years of decay both in the field and laboratory experiments. Moreover, the relative abundance of Lophodermium-derived denaturing gradient gel electrophoresis (DGGE) bands correlated positively with the decomposition in the microcosm experiment. Hence, our results suggest a significant role of endophytic fungi, and particularly L. piceae, in the process of needle decomposition in boreal forests.

A new ascomycetous yeast species, Kazachstania jiainicus, is proposed based on two strains isolated from soil in Taiwan. The species is characterized by forming one or two globose spores in each ascus, fermenting glucose and galactose and assimilating few carbon and nitrogen compounds. Genus assignment and distinction of the strains from recognized species is based on ascosporulation and phylogenetic analysis of nucleotide sequences from domains D1/D2 of the large subunit (26S) rRNA gene. Sequence analysis showed that the species was phylogenetically related to the genus Kazachstania. The species was distinct from recognized species of Kazachstania on the basis of carbon and nitrogen assimilation patterns. Based on the characteristics described above, the species is recognized as a novel species of the genus Kazachstania, and the name Kazachstania jiainicus sp. nov. is proposed. The type strain is SF1S05T (=CBS10587T=NBRC 102655T=BCRC 23098T), which was isolated from soil in Jiain, Hualein, Taiwan.

Fungal diversity in the rhizosphere of healthy and diseased clonal black spruce (Picea mariana) plants was analyzed with regard to nursery production chronosequences. The four key production stages were sampled: mother plants (MP), 8-week-old cuttings (B + 0), second-year cuttings (B + 1), and third-year cuttings (B + 2). A total of 45 fungal taxa were isolated and identified based on cultural, phenotypic, and molecular characters. Members of phylum Ascomycota dominated, followed by Basidiomycota and Zygomycota. Diagnosis characters and distance analysis of the internal transcribed spacer rDNA sequences allowed the identification of 39 ascomycetous taxa. Many belong to the order Hypocreales, families Hypocreaceae and Nectriaceae, which contain many clusters of potentially pathogenic taxa (Cylindrocladium, Fusarium, and Neonectria) and are also ecologically associated with antagonistic taxa (Chaetomium, Hypocrea, Microsphaeropsis, Penicillium, Paecilomyces, Verticillium, Trichoderma, and Sporothrix). This is also the first report of a Cylindrocladium canadense association with disease symptoms and relation with Pestalotiopsis, Fusarium, Exserochilum, Rhizoctonia, and Xenochalara fungal consortia. Both production chronosequence and plant health considerably influenced fungal taxa assemblages. Unweighted pair-group arithmetic average clustering showed that isolates from MP, B + 0, and B + 1 plant rhizospheres clustered together within healthy or diseased health classes, whereas isolates from healthy and diseased B + 2 plants clustered together. Canonical correspondence analysis revealed substantial alteration in community assemblages with regard to plant health and yielded a principal axis direction that regrouped taxa associated with diseased plant rhizosphere soil, whereas the opposite axis direction was associated with healthy plants. Two diversity indices were defined and applied to assess the fungal taxa contribution (Tc) and persistence (Pi) throughout the production.

To appreciate the functional diversity of communities of soil eukaryotic micro-organisms we evaluated an experimental approach based on the construction and screening of a cDNA library using polyadenylated mRNA extracted from a forest soil. Such a library contains genes that are expressed by each of the different organisms forming the community and represents its metatranscriptome. The diversity of the organisms that contributed to this library was evaluated by sequencing a portion of the 18S rDNA gene amplified from either soil DNA or reverse-transcribed RNA. More than 70% of the sequences were from fungi and unicellular eukaryotes (protists) while the other most represented group was the metazoa. Calculation of richness estimators suggested that more than 180 species could be present in the soil samples studied. Sequencing of 119 cDNA identified genes with no homologues in databases (32%) and genes coding proteins involved in different biochemical and cellular processes. Surprisingly, the taxonomic distribution of the cDNA and of the 18S rDNA genes did not coincide, with a marked under-representation of the protists among the cDNA. Specific genes from such an environmental cDNA library could be isolated by expression in a heterologous microbial host, Saccharomyces cerevisiae. This is illustrated by the functional complementation of a histidine auxotrophic yeast mutant by two cDNA originating possibly from an ascomycete and a basidiomycete fungal species. Study of the metatranscriptome has the potential to uncover adaptations of whole microbial communities to local environmental conditions. It also gives access to an abundant source of genes of biotechnological interest.

The relative abundance within a guild of six species of the lichen-forming fungal genus Umbilicaria was studied during primary colonization of rock surfaces in a chronosequence of ca. 245 y in an alpine glacier foreland in southern Norway. Although the density of the guild grew from zero to more than 1000 thalli/m2 and the species differ substantially in life history traits such as initial growth rate, maximal size, maturation rate and propagule types, the relative abundance among the species remained almost unchanged through those years. The relative abundance of species is correlated with their life history parameters, such as initial growth rate and size-related maturation. The pattern of relative abundance was also similar in the saxicolous communities outside the foreland, which are potentially several thousand years old. Outside the foreland however the density of the guild is only 1/10 of that in the oldest parts of the foreland, due to soil formation and vegetation growth that have covered many of the low profile rock habitats. Thus the areas affected by the disturbance of glacier expansions and retreats provide temporary opportunities for large increases in the population sizes of the members of the saxicolous community. The observations support the view that pre-emption of habitat rather than competitive exclusion is common in saxicolous lichen communities and that "succession" consists in the addition but rarely the loss of species.

We developed a procedure to culture microorganisms below freezing point on solid media (cellulose powder or plastic film) with ethanol as the sole carbon source without using artificial antifreezes. Enrichment from soil and permafrost obtained on such frozen solid media contained mainly fungi, and further purification resulted in isolation of basidiomycetous yeasts of the genera Mrakia and Leucosporidium as well as ascomycetous fungi of the genus Geomyces. Contrary to solid frozen media, the enrichment of liquid nutrient solutions at 0 degrees C or supercooled solutions stabilized by glycerol at -1 to -5 degrees C led to the isolation of bacteria representing the genera Polaromonas, Pseudomonas and Arthrobacter. The growth of fungi on ethanol-microcrystalline cellulose media at -8 degrees C was exponential with generation times of 4.6-34 days, while bacteria displayed a linear or progressively declining curvilinear dynamic. At -17 to -0 degrees C the growth of isolates and entire soil community on 14C-ethanol was continuous and characterized by yields of 0.27-0.52 g cell C (g of C-substrate)(-1), similar to growth above the freezing point. The 'state of maintenance,' implying measurable catabolic activity of non-growing cells, was not confirmed. Below -18 to -35 degrees C, the isolated organisms were able to grow only transiently for 3 weeks after cooling with measurable respiratory and biosynthetic (14CO2 uptake) activity. Then metabolic activity declined to zero, and microorganisms entered a state of reversible dormancy.

A hyphomycetous fungus isolated from montane fen soil in the Caucasus Mountains, Russia, had obscurely sympodial conidiogenous cells that suggested a link to the heterogeneous genus Leptodontidium. Sequence analysis of the nuclear ribosomal small subunit and internal transcribed spacer region, however, disclosed that the fungus was an anamorphic member of a clade containing the cleistothecial ascomycetous genus Pseudeurotium. Teberdinia, gen. nov., is proposed for the blastic, generally sympodially proliferating anamorphs in this group, and Teberdinia hygrophila, sp. nov., is proposed for the species from upland fens. Binomials are not proposed for the remaining Teberdinia anamorphs of Pseudeurotium species. Purely anamorphic isolates in this clade are difficult to recognize using current morphological keys and might be more widely distributed and ecologically significant than is currently evident.

Acid mine drainage (AMD) microbial communities contain microbial eukaryotes (both fungi and protists) that confer a biofilm structure and impact the abundance of bacteria and archaea and the community composition via grazing and other mechanisms. Since prokaryotes impact iron oxidation rates and thus regulate AMD generation rates, it is important to analyze the fungal and protistan populations. We utilized 18S rRNA and beta-tubulin gene phylogenies and fluorescent rRNA-specific probes to characterize the eukaryotic diversity and distribution in extremely acidic (pHs 0.8 to 1.38), warm (30 to 50 degrees C), metal-rich (up to 269 mM Fe(2+), 16.8 mM Zn, 8.5 mM As, and 4.1 mM Cu) AMD solutions from the Richmond Mine at Iron Mountain, Calif. A Rhodophyta (red algae) lineage and organisms from the Vahlkampfiidae family were identified. The fungal 18S rRNA and tubulin gene sequences formed two distinct phylogenetic groups associated with the classes Dothideomycetes and Eurotiomycetes. Three fungal isolates that were closely related to the Dothideomycetes clones were obtained. We suggest the name "Acidomyces richmondensis" for these isolates. Since these ascomycete fungi were morphologically indistinguishable, rRNA-specific oligonucleotide probes were designed to target the Dothideomycetes and Eurotiomycetes via fluorescent in situ hybridization (FISH). FISH analyses indicated that Eurotiomycetes are generally more abundant than Dothideomycetes in all of the seven locations studied within the Richmond Mine system. This is the first study to combine the culture-independent detection of fungi with in situ detection and a demonstration of activity in an acidic environment. The results expand our understanding of the subsurface AMD microbial community structure.

We analysed the diversity of yeasts from different soils in a river-floodplain landscape at the river Danube downstream of Vienna, Austria ("Nationalpark Donauauen"). 136 strains were isolated, identification of species was done with molecular methods. Partial sequencing of the 26S rRNA gene resulted in 36 different sequences, they could be assigned to 16 genera, apart from two sequence types (from three isolates), which were not clearly assigned to any genus. 18 species were identified and confirmed by means of PCR fingerprinting. The most frequently isolated genus was Cryptococcus (61 isolates and 12 sequence types). Basidiomycetes dominated with about 60% above the members of the Ascomycetes. About half the yeasts was isolated from the litter, the quantity decreased with soil depth.

The finding that microbial communities are active under snow has changed the estimated global rates of biogeochemical processes beneath seasonal snow packs. We used microbiological and molecular techniques to elucidate the phylogenetic composition of undersnow microbial communities in Colorado, the United States. Here, we show that tundra soil microbial biomass reaches its annual peak under snow, and that fungi account for most of the biomass. Phylogenetic analysis of tundra soil fungi revealed a high diversity of fungi and three novel clades that constitute major new groups of fungi (divergent at the subphylum or class level). An abundance of previously unknown fungi that are active beneath the snow substantially broadens our understanding of both the diversity and biogeochemical functioning of fungi in cold environments.

Strains of insect-pathogenic fungi with high virulence toward certain pest insects have great potential for commercial biological control applications. Identifying such strains has been a central theme in using fungi for biological control. This theme is supported by a persistent paradigm in insect pathology which suggests that the host insect is the predominant influence on the population genetics of insect-pathogenic fungi. In this study, a population genetics analysis of the insect-pathogenic fungus Metarhizium anisopliae from forested and agricultural habitats in Ontario, Canada, showed a nonrandom association of alleles between two distinct, reproductively isolated groups (index of multilocus association = 1.2). Analyses of the mitochondrial DNA showed no differences between the groups. The two groups were associated with different habitat types, and associations with insect hosts were not found. The group from forested areas showed an ability for cold-active growth (i.e., 8 degrees C), while the group from the agricultural area showed an ability for growth at high temperatures (i.e., 37 degrees C) and resilience to UV exposure. These results represent a significant paradigm shift; habitat selection, not host insect selection, drives the population structure of these insect-pathogenic deuteromycetous fungi. With each group we observed recombining population structures as well as clonally reproducing lineages. We discuss whether these groups may represent cryptic species. Worldwide, M. anisopliae may be an assembly of cryptic species, each adapted to certain environmental conditions. The association of fungal genotypes with habitat but not with host insects has implications on the criteria for utility of this, and perhaps other, fungal biocontrol agents.