Search Results (7)

Phytopathogenic fungi and bacteria pose a serious threat to global agriculture, leading to significant economic losses and potential health risks. Consequently, the search for natural alternatives to synthetic agrochemicals has garnered increasing scientific attention, with plant extracts emerging as promising environmentally friendly solutions. In this context, the surface extract of Salvia discolor, obtained using dichloromethane, was analyzed for its bioactive potential. Chemical profiling revealed a rich composition of terpenoids and flavonoids. The antimicrobial potential of the ground extract was evaluated against nine phytopathogenic fungi (Alternaria solani, Botrytis cinerea, Colletotrichum lindemuthianum, Fusarium solani, Fusarium oxysporum f. sp. lactucae race 1, Phoma betae, Phaeomoniella chlamydospora, Pythium dissotocum, and Stemphylium sp.), and two phytopathogenic bacteria (Clavibacter michiganesis subsp. michiganesis and Pectobacterium carotovorum subsp. carotovorum), selected from common pathogens of agricultural interest. Complete inhibition of P. chlamydospora at 1000 µg mL⁻¹ and strong activity against P. dissotocum, F. solani and B. cinerea was observed, and low inhibition (<40%) against C. lindemuthianum and F. oxysporum f. sp. lactucae race 1. However, the extract showed promising results in the post-harvest protection of tomatoes against gray mold. Moderate antibacterial activity was seen against C. michiganensis subsp. michiganensis. These findings indicate that S. discolor extract has the potential to serve as an effective natural crop protection agent, though further optimization may be needed for broader application. Full article

Cyanobacteria are gaining significant importance as potential biocontrol agents against phytopathogenic fungi. We evaluated the inhibitory effects of a suspension of Nostoc sp. BCAC 1226 on Penicillium sp., Phytophthora sp., and Stemphylium sp. in vitro using potato dextrose agar medium. On the 7th day of incubation, Phytophthora sp. showed a reduction in colony area from 18.30 ± 1.68 to 8.55 ± 0.74 cm² (53.6% inhibition). Similarly, Penicillium sp. showed a reduction from 17.64 ± 1.46 to 8.90 ± 0.36 cm² (49.4% inhibition), and Stemphylium sp. showed a reduction from 17.76 ± 1.28 to 13.5 ± 0.73 cm² (23.7% inhibition). The inhibitory effects were more significant on the 14th day, with the growth of Phytophthora sp. further reduced to 4.9 ± 0.40 cm² (72.8% inhibition), Penicillium sp. to 5.54 ± 0.32 cm² (68.8% inhibition), and Stemphylium sp. to 8.71 ± 0.31 cm² (50.8% inhibition). These results indicate the potential antifungal activity of Nostoc sp. suspension, with the highest reduction observed in Phytophthora sp., followed by Penicillium sp. and Stemphylium sp. Future research should focus on the chemical characterization of the antifungal metabolites produced by Nostoc sp. BCAC 1226 and in vivo evaluations on economically important crops to evaluate their practical efficiency under field conditions. Full article

Humulus lupulus L. (hop) is a crucial crop within the brewing industry and a rich source of bioactive compounds. Traditionally concentrated in northeast regions of Europe, hop cultivation has expanded towards southern territories such as Italy over recent decades. Managing phytosanitary threats in Mediterranean climates poses challenges due to limited knowledge and registered agrochemicals. In pursuit of eco-friendly alternatives for disease management, we isolated 262 endophytic fungal strains from wild hop roots, stems, leaves, and flowers. Through phylogenetic analyses, we identified 51 operational taxonomic units. Dominant species such as Ilyonectria macrodidyma, Penicillium sp., Diaporthe columnaris, Plectosphaerella cucumerina, and Fusarium oxysporum were exclusive to roots. In contrast, Alternaria spp. and Epicoccum spp. were prevalent in other tissues, and Botrytis cinerea was exclusively detected in female flowers. We tested seven isolates—Epicoccum sp., Aureobasidium pullulans, Plectosphaerella cucumerina, Stemphylium vesicarium, Periconia byssoides, Talaromyces wortmannii, and Nigrospora sphaerica—against the four phytopathogenic fungi Alternaria sp., Fusarium oxysporum, Botrytis cinerea, and Sclerotinia sclerotiorum. All endophytes exhibited antagonistic effects against at least one pathogen, with Plectosphaerella cucumerina showing the strongest inhibition against Alternaria sp. This study marks the first exploration of endophytic fungi from various hop tissues. All isolated strains were ex situ conserved for future bioactivity assessments and biotechnological applications. Original data with a key relevance for the environmentally friendly management of plant diseases are provided. Full article

The Gulf of Mexico (GoM) is an important source of oil for the United States and Mexico. There has been growing interest, particularly after the Deepwater Horizon oil spill, in characterizing the fungal diversity of the GoM and identifying isolates for use in the bioremediation of petroleum in the event of another spill. Most studies have focused on light crude oil bioremediation processes, while heavy crude oil (HCO) and extra-heavy crude oil (EHCO) have been largely ignored. In this work, we evaluated the ability of fungal isolates obtained from deep-sea sediments of the Mexican economic exclusive zone (EEZ) of the GoM to degrade HCO (16–20° API) and EHCO (7–10° API). Alternaria sp., Penicillium spp., and Stemphylium sp. grew with HCO as the sole carbon source. Remarkably, Alternaria sp. was the only isolate able to grow with EHCO as the sole carbon source, degrading up to 25.6% of the total EHCO and 91.3% of the aromatic fraction, as demonstrated by gas chromatography analysis of the saturate, aromatic, and polar fractions. These findings proved to be significant, identifying Alternaria sp. as one of the few fungi reported so far capable of degrading untreated EHCO and as a suitable candidate for bioremediation of EHCO in future studies. Full article

Three new bianthraquinones, alterporriol Z1–Z3 (1–3), along with three known compounds of the same structural class, were isolated from the culture broth of a marine-derived Stemphylium sp. fungus. Based upon the results of spectroscopic analyses and ECD measurements, the structures of new compounds were determined to be the 6-6′- (1 and 2) and 1-5′- (3) C–C connected pseudo-dimeric anthraquinones, respectively. Three new meroterpenoids, tricycloalterfurenes E–G (7–9), isolated together with the bianthraquinones from the same fungal culture broth, were structurally elucidated by combined spectroscopic methods. The relative and absolute configurations of these meroterpenoids were determined by modified Mosher’s, phenylglycine methyl ester (PGME), and computational methods. The bianthraquinones significantly inhibited nitric oxide (NO) production and suppressed inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in LPS-stimulated RAW 264.7 cells. Full article

In this study, two Burkholderia strains, strain KNU17BI2 and strain KNU17BI3, were isolated from maize rhizospheric soil, South Korea. The 16S rRNA gene and multilocus sequence analysis and typing (MLSA-MLST) were used for the identification of the studied strains. Strain KNU17BI2, which belonged to Burkholderia cenocepacia, was of a novel sequence type (ST) designated ST-1538, while strain KNU17BI3 had a similar allelic profile with the seven loci of Burkholderia contaminans strain LMG 23361. The strains were evaluated in vitro for their specific plant growth promoting (PGP) traits, such as zinc solubilization, phosphate solubilization, ammonia production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, indole acetic acid (IAA) production, siderophore, and hydrolytic enzyme activity. Interestingly, the strains exhibited a positive effect on all of the tested parameters. The strains also showed broad-spectrum antifungal activity against economically important phytopathogens in the dual culture assay. Furthermore, the strains were evaluated under greenhouse conditions for their in vivo effect to promote plant growth and to suppress the root rot of maize that is caused by Fusarium temperatum on four Korean maize cultivars. The results of the greenhouse study revealed that both of the strains were promising to significantly suppress fusarium root rot and enhance plant growth promotion on the four maize cultivars. This study, for the first time, reported in vitro antifungal potential of B. cenocepacia of novel ST against economically important plant pathogens viz., F. temperatum, Fusarium graminearum, Fusarium moniliforme, Fusarium oxysporum f.sp. melonis, Fusarium subglutinans, Phytophthora drechsleri, and Stemphylium lycopersici. This is also the first report of zinc solubilization by B. cenocepacia. Moreover, the present research work reports, for the first time, about the potential of B. cenocepacia and B. contaminans to control the root rot of maize that is caused by F. temperatum. Therefore, we recommend further studies to precisely identify the bioactive chemical compounds behind such activities that would be novel sources of natural products for biological control and plant growth promotion of different crops. Full article

In order to investigate the biological activity of novel 1,2,4-triazole compounds, seventeen novel 1,2,4-triazole derivatives containing pyridine moiety were synthesized under microwave assistant condition by multi-step reactions. The structures were characterized by ¹H NMR, MS and elemental analyses. The target compounds were evaluated for their fungicidal activities against Stemphylium lycopersici (Enjoji) Yamamoto, Fusarium oxysporum. sp. cucumebrium, and Botrytis cinerea in vivo, and the results indicated that some of the title compounds displayed excellent fungicidal activities. Theoretical calculation of the title compound was carried out with B3LYP/6-31G (d,p). The full geometry optimization was carried out using 6-31G (d,p) basis set, and the frontier orbital energy, atomic net charges were discussed, and the structure-activity relationship was also studied. Full article