Search Results (65)

Fungal communities in high plateau ecosystems remain understudied despite their crucial roles in soil ecosystems, and yeasts inhabiting extreme regions have potential for industrial and biotechnological applications. We studied the fungal diversity in soils across 14 Chilean Altiplano sites using amplicon-based metagenomics and isolation of yeasts to assess their growth under various conditions and hydrolytic enzyme secretion. Using the metagenomic approach, the Ascomycota and Basidiomycota phyla were found to be the most abundant (85% and 8%, respectively). Unclassified families and genera prevailed at six and ten sites, respectively. At the other sites, the most abundant families included Cladosporiaceae, Teratosphaeriaceae, and Sporormiaceae, and the genera Oleoguttula, Coniochaeta, and Peziza. Biodiversity indices did not correlate with the soil’s geographic origin, organic matter content, humidity, or pH. Most isolated yeasts belong to the Naganishia, Holtermanniella, and Vishniacozyma genera, growing at temperatures ranging from 4 °C to 26 °C. Most isolates could use glucose, sucrose, and maltose as carbon sources and exhibited amylase, esterase, pectinase, and protease activities at 30 °C and below. Our results indicate that the evaluated soil physicochemical parameters do not explain the fungal distribution in the Altiplano and highlight the region as a reservoir of unknown fungi, including yeasts with industrially relevant enzymes. Full article

In Montenegro, coniferous forests play a key ecological role in maintaining ecosystem stability. Root-associated mycorrhizal fungi and saprotrophic fungi inhabiting forest soils are well known for their roles in nutrient cycling, organic matter decomposition, and supporting host tree health. In contrast, the fungal communities residing within conifer needles, despite potentially important ecological functions, remain largely underexplored, particularly in natural and marginal forest ecosystems such as those in the Balkans. This study aimed to investigate the diversity and community composition of needle-associated fungi in three native conifers: Picea abies and Abies alba (at the edge of their native range), and the endemic Pinus heldreichii, from different mountainous regions in Montenegro. High-throughput sequencing was conducted to assess fungal diversity and community composition. Dothideomycetes dominated fungal communities in all three tree species, followed by Leotiomycetes and Tremellomycetes. Multivariate analysis revealed distinct fungal communities in P. heldreichii, whereas fungal communities in A. alba and P. abies were partially overlapping. Functional classification showed a dominance of saprotrophic, pathogenic, and endophytic fungi, with P. heldreichii exhibiting the highest proportion of saprotrophs, while A. alba and P. abies showed a considerable proportion of pathogens. The findings highlight strong host specificity, biogeographical influences, and the ecological importance of fungal communities in coniferous forests. This study provides new insights into the diversity and functional roles of needle-associated fungi, emphasizing the need for conservation efforts to maintain microbial biodiversity in native forests of Montenegro. Full article

The Clonostachys genus is a saprophytic soil microfungus (Ascomycota). It exhibits significant ecological adaptability and plays a crucial role in maintaining the balance of soil microorganisms. Species within this genus are natural antagonists of insects and nematodes, and they also combat phytopathogenic fungi through mycoparasitism. This process involves producing lytic enzymes and competing for space and nutrients. Clonostachys species are effective biocontrol agents in agriculture and have been utilized to manage pests affecting many high-value commercial crops, acting as a natural biopesticide. They inhabit plant tissues, boosting plant defenses and activating genes for water and nutrient uptake, enhancing plant performance. Additionally, they produce enzymes and bioactive metabolites with antimicrobial, antifungal, nematocidal, anticancer, and antioxidant properties. Clonostachys species can degrade plastic waste and remove hydrocarbons from crude oil-contaminated sites when functioning as endophytes, positioning Clonostachys as a promising candidate for reducing environmental pollution. There are still challenges and limitations, such as the continuous surveillance of the safety of Clonostachys species on plants, the establishment of commercial applications, formulation viability, and variability due to field conditions. These issues will have to be addressed. This review provides an overview of Clonostachys ecology, morphology, classification, and biotechnological applications, emphasizing its significance in various fields. Full article

Background/Objectives:Maerua crassifolia, a threatened medicinal species endemic to drylands, exhibits a pronounced drought sensitivity. Despite the critical role of microorganisms, particularly bacteria and fungi, the microbial consortia in M. crassifolia’s rhizosphere remain underexplored. Methods: Metagenomic whole genome shotgun sequencing (WGS) was employed to elucidate the taxonomic composition of bacterial and fungal communities inhabiting the soil rhizosphere of M. crassifolia. Results: The data revealed a marked predominance of bacterial genomes relative to fungal communities, as evidenced by non-redundant gene analysis. Notably, arbuscular mycorrhizal fungi (AMF), specifically Rhizophagus clarus, Rhizophagus irregularis and Funneliformis geosporum, are key rhizosphere colonizers. This study confirmed the presence of phosphate-solubilizing bacteria (PSB), such as Sphingomonas spp., Cyanobacteria and Pseudomonadota, underscoring the critical role of these microorganisms in the phosphorus cycle. Additionally, the study uncovered the presence of previously uncharacterized species within the phylum Actinobacteria, as well as unidentified taxa from the Betaproteobacteria, Gemmatimonadota and Chloroflexota phyla, which may represent novel microbial taxa with potential plant growth-promoting properties. Conclusions: Findings suggest a complex, symbiotic network where AMF facilitate phosphorus uptake through plant–root interactions. In a tripartite symbiosis, PSB enhance inorganic phosphorus solubilization, increasing bioavailability, which AMF assimilate and deliver to plant roots, optimizing nutrition. This bacterial–fungal interplay is essential for plant resilience in arid environments. Future investigations should prioritize the isolation and characterization of underexplored microbial taxa residing in the rhizosphere of M. crassifolia, with particular emphasis on members of the Actinobacteria, Betaproteobacteria, Gemmatimonadota and Chloroflexota phyla to uncover their roles in nutrient acquisition and sustainability. Full article

It is imperative to investigate the impact of irrigation on the microorganisms inhabiting soil in greenhouses, as this understanding is crucial for the implementation of effective water conservation strategies and optimal soil health sustenance in greenhouse tomato production. To this end, a tomato-cultivating experiment was conducted in a greenhouse, with the control group receiving no planting or irrigation (W0), during the years 2021 and 2022 in the Taiyuan region of Shanxi Province, China. The experiment incorporated three irrigation levels: W1 (50–70% of the field capacity), W2 (60–80% of the field capacity), and W3 (70–90% of the field capacity). The objective of our study was to clarify the effects of different irrigation levels on soil bacterial and fungal community compositions and functions, as well as tomato yield and water use efficiencies, by analyzing the changes in community structural characteristics and potential functional composition of soil bacteria and fungi under different irrigation levels. Our results showed that in comparison with the control treatment, the W3 irrigation treatment exhibited the highest bacterial α-diversity, while its fungal diversity was the lowest. The r-strategy microbial community in tomato soil demonstrated increased abundance under the irrigation treatment. The relative abundance of common beneficial tomato bacteria increased by 0.32–1.70%, but that of beneficial soil fungi decreased by 0.09–3.75%. Among the different irrigation treatments, the relative abundances of Bacillus and Plectosphaerella changed the most. The functional structure of the bacteria in the irrigation treatment remained largely unchanged, while the saprotroph functional group of fungi was increased by 14.72–23.28%. With the increase in irrigation volume, the tomato yield of the W3 treatment increased, though the water use efficiency was not the greatest. The W2 treatment did not significantly reduce the yield, but it did increase the pathotroph functional groups of fungi, which may reduce the stress resistance of plants to soil-borne diseases. The findings of this study serve as a valuable reference point for the prediction of greenhouse soil health and the enhancement of tomato yields. Full article

Although certain hypersaline endorheic lagoons in Spain have been investigated to evaluate the composition, spatial structure, and ecological roles of their macro- and microbiota, the fungi inhabiting these niches remain largely unexplored. In this study, we isolated several microfungi from the Salada Grande de Chiprana and La Playa lagoons, located in the Saladas de Chiprana (Directed Natural Reserve and Ramsar Wetland) and the Saladas de Sástago–Bujaraloz (Ramsar Wetland), respectively. As a result of morphological characterization and phylogenetic analysis using four informative molecular markers, we report the discovery of two new species of the genus Montagnula (M.), M. globospora and M. terricola, as well as one new species of Monosporascus (Mo.), Mo. auratispora. Montagnula globospora, isolated from a sediment sample from Salada Grande de Chiprana lagoon, is the only species of the genus producing unicellular, globose ascospores inside cleistothecial ascomata with a cephalothecoid peridium. Montagnula terricola was originally isolated from a soil sample in Malawi (ex-type strain). However, we have also identified another strain of this species from a sediment sample collected at La Playa lagoon. The remarkable features of M. terricola are the production of non-cephalothecoid cleistothecial ascomata and bicellular, bi-cupulate ascospores. Regarding Mo. auratispora, it was isolated from sediments of Salada Grande de Chiprana and is characterized by the production of golden-brown ascospores that do not turn black with age. Also, due to the results of our phylogenetic analysis, we transferred Herpotrichia striatispora to the genus Montagnula, as M. striatispora, and Montangula jonessi to the new genus Neomontagnula (N.), as N. jonessi. Full article

Environmentally sound insect pest management strategies require continuous isolation and identification of effective biocontrol agents from different ecosystems. The quest for fungal isolates that are adapted to high temperatures is particularly significant, as they hold the potential to produce mycoinsecticides that are highly effective in semiarid and arid areas. This study aimed to collect new virulent isolates of entomopathogenic fungi (EPF) from Kazakhstan that show promise for controlling Colorado potato beetle (CPB) populations under arid conditions. Local isolates could be adapted to abiotic and biotic factors in the environment in which they survive. The findings of this study should provide insights into the species of EPF that inhabit a specific arid region of Kazakhstan, examining their traits in the regional climate, soil composition, and biological diversity. Throughout 2023–2024, a series of soil samples was collected from diverse locations within the Turkestan region of southern Kazakhstan for the isolation of EPF. The isolation of EPF was conducted using susceptible larvae of Tenebrio molitor (Coleoptera: Tenebrionidae), a host that does not have specificity for particular species of EPF. Using this insect bait, 41 pure cultures of EPF were isolated from soils in the arid zone of Kazakhstan. Polymerase chain reaction analysis based on the TEF1-α locus showed that all the isolates were indistinguishable from Beauveria bassiana ARSEF 2860 species. However, analysis of the ITS locus revealed two cryptic species: B. bassiana and B. pseudobassiana. For laboratory evaluation of biological activity EPF, the second and third instars of CPB were collected from potato fields in southern Kazakhstan and placed in plastic containers. Test CPB larvae were treated with conidia suspensions at 1 × 10⁷ spores/mL and survival was recorded daily for 3 weeks. The results of the bioassays revealed that all the new Kazakhstan isolates were pathogenic to larvae CPB and caused complete mortality by the end of the 11-day. These results showed that new isolates of EPF were highly virulent against larvae CPB. Full article

The aim of the present research is the isolation and morphological and molecular–phenological identification of nematophagous fungi of Southern Kazakhstan for the production of effective bionematicides on their basis. Nematophagous fungi, which include nematode-trapping, ovicidal, endoparasitic, toxin-producing, and special substance-producing fungi, are among the most effective biological agents in controlling phytoparasitic nematodes. To isolate and characterize nematophagous fungi, soil samples were collected at 12 sites in three regions of Southern Kazakhstan. The samples were collected using the envelope method. The content of nematophagous fungi in the samples was determined using the standard surface sowing technique. The obtained strains of nematophagous fungi were identified. The attractive and nematophagous activity of the obtained fungal strains was determined by using standard methods. In experiments on the isolation and morphological identification of nematophagous fungi, the nematode species Meloidogyne incognita was used. Identification of the strains was carried out by the method of determining the direct nucleotide sequence of the region of the nuclear ribosomal internal transcribed spacer, followed by determination of nucleotide identity with sequences deposited in the international GeneBank database. As a result, the following species of nematophagous fungi living in the soils of agricultural lands in Southern Kazakhstan were identified: Orbilia oligospora, Duddingtonia flagrans, Orbilia oligospora, and Arthrobotrys superba. Full article

The nests of mound-building ants are unexplored reservoirs of fungal diversity. A previous assessment of this diversity in the nests of Formica ulkei suggested that water availability may be a determinant of the composition of this mycota. To investigate this question, we recovered 3594 isolates of filamentous Ascomycota from the nests of Formica obscuripes and adjacent, non-nest sites, employing Dichloran Rose Bengal agar (DRBA), Dichloran Rose Bengal agar containing glycerol (DRBAG), and malt extract agar containing sucrose (MEA20S). Higher numbers of fungi were isolated from the tops of mounds than from within mounds and non-mound sites. Mound nest soils were dominated by members of the family Aspergillaceae, and up to 50% of the colonies isolated on DRBAG belonged to the genus Aspergillus. Pseudogymnoascus pannorum and species of Talaromyces were also present in higher numbers in mound soils. Species of Penicillium were more abundant in non-nest soils, where they accounted for over 66% of isolates on DRBA. All Aspergillaceae assessed for xerotolerance on a medium augmented with glycerol or sucrose were xerophilic. These results, and our observation that the nests of F. obscuripes are low-water environments, indicate that water availability influences the structure of the fungal communities in these animal-modified habitats. Full article

The general lack of knowledge on the conditions of Western Siberia (Omsk region) and the taxonomic diversity of zonal soils determines the relevance of these studies. The research was carried out in order to study the effect of complex biologics on the taxonomic diversity of the fungal component of the microbiome of the rhizosphere of cereals and the phytosanitary condition of crops in the southern forest-steppe (meadow-chernozem soil) and subtaiga (gray forest soil) zones of the Omsk Irtysh region (Western Siberia). This work was carried out in 2022–2023, using laboratory studies in combination with field experiments and metagenomic and statistical analyses. The objects of research were varieties of cereals and grain forage crops of Omsk selection: soil microorganisms. The scheme of the experiment involved the study of the following options: varieties of cereals (factor A): spring soft wheat—Omsk 42, Omsk 44, Tarskaya 12; durum wheat—Omsk coral; barley—Omsk 101; oats—Siberian hercules; bacterial preparation for seed inoculation (factor B) without the drug—Mizorin and Flavobacterin. The sampling of the plant rhizosphere for metagenomic analysis was carried out during the earing phase (July). For the first time, the taxonomic composition of the fungal community was determined based on the analysis of amplicon libraries of fragments of ribosomal operons of ITS2 fungi during colonization of crop roots by nitrogen-fixing bacteria in various soil and climatic zones of the Omsk region. The fungal component of the microbiome was analyzed in two zones of the Omsk region (southern forest-steppe and subtaiga). The five dominant phyla of soil fungi were located in the following decreasing series: Ascomycota (about 70%) > Mortierellomycota (about 7%) > Basidiomycota (about 5%) > Mucoromycota (3%) > Chytridiomycota (1%). The five main genera of fungi inhabiting the rhizosphere of cereals are located in a decreasing row: Giberella (6.9%) > Mortierella (6.6%) > Chaetomium (4.8%) > Cladosporium (3.8%) > Rhizopus (3.3%). The predominantly positive effect of biologics of associative nitrogen fixation on the fungal community of the soil (rhizosphere) of experimental sites located in different soil and climatic zones has been established. During seed bacterization, the growth of saprotrophic fungal genera was noted in relation to the control variants Pseudogymnoascus, Chloridium, Clonostachys, Trihoderma, etc., and the fungicidal properties of bacterial strains introduced into the soil were actively manifested relative to phytopathogenic fungi of the genera Alternaria, Blumeria, Fusarium, etc. According to the results of determining the number of infectious structures of Rhizoctonia solani, it was found that the population of the soil with viable cells of this pathogen was 1–3 pcs/g (below the threshold of harmfulness, PV 20 pcs/g of soil), which indicates a favorable phytosanitary situation with respect to the pathogen. The fungicidal effect of the applied bacterial fertilizers on Rhizoctonia solani could not be detected. The number of Bipolaris sorokiniana varied depending on the drug used. In the conditions of the southern forest-steppe zone of the Omsk region (meadow-chernozem soil), the greatest fungicidal effect was noted in Flavobacterin application variants on wheat of the Omsk 42 variety, durum wheat of the Omsk coral variety, and barley; the decrease in conidia relative to the control was 73, 35, and 29%, respectively. In the subtaiga zone of the Omsk Irtysh region (gray forest soil), as in the southern forest-steppe zone, pre-sowing bacterization of seeds with Flavobacterin led to a decrease in Bipolaris sorokiniana in the rhizosphere of wheat of the Omsk 42 variety by 18%, and oats by 27%, to control. The use of the drug Mizorin in some variants of the experiment led to an insignificant decrease in the harmful fungus or had no effect at all. Full article

Habenaria and Liparis are well-known orchid genera that grow in terrestrial habitats in the tropics, subtropics or temperate zones. Three species have been found in subtropical regions of China, inhabiting terrestrial to epiphytic habitats. This study focuses on three species, H. dentata (distributed in Asia), H. yachangensis, and L. gigantea. For H. yachangensis and L. gigantea, there is no information about the mycorrhizal community in these species. This study aims to conduct the fungal community screening of Chinese ground orchids from subtropical regions. We performed a comparative analysis of the fungal community among H. dentata, H. yachangensis, and L. gigantea, determining their ITS regions using NGS paired-end sequences. The results clarified the diversity and the predominance of fungal genera. Ascomycota was abundant compared to Basidiomycota or other fungi groups in all communities, with a high dominance in all populations, especially for L. gigantea. At different root spatial locations, the fungal community diversity and richness were higher in the soil than in the rhizosphere or inner root. However, the results suggest that L. gigantea has a different fungal community compared to Habenaria species. In this order, the subtropical terrestrial orchids have a different fungal network compared to the northern terrestrial orchids. Also, there is a high probability of co-existence and co-evolution of endophytic fungi in these terrestrial orchids, indicating the potential role of host plants in selecting an endophytic fungal community. Furthermore, our results highlight the need to elucidate the microbe interactions of these unique orchids for long-term purposes, such as isolating indigenous fungi for suitable inoculants for further orchid propagation, restoration, and conservation. Full article

The sclerotium of the edible mushroom Polyporus umbellatus (Zhuling) exhibits various medicinal properties. However, given its long growth cycle and overexploitation, wild resources are facing depletion. Macrofungal growth depends on diverse microbial communities; however, the impact of soil bacteria on P. umbellatus development is unknown. Here, we combined high-throughput sequencing and pure culturing to characterize the diversity and potential function of bacteria and fungi inhabiting the P. umbellatus sclerotium and tested the bioactivities of their isolates. Fungal operational taxonomic units (OTUs) were clustered and classified, revealing 1275 genera. Bacterial OTUs yielded 891 genera. Additionally, 81 bacterial and 15 fungal strains were isolated from P. umbellatus sclerotia. Antagonism assays revealed three bacterial strains (FN2, FL19, and CL15) promoting mycelial growth by producing indole-3-acetic acid, solubilizing phosphate, and producing siderophores, suggesting their role in regulating growth, development, and production of active compounds in P. umbellatus. FN2-CL15 combined with bacterial liquid promoted growth and increased the polysaccharide content of P. umbellatus mycelia. This study reports new bioactive microbial resources for fertilizers or pesticides to enhance the growth and polysaccharide accumulation of P. umbellatus mycelia and offers guidance for exploring the correlation between medicinal macrofungi and associated microbial communities. Full article

Sodin 5 is a type 1 ribosome-inactivating protein isolated from the seeds of Salsola soda L., an edible halophytic plant that is widespread in southern Europe, close to the coast. This plant, known as ‘agretti’, is under consideration as a new potential crop on saline soils. Considering a possible defence role of sodin 5 in the plant, we report here its antifungal activity against different halophilic and halotolerant fungi. Our results show that sodin 5 at a concentration of 40 µg/mL (1.4 µM) was able to inhibit the growth of the fungi Trimmatostromma salinum (35.3%), Candida parapsilosis (24.4%), Rhodotorula mucilaginosa (18.2%), Aspergillus flavus (12.2%), and Aureobasidium melanogenum (9.1%). The inhibition observed after 72 h was concentration-dependent. On the other hand, very slight growth inhibition was observed in the fungus Hortaea werneckii (4.2%), which commonly inhabits salterns. In addition, sodin 5 showed a cytotoxic effect on the Sf9 insect cell line, decreasing the survival of these cells to 63% at 1.0 µg/mL (34.5 nM). Structural analysis of sodin 5 revealed that its N-terminal amino acid residue is blocked. Using mass spectrometry, sodin 5 was identified as a homologous to type 1 polynucleotide:adenosine glycosylases, commonly known as ribosome-inactivating proteins from the Amaranthaceae family. Twenty-three percent of its primary structure was determined, including the catalytic site. Full article

The process of soil genesis unfolds as pioneering microbial communities colonize mineral substrates, enriching them with biomolecules released from bedrock. The resultant intricate surface units emerge from a complex interplay among microbiota and plant communities. Under these conditions, host rocks undergo initial weathering through microbial activity, rendering them far from pristine and challenging the quest for biomarkers in ancient sedimentary rocks. In addressing this challenge, a comprehensive analysis utilizing Gas Chromatography Mass Spectrometry (GC-MS) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) was conducted on a 520-Ma-old Cambrian rock. This investigation revealed a diverse molecular assemblage with comprising alkanols, sterols, fatty acids, glycerolipids, wax esters, and nitrogen-bearing compounds. Notably, elevated levels of bacterial C₁₆, C₁₈ and C₁₄ fatty acids, iso and anteiso methyl-branched fatty acids, as well as fungal sterols, long-chained fatty acids, and alcohols, consistently align with a consortium of bacteria and fungi accessing complex organic matter within a soil-type ecosystem. The prominence of bacterial and fungal lipids alongside maturity indicators denotes derivation from heterotrophic activity rather than ancient preservation or marine sources. Moreover, the identification of long-chain (>C22) n-alkanols, even-carbon-numbered long chain (>C20) fatty acids, and campesterol, as well as stigmastanol, provides confirmation of plant residue inputs. Furthermore, findings highlight the ability of contemporary soil microbiota to inhabit rocky substrates actively, requiring strict contamination controls when evaluating ancient molecular biosignatures or extraterrestrial materials collected. Full article

Earth structures have a significant sustainable impact on regulating indoor environmental qualities. Yet, using soil materials can lead to fungal growth, impacting occupant health and structural stability. This study investigates the susceptibility of earth-based construction materials with cement, limestone, and acrylic-based additives to fungal growth. Laboratory tests were conducted on mixtures under conditions found in inhabited buildings in hot–arid regions. The proposed methodology was based on a 7-week artificial incubation of fungi obtained from moldy walls through regulating the room temperature to fall between 18 °C and 19 °C and a controlled humidity level of around 45%. These conditions were adopted according to the readings monitored in typical buildings in the study area. The results showed that fungal growth was evident on the surface of mixtures, including higher percentages of soil and lower percentages of additives. Mixtures comprising 50% soil, 15% acrylic-based additive, 15% quicklime, and 20% cement supported the least fungal growth, presenting the best choice as a sustainable, efficient replacement. Visual observation followed by microscopic examination ensured the results. Furthermore, results of an environmental post-occupancy evaluation of a constructed rammed earth building using the optimized mixture showed no signs of fungal proliferation on the inner walls afterward. Full article