Search Results (1,144)

Large-scale production of Bacillus thuringiensis, one of the most widely used biopesticides, is often limited by the high cost of conventional culture media. In this study, fermented cassava paste water (EFM), ripe mango pulp juice (CM), and cashew apple juice (JPC) were evaluated as alternative substrates for the liquid fermentation of B. thuringiensis var. kurstaki HD-1. Physicochemical analyses revealed acidic pH values and classified the substrates into two clusters: CM with high C/N ratios, organic matter, total sugars, and proteins, and EFM and JPC with lower C/N ratios and nutrient levels. Fermentation results indicated that JPC supported the highest biomass production (8.29 × 10¹³ CFU mL⁻¹), exceeding that in the standard Tryptone Soy Broth (TSB) medium. However, CM promoted the highest sporulation rate (1.46 × 10¹³ CFU mL⁻¹) and the greatest bioactive lipopeptides—iturins (102.2 mg L⁻¹) and surfactins (554.7 mg L⁻¹)—surpassing TSB. The antifungal activity of crude fermented CM, EFM, and TSB was evaluated against Sclerotium rolfsii. All samples significantly inhibited mycelial growth of the pathogen with no significant differences among substrates or concentrations tested. This study highlights the potential of B. thuringiensis-fermented agrowaste as a cost-effective, environmentally friendly biocontrol tool for Sclerotium rolfsii. Full article

The molecular mechanisms of mycelial degeneration during subculturing of Auricularia heimuer strain ‘HWS1908’ were investigated across generations G1 to G20. With successive subculturing, mycelial growth rate and compactness declined, cellulase and laccase activities decreased significantly, whereas antioxidant enzyme activities increased. Comparative transcriptome analysis between G1 and G20 identified 2643 differentially expressed genes (DEGs). Gene Ontology (GO) analysis indicated that the DEGs were significantly enriched in terms associated with protein refolding, response to reactive oxygen species, and ferroxidase activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed significant enrichment of DEGs in pathways including phenylpropanoid biosynthesis, peroxisome, fatty acid degradation, and longevity-regulating pathways. Key DEGs, including transcription factors, glycoside hydrolases, lignin-modifying enzymes, chitin synthases, chitinases, ornithine decarboxylase, and Ras/Rho signaling pathway components (Sos, Ras, Rac1), were identified. These genes may be associated with the progressive decline of mycelial vigor, cell wall integrity, and substrate utilization capacity. These findings provide a basis for further exploration of the molecular mechanisms of strain degeneration in A. heimuer, and a practical recommendation to limit subcultures to within 20 generations for maintaining high vitality. Full article

Botrytis cinerea is a major phytopathogenic fungus responsible for substantial economic losses in horticultural crops, underscoring the need for sustainable alternatives to synthetic fungicides. This study investigated the influence of physical, chemical and biological culture parameters on the antifungal activity of culture filtrates produced by Trichoderma harzianum BOL-12QD. Culture conditions were sequentially optimised by evaluating light-filter exposure, carbon and nitrogen source composition, potato ecotype selection, co-cultivation with Botrytis cinerea, and volatile-mediated interactions. Antifungal activity was assessed using mycelial growth inhibition assays against Botrytis cinerea. Among the individual factors, violet-filter illumination, a medium containing 5 g L⁻¹ glucose and 250 g L⁻¹ potato extract, the Leke Pek’e potato ecotype, ammonium nitrate as nitrogen source, and co-cultivation with Botrytis cinerea at 10⁴ conidia mL⁻¹ produced the highest inhibitory effects. Sequential integration of these optimised conditions resulted in enhanced antifungal activity, reaching up to 62% inhibition. Volatile organic compounds produced by Trichoderma harzianum BOL-12QD exhibited only minimal antifungal activity under the conditions tested, suggesting that volatile-mediated antagonism plays a limited role in this system. In contrast, culture-dependent modulation of extracellular metabolite profiles was evidenced by comparative ¹H NMR fingerprinting, which revealed condition-specific spectral differences, with the optimised treatment displaying a distinct metabolic signature relative to all other conditions. Cytotoxicity assays in murine peritoneal macrophages showed no significant reduction in cell viability at concentrations up to 200 μg mL⁻¹. In vivo exposure to the optimised culture filtrate (250 mg kg⁻¹ d⁻¹ for 10 days) induced transient treatment-related clinical observations without mortality, indicating a need for further detailed toxicological characterisation. Overall, these findings demonstrate that the antifungal activity of Trichoderma harzianum BOL-12QD is strongly modulated by interacting environmental, nutritional and biological culture parameters. The results support the potential of optimised culture filtrates as a source of bioactive metabolites for biocontrol applications, while highlighting the importance of integrated biochemical and toxicological evaluation. Full article

Tan spot of wheat, caused by the fungus Pyrenophora tritici-repentis (Ptr), is one of the most destructive foliar diseases of wheat worldwide and in Kazakhstan. Expansion of wheat plantings, the adoption of no-till methods, and the use of ineffective fungicides contribute to the accumulation of inoculum and the spread of the pathogen. Despite the important role of fungicides in plant protection, data on the susceptibility of Ptr populations in Kazakhstan are lacking. This study, for the first time, assessed the susceptibility of Ptr isolates from various regions of Kazakhstan to QoI and DMI fungicides. A predominance of genotypes associated with ToxA (82.9%) was found, with a limited distribution of ToxB (7.9%). Propiconazole demonstrated the highest efficacy, inhibiting mycelial growth by an average of 70.85%, followed by pyraclostrobin (69.04%), while azoxystrobin demonstrated lower efficacy (41.47%). Molecular analysis revealed the widespread prevalence of the G143A mutation in the cytochrome b gene, associated with resistance to the QoI fungicide. These results indicate the emergence of strobilurin resistance in Ptr populations in Kazakhstan and highlight the need for regular monitoring of fungicide susceptibility and the development of effective resistance management strategies. 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

Bretziella fagacearum (formerly Ceratocystis fagacearum (Bretz)) Hunt is a vascular pathogen responsible for oak wilt disease, which affects various oak species in North America. Once established, management options include root disruption, removal of infected wood, and fungicide application, each with variable efficacy. This is the first study to assess three commercial biofertilizers against B. fagacearum in vitro, using Spectrum supplemented with Pepzyme Clear (SPC), EM-1, and Power Gelatinase and Chitinase-producing Microorganism (PGCM), as no biological methods currently exist. These biofertilizers were chosen for microbes associated with improved nutrient uptake and for their potential biocontrol activity. We conducted dual-culture plate assays, volatile organic compounds (VOCs) assays, and non-volatile metabolite assays. EM-1 and PGCM exhibited the strongest antagonistic effects for dual-culture plate assays (56% and 68%, respectively) and for VOCs assays (62% and 47%, respectively). After 15 days of exposure to non-volatile metabolites, microscopic analysis revealed severe hyphal distortions from EM-1 and PGCM. These preliminary in vitro findings suggest that PGCM and EM-1 suppressed mycelial growth of B. fagacearum and may be used as biological control. Further field studies are needed to understand how environmental factors and soil–tree–microbe interactions can affect their efficacy against oak wilt disease. Full article

To investigate the effect of sorbitol feeding on immune responses and its underlying mechanism, this study employed crabapple (Malus micromalus), a species native to China, as the experimental material. Detached leaves were subjected to sorbitol feeding experiments, with water feeding as the control. The dynamic changes in lesion area and cell membrane permeability were measured across four groups of leaves following feeding and fungal inoculation, and transcriptome sequencing was performed on these four groups. The results revealed that compared to the control group, leaves fed with sorbitol prior to inoculation exhibited significantly reduced lesion areas and decreased cell membrane permeability. Transcriptome and KEGG pathway analyses indicated that differentially expressed genes were significantly enriched in the phenylpropanoid biosynthesis pathway. HPLC results demonstrated that quercetin and isorhamnetin contents increased significantly after sorbitol feeding, and both compounds were shown to inhibit the mycelial growth of Alternaria alternata, thereby enhancing the disease resistance of crabapple leaves. Among the associated genes, MmF3H1, which regulates the synthesis of quercetin and isorhamnetin, showed the highest level of enrichment. Co-expression trend analysis and qPCR results revealed that MmNAC17 and MmbZIP1 exhibited strong co-expression relationships with MmF3H1 and responded to sorbitol regulation. Functional validation was conducted by constructing overexpression and silencing vectors for MmNAC17/MmbZIP1 and performing transient transformation, thereby elucidating the molecular and biochemical mechanisms underlying the response of M. micromalus to A. alternata. This study provides a theoretical reference for breeding crabapple varieties with enhanced resistance to leaf spot disease. Full article

The orthogonal design further optimized the culture medium to a combination of ammonium nitrate, sucrose, and magnesium sulfate, achieving a mycelial growth rate of 1.379 mm/d. The mycelia of Gerhardtia borealis contained 26.01% crude protein, 6.03% crude fat, and 1.24% crude polysaccharides. A total of 17 amino acids were detected, with a total content of 26.09 g/kg. The iron and zinc contents in the mycelia were 28.09 mg/kg and 22.17 mg/kg, respectively. The concentrations of arsenic, cadmium, mercury, and lead were all below the national food safety limits. This study provides fundamental data supporting the domestication and functional utilization of Gerhardtia borealis as an edible and medicinal resource. Full article

Fusarium oxysporum f. sp. lycopersici is one of the most destructive soilborne pathogens affecting tomato production, reducing plant growth and yield and highlighting the need for sustainable management alternatives. Streptomyces spp. are promising microbial candidates due to their ability to combine antifungal activity with plant growth promotion characteristics. The objective of this study was to evaluate the biofertilizer and antifungal potential of Streptomyces spp. in Chonto tomato (Solanum lycopersicum Mill.) under greenhouse conditions. Seventy actinobacterial strains were screened in vitro against F. oxysporum, and eight exhibited significant antagonistic activity. Based on antagonistic activity, enzymatic profile, cytotoxicity, and plant growth-promoting potential, strains 1B260 and 445 were selected for greenhouse assays. Strain 1B260 achieved 43.5% mycelial growth inhibition and showed the highest phosphate-solubilizing capacity (420 µg/mL), while both strains displayed proteolytic and cellulolytic activity, low cytotoxicity in human skin cell lines (HaCaT and HDFa), nitrogen fixation, and ammonia production. In greenhouse assays under non-infected conditions, 1B260 showed the most consistent biofertilizer effect, promoting stem elongation. Under pathogen pressure, strain 445 improved plant performance compared to the infected control. Overall, strains 1B260 and 445 exhibited complementary roles in tomato crop management, highlighting the potential of multifunctional Streptomyces inoculants for sustainable biofertilization and biocontrol strategies. Full article

Twelve white-rot fungal isolates were evaluated for their potential to produce mycelium leather from rice straw, based on growth characteristics, biomass production, and mechanical properties. Among these, Trametes sp. SW25-2 exhibited rapid growth on culture medium and dense mycelial formation on rice straw substrate. The effects of nutrient supplementation, substrate-to-medium ratio, and processing conditions on mycelium-leather formation were systematically examined. No significant differences were observed among different carbon (glucose, maltose, and sucrose) and nitrogen sources (yeast extract, peptone, and ammonium sulphate), indicating that the fungus effectively utilised rice straw as the primary substrate. An optimal ratio of 1 g rice straw to 10 mL culture medium (90.9% moisture content) enabled complete colonisation and the formation of a compact mycelial structure, achieving a maximum tensile strength of 2.78 MPa under optimised hot-pressing conditions (120 °C, 60 s, 1 MPa). Hot-pressing conditions significantly influenced material properties. A higher temperature (120 °C) increased tensile strength but reduced elongation at break, while a lower temperature (60 °C) produced more flexible materials. Scanning electron microscopy revealed that post-treatment and hot pressing transformed the mycelial network into a dense and cohesive structure. The resulting mycelium leather demonstrated suitable physical properties and was successfully fabricated into prototype products, highlighting its potential as a sustainable bio-based material derived from agricultural waste. Full article

To explore efficient and sustainable biocontrol resources against anthracnose in Begonia benariensis, endophytic fungi were isolated from healthy host tissues and screened for antagonistic activity against Colletotrichum aotearoa SWBG5. Among 31 isolates, four showed strong inhibition, and the most potent strain, QYN6, exhibited an in vitro mycelial inhibition rate of 63.67%. Based on morphology and multi-gene phylogeny (ITS, TUB2, TEF-1α), QYN6 was identified as Nigrospora sphaerica. Mechanistic assays revealed that QYN6 secretes multiple cell wall-degrading enzymes (chitinase, β-1,3-glucanase, cellulase, protease) and displays hyperparasitism against the pathogen hyphae (entwining, deformation, swelling), acting synergistically to inhibit fungal growth. In greenhouse pot trials, QYN6 achieved a biocontrol efficacy of 48.91% against Begonia anthracnose. Additionally, QYN6 significantly activated host defense responses, increasing the activities of antioxidant enzymes (SOD, POD, PPO, CAT) and the contents of soluble protein and soluble sugar. Furthermore, QYN6 exhibited multiple plant growth-promoting traits, including IAA production, siderophore synthesis, and potassium solubilization. Inoculation with QYN6 markedly improved plant height, leaf number, root length, and biomass of B. benariensis. Overall, N. sphaerica QYN6 possesses dual biocontrol and growth-promoting potential, providing a promising microbial resource and theoretical basis for green management of Begonia anthracnose. Full article

Mucormycosis is a devastating invasive fungal infection primarily caused by Mucor and Rhizopus species, presenting significant clinical challenges due to limited therapeutic options and emerging drug resistance in opportunistic yeasts such as Candida albicans. This study explores foliar endophytic fungi from Thai medicinal plants as potential reservoirs for novel bioactive metabolites targeting both fungal growth and virulence factors. We report the first isolation of Fusarium proliferatum as an endophyte from Lantana camara L. foliage (voucher number 01562), with its identity confirmed through morphological characterization and sequencing of the fungal ITS4/ITS5 regions. Antifungal susceptibility testing showed potent activity against a panel of environmental Mucorales, with minimum inhibitory concentrations (MICs) ranging from 0.3 to 1 mg/L. In dual-culture assays, F. proliferatum demonstrated significant mycelial inhibition rates of 93.30% to 93.67% against Mucor spp. and 88.67% to 93.67% against Rhizopus spp. Furthermore, the crude extract exhibited a potent anti-virulence effect by suppressing the C. albicans yeast-to-hyphal transition, achieving up to 68% germination inhibition in resistant strains. Liquid chromatography–mass spectrometry (LC-MS) analysis identified 51 secondary metabolites, including the cyclic peptide beauvericin and various polyketides and indole derivatives. These findings suggest that F. proliferatum utilizes metabolic mimicry and adaptive synergy with its host plant to produce a diverse chemical arsenal. This study positions foliar endophytes of L. camara as promising candidates for the development of dual-action therapeutics to combat invasive and resistant mycoses. Full article

The use of natural products as alternatives to synthetic fungicides has gained increasing importance in crop protection. Among these, clove (Syzygium aromaticum) and its active compound, eugenol, are well known for their antifungal properties. However, it remains unclear whether the antifungal activity of clove is primarily driven by its major constituent, eugenol, or whether the whole essential oil exhibits greater or synergistic efficacy. Addressing this question is crucial for optimizing their application as biofungicidal agents; The chemical composition of clove essential oil was characterized using gas chromatography–flame ionization detection (GC-FID) and gas chromatography–mass spectrometry(GC-MS). The antifungal activity of the essential oil and pure eugenol (300 µg/mL) was evaluated in vitro against Botryotinia fuckeliana, Rhizoctonia solani, and Verticillium dahliae on potato dextrose agar (PDA). Mycelial growth inhibition was quantified, and data were analyzed using two-way analysis of variance (ANOVA) followed by Tukey’s honestly significant difference (HSD) test (α = 0.05); Eugenol exhibited higher antifungal activity than the essential oil across all tested species. V. dahliae was completely inhibited (100%) by eugenol, while the essential oil showed lower efficacy. Despite the high eugenol content (87.3%) in the oil, its reduced activity suggests that minor constituents may modulate overall antifungal performance. These findings demonstrate that eugenol is more effective than clove essential oil as an antifungal agent. This highlights that the biological activity of clove is largely driven by its major active component, providing key insights for the development of more efficient biofungicidal strategies. Full article

Root rot is a major disease restricting the cultivation and production of Polygonatum kingianum Coll. et Hemsl. This study aimed to identify the causal agent and characterize its biological properties. Pathogens were isolated from diseased rhizomes showing typical symptoms, and their pathogenicity was confirmed through Koch’s postulates using both detached rhizome inoculation and field pot experiments with spore suspension irrigation, in which typical root rot symptoms were reproduced. Based on morphological characteristics and multi-locus phylogenetic analysis (ITS, CaM, RPB2, and TUB), the pathogen was identified as Penicillium crustosum. Biological characterization revealed that the optimal conditions for mycelial growth and sporulation were 25 °C and pH 8–9, with Czapek agar being the most suitable medium. Light conditions significantly influenced fungal development; continuous darkness (24 h) favored mycelial growth, while an alternating light/dark cycle (12 h/12 h) significantly enhanced sporulation. Furthermore, the pathogen exhibited the highest utilization efficiency for soluble starch as a carbon source and peptone or yeast extract as a nitrogen source. These physiological traits suggest a strong adaptive capacity of the pathogen to environmental conditions associated with host rhizomes, which may contribute to disease development under cultivation conditions. To our knowledge, this is the first report of P. crustosum causing root rot in P. kingianum. The findings provide a basis for accurate pathogen identification and improve current understanding of the biological characteristics of this pathogen, thereby supporting future studies on disease monitoring and management. Full article

Saprolegnia parasitica (Oomycota) causes saprolegniosis and poses significant ecological and economic challenges in aquaculture. Experimental research on this pathogen is constrained by the lack of reliable long-term preservation methods, as routine maintenance by serial subculturing is labor-intensive and may result in genetic and phenotypic instability. Deep eutectic solvents (DESs), tunable low-melting mixtures, have recently gained attention as alternative cryoprotectants. However, their application has not been evaluated in oomycetes. Here, twelve glycerol-based two- and multicomponent DESs were assessed for cryopreservation of S. parasitica at −80 °C and compared with glycerol as a conventional cryoprotectant. Cryopreservation efficiency was assessed based on post-thaw survival and mycelial regeneration. Several two-component DESs, particularly glycerol-trehalose, supported 100% survival and high post-thaw mycelial regeneration, performing comparably to glycerol under the tested conditions. Shorter pre-incubation (30 min vs. 1 h and 3 h) and controlled-rate freezing (vs. direct freezing) significantly improved post-thaw growth. Although survival remained 100% under optimized conditions, extending storage from 7 to 32 days significantly reduced mycelial regeneration in the glycerol–trehalose treatment, indicating that survival alone, as done in existing literature, does not reflect physiological recovery. Overall, our results support the use of selected DESs as alternative cryoprotectants in oomycetes and contribute to the development of cryopreservation strategies for S. parasitica. Full article