Microbial detoxification of toxin and antifungal activity of several endophytic bacterial strains against Colletotrichum nymphaeae causal agent of strawberry anthracnose

Abstract Background The development of ecofriendly tools against plant diseases is an important issue in crop protection. Screening and selection process of bacterial strains antagonists of 2 pathogenic bacterial species that limit very important crops, Erwinia amylovora, the causal agent of the fire blight disease, and Pectobacterium carotovorum, the causal agent of bacterial potato soft rot, were reported. Bacterial colonies were isolated from different ecological niches, where both pathogens were found: rhizosphere of potato tubers and fruits and leaves of pear trees from the northwest region of Algeria. Direct and indirect confrontation tests against strains of E. amylovora and P. carotovorum were performed. Results Results showed a significant antagonistic activity against both phytopathogenic species, using direct confrontation method and supernatants of cultures (p<0.005). In vitro assays showed growth inhibitions of both phytopathogenic species. Furthermore, results revealed that the strains of S. plymuthica had a better inhibitory effect than the strains of P. fluorescens against both pathogens. In vivo results on immature pear fruits showed a significant decrease in the progression of the fire blight symptoms, with a variation in the infection index from one antagonistic strain to another between 31.3 and 50%, and slice of potato showed total inhibition of the pathogen (P. carotovorum) by the antagonistic strains of Serratia plymuthica (p<0.005). Conclusion This study highlighted that the effective bacteria did not show any infection signs towards plant tissue, and considered as a potential strategy to limit the fire blight and soft rot diseases.

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Antimicrobial and antioxidant potentials of non-cytotoxic extracts of corticolous lichens sampled in Armenia

AMB Express ◽

10.1186/s13568-021-01271-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Razmik Sargsyan ◽

Arsen Gasparyan ◽

Gohar Tadevosyan ◽

Hovik Panosyan

Keyword(s):

Antifungal Activity ◽

Methanol Extract ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Cytotoxic Activities ◽

Bacterial Strains ◽

Evernia Prunastri ◽

Wide Range ◽

Antibacterial And Antifungal ◽

Acetone Extracts

AbstractDue to wide range of secondary metabolites, lichens were used from antiquity as sources of colorants, perfumes and medicaments. This research focuses on exploring the antioxidant, antimicrobial and cytotoxic activities of methanol, ethanol, acetone extracts and aqueous infusions of corticolous lichens sampled from Armenia. Methanol, ethanol and acetone extracts from all tested lichens were active against Gram-positive bacterial strains. The most effective solvent to retrieve antimicrobial compounds was methanol. Aqueous infusions of tested lichens didn’t show any significant antibacterial and antifungal activity. The highest antimicrobial activity was observed for methanol extract of Ramalina sinensis. The minimum inhibitory concentration of methanol extract of Ramalina sinensis were 0.9–1.8 mg mL− 1. Pseudevernia furfuracea demonstrated antifungal activity (Ø 12 mm). Methanol extract of Parmelia sulcata demonstrated largest 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity (71 %). The cytotoxicity was measured on human HeLa (cervical carcinoma) cell lines using microculture tetrazolium test assay. The IC50 values estimated for methanol extracts of Peltigera praetextata, Evernia prunastri, Ramalina sinensis and Ramalina farinacea species in HeLa cell line were within 1.8–2.8 mg mL− 1 and considered as non-cytotoxic. Obtained results suggest that studied lichens can be prospective in biotechnologies as alternative sources of antimicrobial and antioxidant substances.

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Antimicrobial Activity of Cyclic-Monomeric and Dimeric Derivatives of the Snail-Derived Peptide Cm-p5 against Viral and Multidrug-Resistant Bacterial Strains

Biomolecules ◽

10.3390/biom11050745 ◽

2021 ◽

Vol 11 (5) ◽

pp. 745

Author(s):

Melaine González-García ◽

Fidel Morales-Vicente ◽

Erbio Díaz Pico ◽

Hilda Garay ◽

Daniel G. Rivera ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Antimicrobial Activity ◽

Antifungal Activity ◽

Multidrug Resistant ◽

Moderate Activity ◽

Dependent Manner ◽

Bacterial Strains ◽

Acinetobacter Baumanii ◽

Concentration Dependent Manner ◽

Conventional Antibiotics

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum β-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25–50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.

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Antifungal activity of Serratia marcescens CFFSUR-B2 purified chitinolytic enzymes and prodigiosin against Mycosphaerella fijiensis, causal agent of black Sigatoka in banana (Musa spp.)

BioControl ◽

10.1007/s10526-015-9655-6 ◽

2015 ◽

Vol 60 (4) ◽

pp. 565-572 ◽

Cited By ~ 11

Author(s):

Martha Ingrid Gutiérrez-Román ◽

Francisco Holguín-Meléndez ◽

Michael F. Dunn ◽

Karina Guillén-Navarro ◽

Graciela Huerta-Palacios

Keyword(s):

Antifungal Activity ◽

Serratia Marcescens ◽

Causal Agent ◽

Mycosphaerella Fijiensis ◽

Black Sigatoka ◽

Chitinolytic Enzymes ◽

Musa Spp

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Pyrrolnitrin Biosynthesis From Rhizospheric Serratia Spp. With Antifungal Activity and Binding Interactions of PrnF With Ligands

10.21203/rs.3.rs-56362/v1 ◽

2020 ◽

Author(s):

Shraddha P. Pawar ◽

Ambalal B. Chaudhari

Keyword(s):

Antifungal Activity ◽

Phytopathogenic Fungi ◽

Bacterial Strains ◽

Rrna Sequence ◽

16S Rrna Sequence ◽

Protein Model ◽

Stenotrophomonas Rhizophila ◽

K 12 ◽

Layer Chromatography

Abstract Pyrrolnitrin (PRN) from rhizobacteria displays a key role in biocontrol of phytopathogenic fungi in rhizospheric soil. Therefore, different rhizospheric soils were investigated for the prevalence of PRN producer in minimal salt (MS) medium containing tryptophan (0.2 M NaCl; pH 8) using three successive enrichments. Of 12% isolates, only five bacterial strains had shown PRN secretion, screened with Thin Layer Chromatography (Rf 0.8) and antifungal activity (27 mm) against phytopathogen. The phenetic and 16S rRNA sequence revealed the close affiliation of isolates (KMB, M-2, M-11, TW3, and TO2) to Stenotrophomonas rhizophila (KY800458), Enterobacter spp. (KY800455), Brevibacillus parabrevis (KY800454), Serratia marcescens (KY800456) and Serratia nemtodiphila (KY800457). Purified compound from isolates was characterised using UV, IR, HPLC, LCMS and GCMS as PRN. However, BLASTn hit of prn gene sequences from both Serratia species showed 99% similarity with NADPH dependent FMN reductase component (prnF). The homology protein model of prnF was developed from translated sequence of S. marcescens TW3 with chromate reductase of Escherichia coli K-12. Docking with FMN and NADPH was performed. The study demonstrated the possible role of prnF NADPH dependent FMN reductases in prnD for supply of reduced flavin in rhizobacterial strain of Serratia spp. which may pave a way to understand PRN production.

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In-vitro antifungal activity of several biorational fungicides againstCalonectria pseudonaviculata,the causal agent ofBuxus hyrcanablight

Forest Pathology ◽

10.1111/efp.12442 ◽

2018 ◽

Vol 48 (5) ◽

pp. e12442 ◽

Cited By ~ 2

Author(s):

Ali Yoldashkhan ◽

Samaneh Samavat ◽

Hamidreza Zamanizadeh

Keyword(s):

Antifungal Activity ◽

Causal Agent ◽

In Vitro Antifungal Activity

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Synthesis of Nʹ-Nicotinoyl Sulfonohydrazides and their Antimicrobial Activity

Journal of the chemical society of pakistan ◽

10.52568/000662 ◽

2020 ◽

Vol 42 (4) ◽

pp. 597-597

Author(s):

Zarina Arshad Zarina Arshad ◽

Sumayya Saied Sumayya Saied ◽

Basharat Ali Basharat Ali ◽

Uzma Salar Uzma Salar ◽

Saima Tauseef Saima Tauseef ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antifungal Activity ◽

Aspergillus Niger ◽

Candida Tropicalis ◽

Microsporum Canis ◽

Moderate Activity ◽

Bacterial Strains ◽

Weak Zone ◽

Paratyphi B ◽

Rhizopus Sp

Nʹ-Nicotinoyl sulfonohydrazide derivatives 3-13 were synthesized from nicotinyl hydrazide and evaluated for their antimicrobial potential against Gram positive bacterial strains (Bacillus cereus, Bacillus subtilis, Corynebacterium diphtheriae, Staphylococcus fecalis, Staphylococcus aureus, and MRSA (Methicillin-resistant Staphylococcus aureus)) and Gram negative bacterial strains (Escherichia.coli, Pseudomonas aeruginosa, Salmonella ParatyphiB, Salmonella tyhpi). Compound 13 showed outstanding antibacterial activity against Staphylococcus fecalis and compounds 7 and 13 were found to be moderately activite against Salmonella Paratyphi B, shown by their zone of inhibition values. In addition to that compond 9 also showed moderate activity against Escherichia coli. All derivatives 3-13 were also subjected for the evaluation of their antifungal activity against Saccharomyces cerevisiae, Microsporum canin, Rhizopus, Aspergillus niger, Candida albicans, and Candida tropicalis. Compound 13 showed promising antifungal activity against Rhizopus sp. and compounds 9 and 10 showed moderate antifungal potential against Microsporum canis, Aspergillus niger, and Candida tropicalis. Other molecules demonstrated weak zone of inhibitions.

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