Search Results (145)

Despite increasing interest in fungal remediation systems for the treatment of persistent contaminants, the mechanisms governing fungal transformation of halogenated organic compounds remain poorly resolved. The aim of this study was to determine whether the transformation of halogenated nitrophenols is driven by isolated extracellular enzymes and cofactor-dependent oxidative activity or instead reflects coordinated system-level fungal metabolism. To address this question, we investigated the transformation of 2-chloro-4-nitrophenol (2C4NP) and 5-fluoro-2-nitrophenol (5F2NP) by ascomycete fungi Caldariomyces fumago (C. fumago) and Curvularia sp. under varying nutrient and cofactor conditions. Whole-culture transformation, crude supernatant activity, purified enzyme assays, intracellular detoxification responses, and genome-resolved functional annotation were integrated to evaluate the relative contributions of extracellular and intracellular processes. Transformation was strongly dependent on fungal species, substrate identity, nutrient availability, and cofactor composition. C. fumago achieved complete transformation of 2C4NP and up to 85.3% transformation of 5F2NP, whereas Curvularia sp. exhibited strict Na₃VO₄-dependent transformation of 5F2NP. Crude supernatants retained partial transformation capacity, achieving ~40–45% substrate depletion under conditions supporting whole-culture activity. Purified chloroperoxidase and laccase showed negligible independent activity and did not reproduce whole-culture transformation behavior. Lignin peroxidase activity was consistently induced during contaminant exposure and peaked during periods of maximum transformation. Cytochrome P450 inhibition did not prevent transformation. Baseline glutathione S-transferase activity was detected in both fungi, and comparative genome analysis identified conserved intracellular detoxification-associated enzyme alongside divergent extracellular oxidative enzyme repertoires. Together, these findings demonstrate that transformation of halogenated nitrophenols by fungi cannot be explained by isolated extracellular enzymes alone but is consistent with coordinated extracellular and intracellular system-level metabolism. These findings highlight an underexplored role for integrated fungal metabolic systems in bioremediation and provide a mechanistic basis for developing a scalable fungal platform for treatment of persistent halogenated contaminants. Full article

Background/Objectives: Otomycosis is a recurrent fungal infection of the external auditory canal. This disease is difficult to manage with current antifungal agents due to irritation, ototoxicity risk, and emerging resistance. Natural essential oils have been proposed as alternatives, yet their clinical application in otic formulations remains limited due to their poor solubility and stability. In this study, we report the first ear-drop formulation combining microemulsified Ocimum gratissimum essential oil and acetic acid for otomycosis treatment. Methods: The essential oil was quality-validated with eugenol content superior to 60%. A systematic formulation study was performed, and the Tween 20/isopropanol (4:1, w/w) mixture was selected as the optimal surfactant system, yielding a stable microemulsion with high encapsulation efficiency (~98%) and relevant physicochemical stability (up to 28 days). The final formulation containing 1% acetic acid and 0.3% micro-emulsified essential oil met pharmacopeial requirements in terms of appearance, pH, viscosity, and microbial limits. Results: Importantly, this micro-emulsified eardrop demonstrated significantly greater in vitro antifungal activity than 3% boric acid and 2% acetic acid eardrops in twelve clinical fungal isolates from Vietnamese swimmers, especially on Curvularia, Cunninghamella, Aspergillus terreus, and Bipolaris. Although less pronounced than 1% clotrimazole, the finalized formulation demonstrates better antifungal kinetics and a broader activity spectrum. Conclusions: This work provides relevant experimental evidence on the use of Ocimum gratissimum essential oil in a microemulsion delivery system and demonstrates its efficacy against clinically relevant otomycosis pathogens. The results establish a foundation for future in vivo and clinical studies. Full article

Tomato is susceptible to various fungal pathogens, including Alternaria alternata and Curvularia spicifera, which can cause extensive post-harvest losses. Chemical fungicides have limited effectiveness in controlling post-harvest fungal pathogens and pose risk to human health and the environment. Therefore, this study assessed indigenous isolates of three species of Trichoderma (Tr1: T. longibrachiatum; Tr2: T. harzianum; and Tr3: T. asperellum) as biocontrol agents against two fungal pathogens in vitro and in vivo and determined their physicochemical analysis and plant-growth-promoting traits. The three species of Trichoderma exhibited catalase production in vitro, while T. longibrachiatum and T. asperellum showed the highest potential for plant-growth promotion by producing indole-3-acetic acid and phosphate solubilization but not nitrogen-fixing capability. T. harzianum showed lower potential in these traits. Mycelial growth was found to be maximum (5.77–12.27 cm) at 30 °C and a pH of 7–9, but inhibition (2.60–5.13 cm) was recorded at the highest temperature (45 °C) and pH (11). In vivo, studies on tomato fruits indicated that T. longibrachiatum and T. asperellum significantly (p < 0.05) reduced lesion diameters of A. alternata by 53.60% and 48.71%, respectively, and C. spicifera by 55.58% and 56.19%, respectively, relative to the infected control. Besides their antifungal efficacy, the three species of Trichoderma enhanced tomato seedling growth, particularly at 1/10 filtrate dilution, and improved fruit quality parameters by increasing firmness and nitrate content, while reducing oxidative stress. Physicochemical analysis indicated that Trichoderma-treated fruits had better firmness, pH, and nitrate value coupled with a reduction in oxidative stress (reduced malondialdehyde content) compared to pathogen-infected controls. The indigenous isolates of the three species of Trichoderma provided high efficacy as biocontrol agents of the two fungal pathogens that cause post-harvest losses of tomato, suggesting that biological control can replace synthetic chemicals in preserving tomato under storage conditions and contribute to agricultural sustainability. Full article

Potassium (K) is an essential macronutrient for plants and plays a critical role in soil microbial processes. However, its systemic effects on rhizosphere microorganisms in high-value crops like cherry tomato remain poorly understood. This study established a potassium gradient (K0 represents the no-potassium application, K1 represents low-potassium application, K2 represents a moderate-potassium application, K3 represents the conventional-potassium application, and K4 represents excessive-potassium application) to investigate responses in growth and rhizosphere bacterial and fungal communities of cherry tomato. Moderate potassium (K2) significantly enhanced dry matter accumulation in cherry tomato. Bacterial and fungal communities displayed distinct patterns: bacterial structure shifted continuously along the gradient, with specific enrichment of functional genera (nitrogen-fixing Ensifer, biocontrol-related Lysobacter), increased unique OTUs, and gradual co-occurrence network optimization at K2. In contrast, fungal community composition and network structure showed threshold responses to potassium. Low K (K1) suppressed dominant Ascomycota and increased unclassified fungi, while high potassium (K4) enriched parasitic/pathogenic fungi (Alternaria, Curvularia), increased network modularity, and reduced stability. This microbial ecological perspective highlights that optimized potassium application regulates functional microorganisms and differentially shapes rhizosphere communities, providing a theoretical basis for precision potassium management in cherry tomato. Full article

The clinical cases described in this text add to the limited literature on chronic and allergic rhinosinusitis caused by dematiaceous fungi, particularly Curvularia spicifera. These cases highlight the growing recognition of fungal infections as a significant factor in the etiology of rhinosinusitis, a condition traditionally attributed to bacterial causes It has become evident that a comprehensive clinical approach, involving diagnostic imaging and laboratory examinations, particularly culture-based analysis, has been crucial in identifying the specific fungal pathogen responsible for the infection. Additionally, molecular biology techniques have proven indispensable in enhancing diagnostic accuracy and the understanding of such infections. Importantly, these types of infections are commonly observed in immunocompetent individuals, distinguishing them from other fungal infections that typically affect immunocompromised patients. This study underlines the importance of integrating microbiological findings with clinical, radiological, and histopathological data for the accurate diagnosis of non-invasive fungal rhinosinusitis, particularly given the lack of serological assays specific for this species. The available literature on these infections remains limited, and diagnosis continues to rely on an integrated multimodal approach. Full article

The potential of methanolic extracts from jara (Barkleyanthus salicifolius) and pomegranate carpel membranes (Punica granatum) as biological alternatives for the control of phytopathogenic fungi was evaluated against pathogens associated with commercially important crops in the Ciénega de Chapala region. Extracts were assessed in vitro against Botrytis cinerea and Rhizoctonia solani (strawberry), Curvularia sp., Pestalotiopsis sp., and Fusarium oxysporum (blackberry), Pythium sp. and Fusarium sp. (tomato), and Sclerotium rolfsii (onion). Antifungal bioassays demonstrated that the B. salicifolius extract inhibited the mycelial growth of R. solani, whereas the pomegranate extract inhibited seven of the eight species tested, with the exception of S. rolfsii. Phytochemical screening revealed the presence of alkaloids, flavones, flavonols, chalcones, and quinones in pomegranate, and flavones, flavonols, alkaloids, and sterols in jara. Additionally, phytol and caryophyllene were identified in the latter via GC–MS. Full article

Plant growth-promoting bacteria (PGPB)-based inoculants represent a promising alternative to mineral fertilizers. However, their application may be limited by constraints associated with the use of living microorganisms, particularly under field conditions. The objective of this study was to select a bacterial strain and a suitable carrier for the inoculation of rice cv. Selección 1. The effect of inoculation with 3 Rhizobium spp. strains on rice growth was evaluated under greenhouse conditions, enabling selection of the most promising strain. This strain was further characterized based on its motility, production of indolic compounds in the presence of tryptophan, and antagonistic activity against 3 rice phytopathogenic fungi. In addition, the effects of culture media based on aqueous extracts of soybean and rice seeds on bacterial growth and chemotactic response were evaluated, along with the shelf-life stability of the resulting inoculant formulations. Rhizobium sp. strain 5P1 significantly increased plant height (33%), root length (21%), shoot dry weight (30%), and root dry weight (17%) of rice cultivar Selección 1 under greenhouse conditions. The strain exhibited motility predominantly via swarming and twitching, produced indolic compounds (23.9 ± 0.8 µg mL⁻¹), and showed antagonistic activity against Magnaporthe oryzae (32.5% radial growth inhibition at 16 days), Curvularia oryzae (20.0%), and Bipolaris oryzae (6.6%) under in vitro conditions. Culture media based on molasses and soybean or rice seed extracts did not enhance bacterial growth relative to the conventional medium; however, they elicited a stronger chemotactic response. Formulations supplemented with sodium alginate and carboxymethylcellulose maintained cell viability above 10⁸ CFU mL⁻¹ after 105 days of storage at 4 °C. These findings propose Rhizobium sp. strain 5P1 and a molasses-based carrier formulation as strong candidates for the development of an effective bioinoculant for rice in Ferric Gleysol soils. Full article

Endophytic fungi widely colonize plant tissues without causing severe disease, protect hosts from pathogenic microorganisms, and represent a key potential resource for novel biocontrol agents. To explore the biocontrol potential of endophytic Epichloë fungi and their correlation with alkaloids, 12 Epichloë strains were isolated from six different geographic sites of Festuca sinensis, Achnatherum inebrians, and Hordeum brevisubulatum. The antifungal activity of these strains was evaluated against five phytopathogenic fungi (Alternaria alternata, Bipolaris sorokiniana, Curvularia lunata, Fusarium avenaceum, and Drechslera erythrospila) using dual-culture assays, which measured the inhibition of both colony growth and spore germination. Concurrently, the concentrations of ergonovine and ergine were quantified in the liquid cultures of each Epichloë strain. The results showed that 12 Epichloë strains had varying degrees of inhibitory effects on the colony growth and spore germination of five pathogenic fungi. Among these, strain F2 had the highest inhibition rate on the spore germination of B. sorokiniana (87.73%), while strain H3 had the lowest inhibition rate on F. avenaceum (7.89%). The concentrations of ergonovine and ergine were positively correlated with the inhibition rate of pathogenic fungi, but the degree of these correlations varied among different pathogenic fungi. This study provides further evidence for Epichloë-mediated pathogen inhibition and establishes a basis for their development as biocontrol agents in agricultural systems. Full article

A comprehensive two-year investigation (2024–2025) was conducted across Northeast China’s crucial grain production base to assess the status of maize diseases. Field surveys spanning three provinces and Inner Mongolia revealed a significant shift in the regional disease profile, with diagnosis performed by experienced personnel based on characteristic field symptoms. The results demonstrated that maize white spot (MWS) has emerged as a severe new threat, recording remarkably high disease severity indices exceeding 80 at multiple locations (e.g., LDD25-1: 86.83). Concurrently, gray leaf spot (GLS) was confirmed as the most prevalent foliar disease, forming stable areas of high severity in the eastern mountainous regions where its disease indices consistently surpassed 60 (e.g., LFS25-1: 65.26), thereby exceeding the impact of northern corn leaf blight. In contrast, stalk rot (SR) maintained a low field incidence rate below 10%, while other diseases such as Curvularia leaf spot and maize eyespot were only observed locally or were absent during the 2025 survey period. These findings underscore the emergence of MWS as a critical threat and affirm the dominant status of GLS, offering a scientific foundation for prioritizing disease management strategies in the region. Full article

Aeromycoflora present in the library environment is known to play a significant role in triggering allergies and contributing to the deterioration of both cellulosic and non-cellulosic materials within the intramural setting of the Midnapore College Library. Fungal spores not only accelerate the aging and degradation of books but also pose considerable health risks to students, library visitors, and staff. In total, 480 fungal colonies belonging to 15 genera and 28 species were recorded using the culture plate exposure method. The predominant taxa included Aspergillus/Penicillium, Alternaria alternata, Alternaria solani, Cladosporium cladosporioides, Curvularia lunata, Penicillium oxalicum, Epicoccum sp., Fusarium solanii, Fusarium oxysporum, Periconia sp., Rhizopus sp., and other Penicillium species. Many of these fungi are well-documented allergens and have been reported to cause adverse health manifestations—such as respiratory discomfort and skin irritation—among students, teaching staff, and book handlers exposed to airborne mycobiota. The present study aimed to investigate the aeromycological diversity within the Midnapore College Library and to conduct immuno-clinical assessments to identify specific serum IgE using both in vivo and in vitro diagnostic techniques. Individuals frequently visiting the library reported symptoms including eye irritation, headaches, itchy skin, sore throat, and severe asthma. Spearman’s rank correlation analysis revealed a significant association between total and dominant spore concentrations and the health status of affected individuals. Clinico-immunological evaluations confirmed the allergenicity of Aspergillus fumigatus, with 39.5% of atopic individuals showing positive reactions in skin prick tests (SPT). Additionally, three novel sero-reactive proteins were identified, offering valuable insights for local clinicians in diagnosing and managing fungal-induced allergic conditions. Full article

A severe leaf blight disease was observed on Nageia fleuryi in Fuzhou, China, during 2022–2023, causing necrosis on more than 60% of young leaves in both urban and plantation trees. This study aimed to identify the causal agent of the disease. The pathogen was consistently isolated from symptomatic tissues, and pathogenicity tests confirmed its ability to reproduce the disease on detached leaves, fulfilling Koch’s postulates. The representative isolate ZB-2 produced gray, cottony colonies and curved, 3-septate conidia with a swollen third cell, morphologically resembling Curvularia pseudobrachyspora. Multilocus phylogenetic analyses based on ITS, GAPDH, and Tef1-α sequences placed ZB-2 firmly within the C. pseudobrachyspora clade, confirming its identity. This study constitutes the first global record of C. pseudobrachyspora as a pathogen of leaf blight on N. fleuryi. Full article

Bambara groundnut is an underutilized legume with significant potential for enhancing nutrition and food security. However, limited knowledge of its seed systems hinders the development of targeted interventions. This study assessed the Bambara groundnut seed systems and seed quality in Ghana. A semi-structured questionnaire was used to examine seed production, conditioning, and saving practices, while 150 farmer-saved seed samples were evaluated for quality. The findings revealed that the seed system is predominantly informal, with 99% of farmers relying on their own saved seeds, which showed poor germination and emergence. About 54.4% sourced seeds from local markets, and 60.7% recycled seeds for five years or more. Seeds were stored unshelled in polypropylene bags in Tolon and shelled in the Kintampo South and Talensi Districts. Seed selection was primarily based on size (in Tolon) and visible absence of disease symptoms (in Kintampo South and Talensi). An incidence (7.6%) of seed-borne pathogens was recorded, with Aspergillus flavus (38.8%) and A. niger (16.6%) being most prevalent. Other pathogens included Macrophomina phaseolina (11.5%), Rhizopus spp. (6.5%), Curvularia lunata (5.3%), and A. fumigatus (1.9%). This study highlights the need to support community-based seed systems to improve farmers’ access to quality Bambara groundnut seed. Full article

The crude ethyl acetate extract of the culture of a marine sponge-associated fungus, Aspergillus unguis KUFA 0098, was tested for its capacity to inhibit the growth of ten phytopathogenic fungi, viz. Alternaria brassicicola, Bipolaris oryzae, Colletotrichum capsici, Curvularia oryzae, Fusarium semitectum, Lasiodiplodia theobromae, Phytophthora palmivora, Pyricularia oryzae, Rhizoctonia oryzae, and Sclerotium roflsii. At a concentration of 1 g/L, the crude extract was most active against P. palmivora, causing the highest growth inhibition (55.32%) of this fungus but inactive against R. oryzae and S. roflsii. At a concentration of 10 g/L, the crude extract completely inhibited the growth of most of the fungi, except for L. theobromae, R. oryzae, and S. roflsii, with 94.50%, 74.12%, and 67.80% of inhibition, respectively. The crude extract of A. unguis KUFA 0098 exhibited growth-inhibitory effects against B. oryzae and P. oryzae, causative agents of brown leaf spot disease and leaf blast disease, respectively, on rice plant var. KDML105, under greenhouse conditions. Chromatographic fractionation and purification of the extract led to the isolation of four previously described depsidones, viz. unguinol (1), 2-chlorounguinol (2), 2,4-dichlorounguinol (3), and folipastatin (4), as well as one polyphenol, aspergillusphenol A (5). The major compounds, i.e., 1, 2, and 4, were tested against the ten phytopathogenic fungi. Compounds 1 and 4 were able to inhibit growth of most of the fungi, except L. theobromae, R. oryzae, and S. roflsii. Compound 1 showed the same minimum inhibitory concentration (MIC) values as that of carbendazim against A. brassicicola, C. capsici, C. oryzae, and P. oryzae, while compound 4 showed the same MIC values as that of carbendazim against only C. capsici and P. oryzae. Compound 2 was not active against all of the ten phytopathogenic fungi tested. Full article

Coral bleaching is a multifactorial stress response in which the breakdown of symbiosis with algal and bacterial partners has been well characterized, but the role of fungal communities remains largely unexplored. Here, we tracked the temporal dynamics of coral-associated fungi in Turbinaria sp. across three defined bleaching stages under natural thermal stress. In total, 161 genera from six phyla were detected. From the unbleached to partly bleached stage, fungal Simpson diversity declined, whereas observed richness slightly increased; putative pathogenic genera (e.g., Apiotrichum, Curvularia, Exserohilum, and Schizophyllum) rose sharply (39.44%→69.04%), whereas parasitic fungi decreased (33.01%→11.72%). From the partly to fully bleached stage, diversity rebounded. Co-occurrence networks became more complex initially (nodes 86→98; edges 454→809; average degree 10.56→16.51) but then collapsed below baseline (nodes 98→65; edges 809→196; average degree 16.51→6.03), indicating stress-driven restructuring. The proportion of positive correlations declined steadily (98.68%→93.82%→77.55%), suggesting a shift toward more competitive and unstable community structures under stress. Our findings demonstrate that fungal communities actively respond to thermal stress and exhibit distinct compositional and ecological shifts during bleaching, pointing to their overlooked but potentially significant role in coral health and deterioration. This study highlights the need to integrate fungal dynamics into the broader understanding of holobiont responses to coral bleaching. Full article

Coconut (Cocos nucifera L.) cultivation is increasingly threatened by destructive fungal pathogens that reduce yield and compromise tree health, particularly in tropical regions in China. To address this challenge, the present study aimed to isolate and identify antagonistic bacteria with potential biocontrol activity against key pathogens of coconut, including Ceratocystis paradoxa (crown rot), Pestalotiopsis menezesiana (leaf blight), and Curvularia oryzae (leaf spot). A total of 65 bacterial strains were isolated from 58 soil samples collected from healthy coconut orchards. Among these, strain X1 exhibited the most vigorous antagonistic activity, with inhibition rates exceeding 70% against multiple pathogens in both plate confrontation and mycelial growth rate assays. Morphological, physiological, biochemical, and molecular (16S rDNA and gyrB gene sequencing) analyses confirmed the identity of strain X1 as Bacillus velezensis. Optimization of fermentation conditions for strain X1 revealed that maximum antimicrobial activity was achieved using a medium containing 2% glucose, 3% peptone, 0.3% NaH₂PO₄·2H₂O, and 0.4% Na₂HPO₄·2H₂O, at 28 °C and pH 7.0–7.5, 5% inoculum, 50–70 mL liquid volume in 250 mL flasks, 72 h fermentation, and agitation at 180–220 rpm. These findings highlight B. velezensis X1 as an up-and-coming biocontrol agent with dual functionalities: effective suppression of coconut fungal pathogens and potential plant growth promotion. Its application could significantly reduce the dependence on synthetic fungicides, offering an eco-friendly alternative for integrated disease management in coconut farming. Full article