Isobenzofuranones and isocoumarins from kiwi endophytic fungus Paraphaeosphaeria sporulosa and their antibacterial activity against Pseudomonas syringae pv. actinidiae

2022 ◽  
Vol 195 ◽  
pp. 113050
Author(s):  
Qiong Chen ◽  
Jun-Jie Yu ◽  
Juan He ◽  
Tao Feng ◽  
Ji-Kai Liu
Keyword(s):  
Antibacterial Activity ◽  
Pseudomonas Syringae ◽  
Endophytic Fungus

scholarly journals 3-Decalinoyltetramic acids from kiwi-associated fungus Zopfiella sp. and their antibacterial activity against Pseudomonas syringae

RSC Advances ◽  
2021 ◽  
Vol 11 (31) ◽  
pp. 18827-18831
Author(s):  
Xue-Wen Yi ◽  
Juan He ◽  
Li-Tang Sun ◽  
Ji-Kai Liu ◽  
Guo-Kai Wang ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pseudomonas Syringae

Four rare 3-decalinoyltetramic acid derivatives, zofielliamides A–D (1–4), were obtained from cultures of kiwi-associated fungus Zopfiella sp.

Optimization of cultural conditions affecting improved bioactive metabolite production by endophytic fungus Trichoderma harzianum

Bionatura ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 2187-2192
Author(s):  
Rashid Rahim Hateet ◽  
Zainab Alag Hassan ◽  
Abdulameer Abdullah Al-Mussawi ◽  
Shaima Rabeea Banoon
Keyword(s):  
Antibacterial Activity ◽  
Trichoderma Harzianum ◽  
Endophytic Fungus ◽  
Nitrogen Sources ◽  
Bioactive Metabolites ◽  
Bioactive Metabolite ◽  
Metabolite Production ◽  
Surface Sterilization ◽  
Cultural Conditions

The present study aimed to optimize cultural conditions for optimum bioactive metabolite production by endophytic fungus Trichoderma harzianum, isolated by surface sterilization method from the leaf of the eucalyptus plant. The fungus was identified based on morphological characterization. Fungal metabolites were carried out by ethyl acetate solvent. The antibacterial activity was tested against Escherichia coli (ATCC 25922) and Staphylococcus aureus (NCTC 6571). Various carbon, nitrogen sources, pH, temperature, incubation period, and NaCl on the antibacterial metabolite production were studied. Bioactive metabolite production of T. harzianum exhibits a broad spectrum of in vitro antibacterial activity against two strains of bacteria. For the optimum production of bioactive metabolites, Dextrose and Glucose were found to be the best sources of carbon and the best sources of Nitrogen Yeast extract (YE) and (NH4)2SO. The maximum production of bioactive metabolites occurs at pH 7 and 25°C.; the NaCl showed a positive influence on bioactive metabolites.

scholarly journals Plant defensin antibacterial mode of action against Pseudomonas species

2020 ◽  
Author(s):  
Andrew Edward Sathoff ◽  
Shawn Lewenza ◽  
Deborah A. Samac
Keyword(s):  
Gene Expression ◽  
Antibacterial Activity ◽  
Outer Membrane ◽  
Pseudomonas Syringae ◽  
Mode Of Action ◽  
Fluorescent Microscopy ◽  
Insertion Site ◽  
Membrane Damage ◽  
Plant Defensin ◽  
Plant Defensins

Abstract Background: Though many plant defensins exhibit antibacterial activity, little is known about their antibacterial mode of action (MOA). Antimicrobial peptides with a characterized MOA induce the expression of multiple bacterial outer membrane modifications, which are required for resistance to these membrane-targeting peptides. Mini-Tn5-lux mutant strains of Pseudomonas aeruginosa with Tn insertions disrupting outer membrane protective modifications were assessed for sensitivity against plant defensin peptides. These transcriptional lux reporter strains were also evaluated for lux gene expression in response to sublethal plant defensin exposure. Also, a plant pathogen, Pseudomonas syringae pv. syringae was modified through transposon mutagenesis to create mutants that are resistant to in vitro MtDef4 treatments.Results: Plant defensins displayed specific and potent antibacterial activity against strains of P. aeruginosa. A defensin from Medicago truncatula, MtDef4, induced dose-dependent gene expression of the aminoarabinose modification of LPS and surface polycation spermidine production operons. The ability for MtDef4 to damage bacterial outer membranes was also verified visually through fluorescent microscopy. Another defensin from M. truncatula, MtDef5, failed to induce lux gene expression and limited outer membrane damage was detected with fluorescent microscopy. The transposon insertion site on MtDef4 resistant P. syringae pv. syringae mutants was sequenced, and modifications of ribosomal genes were identified to contribute to enhanced resistance to plant defensin treatments. Conclusions: MtDef4 damages the outer membrane similar to polymyxin B, which stimulates antimicrobial peptide resistance mechanisms to plant defensins. MtDef5, appears to have a different antibacterial MOA. Additionally, the MtDef4 antibacterial mode of action may also involve inhibition of translation.

scholarly journals Antibacterial and Antioxidant Activities of Slender Amaranth Weed

2020 ◽  
Vol 38 ◽  
Author(s):  
M. AKBAR ◽  
I.N. SHERAZI ◽  
M.S. IQBAL ◽  
T. KHALIL ◽  
H.M. WAQAS
Keyword(s):  
Antioxidant Activity ◽  
Antibacterial Activity ◽  
Ethyl Acetate ◽  
Pseudomonas Syringae ◽  
Antioxidant Activities ◽  
Biological Activities ◽  
Radical Scavenging Activity ◽  
Bacterial Species ◽  
Radical Scavenging ◽  
Root Extract

ABSTRACT: In the present study, antibacterial and antioxidant [1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity] activities of a weed, slender amaranth (Amaranthus viridis L.) were investigated. Extracts of different plant parts were prepared in n-hexane, chloroform and ethyl acetate. Antibacterial activity was measured by using 100 mg mL-1 concentration extracts against 4 deadly phytopathogenic bacterial species viz. Pseudomonas syringae Van Hall, Ralstonia solanacearum Smith, Erwinia carotovora (Jones), Holland and Xanthomonas axonopodis Hasse. In antioxidants assays, 10, 20 and 30 mg mL-1 extracts were used keeping DPPH as control. In these bioassays, ethyl acetate fraction of A. viridis leaf exhibited the best antibacterial and antioxidants activity. Ethyl acetate leaf fraction showed the highest inhibition zone diameter (IZD) where it caused 21 mm IZD against P. syringae and 19 mm IZD against E. carotovora. This extract also showed 22, 52 and 84% antioxidant activity at 10, 20 and 30 mg mL-1 concentrations, respectively. Previously there is no report available that describes antibacterial activity of root extract of A. viridis against P. syringae. Moreover, antioxidant activity of stem and root extracts in n-hexane, chloroform and ethyl acetate was investigated first time in the world. It was concluded that the biological activities observed during the present investigation may be due to the presence of bioactive constituents that can be harnessed as natural antibacterials and antioxidants.

scholarly journals Effectiveness of Dunaliella salina Extracts against Bacillus subtilis and Bacterial Plant Pathogens

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 613
Author(s):  
Alfredo Ambrico ◽  
Mario Trupo ◽  
Rosaria Magarelli ◽  
Roberto Balducchi ◽  
Angelo Ferraro ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Pseudomonas Syringae ◽  
Dunaliella Salina ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Economic Losses ◽  
Tomato Plants ◽  
Hexane Extracts

Several bacteria pathogens are responsible for plant diseases causing significant economic losses. The antibacterial activity of Dunaliella salina microalgae extracts were investigated in vitro and in vivo. First, biomass composition was chemically characterized and subjected to extraction using polar/non-polar solvents. The highest extraction yield was obtained using chloroform:methanol (1:1 v/v) equal to 170 mg g−1 followed by ethanol (88 mg g−1) and hexane (61 mg g−1). In vitro examination of hexane extracts of Dunaliella salina demonstrated antibacterial activity against all tested bacteria. The hexane extract showed the highest amount of β-carotene with respect to the others, so it was selected for subsequent analyses. In vivo studies were also carried out using hexane extracts of D. salina against Pseudomonas syringae pv. tomato and Pectobacterium carotovorum subsp. carotovorum on young tomato plants and fruits of tomato and zucchini, respectively. The treated young tomato plants exhibited a reduction of 65.7% incidence and 77.0% severity of bacterial speck spot disease. Similarly, a reduction of soft rot symptoms was observed in treated tomato and zucchini fruits with a disease incidence of 5.3% and 12.6% with respect to 90.6% and 100%, respectively, for the positive control.

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