Search Results (137)

Springs are unique ecosystems found in lowland areas. In urban environments, these springs often have niches that are heavily transformed by human activity. In this study, we identified and compared the taxonomic diversity of diatom communities across various microhabitats—epilithon, epipelon, epipsammon, epibryon, and epixylon—within altered lowland urban springs. Our results revealed differences in diatom communities among the microhabitats, with the highest species richness observed in the epibryon. Notably, the presence of extremely rare species such as Amphora eximia, Caloneis aerophila, and Stauroneis muriella suggest that, even under urban conditions, springs continue to serve a refugial function for diatom diversity. These findings underscore the important role of urban springs in maintaining diatom diversity despite high anthropogenic pressure. We also assessed the ecological status of the springs using the Polish Multimetric Diatom Index (IO), which incorporates indicators of trophy, saprobity, and the abundance of reference species. All studied springs were classified as having very good ecological status. Full article

Mayfly nymphs are reliable indicators of aquatic habitat quality, and whilst their presence and relative abundance are often used in bioassessment schemes, it is important to recognise that these attributes are affected by the sampling method employed. To test these effects, we sampled stream habitats for mayflies using two commonly used techniques in a standardised setup: aquatic sweep nets and manual collection from stones. These methods resulted in different success rates in detecting certain taxa depending on their biological traits (preferred microhabitat and locomotion type). Whilst species lists generally overlapped between the two methods, they yielded different values of total abundance, taxon richness, Shannon–Wiener’s diversity index, assemblage saprobic index, and general community structure. These results suggest that reliance on a single collection method is prone to yield only partial information for ecological assessments and emphasises the importance of employing a sampling technique that is appropriate for the study question and goals or combining more than one method. Based on these findings, we outline the scientific justifications for using each sampling method. Full article

This study presents a biomonitoring study of surface waters in the Krynka River basin, encompassing three major regional reservoirs: Khanzhenkovskoe, Olkhovskoe, and Zuyevskoe. These water bodies face significant anthropogenic pressure from mining effluents, industrial discharges, and domestic wastewater. Key pollutants identified are surfactants (SAAs), sulfates, phenols, chlorides, and manganese, with chemical oxygen demand (COD) exceeding regulatory limits. The research was conducted in September 2024. Based on the Specific Combinatorial Water Pollution Index, surface waters in the studied objects can be characterized as slightly polluted. To assess the negative impact of the identified pollutants on hydrobionts, the species composition of phytoplankton of the studied water bodies was analyzed. In the Olkhovskoe Reservoir and Olkhovaya River, cyanobacterial blooms (Oscillatoria agardhii G.) were observed, altering biodiversity in the Krynka River and Zuyevskoe Reservoir. Phytoplankton genera Synedra, Amphiprora, and Navicula—established bioindicators of aquatic ecosystem health—were dominant in Khanzhenkovskoe Reservoir, signaling nutrient enrichment and organic pollution. Changes in the species composition and structure of phytoplankton in the Krynka River, its tributaries and reservoirs, indicate a change in the level of saprobic water bodies from β to α-mesosaprobic, which indicates both the general level of surface water pollution and the accumulation of pollutants along the course of the river. The paper presents the results of fluorimetric analysis of photosynthetic activity of natural phytoplankton cells and demonstrates the possibility of using fluorescence induction curves for regular monitoring measurements. Fluorescence parameters indicate a general deterioration of photosynthetic activity of natural phytoplankton. The growth of Oscillatoria agardhii in the waters of the Olkhovskoe Reservoir and of green microalgae in the Zuevskoe Reservoir led to an increase in the fluorescence quantum yield (F_v/F_m) and the total photosynthetic activity index (PI), which makes it possible to use these parameters as indicator parameters reflecting the intensity of “blooming” of various phytoplankton species. Full article

Saprobic hyphomycetous fungi exhibit high colonization density and diversity on rotting woody plant material. During our continuing mycological research in the forest ecosystem of Jiangxi, Fujian and Zhejiang provinces, China, several Distoseptispora-like and Helminthosporium-like strains were isolated from unidentified dead branches in terrestrial habitats. Based on morphological comparisons and multi-locus phylogenetic analyses using maximum-likelihood (ML) and Bayesian inference (BI), six novel species of Distoseptispora (D. terrestris, D. wuyishanensis, D. zhejiangensis) and Helminthosporium (H. ganzhouense, H. jiangxiense, H. saprophyticum) were introduced, and one known species, H. velutinum was reported. The species diversity within Distoseptispora and Helminthosporium was supplemented in this study. Full article

Hypocrealean fungi are a well-documented group of fungi, with a wide range of ecological roles that include saprobic, parasitic, and endophytic forms, capable of thriving in diverse environments, both terrestrial and marine. Members in this group are abundant and widely distributed in marine environments around the world. However, the species diversity and distribution of this fungal group in Chinese seas is rarely reported. This study introduces five new species, namely Fusarium flavoides M.M. Wang & W. Li, Gliomastix fasciculata M.M. Wang & W. Li, Marquandomyces ulvae M.M. Wang & W. Li, Stephanonectria arenicola M.M. Wang & W. Li, and Verruciconidia oligospora M.M. Wang & W. Li, based on morphological characteristics and LSU-ITS-tef1-rpb2 phylogenetics. These new species were discovered from marine algae (Ulva spinulosa) and sediments (mud and sand). A detailed comparison of these new species and their close relatives is also presented. Full article

Pleosporalean fungi play significant roles as plant pathogens, saprobes, and endophytes in a wide variety of economically important plant hosts. During an investigation of saprobic fungi from Jilin and Hebei, China, five pleosporalean isolates were obtained from the dead stems of Xanthoceras sorbifolium. Morphological evidence and multi-locus sequence analyses using a combined dataset of ITS, LSU, SSU, rpb2, tef1-α, and tub2 indicate that these isolates represent two new species (Alloleptosphaeria xanthoceratis and Lophiostoma multiforme) and a new record of Lophiostoma montanae. Full morphological descriptions and illustrations are provided herein, and phylogenetic relationships of three pleosporalean taxa are also discussed. Detailed morphological descriptions and illustrations are presented, along with phylogenetic affiliations of three pleosporalean taxa. Full article

Short-term observations suggest that environmental changes affect the diversity and composition of soil fungi, significantly influencing forest resilience, plant diversity, and soil processes. However, time-series experiments should be supplemented with geobiological archives to capture the long-term effects of environmental changes on fungi–soil–plant interactions, particularly in undersampled, floristically diverse tropical forests. We recently conducted trnL-P6 amplicon sequencing to generate a sedimentary ancient DNA (sedaDNA) record of the regional catchment vegetation of the tropical waterbody Lake Towuti (Sulawesi, Indonesia), spanning over one million years (Myr) of the lake’s developmental history. In this study, we performed 18SV9 amplicon sequencing to create a parallel paleofungal record to (a) infer the composition, origins, and functional guilds of paleofungal community members and (b) determine the extent to which downcore changes in fungal community composition reflect the late Pleistocene evolution of the Lake Towuti catchment. We identified at least 52 members of Ascomycota (predominantly Dothiodeomycetes, Eurotiomycetes, and Leotiomycetes) and 12 members of Basidiomycota (primarily Agaricales and Polyporales). Spearman correlation analysis of the relative changes in fungal community composition, geochemical parameters, and paleovegetation assemblages revealed that the overwhelming majority consisted of soil organic matter and wood-decaying saprobes, except for a necrotrophic phytopathogenic association between Mycosphaerellaceae (Cadophora) and wetland herbs (Alocasia) in more-than-1-Myr-old silts and peats deposited in a pre-lake landscape, dominated by small rivers, wetlands, and peat swamps. During the lacustrine stage, vegetation that used to grow on ultramafic catchment soils during extended periods of inferred drying showed associations with dark septate endophytes (Ploettnerulaceae and Didymellaceae) that can produce large quantities of siderophores to solubilize mineral-bound ferrous iron, releasing bioavailable ferrous iron needed for several processes in plants, including photosynthesis. Our study showed that sedaDNA metabarcoding paired with the analysis of geochemical parameters yielded plausible insights into fungal-plant-soil interactions, and inferred changes in the paleohydrology and catchment evolution of tropical Lake Towuti, spanning more than one Myr of deposition. Full article

Hypocreales is one of the largest orders within the class Sordariomycetes and is renowned for its diversity of lifestyles, encompassing plant, insect, and human pathogens, as well as endophytes, parasites, and saprobes. In this study, we focused on saprobic hypocrealean fungi isolated from rice in northern Thailand. Species identification was conducted using morphological characteristics and multilocus phylogenetic analyses, including the internal transcribed spacer region (ITS), 28S large subunit nuclear ribosomal DNA (LSU), translation elongation factor 1–alpha (tef1-α), RNA polymerase II second-largest subunit (rpb2), and calmodulin (cmdA). This research confirmed the presence of 14 species of hypocrealean taxa, viz. Fusarium (9), Ochronectria (1), Sarocladium (2), Trichothecium (1), and Waltergamsia (1). Among these were two new species (Fusarium chiangraiense and F. oryzigenum), four new host records (Fusarium kotabaruense, Ochronectria thailandica, Sarocladium bactrocephalum, and Waltergamsia fusidioides), and three new geographical records (Fusarium commune, F. guilinense, and F. hainanese). Full article

Pathogenic fungi that exhibit the ability to alternate between hyphal and yeast morphology in response to environmental stimuli are considered dimorphic. Under saprobic conditions, some fungi exist as filamentous hyphae, producing conidia. When conidia are inhaled by mammals or traumatically inoculated, body temperature (37 °C) triggers dimorphism into yeast cells. This shift promotes fungal dissemination and immune evasion. Some fungal pathogens undergo dimorphism in the contrary way, forming pseudohyphae and hyphae within the host. While temperature is a major driver of dimorphism, other factors, including CO₂ concentration, pH, nitrogen sources, and quorum-sensing molecules, also contribute to morphological shifts. This morphological transition is associated with increased expression of virulence factors that aid in adhesion, colonization, and immune evasion. Candida albicans is a fungus that is commonly found as a commensal on human mucous membranes but has the potential to be an opportunistic fungal pathogen of immunocompromised patients. C. albicans exhibits a dimorphic change from the yeast form to the hyphal form when it becomes established as a pathogen. In contrast, Histoplasma capsulatum is an environmental dimorphic fungus where human infection begins when conidia or hyphal fragments of the fungus are inhaled into the alveoli, where the dimorphic change to yeast occurs, this being the morphology associated with its pathogenic phase. This review examines the main signaling pathways that have been mostly related to fungal dimorphism, using as a basis the information available in the literature on H. capsulatum and C. albicans because these fungi have been widely studied for the morphological transition from hypha to yeast and from yeast to hypha, respectively. In addition, we have included the reported findings of these signaling pathways associated with the dimorphism of other pathogenic fungi, such as Paracoccidioides brasiliensis, Sporothrix schenckii, Cryptococcus neoformans, and Blastomyces dermatitis. Understanding these pathways is essential for advancing therapeutic approaches against systemic fungal infections. Full article

Macroinvertebrates of the Venta River have been studied since the beginning of the 20th century. However, complex studies along the Venta River from the Latvian–Lithuanian border to its mouth into the Baltic Sea have been irregular and fragmentary. The aim of this study was to assess the ecological status of the Venta River and to analyze the abundance and fauna composition of macroinvertebrates along the entire length of the river in the territory of Latvia. This is the first study of its kind for the Venta River examining the specialization of macroinvertebrates in sediment substrates and their functional feeding groups. Within the framework of the study, the composition and functional importance of macroinvertebrates was assessed in 10 sampling sites together with the ecological quality of the river using several indices. The results show that the Venta River is dominated by benthic invertebrate collectors/gatherers, active filterers, grazers, and scrapers that have adapted to the particular type of sediments formed by silt, macrophytes, rocks, and pebbles. Different indices were calculated in order to assess the ecological quality of the Venta River. According to the saprobity index, the water quality corresponds to β-mesosaprobity, while ecological quality is mostly average; however, according to the multimetric indices, the quality of the Venta River varies from poor to high depending on the sampling station. Full article

The genus Alternaria, functioning as a saprobe, endophyte, and plant pathogen, is widely distributed across various natural and human-impacted environments. Leaf spot and black spot diseases, caused by Alternaria species, are the most prevalent plant diseases within this genus, leading to significant reductions in crop yields and substantial economic losses. To facilitate the timely detection of Alternaria species during the early stages of infection, enable targeted treatments, and mitigate associated damages, we employed a species identification method based on Analysis of whole-GEnome (AGE). We downloaded 148 genomes, including 31 Alternaria species, from the NCBI GenBank database. Through bioinformatics analysis, we constructed a specific-target sequence library and selected a representative sequence per species. The specific target sequences of the seven exemplary Alternaria species were subsequently used for validation and rapid detection, utilizing Sanger sequencing and CRISPR-Cas12a technology, respectively. The results demonstrated that our method accurately identified the target species. Additionally, by combining Enzymatic Recombinase Amplification (ERA) with CRISPR-Cas12a, we achieved rapid and precise identification of genomic DNA samples, with a detection limit as low as 0.01 ng/µL within 30 min. Therefore, AGE proves to be a highly robust and efficient method for the detection of Alternaria species, offering broad potential for various applications. Full article

Species belonging to the Pezizales are mainly saprobes in nature. They are most commonly observed in woodlands and humid environments. As a result of recent research conducted on the distribution of species in sandy areas and some National Forests Parks, five new species belonging to three genera were identified. A total of five species of disk fungi from Northeast China were identified and described based on morphological classification and molecular phylogenetics. These included Pulvinula (Pulvinula elsenensis, Pulvinula sublaeterubra), Microstoma (Microstoma jilinense, Microstoma changchunense), and Sarcoscypha (Sarcoscypha hongshiensis). Maximum likelihood and Bayesian analyses were performed using a combined nuc rDNA internal transcribed spacer region (ITS) and nuc 28S rDNA (nrLSU) dataset for the construction of phylogenetic trees. Morphological descriptions, line illustrations, and photographs of the ascocarps of these new species are provided, along with lists of the salient attributes exhibited by the species in the three genera under consideration. Full article

Patellaria species are widely distributed in terrestrial and marine habitats and are saprobes growing on decaying wood, stems, or bark. However, studies on this genus in Mexico are limited, and only the type species Patellaria atrata Fr. has been cited. This study describes twelve new Patellaria species in Mexico supported by molecular (ITS-LSU-SSU) and morphological data. Phylogenetic analysis shows that species of this genus in Mexico are not closely related to Patellaria atrata. Moreover, the results demonstrate that the greatest species diversity is found in dry climates, particularly in xerophilous scrub. Full article

The ascomycete family Nectriaceae includes soil-borne saprobes, plant pathogens and human pathogens, biodegraders, and biocontrol agents for industrial and commercial applications. Cinnamomum camphora is a native tree species that is widely planted in southern China for landscaping purposes. During a routine survey of Eucalyptus diseases in southern China, disease spots were frequently observed on the leaves of Ci. camphora trees planted close to Eucalyptus. The asexual fungal structures on the leaf spots presented morphological characteristics typical of the Nectriaceae. The aim of this study is to identify these fungi and determine their pathogenic effect on Ci. camphora. Of the isolates obtained from 13 sites in the Fujian and Guangdong Provinces, 54 isolates were identified based on the DNA phylogeny of the tef1, tub2, cmdA, and his3 regions and morphological features. Two isolates were identified as Calonectria crousiana, and fifty-two isolates were described as a new genus, including a single species. These fungi were named Recticladiella inexpectata gen. et sp. nov. The identification of the new genus was based on strong DNA base differences in each of the four sequenced gene regions. The conidiophores of this fungus had several avesiculate stipe extensions tapering toward a straight, occasionally slightly curved terminal cell, distinguishing it from other phylogenetically close Nectriaceae genera. The results indicate that R. inexpectata is distributed in wide geographic regions in southern China. Inoculation showed that R. inexpectata and Ca. crousiana caused lesions on the leaves of Ci. camphora seedlings within 6 days of inoculation, indicating that they are pathogenic to native Ci. camphora in China. Full article

Throughout the world, river basins are directly or indirectly affected by human activities, reducing local and global biodiversity and preventing the ecosystem from properly functioning. Our research focused on the Irpin River basin (Ukraine), whose water bodies have experienced various impacts due to human activities, including the unexpected extremes caused by military operations in the catchment area: long-term flooding, disturbance of free flow, significant water level fluctuations, etc. The study hypothesized that the primary factors determining the structural and spatial distribution of quantitative indicators of microalgae and aquatic macrophytes are the result of various hydromorphological changes, that lead to changes in the physical and chemical parameters of the aquatic environment. Very high values of chlorophyll a in the water column (59–106 µg · L⁻¹), an increase in the abundance (number of cells) and biomass of algae (due to the predominance of certain groups in the transformed sections), as well as saprobic index were recorded in the sections of the Irpin River basin that underwent significant hydromorphological changes. Our results revealed a strong correlation between phytoplanktonic (in the water column) chlorophyll a levels and water temperature (r = 0.76, p < 0.001), as well as organic phosphorus and polyphosphate concentrations (r = 0.61, p < 0.01). ANOVA and Monte Carlo permutation tests in a Canonical Correspondence Analysis (CCA) showed that the abundance of different divisions of phytoplankton and phytobenthos were significantly and similarly related to several environmental variables. We observed a positive correlation between the number of cyanobacteria and the concentration of ammonium nitrogen, nitrites, and phosphorus compounds. An increase in dissolved organic matter in the water can explain the increase in the biomass of Dinoflagellata and Euglenophyta. Species richness and the cover values of the macrophytes also clearly reflected changes in vegetation activity in sections of the Irpin River caused by hydromorphological changes. The results indicated that long-term flooding had the most negative impact on macrophyte communities. At some sites, the impact was so severe that the number of macrophyte species was very low. The total number of macrophyte species showed a significant negative correlation with total suspended solids (r = −0.51, p < 0.05) and phytoplankton chlorophyll a concentration (r = −0.73, p < 0.001). Our results provide a scientific basis for predicting changes in riverine microalgal and aquatic macrophyte communities due to extreme hydrological events. Full article