Antifungal activity and identification of active compounds of Bacillus amyloliquefaciens subsp. plantarum against Botryosphaeria dothidea

2016 ◽  
Vol 46 (6) ◽  
pp. 561-568 ◽  
Author(s):  
M. Cheng ◽  
Q. Xu ◽  
Y. Li ◽  
H. Qin ◽  
J. Chen
2020 ◽  
Vol 77 (1) ◽  
pp. 425-431
Author(s):  
Hong Jiang ◽  
Yuxin Rao ◽  
Li Mei ◽  
Yongjun Wang

2020 ◽  
Vol 110 (2) ◽  
pp. 317-326 ◽  
Author(s):  
Ayaz Farzand ◽  
Anam Moosa ◽  
Muhammad Zubair ◽  
Abdur Rashid Khan ◽  
Muhammad Ayaz ◽  
...  

Sclerotinia sclerotiorum is a devastating necrotrophic pathogen that infects multiple crops, and its control is an unremitting challenge. In this work, we attempted to gain insights into the pivotal role of lipopeptides (LPs) in the antifungal activity of Bacillus amyloliquefaciens EZ1509. In a comparative study involving five Bacillus strains, B. amyloliquefaciens EZ1509 harboring four LPs biosynthetic genes (viz. surfactin, iturin, fengycin, and bacilysin) exhibited promising antifungal activity against S. sclerotiorum in a dual-culture assay. Our data demonstrated a remarkable upsurge in LPs biosynthetic gene expression through quantitative reverse transcription PCR during in vitro interaction assay with S. sclerotiorum. Maximum upregulation in LPs biosynthetic genes was observed on the second and third days of in vitro interaction, with iturin and fengycin being the highly expressed genes. Subsequently, Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry analysis confirmed the presence of LPs in the inhibition zone. Scanning electron microscope analysis showed disintegration, shrinkage, plasmolysis, and breakdown of fungal hyphae. During in planta evaluation, S. sclerotiorum previously challenged with EZ1509 showed significant suppression in pathogenicity on detached leaves of tobacco and rapeseed. The oxalic acid synthesis was also significantly reduced in S. sclerotiorum previously confronted with antagonistic bacterium. The expression of major virulence genes of S. sclerotiorum, including endopolygalacturonase-3, oxalic acid hydrolase, and endopolygalacturonase-6, was significantly downregulated during in vitro confrontation with EZ1509.


2020 ◽  
Vol 13 (9) ◽  
pp. 229
Author(s):  
Volodymyr Horishny ◽  
Victor Kartsev ◽  
Vasyl Matiychuk ◽  
Athina Geronikaki ◽  
Petrou Anthi ◽  
...  

Herein we report the design, synthesis, computational, and experimental evaluation of the antimicrobial activity of fourteen new 3-amino-5-(indol-3-yl) methylene-4-oxo-2-thioxothiazolidine derivatives. The structures were designed, and their antimicrobial activity and toxicity were predicted in silico. All synthesized compounds exhibited antibacterial activity against eight Gram-positive and Gram-negative bacteria. Their activity exceeded those of ampicillin and (for the majority of compounds) streptomycin. The most sensitive bacterium was S. aureus (American Type Culture Collection ATCC 6538), while L. monocytogenes (NCTC 7973) was the most resistant. The best antibacterial activity was observed for compound 5d (Z)-N-(5-((1H-indol-3-yl)methylene)-4-oxo-2-thioxothiazolidin-3-yl)-4-hydroxybenzamide (Minimal inhibitory concentration, MIC at 37.9–113.8 μM, and Minimal bactericidal concentration MBC at 57.8–118.3 μM). Three most active compounds 5d, 5g, and 5k being evaluated against three resistant strains, Methicillin resistant Staphilococcus aureus (MRSA), P. aeruginosa, and E. coli, were more potent against MRSA than ampicillin (MIC at 248–372 μM, MBC at 372–1240 μM). At the same time, streptomycin (MIC at 43–172 μM, MBC at 86–344 μM) did not show bactericidal activity at all. The compound 5d was also more active than ampicillin towards resistant P. aeruginosa strain. Antifungal activity of all compounds exceeded those of the reference antifungal agents bifonazole (MIC at 480–640 μM, and MFC at 640–800 μM) and ketoconazole (MIC 285–475 μM and MFC 380–950 μM). The best activity was exhibited by compound 5g. The most sensitive fungal was T. viride (IAM 5061), while A. fumigatus (human isolate) was the most resistant. Low cytotoxicity against HEK-293 human embryonic kidney cell line and reasonable selectivity indices were shown for the most active compounds 5d, 5g, 5k, 7c using thiazolyl blue tetrazolium bromide MTT assay. The docking studies indicated a probable involvement of E. coli Mur B inhibition in the antibacterial action, while CYP51 inhibition is likely responsible for the antifungal activity of the tested compounds.


Molecules ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 191 ◽  
Author(s):  
Ahmet Çağrı Karaburun ◽  
Betül Kaya Çavuşoğlu ◽  
Ulviye Acar Çevik ◽  
Derya Osmaniye ◽  
Begüm Nurpelin Sağlık ◽  
...  

Discovery of novel anticandidal agents with clarified mechanisms of action, could be a rationalist approach against diverse pathogenic fungal strains due to the rise of resistance to existing drugs. In support to this hypothesis, in this paper, a series of benzimidazole-oxadiazole compounds were synthesized and subjected to antifungal activity evaluation. In vitro activity assays indicated that some of the compounds exhibited moderate to potent antifungal activities against tested Candida species when compared positive control amphotericin B and ketoconazole. The most active compounds 4h and 4p were evaluated in terms of inhibitory activity upon ergosterol biosynthesis by an LC-MS-MS method and it was determined that they inhibited ergosterol synthesis concentration dependently. Docking studies examining interactions between most active compounds and lanosterol 14-α-demethylase also supported the in vitro results.


2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Lorenzo Botta ◽  
Raffaele Saladino ◽  
Paolo Barghini ◽  
Massimiliano Fenice ◽  
Marcella Pasqualetti

Abstract Background Marine fungi are an important repository of bioactive molecules with great potential in different technological fields, the annual number of new compounds isolated from marine fungi is impressive and the general trend indicates that it is still on the rise. In this context, the antifungal and antimicrobial activity of the marine strain Mariannaea humicola IG100 was evaluated and two active terpenoids were isolated and characterized. Methods Preliminary screening of activity of marine strain IG100 was carried out by agar plug diffusion methods against fungal (Penicillium griseofulvum TSF04) and bacterial (Bacillus pumilus KB66 and Escherichia coli JM109) strains. Subsequently, inhibition tests were done by using the cultural broth and the organic extract (ethyl acetate, EtOAc) by the agar well diffusion methods. The main active fractions were identified and tested for their antifungal activity against P. griseofulvum TSF04 in a 24 wells microplate at different concentrations (1000, 100, 10 and 1.0 µg/mL). Two active compounds were characterized and their relative MIC measured by the broth micro-dilution methods in a 96-well microplate against Aspergillus flavus IG133, P. griseofulvum TSF04, and Trichoderma pleuroticola IG137. Results Marine strain IG100 presented significant antifungal activity associated with two active compounds, the terpenoids terperstacin 1 and 19-acetyl-4-hydroxydictyodiol 2. Their MIC values were measured for A. flavus (MIC of 7.9 µg/mL and 31.3 µg/mL for 1 and 2, respectively), P. griseofulvum (MIC of 25 µg/mL and 100 µg/mL for 1 and 2, respectively) and T. pleuroticola (MIC > 500 µg/mL and 125 µg/mL for 1 and 2, respectively). They showed a rather good fungistatic effect. Conclusions In this study, the first marine strain of M. humicola (IG100) was investigated for the production of bioactive molecules. Strain IG100 produced significant amounts of two bioactive terpenoids, terperstacin 1 and 19-acetyl-4-hydroxydictyodiol 2. The two compounds showed significant antifungal activities against A. flavus IG133, T. pleuroticola IG137 and P. griseofulvum TSF04. Compound 2 was identified for the first time in fungi.


2017 ◽  
Vol 2 (3) ◽  
pp. 9-21
Author(s):  
Musa T. Abidov

Intense search for new antimicrobials, including anti-tuberculosis drugs, is dictated by the phenomenon of bacterial multidrug resistance. Hydrazides are considered the key intermediate and valuable starting material for some novel biologically active compounds. Over 70% of recently reported synthetic hydrazide derivatives are evaluated for antimicrobial and/or antifungal activity. The most frequently applied hydrazide is an anti- tuberculosis drug isoniazid/isonicotinic acid hydrazide (NIH). Hydrazide chemicals are sharing a common functional group characterized by a nitrogen- to-nitrogen covalent bond with four substituents with at least one of them being an acyl group, whereas the related hydrazines do not carry an acyl group. Hydrazides can be further classified by atom attached to the oxygen: carbohydrazides, sulfonohydrazides, phosphonic dihydrazides, hydrazone-hydrazides and phthalhydrazides. In addition to their antibacterial and antifungal activities, hydrazide derivatives have recently attracted continuing interest because of their anti-inflammatory properties. A phthalhydrazide derivative tamerit/galavit has been successfully introduced for human therapies.


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