Antifungal activity of bacterial strains from maize silks against Fusarium verticillioides

2021 ◽  
Vol 204 (1) ◽  
Author(s):  
Gisele de Fátima Dias Diniz ◽  
Luciano Viana Cota ◽  
José Edson Fontes Figueiredo ◽  
Frederick Mendes Aguiar ◽  
Dagma Dionísia da Silva ◽  
...  
2021 ◽  
Author(s):  
Gisele de Fátima Dias Diniz ◽  
Luciano Viana Cota ◽  
José Edson Fontes Figueiredo ◽  
Frederick Mendes Aguiar ◽  
Dagma Dionisia da Silva ◽  
...  

Abstract Fusarium verticillioides is pathogenic to maize and mycotoxin-producer, causing yield losses, feed and food contamination, and risks to human and animal health. Endophytic (ISD04 and IPR45) and epiphytic (CT02 and IM14) bacteria from maize silks were tested in vitro and greenhouse against F. verticillioides and for hydrolytic enzyme production (cellulase, pectinase, protease, lipase, and chitinase). The strains were assigned as Achromobacter xylosoxidans (ISD04), Pseudomonas aeruginosa (IPR45), and Bacillus velezensis (CT02 and IM14) by 16S gene sequencing. All strains showed antifungal activity in vitro with inhibition values from 58.5–100%; they changed hyphae morphology and inhibited the conidial germination by up to 100% (IPR45). The four strains produced at least one enzyme with antifungal activity. The microbiolized seeds reduced the fungal development in stored grains and stalk rot severity in the greenhouse by 72.6% (ISD04). These results highlight the potential of these strains as biocontrol agents against F. verticillioides


AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Razmik Sargsyan ◽  
Arsen Gasparyan ◽  
Gohar Tadevosyan ◽  
Hovik Panosyan

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.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 745
Author(s):  
Melaine González-García ◽  
Fidel Morales-Vicente ◽  
Erbio Díaz Pico ◽  
Hilda Garay ◽  
Daniel G. Rivera ◽  
...  

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.


2014 ◽  
Vol 38 (6) ◽  
pp. 531-537 ◽  
Author(s):  
Rojane de Oliveira Paiva ◽  
Lucimar Ferreira Kneipp ◽  
Carla Marins Goular ◽  
Mariana Almeida Albuquerque ◽  
Aurea Echevarria

Mycotoxigenic fungi can compromise the quality of food, exposing human and animal health at risk. The antifungal activity of eight thiosemicarbazones (1-8) and nine semicarbazones (9-17) was evaluated against Aspergillus flavus, A. nomius, A. ochraceus, A. parasiticus and Fusarium verticillioides. Thiosemicarbazones had MIC values of 125-500 µg/ml. The thiosemicarbazones 1 and 2 exerted fungistatic activity against Aspergillus spp., and thiosemicarbazone 2 exerted fungicidal activity against F. verticillioides. Compound 2 showed an iron chelating effect of 63%. The ergosterol content of A. parasiticus had a decrease of 28 and 71% for the 31.2 and 62.5 µg/ml concentrations of thiosemicarbazone 2 compared to the control. The obtained results of antifungal activity revealed that thiosemicarbazone class was more active when compared to semicarbazone class and, the thiosemicarbazone 2 was the most active compound, specially, against Aspergillus spp.


2020 ◽  
Author(s):  
Shraddha P. Pawar ◽  
Ambalal B. Chaudhari

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.


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 ◽  
...  

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.


Author(s):  
Haribhai Rabari ◽  
Hetal Vankar ◽  
Beenkumar Prajapati

The emergence of multidrug microbial resistance is the main challenges that the modern scientists have so far been facing in the recent era. In this respect, new series of drug classes having potential to give antimicrobial effect have been synthesized. A new series of 5- substituted-1,10 b-dihydroimidazole[1,2-c]quinazoline derivatives 8a-e have been synthesized and screened for antibacterial activity and antifungal activity. Synthesized derivatives were characterized by IR, MASS and 1H-NMR spectroscopy. Synthesized compounds show good activity, which was comparable to the standard drug and it can be useful for the further clinical study. Antibacterial activity was evaluated against four different pathogenic bacterial strains like Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudo-monas aeruginosa. Among the screened compounds, 8e show good antibacterial activity against Staphylococcus aureus and Escherichia coli with MIC of 50 and 100 μg/ml respectively. Antifungal activity was evaluated  against two strains of fungi. Among the synthesized derivates, compound 8c was emerged out as the potent antifungal compound against Candida albicans and Aspergillus niger with MIC of 25 μg/ml and 75μg/ml respectively. Compound 8e also shows good antifungal activity with MIC of 50 μg/ml against both Candida albicans and Aspergillus niger. The overall results of this study indicated that  synthesized quinazoline derivatives had the potential to act as an antibacterial and antifungal agent, hence further investigation is warranted.


2002 ◽  
Vol 8 (5) ◽  
pp. 269-274 ◽  
Author(s):  
V. Zelenák ◽  
K. Györyová ◽  
D. Mlynarcík

The antibacterial and antifungal activity of zinc(II) carboxylates with composition Zn(RCOO)2•nH2O(R =H-, CH3− , CH3CH2CH2- , (CH3)2CH- , XCH2- , X=Cl, Br, I, n=0 or 2), [ZnX2(Nia+CH2COO-)2] (Nia=nicotinamide, X=Cl, Br, I) and [Zn(XCH2COO)2(Caf)2]•2H2O (Car=caffeine, X=Cl, Br) is studied against bacterial strains Staphylococcus aureus, Escherichia coli and yeast Candida albicans. The structural types are assigned to the prepared compounds and the influence of (i) carboxylate chain length, (ii) substitution of hydrogen atom of carboxylate by halogen and (iii) presence of N-donor organic ligands on the biological activity is discussed.


Microbiology ◽  
2014 ◽  
Vol 160 (9) ◽  
pp. 2089-2101 ◽  
Author(s):  
Anscha M. Troskie ◽  
Abré de Beer ◽  
Johan A. Vosloo ◽  
Karin Jacobs ◽  
Marina Rautenbach

The tyrocidines, a complex of analogous cyclic decapeptides produced by Bacillus aneurinolyticus, exhibited noteworthy activity against a range of phytopathogenic fungi, including Fusarium verticillioides, Fusarium solani and Botrytis cinerea. The activity of the tyrocidine peptide complex (Trc mixture) and purified tyrocidines exhibited minimum inhibition concentrations below 13 µg ml−1 (~10 µM) and was significantly more potent than that of the commercial imidazole fungicide, bifonazole. Although the tyrocidines’ activity was negatively influenced by the presence of Ca2+, it remained unaffected by the presence of Mg2+, Na+ and K+. Microscopic analysis revealed significant impact on the morphology of F. solani and Bot. cinerea including retarded germination and hyperbranching of hyphae. Studies with membrane-impermeable dyes, SYTOX green and propidium iodide suggested that the main mode of action of tyrocidines involves the disruption of fungal membrane integrity. Because of the tyrocidines’ broad spectrum and potent antifungal activity, possible multiple targets reducing the risk of overt resistance and general salt tolerance, they are promising candidates that warrant further investigation as bio-fungicides.


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