Discovery of edodine, a natural compound from Lentinula edodes with antibacterial activity for the biological control of fire blight pathogen Erwinia amylovora.

Isolation and characterization of an algicolous endophytic Mucor circinelloides from macroalga Colpomenia sinuosa as a promising source of bioactive metabolites for dermocosmetic applications

Marine endophytic fungi have arisen as a prospective source of bioactive secondary metabolites with potential cosmeceutical and pharmaceutical applications. In this study, four endophytic fungal isolates were obtained from Egyptian marine algae Colpomenia sinuosa. Preliminary screening for antibacterial activity against Staphylococcus epidermidis indicated that the isolate EF2 was the most active, exhibiting an inhibition percentage of 40.67%, and therefore was selected for optimization by the Plackett–Burman experiment and response surface methodology. This optimization significantly improved the inhibitory activity from 40.67% to 94.4%. The optimized crude extract of isolate EF2 exhibited strong antioxidant activity with the DPPH assay and significant anti-inflammatory activity by cyclooxygenase-2 (COX-2) enzyme inhibition. Furthermore, it demonstrated pronounced tyrosinase inhibitory activity, suggesting its potential role in melanin biosynthesis regulation. The isolate was molecularly identified as Mucor circinelloides AUMC 16435 with accession number PP837661. Cytotoxicity assessment revealed selective activity against carcinoma cells with relatively low toxicity toward normal fibroblasts, indicating a favorable safety profile. GC–MS analysis of EF2 isolate crude extract (Mucor circinelloides AUMC 16435) demonstrated several bioactive constituents, with 3-methoxy-2, 4, 6-trimethyl-cyclohex-2-enone and 2-fluoro-3-trifluoromethylbenzoicacid-3-hexadecyl ester as the predominant compounds. Molecular docking studies further confirmed favorable binding interactions of the compounds within the tyrosinase active site, with energies of binding -6.1 and -5.9 kcal/mol, respectively. Overall, this study reports the first isolation of M. circinelloides from Egyptian C. sinuosa and highlights its potential as a promising source of bioactive metabolites with enhanced antibacterial activity and multifunctional properties suitable for pharmaceutical and dermocosmetic applications.

Isolation and in vitro Evaluation of Antagonistic Bacterial Endophytes from Eleusine coracana (L.) Gaertn. against Magnaporthe oryzae

Pyricularia oryzae (syn. M. oryzae), the causative agent of blast disease, is among the most destructive fungal pathogens threatening rice production and other cereal crops worldwide. The search for environmentally sustainable alternatives to synthetic fungicides has increased interest in endophytic bacteria as potential biological control agents. In the current study, endophytic bacterial isolates obtained from disease-resilient finger millet were evaluated for their antagonistic activity against P. oryzae using dual-culture, cell-free culture filtrate, and conidial germination assays. Among the tested isolates, AL2 and AN6 exhibited the strongest antagonistic activity in dual culture, inhibiting mycelial growth by more than 82%, while AN2 showed moderate inhibition (52.07%). Cell-free culture filtrates suppressed fungal growth in a concentration-dependent manner across 10%-30% (v/v), with isolate AN6 demonstrating the highest inhibition of mycelial growth (85.24%) at a concentration of 30%, followed by AL2 and AN2. Similarly, the culture filtrates markedly reduced conidial germination after 12 h of incubation. At the highest concentration, AN6 reduced germination to 4.33%, followed by AL2 (6.33%) and AN2 (14.33%), compared with the untreated control. These findings identify finger millet-associated endophytes, particularly isolate AN6, as promising candidates for the biological management of rice blast disease. Further greenhouse and field evaluations are required to confirm their efficacy under natural conditions.

Isolation and characterization of an entomopathogenic Serratia strain against rice delphacid planthoppers.

BACKGROUND Delphacid planthoppers (Hemiptera: Delphacidae), including the brown planthopper (Nilaparvata lugens), pose a significant threat to global rice production, highlighting the urgent need for sustainable and effective biological control agents. Here, we isolated a virulent strain of Serratia nematodiphila named BPH1 from diseased N. lugens and characterized its insecticidal activity, genomic features, and virulence-associated phenotypes. RESULTS S. nematodiphila BPH1 exhibited median lethal concentrations (LC50) of 5.5 × 104 and 2.4 × 108 CFU/mL for N. lugens adults and nymphs, respectively. At a concentration of 108 CFU/mL, the median lethal time (LT50) was approximately 15 h for adults and 45 h for nymphs. Whole-genome sequencing revealed a 5.15 Mb draft genome assembly containing a complete prodigiosin biosynthetic gene cluster and multiple serralysin metalloprotease genes, representing candidate virulence-associated genomic features. The strain exhibited extracellular protease activity and swimming and swarming motility in vitro, which are commonly associated with bacterial entomopathogenicity. In insecticidal-spectrum assays, the strain caused mortality in two additional delphacid planthoppers, Laodelphax striatellus and Sogatella furcifera, and in the mosquito Aedes albopictus, whereas it showed no pathogenicity toward the green peach aphid Myzus persicae under the tested conditions. CONCLUSION These results reveal a virulent Serratia strain with strong insecticidal activity against rice planthoppers, and highlight genomic and phenotypic features potentially associated with pathogenicity. © 2026 Society of Chemical Industry.

Biocontrol mechanisms of a karstic cave-derived Streptomyces sp. GCAL-9 bioactive extract against Colletotrichum musae: insights into ergosterol pathway involvement and metabolomic profiling

Membrane fractionation and characterization of shiitake (Lentinula edodes) polysaccharides with in vitro antifungal activity against phytopathogens.

The shiitake mushroom (Lentinula edodes) is a rich source of bioactive polysaccharides with potential applications in sustainable agriculture, particularly as environmentally friendly alternatives to synthetic fungicides. This study aimed to employ membrane separation technology to streamline the recovery of polysaccharides from shiitake mushrooms and evaluate their antifungal activity against phytopathogens. Crude aqueous extracts and membrane-fractionated polysaccharides were tested in vitro against Colletotrichum gloeosporioides, Fusarium oxysporum, Macrophomina phaseolina, Rhizoctonia solani, and Sclerotinia sclerotiorum. The crude extract exhibited the strongest inhibition, with 13.0 ± 0.07% and 5.87 ± 0.03% growth reduction against R. solani and M. phaseolina, respectively. Membrane ultrafiltration successfully concentrated polysaccharides within a targeted molecular weight range, with glucose, rhamnose, and arabinose confirmed as dominant monosaccharides via HPLC. However, fractionation slightly reduced bioactivity compared to the crude extract. These findings demonstrate that shiitake-derived polysaccharides exhibit measurable in vitro antifungal activity and highlight their potential for further investigation as bioactive natural compounds. Furthermore, the results support the use of membrane separation technology as a sustainable strategy for the recovery and concentration of bioactive mushroom-derived polysaccharides.

A novel Aureobasidium pullulans isolate for the biological control of Penicillium commune in potato decay and its optimization for enhanced antifungal activity using the Taguchi method.

Penicillium commune is a significant postharvest fungal pathogen responsible for blue mold rot in stored potatoes, resulting in substantial economic losses worldwide. In this study, we isolated and characterized a novel epiphytic strain of Aureobasidium pullulans SBAN-IAUF-1 from potato foliage and evaluated its antagonistic activity against Penicillium commune SBAN-IAUF-12. The new isolate exhibited strong inhibitory effects, reducing pathogen growth by 60% in vitro and 69.41% in vivo, outperforming values reported for most previously studied A. pullulans strains. Extracellular antifungal metabolites produced by Aureobasidium pullulans SBAN-IAUF-1 also showed substantial antifungal activity, indicating that extracellular antifungal metabolites play a key role in antagonism. To further enhance extracellular antifungal metabolites activity, we applied a Taguchi L9 orthogonal design, which identified optimal culture conditions and significantly increased the extracellular antifungal metabolites activity. The optimal conditions suggested by L9 analysis for maximizing extracellular antifungal metabolites production were 20 °C, 7 days of incubation, pH 5, and 1% (wv- 1) YMB concentration. This study provides the first report of a potato-derived A. pullulans isolate optimized through Taguchi methodology for controlling Penicillium commune. The strong biocontrol activity of Aureobasidium pullulans SBAN-IAUF-1 highlights its potential as an environmentally safe and effective candidate for postharvest management of blue mold disease in potatoes.