Unveiling fungi associated with Castanopsis woody litter in Yunnan Province, China: Insights into Pleosporales (Dothideomycetes) species.

During a survey of the diversity of lignicolous fungi in Yunnan Province, China, we collected and identified five microfungi species from dead woody litters of Castanopsis trees in terrestrial habitats. Through both morphological comparisons and phylogenetic analyses of multi-gene sequences, we identified two taxa as new species and three collections as new host records within Pleosporales. Pseudolophiostomalincangense sp. nov. is introduced as a sexual morph in Lophiostomataceae, Pleopunctumbaoshanense sp. nov. is introduced as a hyphomycetous fungi in Phaeoseptaceae, and Paraphomaaquatica as a first report of sexual morph in Paraphoma. In addition, Occultibambusakunmingensis and Pleopunctummegalosporum were isolated for the first time from the dead twigs of Castanopsisdelavayi and C.calathiformis, respectively. Comprehensive morphological descriptions, illustrations, and phylogenetic analysis results are provided for the above-mentioned species.

Multi-gene phylogenetic analyses revealed two novel species and one new record of Trichobotrys (Pleosporales, Dictyosporiaceae) from China.

The rotting wood in freshwater is a unique eco-environment favoring various fungi. During our investigation of freshwater fungi on decaying wood, three hyphomycetes were collected from Jiangxi and Guangxi Provinces, China. Based on the morphological observations and phylogenetic analysis of a combined DNA data containing ITS, LSU, SSU and tef1-α sequences, two new Trichobotrys species, T.meilingensis and T.yunjushanensis, as well as a new record of T.effusa, were introduced. Additionally, a comprehensive description of the genus with both morphological and molecular data was first provided.

Multiple stressors affecting microbial decomposer and litter decomposition in restored urban streams: Assessing effects of salinization, increased temperature, and reduced flow velocity in a field mesocosm experiment.

A multitude of anthropogenic stressors impact biological communities and ecosystem processes in urban streams. Prominent among them are salinization, increased temperature, and altered flow regimes, all of which can affect microbial decomposer communities and litter decomposition, a fundamental ecosystem process in streams. Impairments caused by these stressors individually or in combination and recovery of communities and ecosystem processes after release from these stressors are not well understood. To improve our understanding of multiple stressors impacts we performed an outdoor stream mesocosm experiment with 64 experimental units to assess the response of microbial litter decomposers and decomposition. The three stressors we applied in a full-factorial design were increased salinity (NaCl addition, 0.53 mS cm-1 above ambient), elevated temperature (3.5 °C above ambient), and reduced flow velocity (3.5 vs 14.2 cm s-1). After two weeks of stressor exposure (first sampling) and two subsequent weeks of recovery (second sampling), we determined leaf-associated microbial respiration, fungal biomass, and the sporulation activity and community composition of aquatic hyphomycetes in addition to decomposition rates of black alder (Alnus glutinosa) leaves confined in fine-mesh litter bags. Microbial colonization of the litter was accompanied by significant mass loss in all mesocosms. However, there was little indication that mass loss, microbial respiration, fungal biomass, sporulation rate or community composition of aquatic hyphomycetes was strongly affected by either single stressors or their interactions. Two exceptions were temperature effects on sporulation and decomposition rate. Similarly, no notable differences among mesocosms were observed after the recovery phase. These results suggest that microbial decomposers and leaf litter decomposition are either barely impaired by exposure to the tested stressors at the levels applied in our experiment, or that communities in restored urban streams are well adapted to cope with these stressor levels.

Response of a simulated aquatic fungal community to nanoplastics exposure and functional consequence on leaf decomposition.

Nanoplastics pose a potential threat to a wide variety of aquatic organisms. Despite the awareness of this existing hazard, the impact of nanoplastics on natural fungal communities remains a research gap. In this study, five dominant fungi species, isolated from a stream ecosystem, were used to explore the effects of different nano-polystyrene (nano-PS) particles concentrations on a simulated fungal community. Specifically, the evaluation was conducted regarding the fungal growth, reproductivity, structural composition, and ecological function in leaf litter decomposition. A 15-day exposure experiment showed that 100 µg/L nano-PS significantly reduced the microcosm pH. The extracellular enzyme activities of ß-glucosidase, leucine-aminopeptidase, and peroxidase were significantly promoted by nano-PS exposure for 5 days or 15 days. Total sporulation rate significantly decreased after the 15-day exposure to 1 and 100 µg/L nano-PS and significantly increased under 10 µg/L nano-PS. In contrast, nano-PS concentrations had no effects on fungal biomass. In addition, the reduced relative abundance of Geotrichum candidum lowered its contribution to leaf decomposition, resulting in a decreased litter decomposition rate of a 24.5-27.9 % after exposure. This suggests that 1-100 µg/L nano-PS inhibited leaf decomposition by inhibiting fungal reproduction and reducing the contribution of specific fungal species. In addition, the findings highlight the importance of exploring the potential mechanisms of the interaction between nanoplastics and fungal species.

Does functionalised nanoplastics modulate the cellular and physiological responses of aquatic fungi to metals?

Co-contamination of freshwaters by nanoplastics (NPs; ≤ 1 µm) and metals is an emerging concern. Aquatic hyphomycetes play a crucial role as primary decomposers in these ecosystems. However, concurrent impacts of NPs and metals on the cellular and physiological activities of these fungi remain poorly understood. Here, the effects of environmentally realistic concentrations of two types of polystyrene (PS) NPs (bare and -COOH; up to 25 µg L-1) and copper (Cu; up to 50 µg L-1) individually and all possible combinations (NPs types and Cu) on Articulospora tetracladia, a prevalent aquatic hyphomycete, were investigated. Endpoints measured were intracellular reactive oxygen species accumulation, plasma membrane disruption and fungal growth. The results suggest that functionalised (-COOH) NPs enhance Cu adsorption, as revealed by spectroscopic analyses. Notably, NPs, Cu and their co-exposure to A. tetracladia can lead to ROS accumulation and plasma membrane disruption. In most cases, exposure to treatments containing -COOH NPs with Cu showed greater cellular response and suppressed fungal growth. By contrast, exposure to Cu individually showed stimulatory effects on fungal growth. Overall, this study provides novel insight that functionalisation of NPs facilitates metal adsorption, thus modulating the impacts of metals on aquatic fungi.

Insights from the Endophytic Fungi in Amphisphaeria (Sordariomycetes): A. orixae sp. nov. from Orixa japonica and Its Secondary Metabolites.

Endophytic fungi are a remarkably diverse group of microorganisms that have imperceptible associations with their hosts for at least a part of their life cycle. The enormous biological diversity and the capability of producing bioactive secondary metabolites such as alkaloids, terpenoids, and polyketides have attracted the attention of different scientific communities, resulting in numerous investigations on these fungal endophytes. During our surveys of plant-root-based fungi in the mountain areas of Qingzhen, Guizhou Province, several isolates of endophytic fungi were identified. In this study, a novel endophytic fungus was discovered in the roots of a medicinal plant (Orixa japonica) in Southern China and introduced as a new species (Amphisphaeria orixae) based on morphological evidence and molecular phylogenetic analysis (combined ITS and LSU sequence data). To the best of our knowledge, A. orixae is the first reported endophyte as well as the first hyphomycetous asexual morph in Amphisphaeria. A new isocoumarin, (R)-4,6,8-trihydroxy-5-methylisochroman-1-one (1), and 12 known compounds (2-13) were isolated from the rice fermentation products of this fungus. Using 1D- and 2D-NMR, mass spectrometry, and ECD studies, their structures were identified. The antitumor activity of these compounds was tested. Unfortunately, none of the compounds tested showed significant antitumor activity.

Seasonal fluctuations and diversity of Ingoldian mycobiota in two water bodies receiving different effluents at Assiut Governorate (Upper Egypt).

In the current study, fifty-eight Ingoldain fungal species assignable to forty-one genera were recovered from two water bodies receiving the treated sewage and the effluents of oils and soaps factory at Assiut Governorate (Upper Egypt), of which Anguillospora, Amniculicola, Flagellospora, and Mycocentrospora were the most prevalent genera. The most widespread identified species were Anguillospora furtive, Amniculicola longissima and Flagellospora fusarioides. Forty-three species were identified for the first time in Egypt. The most Ingoldain taxa were estimated for El-Zinnar canal, with the highest recorded taxa in winter. Whereas, the highest dominance of Ingoldian fungi was estimated for the El-Ibrahimia canal. The highest Simpson and Shannon diversity indexes were estimated for El-Zinnar canal samples recording 0.9683 and 3.741, respectively. The poorest water sites with Ingoldian fungi were those exposed directly to either treated sewage or industrial effluents, with which relatively higher values of water conductivity, cations and anions. Water temperature was the main abiotic factor driving the seasonal occurrence of Ingoldian fungi. It is interesting to isolate some Ingoldian fungal species from the stressful water sites receiving the effluents which provide valuable insights regarding their adaptation, predictive and putative role as bioindicators and their potentiality in pollutants degradation, organic decomposition, and transformation of xenobiotic compounds.

Warming overrides eutrophication effects on leaf litter decomposition in stream microcosms.

Several human activities often result in increased nitrogen (N) and phosphorus (P) inputs to running waters through runoff. Although headwater streams are less frequently affected by these inputs than downstream reaches, the joint effects of moderate eutrophication and global warming can affect the functioning of these ecosystems, which represent two thirds of total river length and thus are of major global relevance. In a microcosm study representing streams from a temperate area (northern Spain), we assessed the combined effects of increased water temperature (10.0, 12.5, and 15.0 °C) and nutrient enrichment (control, high N, high P, and high N + P concentrations) on the key process of leaf litter decomposition (mediated by microorganisms and detritivores) and associated changes in different biological compartments (leaf litter, aquatic hyphomycetes and detritivores). While warming consistently enhanced decomposition rates and associated variables (leaf litter microbial conditioning, aquatic hyphomycete sporulation rate and taxon richness, and detritivore growth and nutrient contents), effects of eutrophication were weaker and more variable: P addition inhibited decomposition, addition of N + P promoted leaf litter conditioning, and detritivore stoichiometry was affected by the addition of both nutrients separately or together. In only a few cases (variables related to detritivore performance, but not microbial performance or leaf litter decomposition) we found interactions between warming and eutrophication, which contrasts with other experiments reporting synergistic effects. Our results suggest that both stressors can importantly alter the functioning of stream ecosystems even when occurring in isolation, although non-additive effects should not be neglected and might require exploring an array of ecosystem processes (not just leaf litter decomposition) in order to be detected.

Taxonomy and Phylogeny of Hyphomycetous Muriform Conidial Taxa from the Tibetan Plateau, China.

During the investigation of lignicolous freshwater fungi in the Tibetan Plateau habitat, fifteen collections were isolated from submerged decaying wood. Fungal characteristics are commonly found as punctiform or powdery colonies with dark pigmented and muriform conidia. Multigene phylogenetic analyses of combined ITS, LSU, SSU and TEF DNA sequences showed that they belong to three families in Pleosporales. Among them, Paramonodictys dispersa, Pleopunctum megalosporum, Pl. multicellularum and Pl. rotundatum are established as new species. Paradictyoarthrinium hydei, Pleopunctum ellipsoideum and Pl. pseudoellipsoideum are reported as new records on the freshwater habitats in Tibetan Plateau, China. The morphological descriptions and illustrations of the new collections are provided.

Morphological and Phylogenetic Analyses Reveal Three New Species of Distoseptispora (Distoseptisporaceae, Distoseptisporales) from Yunnan, China.

Three new species of Distoseptispora, viz. D. mengsongensis, D. nabanheensis, and D. sinensis, are described and illustrated from specimens collected on dead branches of unidentified plants in Yunnan Province, China. Phylogenetic analyses of LSU, ITS, and TEF1 sequence data, using maximum-likelihood (ML) and Bayesian inference (BI), reveal the taxonomic placement of D. mengsongensis, D. nabanheensis, and D. sinensis within Distoseptispora. Both morphological observations and molecular phylogenetic analyses supported D. mengsongensis, D. nabanheensis, and D. sinensis as three new taxa. To extend our knowledge of the diversity of Distoseptispora-like taxa, a list of recognized species of Distoseptispora with major morphological features, habitat, host, and locality is also provided.

Neogrisphenol A, a Potential Ovarian Cancer Inhibitor from a New Record Fungus Neohelicosporium griseum.

From the rice fermentation product of a new record fungus, Neohelicosporium griseum, two new polyketides, neogrisphenol A (1) and neogrisphenol B (2), one new isochroman-1-one, (S)-6-hydroxy-7-methoxy-3,5-dimethylisochroman-1-one (3), and four known compounds (4-7) were isolated. Their structures were determined using 1D- and 2D-NMR, mass spectrometry, and chemical calculations. The C-3~C-2' polymerization mode between the two α-naphthalenone derivative moieties is uncommon in compounds 1 and 2. Meanwhile, compounds 1-2 and 5 exhibited antibacterial activity against Bacillus subtilis, Clostridium perfringens, Staphylococcus aureus, and Staphylococcus aureus, with MIC values ranging between 16 and 31 µg/mL. In addition, compound 5 showed antifungal activity against Sclerotinia sclerotiorum and Phytophthora nicotianae var. nicotianae, with respective IC50 values of 88.14 ± 2.21 µg/mL and 52.36 ± 1.38 µg/mL. Compound 1 showed significant cytotoxicity against A2780, PC-3, and MBA-MD-231 cell lines with respective IC50 values of 3.20, 10.68, and 16.30 µM, and the cytotoxicity against A2780 cells was even higher than that of cisplatin (CDDP). With an IC50 value of 10.13 µM, compound 2 also exhibited cytotoxicity against A2780. The in vitro results showed that compound 1 inhibited A2780 cell proliferation, induced apoptosis, and arrested the cell cycle at the S-phase in a concentration-dependent manner.

Temperature and interspecific interactions drive differences in carbon use efficiencies and biomass stoichiometry among aquatic fungi.

Saprotrophic fungi play important roles in transformations of carbon (C), nitrogen (N), and phosphorus (P) in aquatic environments. However, it is unclear how warming will alter fungal cycling of C, N, and P. We conducted an experiment with four aquatic hyphomycetes (Articulospora tetracladia, Hydrocina chaetocladia, Flagellospora sp., and Aquanectria penicillioides), and an assemblage of the same taxa, to test how temperature alters C and nutrient use. Specifically, we evaluated biomass accrual, C:N, C:P, δ13C, and C use efficiency (CUE) over a 35-d experiment with temperatures ranging from 4ºC to 20ºC. Changes in biomass accrual and CUE were predominantly quadratic with peaks between 7ºC and 15ºC. The C:P of H. chaetocladia biomass increased 9× over the temperature gradient, though the C:P of other taxa was unaffected by temperature. Changes in C:N were relatively small across temperatures. Biomass δ13C of some taxa changed across temperatures, indicating differences in C isotope fractionation. Additionally, the 4-species assemblage differed from null expectations based on the monocultures in terms of biomass accrual, C:P, δ13C, and CUE, suggesting that interactions among taxa altered C and nutrient use. These results highlight that temperature and interspecific interactions among fungi can alter traits affecting C and nutrient cycling.

Cladosporium Species Associated with Fruit Trees in Guizhou Province, China.

During an investigation of fungal diversity on fruit trees in Guizhou Province, 23 Cladosporium strains were isolated from various locations in Guizhou Province. Culture characteristics, morphology and molecular phylogenetic analysis of three genetic markers, namely, the internal transcribed spacer regions (ITS) of the rDNA, partial fragments of actin (act), and the translation elongation factor 1-α (tef1-ɑ) loci were used to characterize these isolates. Seven new Cladosporium species and new host records for five other species were introduced, with detailed descriptions and illustrations. This study showed that there is a rich diversity of Cladosporium spp. in fruit trees in Guizhou Province.

Drying shapes the ecological niche of aquatic fungi with implications on ecosystem functioning.

Fungi are among the most abundant and diverse organisms on Earth and play pivotal roles in global carbon processing, nutrient cycling and food webs. Despite their abundant and functional importance, little is known about the patterns and mechanisms governing their community composition in intermittent rivers and ephemeral streams, which are the most common fluvial ecosystems globally. Thus far, it is known that aquatic fungi have evolved various life-history strategies and functional adaptations to cope with drying. Nevertheless, some of these adaptations have a metabolic cost and trade-offs between growth, reproduction and dispersion that may affect ecosystem functioning. Thus, understanding their ecological strategies along a gradient of drying is crucial to assess how species will respond to global change and to identify meaningful taxa to maintain ecosystem functions. By combining in situ hydrological information with a niche-based approach, we analysed the role of drying in explaining the spatial segregation of fungal species, and we determined their specialization and affinity over a gradient of drying. In addition, we estimated whether species niches are good predictors of two key ecosystem processes: organic matter decomposition and fungal biomass accrual. Overall, we found that annual drying duration and frequency were the most influential variables upon species niche differentiation across the 15 studied streams. Our cluster analysis identified four drying niche-based groups with contrasting distributions and responses over the drying gradient: drying-sensitive, partly tolerant to drying, generalist, and drying-resistant specialist. In addition, we found that species belonging to the drying specialist group showed a weak contribution to both ecosystem processes, suggesting trade-offs between drying resistance strategies and the energy invested in growth. Taken together, our results suggest that increased water scarcity may jeopardise the capacity of aquatic fungi to guarantee ecosystem functioning and to maintain biogeochemical cycles despite their ability to cope with drying.

Eco-physiological Responses of Aquatic Fungi to Three Global Change Stressors Highlight the Importance of Intraspecific Trait Variability.

Anthropogenic change at a global scale is affecting life on Earth with impacts on freshwaters. Aquatic hyphomycetes are fungi that drive organic matter decomposition in freshwaters and mediate energy transfer to higher trophic levels. Intraspecific trait variability affects ecological processes and can account for species adaptations to environmental change. To ascertain how aquatic hyphomycetes respond to global change related stressors, we selected 20 strains (7 species), based on their co-occurrence in streams and phylogenetic relatedness. We measured fungal growth rates at different temperatures (7 levels), nutrient concentrations (6 levels) and medium moisture (6 levels). Our results indicate that all stressors affected fungal growth, and responses to nutrient enrichment and moisture were strain specific. Fungal responses to the stressors were not explained by their phylogenetic relatedness. In the absence of stressors, interspecific diversity best explained the variance in fungal traits, while the increase in the stress gradient increased the importance of intraspecific diversity.

Molecular phylogeny and morphology reveal two new graminicolous species, Curvularia aurantiasp. nov. and C. vidyodayana sp. nov. with new records of Curvularia spp. from Sri Lanka.

Despite being a small island, Sri Lanka is rich in fungal diversity. Most of the fungi from Sri Lanka have been identified as pathogens of vegetables, fruits, and plantation crops to date. The pleosporalean genus Curvularia (Dothideomycetes) includes phytopathogenic, saprobic, endophytic, and human/animal opportunistic pathogenic fungal species. The majority of the plant-associated Curvularia species are known from poaceous hosts. During the current study, 22 geographical locations of the country were explored and collections were made from 10 different poaceous hosts. Morphology and molecular phylogeny based on three loci, including nuclear internal transcribed spacers 1 and 2 with 5.8S nrDNA (ITS), glyceraldehyde-3-phosphate dehydrogenase (gapdh), and translation elongation factor 1-α (tef1) supported the description of two new species of fungi described herein as C. aurantia sp. nov. and C. vidyodayana sp. nov. Moreover, novel host-fungal association records for C. chiangmaiensis, C. falsilunata, C. lonarensis, C. plantarum, and C. pseudobrachyspora are updated herein. In addition, five species within the genus Curvularia, viz., C. asiatica, C. geniculata, C. lunata, C. muehlenbeckiae, and C. verruculosa represent new records of fungi from Sri Lanka. Citation: Ferdinandez HS, Manamgoda DS, Udayanga D, Munasinghe MS, Castlebury LA (2023). Molecular phylogeny and morphology reveal two new graminicolous species, Curvularia aurantia sp. nov. and C. vidyodayana sp. nov. with new records of Curvularia spp. from Sri Lanka. Fungal Systematics and Evolution 12: 219-246. doi: 10.3114/fuse.2023.12.11.

Three novel species of Distoseptispora (Distoseptisporaceae) isolated from bamboo in Jiangxi Province, China.

Decaying bamboo in freshwater is a unique eco-environment for fungi. Three new Distoseptispora (Distoseptisporaceae) species, D.meilingensis, D.yongxiuensis and D.yunjushanensis from submerged decaying bamboo culms in Jiangxi Province, China, were discovered, based on phylogenetic analyses and morphological characters. The combined data of ITS-LSU-SSU-Tef1 sequences were used to infer the phylogenetic relationship between D.meilingensis, D.yongxiuensis, D.yunjushanensis and related species. Both molecular analyses and morphological data supported D.meilingensis, D.yongxiuensis and D.yunjushanensis as three independent taxa.

The plethora of Tubeufiaceae in lakes of the northwestern Yunnan plateau, China.

The diversity of lignicolous freshwater fungi in northwestern Yunnan, China, has been studied for several years in the College of Agriculture and Biological Science, at Dali University. Over the last 5 years, we published two new genera and nine new species of Tubeufiaceae from northwestern Yunnan. This study focused on introducing tubeufia-like hyphomycetous fungi found in freshwater lakes in the northwestern Yunnan plateau. Eleven fresh collections of tubeufiaceous taxa were gathered and identified. Among them, a new genus, Neomanoharachariella, is introduced to accommodate Neomanoharachariella aquatica, which is characterized by a light brown to dark brown color, dictyoseptate, and broadly oval to ellipsoid and well-developed conidiophores. Two new species, viz., Neohelicosporium suae and Parahelicomyces suae, one new record, Helicoma rufum, and three new collections, namely, H. rugosum, P. hyalosporus, and Tubeufia cylindrothecia are introduced based on morphological evidence and molecular phylogenetic analysis of combined ITS, LSU, tef 1-α, and RPB2 sequence data. Detailed descriptions and illustrations of these species are provided, and a morphological comparison with similar taxa is discussed.

Tropical stream microcosms of isolated fungal species suggest nutrient enrichment does not accelerate decomposition but might inhibit fungal biomass production.

Terrestrial leaf litter is an essential energy source in forest streams and in many tropical streams, including Cerrado, litter undergoes biological decomposition mainly by fungi. However, there is a limited understanding of the contribution of isolated fungal species to in-stream litter decomposition in the tropics. Here we set a full factorial microcosms experiment using four fungal species (Aquanectria penicillioides, Lunulospora curvula, Pestalotiopsis submerses, and Pestalotiopsis sp.) incubated in isolation, two litter types (rapid and slow decomposing litter) and two nutrient levels (natural and enriched), all characteristics of Cerrado streams, to elucidate the role of isolated fungal species on litter decomposition. We found that all fungal species promoted litter mass loss but with contributions that varied from 1% to 8% of the initial mass. The fungal species decomposed 1.5 times more the slow decomposing litter and water nutrient enrichment had no effect on their contribution to mass loss. In contrast, fungal biomass was reduced by nutrient enrichment and was different among fungal species. We showed fungal contribution to decomposition depends on fungal identity and litter type, but not on water nutrients. These findings suggest that the identity of fungal species and litter types may have more important repercussions to in-stream decomposition than moderate nutrient enrichment in the tropics.

Acrogenospora terricola sp. nov., a fungal species associated with seeds of pioneer trees in the soil seed bank of a lowland forest in Panama.

As currently circumscribed, Acrogenospora (Acrogenosporaceae, Minutisphaerales, Dothideomycetes) is a genus of saprobic hyphomycetes with distinctive conidia. Although considered common and cosmopolitan, the genus is poorly represented by sequence data, and no neotropical representatives are present in public sequence databases. Consequently, Acrogenospora has been largely invisible to ecological studies that rely on sequence-based identification. As part of an effort to identify fungi collected during ecological studies, we identified strains of Acrogenospora isolated in culture from seeds in the soil seed bank of a lowland tropical forest in Panama. Here we describe Acrogenospora terricola sp. nov. based on morphological and phylogenetic analyses. We confirm that the genus has a pantropical distribution. The observation of Acrogenospora infecting seeds in a terrestrial environment contrasts with previously described species in the genus, most of which occur on decaying wood in freshwater environments. This work highlights the often hidden taxonomic value of collections derived from ecological studies of fungal communities and the ways in which rich sequence databases can shed light on the identity, distributions and diversity of cryptic microfungi.