Fungal Isolates Research Articles

Seedborne Fungal Detection Differs with Seed Assay Method, and Fungal Diversity and Abundance Are Impacted by Fungicide Treatment, Harvest Timing, and Storage Environment

Previous studies have shown that foliar fungicides increase the abundance of Diaporthe spp. in mature soybean seeds, thereby reducing seed quality and potentially increasing seedling, stem, and pod disease in subsequent plantings. To mitigate this, we examined a fungicide containing mefentrifluconazole, fluxapyroxad, and pyraclostrobin applied during the R3 growth stage. We compared the seedborne fungal community from soybeans harvested at full maturity and 2 to 3 weeks later to assess fungal colonization. Six trials were conducted in Iowa and South Dakota in 2021 and 2022. Asymptomatic, recently harvested seed was assayed using either an agar-plate or a seed-blotter test, and the results were compared. The agar-plate method involved disinfesting seeds in sodium hypochlorite and ethanol and then transferring them to acidified water agar plates. Fungal isolates were identified using morphology and DNA sequences. This method detected 562 fungal isolates from 25 species and 14 genera. Dry conditions reduced seed infection, but a 2-week delay in harvest increased the likelihood of Alternaria and Cercospora infection in nontreated controls. The seed-blotter test involved disinfesting seeds, placing them on blotter paper, and incubating them. This assay detected higher numbers of fungal infected seed, with Aspergillus as the dominant genus. Storage conditions significantly impacted fungal presence, with more Aspergillus in seeds stored in a shed than in the cooler. Both assay methods showed that the fungicide treatment reduced the number of seeds infected with Alternaria, Cercospora, and Aspergillus. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Efficiency of the fungi isolated from the tomato rhizosphere to control the north root-knot nematode Meloidogyne hapla Chitwood 1949

Abstract Background In the South of Russia, due to the large acreage of tomato crops (Solanum lycopersicum Mill.), there is an acute problem of plant protection against the obligate endoparasitic of the root system Meloidogyne hapla Chitwood 1949. The aim of this study was to assess the nematicidal activity of fungal strains isolated from the rhizosphere of tomato plants infected with root-knot nematodes (RKN) (Meloidogyne spp.). Results After conducting route surveys, 10 soil samples were selected from the rhizosphere of tomato plants affected by RKN. Fifteen isolates of fungi belonging to different species were isolated from the soil samples. The species composition of the isolated fungal strains was determined: Metarhizium anisopliae IG01, Penicillium citrinum IG02, Trichoderma harzianum IG03, Aspergillus niger IG04, Trichoderma ghanense IG05, Trichoderma harzianum IG06, Trichoderma atroviride IG07, Aspergillus awamori IG08, Trichoderma atroviride IG09, Paramyrothecium roridum IG10, Trichoderma atroviride IG11, Trichoderma hamatum IG12, Beauveria bassiana IG13, Aspergillus ochraceus IG14, Purpureocillium lilacinum IG15. After initial screening in the laboratory, strains with the greatest nematicidal activity and safe for humans were selected: M. anisopliae ИГ01, T. harzianum IG03, T. ghanense IG05, T. atroviride IG07, T. atroviride IG09. The mortality rate of RKN when using these fungal strains varied from 79.4 ± 1.8 to 93.9 ± 3.1%. In the greenhouse, the fungal strains M. anisopliae IG01, T. harzianum IG03, T. ghanense IG05, T. atroviride IG07, T. atroviride IG09 showed high results in reducing the number of galls on the roots of tomato plants, and their biological efficacy was 71.4–83.0%. Conclusion Work on the study of the nematicidal activity of fungi, in vitro and in vivo, allows us to conclude that strains isolated from the rhizosphere of plants can be effective in combating the north RKN (M. hapla). In the future, it is planned to establish the compatibility of M. anisopliae IG01, T. harzianum IG03, T. ghanense IG05, T. atroviride IG07, T. atroviride IG09 with each other and selecting the ratios of the studied strains to obtain mixtures to create an effective biological nematicide.

Molecular identification of Fusarium species in commercial vanilla and crop wild relatives in Colombia

AbstractVanilla is an economically important crop for low‐lying humid tropical regions, but cultivated plants face serious phytosanitary problems. Fusarium wilt is a devastating disease affecting vanilla crops, caused by the fungal pathogens Fusarium oxysporum f. sp. vanillae (Fov) and F. oxysporum f. sp. radicis‐vanillae (Forv), part of the F. oxysporum species complex (FOSC). We characterized 29 fungal isolates from a vanilla crop and crop wild relatives (CWR) using molecular (EF1‐α and ITS‐rRNA loci) and morphological traits. Fusarium was the predominant genus, followed by Colletotrichum and Clonostachys. Four Fusarium species were identified: F. oxysporum (37.9%), Fusarium solani (20.7%), Fusarium pseudocircinatum (13.8%) and Fusarium concentricum (10.3%). The latter three species were isolated only from CWR and may represent latent pathogens. Fov was isolated from both the crop and CWR, while a Forv‐affiliated isolate was also found in a vanilla crop, marking the first report in the neotropical region. The EF1‐α locus provided greater genotype resolution, as well as having reference sequences for Forv. However, the fungal barcode ITS locus is widely applied. We recommend the continued use of both loci for Fusarium diagnosis in vanilla to facilitate early detection and the development of effective integrated crop management strategies.

The Use of Thyme (Thymus vulgaris) Essential Oil for Controlling Cercospora Leaf Spot (Cercospora beticola) on Sugar Beets (Beta vulgaris)

Decreasing efficacy of fungicides and the withdrawal of further hazardous active ingredients in pesticides from use have prompted the search for alternative methods of crop protection. Essential oils (EOs) are secondary metabolites of plants and have been proven to show antibacterial, antifungal, and pest-repellent properties. This study was undertaken to determine the activity of grapefruit, rosemary, pine, sage, and thyme EOs against the fungus Cercospora beticola, which is the most dangerous pathogen of sugar beet and the causal agent of Cercospora leaf spot. According to the determined Minimum Inhibitory Concentration (MIC), thyme EO was found the most effective against C. beticola. For most of the fungal isolates tested, the MIC of this EO was 0.313 mL/L. Thyme EO also inhibited the growth of multi-resistant isolates. Based on the results obtained, thyme EO was subjected to further testing in field conditions, where its efficiency in controlling C. beticola was also proven. The results indicate that the use of thyme EO may be a promising method for the protection of sugar beets, although it requires further optimization in the context of its inclusion in sustainable protection programs assuming a reduced number of synthetic fungicide treatments.

Isolation and identification of phytopathogenic fungi from blueberry (Vaccinium corymbosum) and their biocontrol by Meyerozyma guilliermondii LMA-Cp01

Isolation and identification of phytopathogenic fungi from blueberry (Vaccinium corymbosum) and their biocontrol by Meyerozyma guilliermondii LMA-Cp01

An Etiology of Sputum Culture Contamination and their Drugs Susceptibility Patterns among TB-suspected Patients at Epicentre Mbarara Research Centre, Uganda

Aims: Contamination in TB cultures is problematic as it allows the growth of non-target bacterial or fungal species in sputum samples, potentially concealing M. tuberculosis. This study aimed to determine the prevalence, characterization, and drug susceptibility patterns of contaminants in sputum cultures from TB-suspected patients. Methods: A laboratory-based cross-sectional study was conducted from October 2023 to June 2024 at the Epicentre Mbarara Research Centre, involving 81 sputum samples from TB-suspected patients. Conventional decontamination procedures were used, and both solid Lowenstein Jensen (LJ) and liquid Mycobacterium Growth Indicator Tube (MGIT) culture methods were applied. Standard culture techniques and physicochemical analyses were employed. Bacteria were incubated at 37°C in O2 and Co2 incubators, with growth observed within 24 to 48 hours and up to three days for yeast contaminants. Sabouraud Dextrose Agar cultures were monitored for two weeks for filamentous fungi. Antibiograms for bacterial isolates were determined using the Kirby-Bauer, while broth microdilution was used for fungal isolates. Results: Of 81 samples, 14(17.28%) were contaminated. The most common bacterial contaminants were Staphylococcus aureus, Bacillus subtilis, Streptococcus viridans, Staphylococcus epidermidis, and Escherichia coli. Fungal contaminants included Aspergillus flavus, Penicillium species, Candida albicans, Cryptococcus neoformans, and non-albican Candida species. High resistance to erythromycin (73%) and tetracycline (50%) was noted among bacterial isolates, with sensitivity to vancomycin (67%), gentamycin (60%), and chloramphenicol (58%). Yeast isolates showed (87.5%) susceptibility to itraconazole and (75%) to amphotericin B but (50%) resistance to 5-flucytosine. Mold isolates exhibited (100%) susceptibility to itraconazole, amphotericin B, and 5-flucytosine but complete resistance to caspofungin. Conclusion: The level of contamination in TB cultures was noted, and Staphylococcus aureus and Candida albicans were observed as the most common contaminants. Bacterial isolates resisted erythromycin and tetracycline, while fungal isolates were generally susceptible to itraconazole and amphotericin B. We recommend Strengthening decontamination and monitoring common resistant contaminants.

Isolation and characterization of non-rhizobial bacteria and arbuscular mycorrhizal fungi from legumes

This study investigates non-rhizobial endophytic bacteria in the root nodules of chickpea (Cicer arietinum L), faba bean (Vicia faba), and cowpea (Vigna unguiculata L. Walp), as well as arbuscular mycorrhizal fungi in the rhizospheric soil of chickpea and faba bean. Out of the 34 endophytic bacterial populations examined, 31 strains were identified as non-rhizobial based on nodulation tests. All strains were assessed for their plant growth-promoting (PGP) activities in vitro. The results revealed that most isolates exhibited multiple PGP activities, such as nitrogen fixation, indole-3-acetic acid (IAA) and ammonia (NH3) production, phosphate solubilization, and exopolysaccharide production. The most effective PGP bacteria were selected for 16S rRNA analysis. Additionally, a total of 36 species of native arbuscular mycorrhizal fungi (AMF) were identified. Acaulospora (100%) and Scutellospora (91.66%) were the most prevalent genera in Cicer arietinum L. and Vicia faba L. plants, respectively. Acaulospora also exhibited the highest spore density and relative abundance in both plants. Moreover, the root colonization of Cicer arietinum L. and Vicia faba L. plants by hyphae, vesicles, and arbuscules (HVA) was significant. The findings of this study provide valuable insights into non-rhizobial endophytic bacteria associated with legume root nodules and the diversity of AMF. These organisms have great potential for PGP and can be manipulated by co-inoculation with rhizobia to enhance their biofertilizer effectiveness. This manipulation is crucial for promoting sustainable agriculture, improving crop growth, and advancing biofertilizer technology.

First Report of Southern Blight of Epimedium sagittatum Caused by Agroathelia rolfsii in Henan, China.

Epimedium [Epimedium sagittatum (Sieb. et Zucc.) Maxim., E. brevicornu Maxim., E. pubescens Maxim., E. koreanum Nakai] plants are perennial herbs and the dry leaves were used in traditional Chinese medicine with different medicinal effects (Chinese Pharmacopoeia, 2020 edition). In early August 2022 (the high temperature was 33 ℃ and the low temperature was 25 ℃ on average with above 70% relative humidity), large necrotized leaf spots were initially observed in one-year and two-year old E. sagittatum plants in Dengzhou (32°35'26.84" N, 112°11'8.37" E), Henan province, China. White mycelia, yellow and brown sclerotia were observed along the petioles and colonized to the back of leaves and also on soil-petioles interface around the diseased Epimedium plants. White mycelia spread rapidly from the disease plants as a center to neighboring plants and the infected plants eventually wilted. The disease incidence was 16.0% and 28.0% in the surveyed cultivation fields in Dengzhou (Henan) and Danjiangkou (Hubei), respectively, which resulted in above 20% of yield loss. The symptomatic tissues (petioles, n≥10) were cut into 0.5 cm sections with autoclaved scissors and surface sterilized with 75% ethanol for 30 s, followed by 3 min in 1% NaClO, rinsed three times with distilled sterile water, plated on autoclaved filter paper to remove excess moisture in a biological laminar hood, transferred onto potato dextrose agar (PDA) plates and incubated at 28℃ in incubator in the dark for 3-5 days. Twelve fungal isolates with white radial colony morphology were obtained and purified by hyphal-tip method. The isolates formed radial colonies showing abundant aerial mycelia with a growth rate of 19.25 to 22.25 mm/day (mean = 21.67 ± 0.77 mm; n = 36) and white abundant sclerotia were observed after 5-7 days post inoculation at 28℃. The hyphae of the isolates were hyaline, branched with clamp connections at septa. The isolates formed dark brown sclerotia on PDA plate post 10-14 days incubation. The diameter of mature brown sclerotia ranged from 1.31 to 3.07 mm (mean = 1.91 ± 0.39 mm; n = 40) and 13 to 45 sclerotia (mean = 28; n = 24) were observed on each Petri dish. The isolates were tentatively identified as Agroathelia rolfsii based on morphological characteristics (Yi Y., et al. 2024) and isolate YYHBJ1 was selected as representative isolate for molecular identification and pathogenicity test. The genomic DNA was extracted using CTAB method. For molecular identification, ITS region, translation elongation factor-1alpha (TEF-1α) and nuclear large-subunit ribosomal DNA (nLSU-rDNA) were amplified (White et al. 1990, Wendland and Kothe, 1997). The sequences 684-bp ITS (OR428367), 534-bp TEF1α (OR485567), and 965-bp nLSU-rDNA (OR426612) of isolate YYHBJ1 were deposited in GenBank. Sequence analysis revealed that ITS, TEF1α and nLSU-rDNA sequences of YYHBJ001 showed 100%, 99.63%, and 100% identity to ITS (MN380242 and JF819727), EF1α (MN262527) and nLSU-rDNA (MT225781 and AY635773) sequences of Agroathelia rolfsii (Sacc.) Redhead & Mullineux (Redhead and Mullineux 2023). Pathogenicity tests was confirmed by inoculating 1 year-old E. sagittatum plants grown in pots with sterile soil. PDA plug (5 mm diameter) colonized with 3 brown sclerotia and the fungal culture which was cultivated for 12 days was deposited beside the petiole on the surface of the soil. The control plants were inoculated with PDA plugs without the pathogen. Five plants were used in each treatment. The plants were cultivated in incubator at 28℃ with 80% relative humidity. Fourteen days later, white mycelia growing out from the sclerotia and spread along the petioles to the leave and the infected leaves were yellow. After 21 to 24 days, all inoculated plants displayed symptoms like those observed in field, while no symptoms were observed on the controls. The fungus was re-isolated from the inoculated plants as described above, fulfilling Koch's postulates. The pathogenicity tests were repeated three times. Based on morphological feature and DNA sequences, the pathogen of southern blight on Epimedium plants was identified as A. rolfsii (anamorph S. rolfsii). The pathogen A. rolfsii usually infect kinds of crops and cause southern blight, such as peanuts, chili peppers, green onion and so on (Daunde et al. 2018). To our knowledge, this is the first report of A. rolfsii causing southern blight on E. sagittatum plants in Henan in China.

Prevalence of Seed-Borne Fungi on Soybean (Glycine max L. Merr.) Seeds Stored Under Medium-Term Cold Room Facilities: Implications for Genebanks

This study examined the prevalence of seed-borne fungi in polyethylene plastic-packaged soybean seeds stored in a genebank and identified factors influencing their incidence. Twenty-four seed lots were sampled from the collection stored at 10 °C in the World Vegetable Center genebank in Arusha, Tanzania. The seeds used were those regenerated and harvested in 2015, 2016, and 2017. A seed health test was conducted for sterilized seeds on potato dextrose agar, sterilized seeds on top of the paper, and unsterilized seeds on top of the paper. Seven-year-old sterilized seeds plated on top of the paper exhibited the highest germination percentage (74 ± 7.09%) and lowest fungal incidence (7.00 ± 4.41%). Conversely, seven-year-old unsterilized seeds plated on top of the paper had the lowest germination (22.00 ± 6.97%) and highest fungal incidence (79.00 ± 8.31%). Older seed lots showed significantly higher equilibrium seed moisture content (Eqmc), though seed age had no significant influence on germination percentage or fungal incidence. Seed germination percentage showed a significant negative relationship with Eqmc, though Eqmc had no significant effect on fungal incidence. Meanwhile, germination percentage showed a significant negative relationship with fungal incidence. Six fungi isolates were identified using their morphological features from soybean seed samples: Absidia glauca, Aspergillus niger, Fusarium spp., Mucor hiemalis, Pestalotiopsis versicolor, and Sordaria macrospora. It is concluded that high fungal incidence negatively affects seed germination but is not significantly correlated with seed moisture content. The dry and cold storage conditions in the genebank, while effective in extending seed longevity, can unintentionally allow seed-borne mycoflora to persist. Although fungi may not actively proliferate under these conditions, they may do so when favorable conditions are restored, such as during germination tests, and consequently may compromise seed viability. Therefore, this study emphasizes the importance of increased systematic seed health checks before storage in genebanks to ensure optimal seed quality, and the replacement of all polyethylene plastic bags to aluminium foil packaging.

Antibacterial Activity of Endophytic Fungi Isolate from Bidara Plant (Ziziphus mauritiana Lam.) Against Bacteria That Cause Digestive Infections by Agar Diffusion Method

Isolates of endophytic fungi coded IFAZ-6 derived from bidara plants (Ziziphus mauritiana Lam) has antibacterial abilities. This study determine whether those isolates has antibacterial activity against bacteria Escherichia coli. Isolates of endophytic fungi were purified and fermented for 21 days and the fermentation results were extracted using ethyl acetate solvent. The ethyl acetate extract obtained was carried out with a minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) as well as activity tests with the agar diffusion method. From the test results, statistical tests were carried out, the highest concentration IFAZ-6 isolate extracts that has highest inhibitory zone was 300,000 ppm in E. coli bacteria but only significantly different to 200.000 ppm.

Antibacterial Properties in Fermentate Extracts of Endophytic Fungus Derived from Marine Algae Caulerpa lentillifera Against Gastrointestinal Pathogenic Bacteria

Endophytic fungi, residing symbiotically within living plant tissues, are a promising source of novel bioactive compounds. These fungi are known to produce secondary metabolites with a wide range of biological activities, including antibacterial properties. This study explored the antibacterial potential of fermented extracts from endophytic fungi isolated from the marine alga Caulerpa lentillifera, a food source consumed by coastal communities and traditionally used for medicinal purposes. Thin-layer chromatography (TLC) bioautography was employed to identify extracts with activity against common gastrointestinal pathogenic bacteria, such as Escherichia coli, Shigella dysenteriae, and Salmonella typhi. Two endophytic fungal isolates displayed promising antibacterial activity against these pathogens. TLC analysis tentatively identified the presence of flavonoids and alkaloids, potentially responsible for the observed effects. This research sheds light on the pharmacological potential of endophytic fungi and their applications in combating bacterial infections.

Whitefly‐Pathogenic Beauveria bassiana JEF‐507 as a Competitive Biopesticide, Chongchae‐Stop

ABSTRACTSilverleaf whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is a destructive insect pest damaging to diverse crops by vectoring several plant pathogenic viruses, which consequently causes economic losses in crop production. As the resistance of whiteflies to chemical insecticides is increasing, this study aimed to investigate the potential of entomopathogenic fungi as an alternative. A total of 72 entomopathogenic fungal isolates, collected from soils using Tenebrio molitor larvae as an insect baiting method, were assessed for their virulence against 2nd nymphs of whitefly. Their virulence was assayed by dipping whitefly‐infested tomato leaves in fungal conidia suspensions at 1.0 × 107 conidia/mL. Among the tested isolates, two isolates of Beauveria bassiana JEF‐462 and JEF‐507 showed high virulence. In the assessment of virulence depending on conidia concentrations, the estimated LC50 values for JEF‐462 and JEF‐507 were similarly 8.7–14.0 × 107 conidia/mL. However, B. bassiana JEF‐507 showed higher conidial productivity and thermotolerance on most of tested 12 grain substrates than B. bassiana JEF‐462, and millet was the most suitable grain substrate. Additionally, siloxane as a surfactant was able to sufficiently exhibit the insecticidal activity of JEF‐507 against whitefly nymphs compared with other surfactants. In a pot‐based greenhouse trial, JEF‐507 showed higher control efficacy than chemical insecticides, dinotefuran and spinetoram. This work suggests that B. bassiana JEF‐507 could be competitively used as a biopesticide to control silverleaf whiteflies while overcoming current resistance issues. The JEF‐507 isolate has been registered in Korea, 2022 and successfully commercialised as the name of Chongchae‐Stop in this local market to control whitefly and thrips.

Antibacterial Activity of Endophytic Fungi Isolated from Parang Romang (Boehmeria virgata (G.Forst) Guill) Leaves Against Gastrointestinal Pathogens

Parang romang (Boehmeria virgata (G.Forst) Guill) is a plant traditionally used for treating various digestive tract infections. However, obtaining bioactive compounds directly from the plant requires significant biomass. Therefore, endophytic fungi, sourced from specific plant parts, are explored for their ability to produce similar bioactive compounds. The research examined the potential antibacterial activity of endophytic fungi isolated from parang romang leaves against common gastrointestinal pathogens. The methods used in was, characterization of endophytic fungal isolates, and antagonistic activity was evaluated using the agar diffusion method. The results showed that the endophytic fungal strains, namely isolates IFBV 6, IFBV 7, and IFBV 10 could inhibit the bacteria Escherichia coli, Salmonella typhi, Shigella dysenteriae, and Vibrio cholera. With an average zone of inhibition for each strains isolate against Esherichia coli respectively 11.53 mm, 10.49 mm, and 14.85 mm; Salmonella typhi 14.47 mm, 8.66 mm, and 15.51 mm; Shigella dysenteriae 22.28 mm, 13.76 mm, and 15.33 mm; and Vibrio cholera 16.91mm, 11.94mm, 15.16mm. In conclusion, isolated endophytic fungal strains hold promise as potential as antibacterialn agents.

Production of Antibiotics from Endophyte Fungi Isolates of Bidara Plants (Ziziphus mauritina L.) Isolates Codes IFAZ-6, IFBZ-6, IFDZ-8 With Variations in Carbon Sources

Research has been carried out on antibiotic production from endophytic fungal isolates coded IFAZ-6, IFBZ-6, and IFDZ-8 from bidara plants (Ziziphus mauritina L.) with variations in carbon sources. This research aims to determine antibiotic production with variations in carbon sources. The first stage was the purification of each selected endophytic fungal isolate. The endophytic fungal isolate was inoculated into the fermentation medium using a variety of carbon sources, namely glucose, fructose, and galactose for 21 days. The antibiotic activity was carried out using the agar diffusion method against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli bacteria. The results obtained showed that the glucose carbon source was better in producing antibiotic compounds than the galactose carbon source in endophytic fungal isolates coded IFAZ-6, the glucose carbon source was better in producing antibiotic compounds than the fructose and galactose sources in endophytic fungal isolates coded IFBZ-6, and the fructose carbon source is better at producing antibiotic compounds than the galactose source in endophytic fungal isolates coded IFDZ-8.

Structure-based design and synthesis of (E)-l-(s-pheny1)-N-(4-(2,2,4-trimethy1-2,3-dihydro-lH-benzo[b][l,4]diazepin-l-yl)phenyl)methanimine motifs as antimicrobial and anti-tubercular agents

Benzodiazepines' chemistry and synthesis as heterocyclic compounds have recently attracted a lot of attention, due to their extensive biological diversity in drug design and potential for usage in agrochemicals. Eco-friendly and highly efficient method was herein reported for the synthesis of a new series of Schiff base of benzodiazepine derivatives 3a-l using microwave-assisted approach. Firstly, 2,2,4-trimethy1-2,3-dihydro-lH-benzo[b][l,4]diazepine (1) was synthesized by AgNO3-catalyzed reaction of o-phenylenediamine with excess of acetone. Coupling of benzodiazepine 1 with 4-chloroaniline afforded intermediate benzodiazepine 2 which was subsequently reacted with benzaldehyde derivatives via microwave irradiation technique to access twelve final targeted benzodiazepine Schiff bases, 3a-l. The chemical structures of the scaffolds 3a-l were authenticated using analytical and spectroscopic data. Benzodiazepine Schiff bases 3a-l were investigated for their in vitro antimicrobial activities using Agar diffusion technique and screened for their minimum inhibitory concentration (MIC) using microtube dilution technique. Ten pathogenic organisms comprising of seven bacterial and three fungal isolates were utilized for the screening. Ciprofloxacin was the positive control for antibacterial screening while fluconazole was engaged as the positive control for the antifungal screening. The most efficacious antimicrobial agent among the series was (E)-l-(2-Chloropheny1)-N-(4-(2,2,4-trimethyl-2,3-dihydro-lH-benzo[b][l,4] diazepinlyl)phenyl)methanimi ne (3b) with a MIC value of 3.13 µg/mL and MBC of 6.25 µg/mL among all the synthesized compounds synthesized and screening for antimicrobial assessment. Compound 3b also emerged as the best anti-tubercular agent IC50 of 40 µg/mL against Mycobacterium tuberculosis, Mycobacterium bovis and H37Rv

Insights into the culturable fungal endophytes of Dioscorea bulbifera L. in terms of their diversity, antidiabetic and antioxidant activity

The research on endophytes is focused on understanding the complex microbiome compositions, their interactions with host plants and their bioactive potential. Our study provided an overview of the diversity, distribution and bioactivities of culturable endophytic fungi associated with fungal endophytes of Dioscorea bulbifera L. The phylogenetic analysis depicted the evolutionary relationship among taxa of endophytic fungal isolates. The isolated fungal endophytes belonged to twenty-five genera and thirty-eight species. Further, diversity indices demonstrated significant diversity of fungal endophytes in the different tissues: stem, leaf, tuber and bulbil. A higher consistency of endophytic fungal isolates in the bulbils was found using Shannon index. Furthermore, Simpson's index revealed that the leaf tissue harboured highly diverse fungal endophytes. Likewise, Margalef's index depicted high taxonomic richness in bulbils. The isolates such as Acrocalymma medicaginis, Curvularia lycoperscii, Talaromyces macrospora, Fusarium laceratum, Paecilomyces formosus and Microascus cirrosus isolated in this study have been reported as endophytes for the first time from any plant. In-vitro antioxidant and antidiabetic activities of the ethyl acetate extracts revealed that Nigrospora oryzae (Z2) effectively inhibited α-glucosidase activity with IC50 value of 0.6 µg/ml whereas IC50 value of the acarbose, the positive control was reported to be 0.040 µg/ml. The results of antioxidant activity demonstrated that H15A (Acrocalymma medicaginis) and BD5 (Phomopsis longicolla) could be used as potential sources of antioxidant agents. Moreover, H15A (Acrocalymma medicaginis) was reported to produce 687.1 ± 0.17 µg GAE/mg of TPC and 78.55 ± 0.29 µg QE/mg of TFC quantitatively. These findings suggest that the potential endophytes could be explored using systematic bio-guided investigations to further discover novel natural products. Our study provides an important resource for a deeper understanding of endophyte-plant interactions at molecular and genetic levels.

Pore-forming aegerolysin and MACPF proteins in extremotolerant or extremophilic fungi.

Aegerolysin proteins are involved in various interactions by recognising a molecular receptor in the target organism. The formation of pores in combination with larger, non-aegerolysin-like protein partners (such as membrane attack complex/perforin proteins [MACPFs]) is one of the possible responses in the presumed competitive exclusion of other organisms from the ecological niche. Bicomponent pairs are already observed at the gene level. Fungi growing under extreme conditions can be divided into ubiquitous and extremotolerant generalists which can compete with mesophilic species and rare, isolated extremophilic and extremotolerant specialists with narrow ecological amplitude that cannot compete. Under extreme conditions, there are fewer competitors, so fungal specialists generally produce less diverse and complicated profiles of specialised molecules. Since extremotolerant and extremophilic fungi have evolved in numerous branches of the fungal tree of life and aegerolysins are unevenly distributed across fungal genomes, we investigated whether aegerolysins, together with their partner proteins, contribute to the extreme survival ecology of generalists and specialists. We compiled a list of 109 thermo-, psihro-, acido-, alkali-, halo-, metallo- and polyextremo-tolerant/-philic fungal species. Several challenges were identified that affected the outcome: renaming fungal species, defining extremotolerant/extremophilic traits, identifying extremotolerant/extremophilic traits as metadata in databases and linking fungal isolates to fungal genomes. The yield of genomes coding aegerolysins or MACPFs appears to be lower in extremotolerant/extremophilic fungi compared to all fungal genomes. No candidates for pore-forming gene pairs were identified in the genomes of extremophilic fungi. Aegerolysin and MACPFs partner pairs were identified in only two of 69 species with sequenced genomes, namely in the ubiquitous metallotolerant generalists Aspergillus niger and A. foetidus. These results support the hypothesised role of these pore-forming proteins in competitive exclusion.

Isolation and Molecular Identification of Fungal Contamination on the Eggshells of Lepidochelys olivacea L. Collected from Coastal Waters

Background: One of the causes of the decline in the Olive ridley turtle population is the low egg hatching rate due to contamination by pathogenic fungi. Purpose: This study aims to evaluate the results of the isolation and molecular identification of fungal contamination on the eggshells of olive ridley turtles that failed to hatch from three coastal waters in Bali province. Method: Sampling was done using the purposive sampling technique. Samples of failed hatching eggshells from the coast were collected, as many as 2 eggs/semi-natural nest at TCEC. Samples were cultured on PDA media. Macroscopic and molecular identification methods were carried out to determine the species level of fungal isolates. Results: The results showed that 10 fungal isolates were successfully collected. Isolates KL1 and SG1 had white colony surface characteristics, isolates KL4, SY2 and SY3 showed black colonies, and isolates KL2, KL3, SG2, SG3, SY4 had green colonies. Three similar isolates were sent for further molecular identification. The BLASTn results of the nucleotide sequences of isolates SY2 and SG3 showed a similarity to Aspergillus niger strain PHY105 (91%), while fungal isolate KL1 had a similarity to Fusarium solani strain 87, by 98%. Conclusion: This study provides new information about the pathogenic fungi, Fusarium solani strain 87 and Aspergillus niger strain PHY105, which are suspected to be the cause of the hatching failure of olive ridley turtle eggs.

Spatial Distribution and Disease Incidence of Guava Wilt Village Survey Across Prayagraj and Kaushambi, Uttar Pradesh, India

A comprehensive roving survey was conducted in the Prayagraj and Kaushambi districts of Uttar Pradesh, India, both prominent guava-producing regions. The survey, which included 30 villages, revealed widespread guava wilt with incidence rates ranging from 19.04% to 37.93%, averaging 30.19% across the region. Three forms of wilt these are quick, slow, and partial were identified. Kaushambi district had a higher incidence rate (31.56%) compared to Prayagraj district (28.82%). Indarapur village in Kaushambi recorded the highest wilt incidence (37.93%). The survey also found that 66.67% of farmers lacked formal training in guava cultivation, contributing to poor disease management. Guava wilt was most prevalent in older orchards (10+ years) and primarily affected the Allahabad Safeda variety, which had the highest wilt incidence (33.64%). In contrast, the Pant Prabhat variety exhibited the lowest wilt incidence (22.95%). The causal pathogen, Fusarium oxysporum f. sp. psidii, was isolated from diseased plants. Three fungal isolates displayed variations in colony morphology, growth, and sporulation. Microconidia were non-septate and kidney-shaped, while macroconidia were thin- walled and typically 2-3 septate. Two isolates also produced chlamydospores. This study highlights the need for enhanced farmer training and the potential for cultivating wilt-tolerant varieties to mitigate the spread of the disease in the region.

Regional Variability of Chestnut (Castanea sativa) Tolerance Toward Blight Disease

Since its introduction into Europe in the first half of the 20th century, Cryphonectria parasitica has been gradually spreading across the natural range of the sweet chestnut (Castanea sativa Mill.), infecting the trees and causing lethal bark cankers. Serendipitously, a hyperparasitic Cryphonectria hypovirus 1 (CHV1), which attenuates C. parasitica virulence in combination with more tolerant European chestnut species, was able to ward off the worst effect of the disease. In North America, unfortunately, the native Castanea dentata is now functionally extinct since it occurs only as root sprouts in eastern deciduous forests where it was once dominant. In our work, we investigated changes in C. parasitica populations over time and the regional variability in chestnut populations’ tolerance toward the blight disease. While vegetative compatibility (vc) type diversity and prevalence of hypovirulence remained similar as in previous studies, in the Buje population, unlike in previous studies, we were unable to find any hypovirulent fungal strains. The most common vegetative compatibility types (vc types) were EU-1, EU-2 and EU-12. However, several rare EU-types were found, including one previously unreported: EU-46. By inoculating several C. parasitica strains on tree stems from several chestnut populations, we observed that the induced lesion size was affected by the type of inoculum (CHV1-free or CHV1-infected), genotype-related individual chestnut stem and chestnut stem population of origin-related variability. The largest lesions were induced by CHV1-free fungal isolate DOB-G: 20.13 cm2 (95% C.I. 18.10–22.15) and the smallest by CHV1-infected L14/EP713: 2.49 cm2 (95% C.I. 1.59–3.39). Surprisingly, the size of the lesions induced by other CHV1-infected strains fell somewhere in between these extremes. The size of induced lesions was dependent on the population of origin as well and ranged from 11.60 cm2 (95% C.I. 9.87–13.33) for stems from the Moslavačka gora population to 17.75 cm2 (95% C.I. 15.63–19.87) for stems from Ozalj.