The genus Cladosporium

Structure and dynamics of microbial communities associated with the resurrection plant Boea hygrometrica in response to drought stress

MAIN CONCLUSION

The resurrection plant Boea hygrometrica selectively recruits and assembles drought-specific microbial communities across the plant-soil compartments, which may benefit plant growth and fitness under extreme drought conditions. Plant-associated microbes are essential for facilitating plant growth and fitness under drought stress. The resurrection plant Boea hygrometrica in natural habitats with seasonal rainfall can survive rapid desiccation, yet their interaction with microbiomes under drought conditions remains unexplored. This study examined the bacterial and fungal microbiome structure and drought response across plant-soil compartments of B. hygrometrica by high-throughput amplicon sequencing of 16S rRNA gene and internal transcribed spacer. Our results demonstrated that the diversity, composition, and functional profile of the microbial community varied considerably across the plant-soil compartments and were strongly affected by drought stress. Bacterial and fungal diversity was significantly reduced from soil to endosphere and belowground to aboveground compartments. The compartment-specific enrichment of the dominant bacteria phylum Cyanobacteriota and genus Methylorubrum in leaf endosphere, genera Pseudonocardia in rhizosphere soil and Actinoplanes in root endosphere, and fungal phylum Ascomycota in the aboveground compartments and genera Knufia in root endosphere and Cladosporium in leaf endosphere composed part of the core microbiota with corresponding enrichment of beneficial functions for plant growth and fitness. Moreover, the recruitment of dominant microbial genera Sphingosinicella and Plectosphaerella, Ceratobasidiaceae mycorrhizal fungi, and numerous plant growth-promoting bacteria involving nutrient supply and auxin regulation was observed in desiccated B. hygrometrica plants. Our results suggest that the stable assembled drought-specific microbial community of B. hygrometrica may contribute to plant survival under extreme environments and provide valuable microbial resources for the microbe-mediated drought tolerance enhancement in crops.

Early-life factors shaping the gut microbiota of Common buzzard nestlings

BACKGROUND

Exploring the dynamics of gut microbiome colonisation during early-life stages is important for understanding the potential impact of microbes on host development and fitness. Evidence from model organisms suggests a crucial early-life phase when shifts in gut microbiota can lead to immune dysregulation and reduced host condition. However, our understanding of gut microbiota colonisation in long-lived vertebrates, especially during early development, remains limited. We therefore used a wild population of common buzzard nestlings (Buteo buteo) to investigate connections between the early-life gut microbiota colonisation, environmental and host factors.

RESULTS

We targeted both bacterial and eukaryotic microbiota using the 16S and 28S rRNA genes. We sampled the individuals during early developmental stages in a longitudinal design. Our data revealed that age significantly affected microbial diversity and composition. Nest environment was a notable predictor of microbiota composition, with particularly eukaryotic communities differing between habitats occupied by the hosts. Nestling condition and infection with the blood parasite Leucocytozoon predicted microbial community composition.

CONCLUSION

Our findings emphasise the importance of studying microbiome dynamics to capture changes occurring during ontogeny. They highlight the role of microbial communities in reflecting host health and the importance of the nest environment for the developing nestling microbiome. Overall, this study contributes to understanding the complex interplay between microbial communities, host factors, and environmental variables, and sheds light on the ecological processes governing gut microbial colonisation during early-life stages.

Molecular identification and lipolytic potential of filamentous fungi isolated from residual cooking oil

Filamentous fungi, microorganisms that develop and are located in different habitats, are considered important producers of enzymes and metabolites with potential for the biotechnology industry. The objective of this work was to isolate and identify filamentous fungi that grow in used oil. Two fungal species were characterised through their morphology and molecular identification. The DNA of each extracted strain was amplified by PCR using primers ITS1 and ITS4, obtaining sequences that were later in GenBank (NCBI). A white coloured strain (HB) with a cottony, white, hyaline morphology and irregular borders was observed; so too, a brown colony (HC) with a sandy surface, a well-defined border of beige colour in early growth until it became a dark brown colour. The identity result by homology of the sequences in the BLASTn database was 100% and 99.55%, indicating that they correspond to Cladosporiumtenuissimum and Fomitopsismeliae, respectively. Finally, the results in lipolytic activity show greater potential for Fomitopsismeliae with 0.61 U/l in residual oil. Thus, it is important to highlight the potential of this type of waste to favour the prospection of microorganisms for a sustainable alternative for future studies of biological conversion.

The Genus Cladosporium: A Prospective Producer of Natural Products

Cladosporium, a genus of ascomycete fungi in the Dematiaceae family, is primarily recognized as a widespread environmental saprotrophic fungus or plant endophyte. Further research has shown that the genus is distributed in various environments, particularly in marine ecosystems, such as coral reefs, mangroves and the polar region. Cladosporium, especially the marine-derived Cladosporium, is a highly resourceful group of fungi whose natural products have garnered attention due to their diverse chemical structures and biological activities, as well as their potential as sources of novel leads to compounds for drug production. This review covers the sources, distribution, bioactivities, biosynthesis and structural characteristics of compounds isolated from Cladosporium in the period between January 2000 and December 2022, and conducts a comparative analysis of the Cladosporium isolated compounds derived from marine and terrestrial sources. Our results reveal that 34% of Cladosporium-derived natural products are reported for the first time. And 71.79% of the first reported compounds were isolated from marine-derived Cladosporium. Cladosporium-derived compounds exhibit diverse skeletal chemical structures, concentrating in the categories of polyketides (48.47%), alkaloids (19.21%), steroids and terpenoids (17.03%). Over half of the natural products isolated from Cladosporium have been found to have various biological activities, including cytotoxic, antibacterial, antiviral, antifungal and enzyme-inhibitory activities. These findings testify to the tremendous potential of Cladosporium, especially the marine-derived Cladosporium, to yield novel bioactive natural products, providing a structural foundation for the development of new drugs.

Cladosporium-Insect Relationships

The range of interactions between Cladosporium, a ubiquitous fungal genus, and insects, a class including about 60% of the animal species, is extremely diverse. The broad case history of antagonism and mutualism connecting Cladosporium and insects is reviewed in this paper based on the examination of the available literature. Certain strains establish direct interactions with pests or beneficial insects or indirectly influence them through their endophytic development in plants. Entomopathogenicity is often connected to the production of toxic secondary metabolites, although there is a case where these compounds have been reported to favor pollinator attraction, suggesting an important role in angiosperm reproduction. Other relationships include mycophagy, which, on the other hand, may reflect an ecological advantage for these extremely adaptable fungi using insects as carriers for spreading in the environment. Several Cladosporium species colonize insect structures, such as galleries of ambrosia beetles, leaf rolls of attelabid weevils and galls formed by cecidomyid midges, playing a still uncertain symbiotic role. Finally, the occurrence of Cladosporium in the gut of several insect species has intriguing implications for pest management, also considering that some strains have proven to be able to degrade insecticides. These interactions especially deserve further investigation to understand the impact of these fungi on pest control measures and strategies to preserve beneficial insects.

Diffuse Associations Between Drosophila suzukii and Filamentous Fungal Microbes May Alter Caneberry Disease Dynamics

Interactions between microorganisms and frugivorous insects can modulate fruit rot disease epidemiology. Insect feeding and/or oviposition wounds may create opportunities for fungal infection. Passive and active dispersal of fungal inoculums by adult insects also increases disease incidence. In fall-bearing raspberries and blackberries, such vectoring interactions could increase crop damage from the invasive pestiferous vinegar fly Drosophila suzukii (spotted-wing drosophila). Periods of peak D. suzukii activity are known to overlap with several species of primary fruit rot pathogen, particularly Botrytis cinerea and Cladosporium cladosporioides, and previous work indicates that larvae co-occur with and feed on various filamentous fungi at low rates. To further our understanding of the epidemiological consequences that may emerge from these associations, we surveyed the filamentous fungal community associated with adult D. suzukii, isolating and molecularly identifying fungi externally and internally (indicating feeding) from field-collected adults over 3 years. We isolated and identified 37 unique genera of fungi in total, including known raspberry pathogens. Most fungi were detected infrequently, and flies acquired and carried fungi externally at higher richness, frequency, and density relative to internally. In a worst-case scenario laboratory vectoring assay, D. suzukii adults were able to transfer B. cinerea and C. cladosporioides to sterile media at 0, 24, 48, and 72 h after exposure to sporulating cultures in Petri dishes. These results collectively suggest an adventitious vectoring association between D. suzukii and fruit rot fungi that has the potential to alter caneberry disease dynamics.

Fungal community dynamics on limestone at the Chichén Itzá archaeological site in Mexico driven by protective treatments

Microorganisms naturally colonize rock-based materials in outdoor environments, thereby contributing to their degradation. Fungi, especially in tropical environments with abundant water and favorable temperatures, play a significant role in biodegradation. However, many aspects of the microorganism-stone interaction, including fungal colonization dynamics and the impact of treatment applications, remain unclear. This study conducted a four-year in-situ evaluation of fungal community dynamics on limestone surfaces in the Temple of the Warriors at the Chichén Itzá archaeological site in Mexico, focusing on cleaning and treatment using nanoparticles (NPs). These NPs included zinc oxide (ZnO) and CaZn2(OH)6·2H2O (CZ)-based NPs synthesized via sol-gel (CZ-SG) and mechanochemical methods (CZ-MC), as well as CZ/Ca(OH)2-based products (CZ:Ca-SG). The microbial colonization cover was assessed using colorimetric measurements, and the surface was sampled for fungal community isolation and identification. The results demonstrated significant impacts of cleaning and nanomaterial applications on cultivable fungal communities (melanized filamentous, hyaline, and microcolonial fungi), altering composition, dynamics, and stone surface coloration. In particular, ZnO NPs caused 50 % decline in fungal species and individuals, whereas CZ:Ca-SG NPs displaced most species, indicating effective inhibition of the cultivable fungal community. Microcolonial fungi (MCF), known for their tolerance to withstand harsh environmental conditions, were the only fungal group found in the CZ:Ca-SG treatment. In contrast, CZ-SG and CZ-MC increased the abundance of melanized species, resulting in darkening and reduced color intensity. This study highlights the importance of microcolonial fungi that are tolerant to cleaning and coating procedures in the preservation of stone cultural heritage. These findings enhance our understanding of fungal colonization dynamics following treatment and provide valuable insights into the challenges associated with preserving stone materials in tropical environments.

Beach sand mycobiome: The silent threat of pathogenic fungi and toxic metal contamination for beachgoers

Emphasis is always placed on bacterial but not fungal pathogens in marine environments. We analysed the fungal diversity, functional predictions, and toxic metals and metalloids contamination in beach sand from different South African locations. Results revealed a diverse fungal community, with Ascomycota, Rozellomycota, and Basidiomycota being the dominant phyla. Functional predictions highlighted fungal metabolic pathways related to of carbohydrates, amino acids, and lipids, in different beach samples. Elevated concentrations of toxic metals and metalloids were detected in Central and Harbour beach sands, likely due to anthropogenic activities. Correlations among different elements were observed, suggesting complex interactions in the coastal environment. Fungal pathogens like Cladosporium, Fusarium, Aspergillus, and Candida in beach sands raise potential public health risk concerns. Therefore, monitoring fungal diversity (including pathogens) alongside bacterial contamination in beach environments is imperative. The results contribute to understanding fungal community dynamics, functional potential, toxic metal and metalloid contamination, and potential risks associated with beach sand ecosystems.

Uncovering the Fungal Diversity and Biodeterioration Phenomenon on Archaeological Carvings of the Badami Cave Temples: A Microcosm Study

The Badami Caves are a significant example of ancient Indian rock-cut architecture, dating back to the 6th century. These caves are situated in the Malaprabha River valley and are part of the candidate UNESCO World Heritage Site known as the "Evolution of Temple Architecture-Aihole-Badami-Pattadakal", which is considered to be the cradle of temple architecture in India. Our study aimed to investigate the diversity, distribution, and biodeterioration phenomena of the fungal communities present on the cave surfaces. The study also conducted a comprehensive analysis of fungal biodeterioration on the cave carvings. Utilizing specialized techniques, the dissolution of calcite, alterations in pH levels, and biomineralization capabilities of isolated fungal strains were monitored. Additionally, this study analyzed fungal acid production using high-performance liquid chromatography (HPLC). Our findings revealed that the major genera of fungi found on the cave surfaces included Acremonium, Curvularia, Cladosporium, Penicillium, and Aspergillus. These isolated fungi were observed to produce acids, leading to the dissolution of calcium carbonate and subsequent decrease in pH values. Notably, the dominant genus responsible for acid production and the promotion of biomineralization was Aspergillus. These discoveries provide valuable insight into the ecology and functions of fungi inhabiting stone surfaces, contributing to our understanding of how to preserve and protect sculptures from biodeterioration.

The genus Rachicladosporium: introducing new species from sooty mould communities and excluding cold adapted species

The fungal genus Rachicladosporium (Cladosporiales, Cladosporiaceae), typified by cladosporium-like Rachicladosporium luculiae, includes a morphologically diverse assemblage of species. The species of this genus were reported from different substrates, habitats and environments, including plant leaves and needles, twig, black mould on baobab trees, rocks and insects. In this study, four new Rachicladosporium species (R. europaeum, R. ignacyi, R. kajetanii, R. silesianum) isolated from sooty mould communities covering leaves and needles of trees and shrubs in Poland are described. The new species are delineated based on morphological characteristics and molecular phylogenetic analyses using concatenated ITS, LSU, and rpb2 sequences. All newly described species are nested in the main Rachicladosporium lineage (centred around the type species), which contains species that are able to grow at 25 °C. By contrast, four cold adapted, endolithic species known from Antarctica (R. antarcticum, R. aridum, R. mcmurdoi) and Italian Alps (R. monterosanum) form distant phylogenetic lineage and do not grow at this temperature. Therefore, they are accommodated in the new genus Cryoendolithus, typified by Cryoendolithus mcmurdoi.

Changes in fungal taxonomy: mycological rationale and clinical implications

Numerous fungal species of medical importance have been recently subjected to and will likely continue to undergo nomenclatural changes as a result of the application of molecular approaches to fungal classification together with abandonment of dual nomenclature. Here, we summarize those changes affecting key groups of fungi of medical importance, explaining the mycological (taxonomic) rationale that underpinned the changes and the clinical relevance/importance (where such exists) of the key nomenclatural revisions. Potential mechanisms to mitigate unnecessary taxonomic instability are suggested, together with approaches to raise awareness of important changes to minimize potential clinical confusion.

From Child to Old Man: A Slowly Evolving Case of Chromoblastomycosis Caused by Cladosporium cladosporioides

Chromoblastomycosis is a chronic granulomatous mycosis of the skin and subcutaneous tissue caused by traumatic inoculation with dematiaceous fungi. This disease primarily affects agricultural workers, who are mostly men. We present a case of chromoblastomycosis in a 63-year-old male farmer patient with dermatosis over 50 years of evolution, with warty, erythematous, and scaly plaques that predominate on the left hemithorax. Direct examination with potassium hydroxide (KOH) revealed numerous fumagoid cells. Amplification and sequencing of the internal transcribed spacer (ITS) and translation elongation factor 1-alpha (TEF-1a) gene revealed that chromoblastomycosis was caused by Cladosporium cladosporioides. The chromoblastomycosis was treated with itraconazole and fluconazole without any improvement, and amphotericin B was administered with partial improvement.

Interactions with fungi vary among Tripsacum dactyloides genotypes from across a precipitation gradient

Plant-associated microbes, specifically fungal endophytes, augment the ability of many grasses to adapt to extreme environmental conditions. Tripsacum dactyloides (Eastern gamagrass) is a perennial, drought-tolerant grass native to the tallgrass prairies of the central USA. The extent to which the microbiome of T. dactyloides contributes to its drought tolerance is unknown. Ninety-seven genotypes of T. dactyloides were collected from native populations across an east-west precipitation gradient in Kansas, Oklahoma and Texas, and then grown together in a common garden for over 20 years. Root and leaf samples were visually examined for fungal density. Because fungal endophytes confer drought-tolerant capabilities to their host plants, we expected to find higher densities of fungal endophytes in plants from western, drier regions, compared to plants from eastern, wetter regions. Results confirmed a negative correlation between endophyte densities in roots and precipitation at the genotype's original location (r = -0.21 P = 0.04). Our analyses reveal that the host genotype's origin along the precipitation gradient predicts the absolute abundance of symbionts in the root, but not the relative abundances of particular organisms or the overall community composition. Overall, these results demonstrate that genetic variation for plant-microbe interactions can reflect historical environment, and reinforce the importance of considering plant genotype in conservation and restoration work in tallgrass prairie ecosystems.

Genome Sequence Resource of Cladosporium velox Strain C4 Causing Cotton Boll Disease in Xinjiang, China

Cladosporium spp., as one of the largest and most heterogeneous genera of hyphomycetes, are widely distributed worldwide. This genus is usually adaptable to a wide variety of extreme environments. However, only 11 genomes of Cladosporium genus have been publicly released. From 2017, we found for the first time that Cladosporium velox could cause cotton boll disease and lead to stiffness and cracking boll in Xinjiang, China. Herein, we provide a high-quality reference genome for the C. velox strain C4 isolated from cotton boll in Xinjiang, China. The genome size and encoding gene number of the C. velox strain C4 and C. cucumerinum strain CCNX2, which was recently released and caused the cucumber scab, showed minor differences. This resource will contribute to future research that aims to elucidate the genetic basis of C. velox pathogenicity and could expand our knowledge of Cladosporium spp. genomic characteristics that will be valuable for the development of Cladosporium disease control measures.

Two new Cladosporium species from a quartzite cave in Brazil

Caves are underground and natural environments mainly found in rocky terrain. Caves have a very specific microclimate, which benefits the occurrence of specific fungi. In recent studies, researchers have observed that caves harbour a great diversity of fungi. However, studies on fungal diversity in Brazilian caves are still incipient. In September 2019, airborne spore and soil samples were collected from the Monte Cristo cave, in the Southern Espinhaço Range, Diamantina, Minas Gerais state, Brazil. Two Cladosporium single-spore isolates, among other genera, were obtained from these samples. This study aimed to characterise these two fungal isolates based on their DNA sequence data and morphology. Phylogenetic analyses of the rDNA-ITS, ACT and TEF1-α loci revealed that the isolates belonged to the Cladosporium cladosporioides species complex. Both isolates did not cluster with any known species and were formally described and named herein as C. diamantinense and C. speluncae. This study presents taxonomic novelties and contributes to the knowledge about the fungal diversity in Brazilian caves.

Physiological response mechanism of heavy metal-resistant endophytic fungi isolated from the roots of Polygonatum kingianum

This study aims to evaluate the tolerance of endophytic fungi isolated from the fibrous roots of Polygonatum kingianum to arsenic (As) and cadmium (Cd) and their physiological response mechanisms. Five isolated strains were obtained with EC50 values for As(V) ranging from 421 to 1281 mg/L, while the other three strains tolerated Cd(II) with an EC50 range of 407-1112 mg/L. Morphological and molecular identification indicated that these eight strains were Cladosporium spp. belonging to dark septate endophytes (DSEs). The contents of metal ions in mycelium sharply increased, reaching 38.87 mg/kg for strain MZ-11 under As(V) stress and 0.33 mg/kg for fungus PR-2 under Cd(II). The physiological response revealed that the biomass decreased with increasing concentrations of As(V) or Cd(II), and the activity of superoxide dismutase significantly improved under the corresponding EC50 -concentration As/Cd of the strains, as well as the contents of antioxidant substances, including metallothionein, glutathione, malondialdehyde, melanin, and proline. Taken together, the filamentous fungi of Cladosporium spp. accounted for a high proportion of fungi isolated from the fibrous roots of P. kingianum and had a strong capacity to tolerate As(V) or Cd(II) stress by improving antioxidase activities and the content of antioxidant substances, and immobilization of metal ions in hyphae.

Cladosporium halotolerans: Exploring an Unheeded Human Pathogen

BACKGROUND

Cladosporium halotolerans is a saprobic fungus, rarely implicated in human infections. The identification is challenging due to non-specific phenotypic features.

OBJECTIVE

To decipher clinical spectrum, microbiological and susceptibility profile of clinical and environmental isolates of Cladosporium halotolerans.

METHOD

All the isolates identified as Cladosporium halotolerans deposited in National Culture Collection for Pathogenic Fungi (NCCPF), Postgraduate Institute of Medical Education and Research, Chandigarh, India were revived. Phenotypic and molecular characterization targeting internal transcribed spacer (ITS) region of ribosomal DNA, large subunit of ribosomal DNA (LSU; NL1 and NL4), actin (ACT) and beta-tubulin (TUB) was done. Scanning electron microscopy (SEM) was performed to determine any phenotypic variations. Antifungal susceptibility testing (AFST) was carried out for eight antifungal agents as per CLSI M38 Ed3 guidelines. We also performed systematic literature review of all the cases of Cladosporium halotolerans reported till date.

RESULTS

A total of four isolates (clinical, n = 3; soil, n = 1) identified as Cladosporium halotolerans were included in the study. The clinical sites were skin, maxillary tissue and nail. All patients were apparently immunocompetent, and history of trauma was recorded in one patient. All patients improved on antifungal therapy. The cultures revealed growth of black mycelial fungus and microscopic examination demonstrated dematiaceous septate hyphae with erect conidiophores and conidia in branched acropetal chains. Based on molecular methods, all the four isolates were identified as C. halotolerans. SEM revealed no variation in length and width of the conidia, conidiophores, ramoconidium and hyphae among the isolates. All molecular targets, such as ITS region, LSU (partially sequenced), ACT and TUB were able to differentiate the isolates. Minimum inhibitory concentrations for antifungals were: triazoles (0.12-2 μg/ml), amphotericin B (4 μg/ml) and echinocandins (2-8 μg/ml).

CONCLUSION

We report role of the rarely isolated dematiaceous fungus, C. halotolerans, in causing human infections. The study emphasizes the role of molecular methods in precisely identifying these species. Triazoles are more active against these black fungi compared to polyenes or echinocandins.

A, B.M. M, Sherpa DC, C A, Suresh A, Kammar S, M S, S S, B.N. G, Doss S G. Diversity of fungal pathogens in leaf spot disease of Indian mulberry and its management

Leaf spot disease in mulberry significantly affects silk production by reducing the nutritive quality of the leaves. This disease caused by various pathogens, regardless of the localities under the same climatic region. In the present investigation, an approximate incidence rate of 84 % was recorded in Karnataka based on surveys conducted in both farmer fields and germplasm locations. The causative agents have shown diversification, including new candidates such as Bipolaris sorokiniana, Curvularia lunata, Cladosporium sphaerospermum, and Epicoccum sorghinum. These findings mark the first report of these pathogens in Indian mulberry production. The investigation involved detailed pathogenicity assessments on the predominant mulberry silk production cultivar under controlled and field environments. Pathogens were identified using morpho-cultural, microscopic and phylogenetic analyses, including the internal transcribed spacer (ITS). Various concentrations of fungicides, both individually and in combinations, were evaluated to identify effective measures for mitigating yield losses. Among the fungicides tested against the new pathogens, Hexaconazole 5 % SC and Hexaconazole 5 % + Captan 70 % WP demonstrated high promise and cost-effectiveness. Consequently, these fungicides could serve as immediate solutions to prevent further yield reduction. However, it is essential to conduct comprehensive field investigations before recommending them as standard practices. Future research endeavors should focus on assessing the extent of crop loss caused by these newly identified pathogens in mulberry cultivation.

A new hydrophobin candidate from Cladosporium macrocarpum with super-hydrophobic surface

Hydrophobins are amphipathic proteins with small molecular weights produced in filamentous fungi. These proteins are highly stable due to the disulfide bonds formed between the protected cysteine residues. They have great potential for usage in many different fields such as surface modifications, tissue engineering, and drug transport systems because hydrophobins are surfactants and soluble in harsh mediums. In this study, it was aimed to determine the hydrophobin proteins responsible for the hydrophobicity of the super-hydrophobic fungi isolates in the culture medium and to carry out the molecular characterization of the hydrophobin producer species. As a result of measuring surface hydrophobicity by determining the water contact angle, five different fungi with the highest hydrophobicity were classified as Cladosporium by classical and molecular (ITS and D1-D2 regions) methods. Also, protein extraction according to the recommended method for obtaining hydrophobins from spores of these Cladosporium species indicated that the isolates have similar protein profiles. Ultimately, the isolate named A5 with the highest water contact angle was identified as Cladosporium macrocarpum, and the 7 kDa band was appointed as a hydrophobin since it was the most abundant protein in protein extraction for this species.

Impact of Different Drying Methods on the Microbiota, Volatilome, Color, and Sensory Traits of Sea Fennel (Crithmum maritimum L.) Leaves

Sea fennel (Crithmum maritimum L.) is a strongly aromatic herb of the Apiaceae family, whose full exploitation by the modern food industry is of growing interest. This study aimed at investigating the microbiological quality, volatile profile, and sensory traits of sea fennel spices produced using room-temperature drying, oven drying, microwave drying, and freeze drying. All the assayed methods were able to remove moisture up until water activity values below 0.6 were reached; however, except for microwave drying, none of the assayed methods were effective in reducing the loads of contaminating microorganisms. The metataxonomic analysis highlighted the presence of phytopathogens and even human pathogens, including members of the genera Bacillus, Pseudomonas, Alternaria, and Cryptococcus. When compared to fresh leaves, dried leaves showed increased L* (lightness) and c* (chroma, saturation) values and reduced hue angle. Dried leaves were also characterized by decreased levels of terpene hydrocarbons and increased levels of aldehydes, alcohols, and esters. For the sensory test, the microwave-dried samples obtained the highest appreciation by the trained panel. Overall, the collected data indicated microwave drying as the best option for producing sea fennel spices with low microbial loads, brilliant green color, and high-quality sensory traits.

Speleomycology of Air in Stopića Cave (Serbia)

Fungi can colonize organic matter present in subterranean sites and have a significant role as dwellers in different microniches of cave habitats. In order to analyze the content of airborne fungal propagules in different parts of "Stopića Cave," a touristic site in Serbia, air sampling was carried out in three seasons during 2020, prior to and during the onset of COVID-19 pandemic. Culturable mycobiota was identified using both microscopic techniques and ITS region/BenA gene barcoding, while multivariate analyses were employed to establish the link between fungal taxa and different environmental factors. The maximal measured fungal propagule concentrations were recorded during spring sampling which were based on fungal propagule concentration categories; the cave environment matches the category V. A total of 29 fungal isolates were identified, while Aspergillus, Cladosporium, Fusarium, Lecanicillium, Mucor, and Penicillium were the most diverse genera. According to the trophic mode, most of the isolated fungal species were pathotrophs (75.86%), but when regarding ecological guilds, the most dominant were undefined saprobes and animal pathogens (41.38% for each). Show caves are especially vulnerable to human impacts, and the fungal propagules' concentration within the caves could be good indices for the level of ecological disturbance.

On predatory fungi feeding on free-living amoebae harbouring yeast-like endoparasites

Amoebae of the genus Vannella isolated from an ornamental fish aquarium were found to be infected with fungi. Upon plate culture, amoeba-trapping hyphal filaments were developed, and the amoeba trophozoites were found to harbour yeast-like parasites in their cytoplasm. Transfection of hyphae to a laboratory strain of Vannella resulted in the formation of conidia indicating the possible presence of zygomycetes of the genus Acaulopage, while efforts to culture the endoparasite remained unsuccessful. Biomolecular analysis based on rDNA revealed the presence of two distinct types of fungi, confirming the filamentous form as Acaulopage sp. (Zoopagomycota, Zoopagales) and identifying the yeast-like endoparasite as Cladosporium sp. (Ascomycota, Cladosporiales). To our knowledge, this is the first report of amoebae infected with Cladosporium.

Evaluation of MALDI-TOF MS, sequencing of D2 LSU rRNA and internal transcribed spacer regions (ITS) for the identification of filamentous fungi isolated from a pharmaceutical facility

The identification of filamentous fungi through culture characterization may be hampered by phenotypic variability. Information obtained from the identification of microorganisms are important for investigation of sources of contamination of a product or process. The aim of this study was to identify filamentous fungal strains (n = 50) isolated from a pharmaceutical facility by using Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), as well as D2 domain of the large-subunit (LSU) ribosomal RNA gene and internal transcribed spacer regions (ITS) sequencing. MALDI-TOF MS system only identified five strains at the species level, while 45 were not identified. The analysis through GenBank allowed the identification of up to 19 strains at the species level, while MycoBank allowed the identification of up to nine strains at the species level. The databases identified up to 11 genera: Penicillium, Aspergillus, Cladosporium, Chaetomium, Coniochaeta, Curvularia, Diaporthe, Fusarium, Trichoderma, Rhizopus and Microdochium. MALDI-TOF MS showed an insufficient database to identify the species of fungi. DNA sequencing was the best methodology to identify to the genus level but was unable to differentiate between closely related species. Therefore further methods for the identification of filamentous fungi from pharmaceutical areas at species level need to be developed.

Surveying potentially antagonistic fungi to myrtle rust (Austropuccinia psidii) in Brazil: fungicolous Cladosporium spp

The myrtle rust (MR), caused by Austropuccinia psidii, is a worldwide threat to the cultivated and wild Myrtaceae. Originally from the neotropics, it has spread to North America, Africa, and Asia and has reached geographically isolated areas in the Pacific and Australasia. It is attacking native species in those new ranges and is still spreading and causing great concern for the damage caused to endemic Myrtaceae, and to the environment. Classical biological control is regarded as the most sustainable management option for mitigating such biological invasions. However, there are no examples of introductions of host-specific co-evolved natural enemies of plant pathogens, from their native range, as a management strategy for plant pathogens. In order to explore this neglected approach, a survey of potential fungal natural enemies of A. psidii was initiated recently in the state of Minas Gerais (Brazil). Several purported mycoparasites have been collected from A. Psidii pustules formed on myrtaceous hosts. This included some isolates of dematiaceous fungi recognized as having a Cladosporium-like morphology. Here we present the results of the investigation aimed at elucidating their identity through a polyphasic taxonomic approach. Besides morphological and cultural features, molecular analyses using sequences of translation elongation factor 1-α (EF1) and actin (ACT) were performed. The combination of data generated is presented herein and placed all Cladosporium-like isolates in six species of Cladosporium, namely, Cladosporium angulosum, C. anthropophilum, C. bambusicola, C. benschii, C. guizhouense, and C. macadamiae. None of these have ever been recorded in association with A. psidii. Now, with the identification of these isolates at hand, an evaluation of biocontrol potential of these fungi will be initiated. In contrast with the ready finding of fungicolous (possibly mycoparasitic) fungi on MR in this study, no evidence of those was recorded from Australasia until now.

Field Control Effect and Initial Mechanism: A Study of Isobavachalcone against Blister Blight Disease

Blister blight (BB) disease is caused by the obligate biotrophic fungal pathogen Exobasidium vexans Massee and seriously affects the yield and quality of Camellia sinensis. The use of chemical pesticides on tea leaves substantially increases the toxic risks of tea consumption. Botanic fungicide isobavachalcone (IBC) has the potential to control fungal diseases on many crops but has not been used on tea plants. In this study, the field control effects of IBC were evaluated by comparison and in combination with natural elicitor chitosan oligosaccharides (COSs) and the chemical pesticide pyraclostrobin (Py), and the preliminary action mode of IBC was also investigated. The bioassay results for IBC or its combination with COSs showed a remarkable control effect against BB (61.72% and 70.46%). IBC, like COSs, could improve the disease resistance of tea plants by enhancing the activity of tea-plant-related defense enzymes, including polyphenol oxidase (PPO), catalase (CAT), phenylalanine aminolase (PAL), peroxidase (POD), superoxide dismutase (SOD), β-1,3-glucanase (Glu), and chitinase enzymes. The fungal community structure and diversity of the diseased tea leaves were examined using Illumina MiSeq sequencing of the internal transcribed spacer (ITS) region of the ribosomal rDNA genes. It was obvious that IBC could significantly alter the species' richness and the diversity of the fungal community in affected plant sites. This study broadens the application range of IBC and provides an important strategy for the control of BB disease.

Diversity of Cladosporium (Cladosporiales, Cladosporiaceae) species in marine environments and report on five new species

Cladosporium species are cosmopolitan fungi, characterized by olivaceous or dark colonies with coronate conidiogenous loci and conidial hila with a central convex dome surrounded by a raised periclinal rim. Cladosporium species have also been discovered in marine environments. Although many studies have been performed on the application of marine originated Cladosporium species, taxonomic studies on these species are scarce. We isolated Cladosporium species from three under-studied habitats (sediment, seawater, and seaweed) in two districts including an intertidal zone in the Republic of Korea and the open sea in the Western Pacific Ocean. Based on multigenetic marker analyses (for the internal transcribed spacer, actin, and translation elongation factor 1), we identified fourteen species, of which five were found to represent new species. These five species were C.lagenariiformesp. nov., C.maltirimosumsp. nov., C.marinumsp. nov. in the C.cladosporioides species complex, C.snafimbriatumsp. nov. in the C.herbarum species complex, and C.marinisedimentumsp. nov. in the C.sphaerospermum species complex. Morphological characteristics of the new species and aspects of differences with the already known species are described herein together with molecular data.

First record of Cladosporium oxysporum as a potential novel fungal hyperparasite of Melampsora medusae f. sp. deltoidae and screening of Populus deltoides clones against leaf rust

Melampsora medusae f. sp. deltoidae is causing serious foliar rust disease on Populus deltoides clones in India. In the present study, a novel fungal hyperparasite on M. medusae has been reported. The hyperparasitic fungus was isolated from the uredeniospores of the rust fungi and identified as Cladosporium oxysporum by morphological characterization and DNA barcode technique based on the Internal Transcribed Spacer (ITS) region of nrDNA and beta-tubulin (TUB) gene region. Hyperparasitism was further confirmed through leaf assay and cavity slide methods. Leaf assay method showed no adverse effect of C. oxysporum on poplar leaves. However, the mean germination percentage of urediniospores was significantly decreased (p < 0.05) in the cavity slide method when a conidial suspension (1.5 × 107 conidia per ml) of C. oxysporum was applied in different deposition sequences. Scanning and light microscopic observations were made to explore the mode of action of the hyperparasitism. The antagonistic fungus vividly showed three different types of antagonism mechanisms, including enzymatic, direct, and contact parasitism. Alternatively, by screening 25 high-yielding clones of P. deltoides, five clones (FRI-FS-83, FRI-FS-92, FRI-FS-140, FRI-AM-111, and D-121) were enlisted under highly resistant category. Present study revealed an antagonistic relationship between C. oxysporum and M. medusae, which could be an effective method of biocontrol in field plantations of poplar. Combining this biocontrol approach with the use of resistant host germplasm could be an environment friendly strategy for preventing foliar rust and increasing poplar productivity in northern India.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03623-x.

Cladosporium tenuissimum-induced sinusitis in a woman with immune-deficiency disorder

Fungal sinusitis is a widespread infection that affects both healthy and immunocompromised individuals. Reports of sinus fungal infections have increased due to recent advances in diagnosis. Furthermore, susceptible and immune-compromised patients play an important role in increasing the number of reported cases. Infections with lesser-known fungi have been reported infrequently around the world. This paper describes a Cladosporium tenuissimum infection caused by chronic fungal sinusitis in a woman who had traveled to several countries. We used morphological and molecular methods to confirm the infection. The infection is most likely caused by the use of sulfasalazine, which is related to the patient's rheumatism. Sulfasalazine inhibits neutrophilic chemoattractant lipid synthesis in neutrophils, which play a key role in antifungal immunity. The patient is also undergoing root canal therapy and has several upper jaw implants, which may have contributed to the development of sinusitis.

Biodegradation of Low Density Polyethylene by the Fungus Cladosporium sp. Recovered from a Landfill Site

Low density polyethylene (LDPE) has been widely used commercially for decades; however, as a non-degradable material, its continuous accumulation has contributed to serious environmental issues. A fungal strain, Cladosporium sp. CPEF-6 exhibiting a significant growth advantage on MSM-LDPE (minimal salt medium), was isolated and selected for biodegradation analysis. LDPE biodegradation was analyzed by weight loss percent, change in pH during fungal growth, environmental scanning electron microscopy (ESEM), and Fourier transformed infrared spectroscopy (FTIR). Inoculation with the strain Cladosporium sp. CPEF-6 resulted in a 0.30 ± 0.06% decrease in the weight of untreated LDPE (U-LDPE). After heat treatment (T-LDPE), the weight loss of LDPE increased significantly and reached 0.43 ± 0.01% after 30 days of culture. The pH of the medium was measured during LDPE degradation to assess the environmental changes caused by enzymes and organic acids secreted by the fungus. The fungal degradation of LDPE sheets was characterized by ESEM analysis of topographical alterations, such as cracks, pits, voids, and roughness. FTIR analysis of U-LDPE and T-LDPE revealed the appearance of novel functional groups associated with hydrocarbon biodegradation as well as changes in the polymer carbon chain, confirming the depolymerization of LDPE. This is the first report demonstrating the capacity of Cladosporium sp. to degrade LDPE, with the expectation that this finding can be used to ameliorate the negative impact of plastics on the environment.

Dispersion characteristics of bioaerosols during treatment of rural solid waste in northwest China

In rural China, the release of bioaerosols containing pathogens from solid waste dumps poses a potential health risk to the local population. Here, we sampled bioaerosols from rural solid waste-treatment in four provinces of northwest China to investigate their emission and dispersion characteristics in order to provide a scientific basis for control and risk reduction of bioaerosols released from rural sanitation facilities. The airborne bioaerosol concentrations and particle size distributions were calculated using an Anderson six-stage airborne microbial sampler and counting with its internal Petri dish culture. High-throughput sequencing was used to characterize the microbial composition at different sampling sites and to explore possible influencing factors, while the health risk associated with exposure was estimated based on average daily dose-rate. The highest concentration point values of bacteria and fungi in bioaerosols near the solid waste were 63,617 ± 15,007 and 8044 ± 893 CFU/m³, respectively. Furthermore, the highest concentration point values of Enterobacteriaceae was 502 ± 35 CFU/m³. Most bioaerosols were coarse particles larger than 3.3 μm. Potentially pathogenic genera of winter-indicator species detected in the air were primarily Delftia, Rhodococcus and Aspergillus. The composition of solid waste and environmental conditions are important factors in determining the characteristics of bioaerosols. Local residents are exposed to bioaerosols mainly through inhalation. Children are at a particularly high risk of exposure through both inhalation and skin contact. The results of this study show that bioaerosols in the vicinity of rural solid waste dumps pose a health risk to the surrounding population. More suitable risk assessment criteria for rural areas should be established, and corresponding control and protection measures should be taken from three aspects: generation source and transmission pathway, as well as the recipient.

Antifungal Activity of Cell-Free Filtrate of Probiotic Bacteria Lactobacillus rhamnosus ATCC-7469 against Fungal Strains Isolated from a Historical Manuscript

Herein, twelve fungal strains were isolated from a deteriorated historical manuscript dated back to the 18th century. The obtained fungal strains were identified, using the traditional method and ITS sequence analysis, as Cladosporium herbarum (two strains), Aspergillus fumigatus (five strains), A. ustus (one strain), A. flavus (two strains), A. niger (one strain), and Penicillium chrysogenum (one strain). The ability of these fungal strains to degrade the main components of the paper was investigated by their activity to secrete extracellular enzymes including cellulase, amylase, gelatinase, and pectinase. The cell-free filtrate (CFF) ability of the probiotic bacterial strain Lactobacillus rhamnosus ATCC-7469 to inhibit fungal growth was investigated. The metabolic profile of CFF was detected by GC-MS analysis, which confirmed the low and high molecular weight of various active chemical compounds. The safe dose to be used for the biocontrol of fungal growth was selected by investigating the biocompatibility of CFF and two normal cell lines, Wi38 (normal lung tissue) and HFB4 (normal human skin melanocyte). Data showed that the CFF has a cytotoxic effect against the two normal cell lines at high concentrations, with IC₅₀ values of 525.2 ± 9.8 and 329.1 ± 4.2 µg mL^-1 for Wi38 and HFB4, respectively. The antifungal activity showed that the CFF has promising activity against all fungal strains in a concentration-dependent manner. The highest antifungal activity (100%) was recorded for a concentration of 300 µg mL^-1 with a zone of inhibition (ZOI) in the ranges of 21.3 ± 0.6 to 17.7 ± 0.5 mm. At a concentration of 100 µg mL^-1, the activity of CFF remained effective against all fungal strains (100%), but its effectiveness decreased to only inhibit the growth of eight strains (66%) out of the total at 50 µg mL^-1. In general, probiotic bacterial strains containing CFF are safe and can be considered as a potential option for inhibiting the growth of various fungal strains. It is recommended that they be used in the preservation of degraded historical papers.

Mycosynthesis of Zinc Oxide Nanoparticles Exhibits Fungal Species Dependent Morphological Preference

Filamentous fungi can synthesize a variety of nanoparticles (NPs), a process referred to as mycosynthesis that requires little energy input, do not require the use of harsh chemicals, occurs at near neutral pH, and do not produce toxic byproducts. While NP synthesis involves reactions between metal ions and exudates produced by the fungi, the chemical and biochemical parameters underlying this process remain poorly understood. Here, the role of fungal species and precursor salt on the mycosynthesis of zinc oxide (ZnO) NPs is investigated. This data demonstrates that all five fungal species tested are able to produce ZnO structures that can be morphologically classified into i) well-defined NPs, ii) coalesced/dissolving NPs, and iii) micron-sized square plates. Further, species-dependent preferences for these morphologies are observed, suggesting potential differences in the profile or concentration of the biochemical constituents in their individual exudates. This data also demonstrates that mycosynthesis of ZnO NPs is independent of the anion species, with nitrate, sulfate, and chloride showing no effect on NP production. These results enhance the understanding of factors controlling the mycosynthesis of ceramic NPs, supporting future studies that can enable control over the physical and chemical properties of NPs formed through this "green" synthesis method.

Cladamide: a new ceramide from the endophytic fungus Cladosporium cladosporioides

A new ceramide, named cladamide (1), in addition to cinnamic acid (2), para-coumaric acid (3), stigmasterol-3-O-β-D-glucoside (4), and uracil (5), was isolated from the white beans culture of Cladosporium cladosporioides, a marine-derived endohpytic fungus isolated from the leaves of the mangrove, Avicennia marina (Forssk.) Vierh. Structure elucidation of compound 1 was established on the basis of extensive 1D and 2D NMR spectroscopic techniques in combination with HR-ESI-MS. The ability of the isolated compounds to inhibit acetylcholine esterase was evaluated. Compound 3 showed the highest acetylcholine esterase inhibitory activity (IC₅₀ = 0.057 ± 0.003 µM), followed by compound 4 (IC₅₀ = 0.068 ± 0.003 µM) and compound 1 (IC₅₀ = 0.099 ± 0.005 µM) compared to donepezil, the positive control, (IC₅₀ = 0.044 ± 0.002 µM). Compounds 2 and 5 showed lower activity (IC₅₀ = 0.182 ± 0.009 and 0.236 ± 0.012 µM, respectively). The results were further validated by molecular docking study.

Fungal Screening for Potential PET Depolymerization

Approximately 400 billion PET bottles are produced annually in the world, of which from 8 to 9 million tons are discarded in oceans. This requires developing strategies to urgently recycle them. PET recycling can be carried out using the microbial hydrolysis of polymers when monomers and oligomers are released. Exploring the metabolic activity of fungi is an environmentally friendly way to treat harmful polymeric waste and obtain the production of monomers. The present study addressed: (i) the investigation of potential of strains with the potential for the depolymerization of PET bottles from different manufacturers (crystallinity of 35.5 and 10.4%); (ii) the search for a culture medium that favors the depolymerization process; and (iii) gaining more knowledge on fungal enzymes that can be applied to PET recycling. Four strains (from 100 fungal strains) were found as promising for conversion into terephthalic acid from PET nanoparticles (npPET): Curvularia trifolii CBMAI 2111, Trichoderma sp. CBMAI 2071, Trichoderma atroviride CBMAI 2073, and Cladosporium cladosporioides CBMAI 2075. The fermentation assays in the presence of PET led to the release of terephthalic acid in concentrations above 12 ppm. Biodegradation was also confirmed using mass variation analyses (reducing mass), scanning electron microscopy (SEM) that showed evidence of material roughness, FTIR analysis that showed band modification, enzymatic activities detected for lipase, and esterase and cutinase, confirmed by monomers/oligomers quantification using high performance liquid chromatography (HPLC-UV). Based on the microbial strains PET depolymerization, the results are promising for the exploration of the selected microbial strain.

Application of Membrane Filtration to Cold Sterilization of Drinks and Establishment of Aseptic Workshop

Aseptic packaging of high quality beverage is necessary and its cold-pasteurization or sterilization is vital. Studies on application of ultrafiltration or microfiltration membrane to cold- pasteurization or sterilization for the aseptic packaging of beverages have been reviewed. Designing and manufacturing ultrafiltration or microfiltration membrane systems for cold-pasteurization or sterilization of beverage are based on the understanding of size of microorganisms and theoretical achievement of filtration. It is concluded that adaptability of membrane filtration, especially its combination with other safe cold method, to cold- pasteurization and sterilization for the aseptic packaging of beverages should be assured without a shadow of doubt in future.

Marketed Quinoa (Chenopodium quinoa Willd.) Seeds: A Mycotoxin-Free Matrix Contaminated by Mycotoxigenic Fungi

A total of 25 marketed quinoa seed samples different for origin, farming system and packaging were analyzed for the presence of mycotoxigenic fungi (by isolation both on Potato Dextrose Agar and with the deep-freezing blotter method) and relative contamination by mycotoxins (by LC-MS/MS analysis). Fungal microorganisms, but not mycotoxins, were detected in all the samples, and 25 isolates representative of the mycobiota were obtained. Morphological and molecular characterization and, for some isolates, the in vitro mycotoxigenic profile, allowed the identification of 19 fungal species within five different genera: Alternaria, Aspergillus, Penicillium, Cladosporium and Fusarium. Among the identified species, Alternaria abundans, A. chartarum, A. arborescens, Cladosporium allicinum, C. parasubtilissimum, C. pseudocladosporioides, C. uwebraunianum, Aspergillus jensenii, A. tubingensis, Penicillium dipodomyis, P. verrucosum and P. citreosulfuratum were first reported on quinoa, and Alternaria infectoria and Fusarium oxysporum were first reported on quinoa seeds. The geographical origin, farming system and packaging were showed to affect the amount and type of the isolated fungal species, highlighting that the level of fungal presence and their related secondary metabolites is conditioned by different steps of the quinoa supply chain. However, despite the presence of mycotoxigenic fungi, the marketed quinoa seeds analyzed resulted in being free from mycotoxins.

First Report of Cladosporium tenuissimum causing Postharvest rot of Elaeagnus conferta Fruit in Kunming, China

Elaeagnus conferta Roxb. is a perennial evergreen climbing shrub and is mainly native to India, Vietnam, Malaysia, and South China (Gupta & Singh, 2021). Various parts of this plant are used to treat multiple diseases(Gupta et al., 2021). Between during the months of March and April of 2021, in Kunming city of grower fields, Yunnan Province (N 25°02'; E 102°42'), southwest China. Some postharvest E. conferta fruits showed brown spots of decay with a greyish mycelium, which symptom only appears on fruit, and did not find it on this plant. The incidence of this disease in postharvest E. conferta fruits ranges from 45 % to 65 % in natural conditions. This pathogen is harmful and causes many plant diseases. Such as rice, oriental persimmon, pear, panicles of mango, and so on (Cho & Shin, 2004; Guillén-Sánchez et al., 2007; Lee et al., 2009). The infected fruit samples surface was disinfected with 75 % ethanol and 0.3 % NaClO for 30 s and 2 min respectively, then aseptic water washing three times. The fruit tissue is rich in carbohydrates and water content, which aid the growth of fungal species. Putting these diseased tissues on a potato dextrose agar (PDA) medium, cultured at 25 ± 1 ℃ for 7 days. The colonies grow on the PDA medium, then separated and puried again. Three pure cultures (YNGH01, YNGH03, YNGH05) were obtained, which were stored in 15 % glycerol at -80 ℃ refrigerator in the State Key Laboratory for Conservation and Utilization of Bio-Resources, Yunnan Agricultural University. After 7 days of cultivation, the colonies were round and the diameter attained up to 38 mm, the surface of the colony showed tiled, fluffy, with a velvet-like texture, greyish-green to smoke-gray, slightly raised in the middle, the edges were radial hollow and wrinkle (Fig. 1A). Conidiophores were solitary, erect, unbranched or rarely branched, slightly flexuous at the apex, septate, dark brown, 254 to 680 µm long, 3.6 to 4.5 µm wide, top of the conidiophores or the rostral were slightly swollen (Fig. 1B). Conidia were light gray or grey, solitary or bispora, irregular in shape and size (Fig. 1C), nearly circular (3.21 × 3.31 µm), oval to lemon-shaped (6.59 × 3.21 µm) or elliptical (8.35 × 4.65 µm). The CTAB method extracts 3 isolates (YNGH01, YNGH03, YNGH05) genomic DNA (Aboul-Maaty & Oraby, 2019). To confirm identity with molecular identification, performed by three different genomic DNA regions, fragments of internal transcribed spacer (ITS), partial translation elongation factor-1 alpha (TEF-1α), and actin (ACT) genomic regions. These genomic DNA were amplified with primers ITS1/4, EF1-728F/986R, and ACT-512F/783R, respectively (Carbone & Kohn, 1999). The sequences of these isolates were uploaded to GenBank (YNGH01: ON753810, ON868696, ON912090 YNGH03: ON753812, ON868698, ON912092, and YNGH05: ON753814, ON868700, ON912094). NCBI's BLASTn search of those ITS sequences showed 99.81% similar to C. tenuissimum (MG873077.1), and sequences TEF-1α and ACT were 100% identical to several isolates of C. tenuissimum (OM256526.1 and MT154171.1). Combined the ITS region, TEF-1α, and actin (ACT) genomic regions of isolates YNGH01, YNGH03 and YNGH05 to construct a phylogenetic tree with MEGA11. Maximum likelihood phylogenetic analyses further confirmed the results (Fig. 2)(Santos et al., 2020). Healthy and mature E. conferta fruits were used for pathogenicity test. Pathogens were washed with sterilized water at a final concentration of 2× 106 spores/mL (Jo et al., 2018). The test was divided into A and B groups (A: The surface of fruits was pierced with a sterilized needle that carried pathogenic fungus of final concentration at 2×106 spores/mL B: Sprayed at the concentration of 2×106 spores/mL on fruits). The control fruits were treated with sterilized water and stored at 25 ± 1 ℃ with a relative humidity of 80 %, average group with 10 fruits in this test, which was repeated three times. After 7 days, the fruits of group A were initially sesame seed size of the disease spots, nearly round, irregular, with grayish-brown spots, and slightly depressed. Later, the lesion gradually turns dark brown (Fig. 1D). And group B began with small patches of brown fungal growth on the pericarp, with the development of the disease, the necrotic spots enlarged and developed irregular and coalesced, the color of spots became gray or black gradually (Fig. 1E). The symptoms were similar to previously observed and the pathogen was reisolated and identified as C. tenuissimum. Control fruits were healthy (Fig. 1F). The pathogens test fulfilled Koch's postulates. According to morphology (Bensch et al., 2012), rDNA-ITS, TEF-1α, and ACT sequence analysis, phylogenetic analysis, and pathogenicity test, the pathogen was identified as C. tenuissimum. To our knowledge, this is the first report of C. tenuissimum occurring on E. conferta fruits in China.

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.

A Lethal Case of Disseminated Cladosporium allicinum Infection in a Captive African Bullfrog

Cladosporium infections have a poor prognosis in animals, most likely due to a lack of knowledge about diagnosis and treatment. In this study, we described a case of a lethal Cladosporium allicinum infection in a captive bullfrog (Pyxicephalus adspersus) in Europe. One adult male bullfrog was referred with clinical signs of lethargy and a cutaneous nodule. Fungal infection was suspected on cytology and confirmed by histology and cultural isolation. The mold was identified by molecular methods using partial sequencing of the TEF1α gene and the ITS region of rDNA. Climbazole antifungal treatment was started but the frog died after 30 days, and necropsy was done. Pigmented hyphae and structures consistent with muriform bodies were found on a background of diffuse granulomatous inflammation at cytological and histopathological examinations. Fungal culture revealed the presence of pigmented fungi identified as Cladosporium allicinum only by partial sequencing of the TEF1α gene. A focally extensive granuloma with intralesional hyphae and muriform bodies effacing the architecture of head, liver, kidneys, lungs, and large intestine were retrieved after necropsy. This study is the first Italian report of the occurrence of lethal C. allicinum infection in a frog and highlights the role of this Cladosporium sp. in chromoblastomycosis.

Differences in fungal communities in the fur of two- and three-toed sloths revealed by ITS metabarcoding

Sloths have dense fur on which insects, algae, bacteria and fungi coexist. Previous studies using cultivation-dependent methods and 18S rRNA sequencing revealed that the fungal communities in their furs comprise members of the phyla Ascomycota and Basidiomycota. In this note, we increase the resolution and knowledge of the mycobiome inhabiting the fur of the two- (Choloepus hoffmanni) and three-toed (Bradypus variegatus) sloths. Targeted amplicon metagenomic analysis of ITS2 nrDNA sequences obtained from 10 individuals of each species inhabiting the same site revealed significant differences in the structure of their fungal communities and also in the alpha-diversity estimators. The results suggest a specialization by host species and that the host effect is stronger than that of sex, age and animal weight. Capnodiales were the dominant order in sloths' fur and Cladosporium and Neodevriesia were the most abundant genera in Bradypus and Choloepus, respectively. The fungal communities suggest that the green algae that inhabit the fur of sloths possibly live lichenized with Ascomycota fungal species. The data shown in this note offer a more detailed view of the fungal content in the fur of these extraordinary animals and could help explain other mutualistic relationships in this complex ecosystem.

Diversity and enzymatic activity of the microbiota isolated from compost based on restaurant waste and yard trimmings

Introduction

The bad management of organic waste negatively affects environmental quality and composting has been a viable recycling alternative. Microorganisms are responsible for waste degradation during the composting process and, consequently, for transforming this waste into natural fertilizer. This work aimed to analyze and identify the biodiversity of yeasts and filamentous fungi throughout a composting process based on organic residues under different treatments (commercial inoculum, non-commercial inoculum, and control treatment) and to investigate the enzymatic activity of these microorganisms.

Methods

Microorganisms were isolated and identified from samples at 0, 5, 10, 20, 40, 60, and 120 days. Filamentous fungi were identified according to their macroscopic and microscopic characteristics, and yeasts were identified by sequencing the 18S rDNA region. All identified strains were evaluated for ligninolytic, cellulolytic, hemicellulolytic, amylolytic, pectinolytic, proteolytic, lipolytic, and ammonification. During the composting phases, the filamentous fungi were higher than the yeast population.

Results and discussion

At the beginning of the process, a higher species diversity was observed, and the population of yeasts and filamentous fungi was, on average, 6.50 log CFU g−1. The microbial communities were similar throughout the process in the two inoculated treatments, which showed more significant microbial activity, diversity, and efficiency in the transformation of organic matter, and consequently, advantages in terms of the final product quality compared to the control treatment. The yeasts Pichia kudriavzevii, Pichia farinosa, Issatchenkia orientalis, and the filamentous fungi of the genus Aspergillus spp. proved to have high biotechnological value and could be used as starter cultures to accelerate the composting process.

The complete mitochondrial genome of Cladosporium anthropophilum (cladosporiaceae, dothideomycetes)

The genus Cladosporium (Cladosporiaceae, Capnodiales) is a large genus of Ascomycota. Although the genus is mostly reported as saprobes from a wide range of substrates with a worldwide distribution, members of this genus comprise infectious agents in animals and plants. Of those, Cladosporium anthropophilum is a common saprophytic fungus and has been found to be a human opportunistic pathogen and plant pathogen. The complete mitochondrial genome of C. anthropophilum is characterized through the de novo assembly of Illumina sequencing data. The mitochondrial genome is a circular molecule of 35,937 bp with 30.23% GC content and has a total of 47 genes including 16 protein-coding genes, 29 transfer RNA genes, and two ribosomal RNA genes. Based on protein-coding sequences of the mitochondrial genome sequence, a phylogenetic tree was constructed to demonstrate the phylogenetic relationship of C. anthropophilum and its related genera.

Microbiome analysis of raw honey reveals important factors influencing the bacterial and fungal communities

Raw honeys contain diverse microbial communities. Previous studies have focused on isolating bacteria and fungi that are culturable, while missing a large proportion of the microbial community due to culture-based constraints. This study utilized next-generation sequencing (NGS) to analyze the composition of microorganisms in raw honey; these data can reveal environmental and physicochemical variables that are associated with different microbial communities. To examine the microbial composition (bacteria and fungi) of raw honey and analyze its association with physicochemical properties, four types of honey (monofloral, wildflower, manuka, and feral; n total = 36) were analyzed via amplicon metagenomics. The analyzed honey samples had relatively similar bacterial communities but more distinct and diverse fungal communities. Honey type was determined as a significant factor influencing alpha and beta diversity metrics of bacterial and fungal communities. For the bacterial communities, titratable acidity (TA) was associated with community richness and diversity. For the fungal communities, Brix, TA, and color were associated with community richness, while water activity and color were associated with community diversity. Additionally, important bacterial and fungal amplicon sequence variants (ASVs) that influenced the overall community were identified. Results from this study provide important insights into the microbial communities associated with different types of raw honey, which could improve our understanding of microbial dynamics in beehives, improve honey production, and prevent honeybee disease.

Habitat and tree species identity shape aboveground and belowground fungal communities in central European forests

Introduction

Trees interact with fungi in mutualistic, saprotrophic, and pathogenic relationships. With their extensive aboveground and belowground structures, trees provide diverse habitats for fungi. Thus, tree species identity is an important driver of fungal community composition in forests.

Methods

Here we investigate how forest habitat (bark surface vs. soil) and tree species identity (deciduous vs. coniferous) affect fungal communities in two Central European forests. We assess differences and interactions between fungal communities associated with bark surfaces and soil, in forest plots dominated either by Fagus sylvatica, Picea abies, or Pinus sylvestris in two study regions in southwestern and northeastern Germany.

Results

ITS metabarcoding yielded 3,357 fungal amplicon sequence variants (ASVs) in the northern and 6,088 in the southern region. Overall, soil communities were 4.7 times more diverse than bark communities. Habitat type explained 48-69% of the variation in alpha diversity, while tree species identity explained >1-3%. NMDS ordinations showed that habitat type and host tree species structured the fungal communities. Overall, few fungal taxa were shared between habitats, or between tree species, but the shared taxa were highly abundant. Network analyses, based on co-occurrence patterns, indicate that aboveground and belowground communities form distinct subnetworks.

Discussion

Our study suggests that habitat (bark versus soil) and tree species identity are important factors structuring fungal communities in temperate European forests. The aboveground (bark-associated) fungal community is currently poorly known, including a high proportion of reads assigned to "unknown Ascomycota" or "unknown Dothideomycetes." The role of bark as a habitat and reservoir of unique fungal diversity in forests has been underestimated.

The variation of microorganisms and organics during methane production from lignite under an electric field

OBJECTIVES

The succession of microbial communities and intermediates during methane production was determined by pyrosequencing and GC-MS to investigate the mechanism of biomethanation enhancement from coal.

RESULTS

The maximum methane production at 1.2 V was significantly higher than that at 0 V. Bacterial flora have been changed as a result of the addition of an electric field, e.g., the abundance of Pseudomonas significantly increased to enhance the coal degradation which improved the methane yield by facilitating the electron transfer. The fungal structure was also found stabilized by the electric field when compared to the control after 7 days of cultivation. The predominance of Methanosarcina could also stimulate interspecies electron transfer. The GC-MS analysis revealed that the electric field can selectively promote the metabolism of refractory intermediates such as esters and aromatics during coal biodegradation.

CONCLUSION

The application of an electric field could enhance methane production from coal by changing the structure and succession of microbial communities, improving electron transfer, and enhancing the fermentation of intermediates during coal biodegradation.

Assessing the causes and consequences of gut mycobiome variation in a wild population of the Seychelles warbler

BACKGROUND

Considerable research has focussed on the importance of bacterial communities within the vertebrate gut microbiome (GM). However, studies investigating the significance of other microbial kingdoms, such as fungi, are notably lacking, despite their potential to influence host processes. Here, we characterise the fungal GM of individuals living in a natural population of Seychelles warblers (Acrocephalus sechellensis). We evaluate the extent to which fungal GM structure is shaped by environment and host factors, including genome-wide heterozygosity and variation at key immune genes (major histocompatibility complex (MHC) and Toll-like receptor (TLR)). Importantly, we also explore the relationship between fungal GM differences and subsequent host survival. To our knowledge, this is the first time that the genetic drivers and fitness consequences of fungal GM variation have been characterised for a wild vertebrate population.

RESULTS

Environmental factors, including season and territory quality, explain the largest proportion of variance in the fungal GM. In contrast, neither host age, sex, genome-wide heterozygosity, nor TLR3 genotype was associated with fungal GM differences in Seychelles warblers. However, the presence of four MHC-I alleles and one MHC-II allele was associated with changes in fungal GM alpha diversity. Changes in fungal richness ranged from between 1 and 10 sequencing variants lost or gained; in some cases, this accounted for 20% of the fungal variants carried by an individual. In addition to this, overall MHC-I allelic diversity was associated with small, but potentially important, changes in fungal GM composition. This is evidenced by the fact that fungal GM composition differed between individuals that survived or died within 7 months of being sampled.

CONCLUSIONS

Our results suggest that environmental factors play a primary role in shaping the fungal GM, but that components of the host immune system-specifically the MHC-may also contribute to the variation in fungal communities across individuals within wild populations. Furthermore, variation in the fungal GM can be associated with differential survival in the wild. Further work is needed to establish the causality of such relationships and, thus, the extent to which components of the GM may impact host evolution. Video Abstract.