scholarly journals Biocontrol Ability and Mechanism of a Broad-Spectrum Antifungal Strain Bacillus safensis sp. QN1NO-4 Against Strawberry Anthracnose Caused by Colletotrichum fragariae

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaojuan Li ◽  
Miaoyi Zhang ◽  
Dengfeng Qi ◽  
Dengbo Zhou ◽  
Chunlin Qi ◽  
...  

Strawberry is a very popular fruit with a special taste, color, and nutritional value. Anthracnose caused by Colletotrichum fragariae severely limits fruit shelf life during post-harvest storage. Use of traditional chemical fungicides leads to serious environment pollution and threatens food safety. Biocontrol is considered as a promising strategy to manage the post-harvest fruit diseases. Here, strain QN1NO-4 isolated from noni (Morinda citrifolia L.) fruit exhibited a high antifungal activity against C. fragariae. Based on its physicochemical profiles and phylogenetic tree of the 16S rRNA sequence, strain QN1NO-4 belonged to the genus Bacillus. The average nucleotide identity (ANI) calculated by comparing two standard strain genomes was below 95–96%, suggesting that the strain might be a novel species of the genus Bacillus and named as Bacillus safensis sp. QN1NO-4. Its extract effectively reduced the incidence of strawberry anthracnose of harvested fruit. Fruit weight and TSS contents were also maintained significantly. The antifungal mechanism assays indicated that the extract of the test antagonist inhibited mycelial growth and spore germination of C. fragariae in vitro. Cells of strain QN1NO-4 demonstrated the cytoplasmic heterogeneity, disappeared organelles, and ruptured ultrastructure. Notably, the strain extract also had a broad-spectrum antifungal activity. Compared with the whole genome of strain QN1NO-4, several functional gene clusters involved in the biosynthesis of active secondary metabolites were observed. Fifteen compounds were identified by gas chromatography–mass spectrometry (GC-MS). Hence, the fruit endophyte B. safensis sp. QN1NO-4 is a potential bio-agent identified for the management of post-harvest disease of strawberry fruit.

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3532
Author(s):  
Ben Salha ◽  
Herrera Díaz ◽  
Lengliz ◽  
Abderrabba ◽  
Labidi

In this study, Carum carvi L. essential oil (CEO) and Origanum majorana L. essential oil (MEO) was steam-distillated under reduced pressure. We henceforth obtained three fractions for each essential oil: CF1, CF2, CF3, MF1, MF2, and MF3. Then, these fractions were characterized using the gas chromatography–mass spectrometry (GC-MS) technique. The results indicated that some fractions were rich in oxygenated compounds (i.e., CF2, CF3, MF2, and MF3) with concentrations ranging from 79.21% to 98.56%. Therefore, the influence of the chemical composition of the essential oils on their antifungal activity was studied. For this purpose, three food spoilage fungi were isolated, identified, and inoculated in vitro, in order to measure the antifungal activity of CEO, MEO, and their fractions. The results showed that stronger fungi growth inhibitions (FGI) (above 95%) were found in fractions with higher percentages of oxygenated compounds, especially with (−)-carvone and terpin-4-ol as the major components. Firstly, this work reveals that the free-terpenes hydrocarbons fractions obtained from MEO present higher antifungal activity than the raw essential oil against two families of fungi. Then, it suggests that the isolation of (−)-carvone (97.15 ± 5.97%) from CEO via vacuum distillation can be employed successfully to improve antifungal activity by killing fungi (FGI = 100%). This study highlights that separation under reduced pressure is a simple green method to obtain fractions or to isolate compounds with higher biological activity useful for pharmaceutical products or natural additives in formulations.


2010 ◽  
Vol 65 (7-8) ◽  
pp. 433-436
Author(s):  
Hui Xu ◽  
Huan Qu

Several 2,6-bis-(un)substituted phenoxymethylpyridines were synthesized and evaluated in vitro against Fusarium graminearum, Helminthosporium sorokinianum, Alternaria brassicae, Alternaria alternata, and Fusarium oxysporum f. sp. vasinfectum. Among all derivatives, compound 3 a exhibited a broad-spectrum antifungal activity against the five phytopathogenic fungi.


2020 ◽  
Vol 13 (2) ◽  
pp. 247-258 ◽  
Author(s):  
A.D. Gong ◽  
G.J. Sun ◽  
Z.Y. Zhao ◽  
Y.C. Liao ◽  
J.B. Zhang

Controlling proliferation and aflatoxin production by Aspergillus flavus is a pressing challenge for global food safety and security. Marine bacterium Staphylococcus saprophyticus strain L-38 showed excellent antifungal activity toward A. flavus in vitro and in vivo. In sealed, non-contact confrontation assays, L-38 completely inhibited conidial germination and mycelial growth of A. flavus through the production of volatile organic compounds (VOCs). Gas chromatography-mass spectrometry identified 3,3-dimethyl-1,2-epoxybutane (3-DE) as the most abundant VOC (32.61% of total peak area, 78% matching). Exposure of A. flavus cultures to synthetic 3-DE similarly demonstrated strong inhibition of growth. Moreover, culture of L-38 in a sealed chamber with maize or peanuts artificially inoculated with A. flavus, at high water activity, resulted in significant inhibition of A. flavus germination and aflatoxin biosynthesis. Scanning electron microscopy of these samples revealed severe damage to conidial cells and hyphae compared to samples not exposed to L-38. L-38 also showed broad and effective antifungal activity toward eight other phytopathogenic fungi including Aspergillus niger, Fusarium verticillioides, Fusarium graminearum, Sclerotinia sclerotiorum, Rhizoctonia solani, Alternaria alternata, Monilinia fructicola, and Botrytis cinerea. This work introduces S. saprophyticus L-38 as a potential biocontrol agent and demonstrates the efficacy of the volatile 3-DE in the control of A. flavus and other destructive plant pathogens for post-harvest food safety.


2020 ◽  
Vol 64 (10) ◽  
Author(s):  
Sean D. Liston ◽  
Luke Whitesell ◽  
Catherine A. McLellan ◽  
Ralph Mazitschek ◽  
Vidmantas Petraitis ◽  
...  

ABSTRACT The glycosylphosphatidylinositol anchor biosynthesis inhibitor gepinacin demonstrates broad-spectrum antifungal activity and negligible mammalian toxicity in culture but is metabolically labile. The stability and bioactivity of 39 analogs were tested in vitro to identify LCUT-8, a stabilized lead with increased potency and promising single-dose pharmacokinetics. Unfortunately, no antifungal activity was seen at the maximum dosing achievable in a neutropenic rabbit model. Nevertheless, structure-activity relationships identified here suggest strategies to further improve compound potency, solubility, and stability.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
M. S. Abu-Darwish ◽  
C. Cabral ◽  
I. V. Ferreira ◽  
M. J. Gonçalves ◽  
C. Cavaleiro ◽  
...  

Salvia officinalisL. (Lamiaceae) is a Mediterranean species, naturalized in many countries. In Jordan, it is used in traditional medicine as antiseptic, antiscabies, antisyphilitic, and anti-inflammatory, being frequently used against skin diseases. This study aimed the assessment of the antifungal and anti-inflammatory potential of its essential oils, and their cytotoxicity on macrophages and keratinocytes. The oils were investigated by gas chromatography and gas chromatography-mass spectrometry and the antifungal activity was evaluated against yeasts, dermatophyte andAspergillusstrains. Assessment of cell viability was made by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and thein vitroanti-inflammatory potential was evaluated by measuring nitric oxide production using lipopolysaccharide-stimulated mouse macrophages. The main compounds ofS. officinalisoils were 1,8-cineole (39.5–50.3%) and camphor (8.8–25.0%). The oils revealed antifungal activity against dermatophyte strains and significantly inhibited NO production stimulated by LPS in macrophages, without affecting cell viability, in concentrations up to 0.64 μL/mL. This is the first report addressing thein vitroanti-inflammatory potential ofS. officinalisoil. These findings demonstrated that bioactive concentrations ofS. officinalisoils do not affect mammalian macrophages and keratinocytes viability making them suitable to be incorporated in skin care formulations for cosmetic and pharmaceutical purposes.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11242
Author(s):  
Sarunpron Khruengsai ◽  
Patcharee Pripdeevech ◽  
Chutima Tanapichatsakul ◽  
Chanin Srisuwannapa ◽  
Priya Esilda D’Souza ◽  
...  

Fungal endophytes are microorganisms living symbiotically with a host plant. They can produce volatile organic compounds (VOCs) that have antimicrobial activity. This study aimed to isolate endophytic fungi from Barleria prionitis plants grown in Thailand and to investigate the antifungal properties of their VOCs against Colletotrichum acutatum, a causal agent of anthracnose disease on post-harvest strawberry fruits. A total of 34 endophytic fungi were isolated from leaves of B. prionitis. The VOCs produced from each individual isolate were screened for their antifungal activity against C. acutatum using a dual-culture plate method. From this in vitro screening experiment, the VOCs produced by the endophytic isolate BP11 were found to have the highest inhibition percentage (80.3%) against the mycelial growth of C. acutatum. The endophytic isolate BP11 was molecularly identified as Daldinia eschscholtzii MFLUCC 19-0493. This strain was then selected for an in vivo experiment. Results from the in vivo experiment indicated that the VOCs produced by D. eschscholtzii MFLUCC 19-0493 were able to inhibit infections by C. acutatum on organic fresh strawberry fruits with an average inhibition percentage of 72.4%. The quality of the pathogen-inoculated strawberry fruits treated with VOCs produced by D. eschscholtzii MFLUCC 19-0493 was evaluated. Their fruit firmness, total soluble solids, and pH were found to be similar to the untreated strawberry fruits. Solid phase microextraction-gas chromatographic-mass spectrometric analysis of the VOCs produced by D. eschscholtzii MFLUCC 19-0493 led to the detection and identification of 60 compounds. The major compounds were elemicin (23.8%), benzaldehyde dimethyl acetal (8.5%), ethyl sorbate (6.8%), methyl geranate (6.5%), trans-sabinene hydrate (5.4%), and 3,5-dimethyl-4-heptanone (5.1%). Each major compound was tested for its antifungal activity against C. acutatum using the in vitro assay. While all these selected VOCs showed varying degrees of antifungal activity, elemicin was found to possess the strongest antifungal activity. This work suggests that D. eschscholtzii MFLUCC 19-0493 could be a promising natural preservative for controlling C. acutatum associated anthracnose disease in strawberry fruits during the post-harvest period.


2018 ◽  
Vol 13 (9) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Daniele Fraternale ◽  
Donata Ricci

The present study reports the results of gas chromatography-mass spectrometry (GC/MS) analyses of the essential oil from flowering aerial parts of Cotinus coggygria Scoop. (Anacardiaceae), as well as its in vitro antifungal activity against nine plant pathogenic fungi. Moreover, the essential oil was evaluated for its antifungal activity using the agar dilution method, and also MICs (minimum inhibitory concentrations) and MFCs (minimum fungicidal concentrations) were determined. The major compounds identified by GC-MS were limonene (49.2%), (Z)-β-ocimene (13.6%), α-pinene (8.8%) and (E)-β-ocimene (5.9%). The oil showed in vitro antifungal activity against some species of the Fusarium genus, Botrytis cinerea, and Alternaria solani. Our study indicates that the oil of C. coggygria could be used as a control agent for plant pathogenic fungi in natural formulations.


Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 354 ◽  
Author(s):  
Hilania Valéria Dodou Lima ◽  
Carolina Sidrim de Paula Cavalcante ◽  
Gandhi Rádis-Baptista

Venoms from ants comprise a rich source of bioactive peptides, including antimicrobial peptides. From the proteome and peptidome of the giant ant Dinoponera quadriceps venom, members of five known classes of antimicrobial peptides were disclosed (e.g., dermaseptin-, defensin-, ICK-, pilosulin- and ponericin-like types). Based on comparative analysis, these family members have structural determinants that indicate they could display antimicrobial activities. In previous works, pilosulin- and ponericin-like peptides were demonstrated to be active against bacteria, fungi, and parasites. Herein, the antifungal activity of ponericin- and pilosulin-like peptides were assessed, aiming at the expansion of the knowledge about AMPs in predatory ants and the development of new microbicide strategies to deal with difficult-to-treat fungal infections. Synthetic pilosulin- (Dq-2562, Dq-1503, and Dq-1319) and ponericin-like (Dq-3162) peptides were evaluated for their fungicide and fungistatic activities against different species of Candida, including a drug-resistant clinical strain. The MICs and MLCs were determined for all peptides individually and in combination with general antifungal drugs by the microdilution method. The time-kill kinetic curves were set up by means of a luminescent reagent, of which the light signal is proportional to the number of viable cells. The candicidal synergism observed by the combination of subinhibitory concentrations of peptides and general antimycotic drugs were quantified by the checkerboard test and fluorescent dye permeation assay. The influence of ergosterol on the antifungal activity was verified by supplementation of culture medium. The pilosulin- (Dq-2562 and Dq-1503) and ponericin-like (Dq-3162) were the most active peptides, displaying a broad spectrum of antifungal activity in vitro, with MICs in the range of 0.625 to 10 µM. The combination of peptides and conventional antimycotic drugs displayed a synergistic reduction in the MIC values of individual peptides and drugs, while soluble ergosterol in the culture medium increased the MICs. The fungicide and fungistatic activity of the individual peptides and peptides in combination with antimycotics were time-dependent with a rapid onset of action and long-lasting effect, which involved membrane disruption as an underlying mechanism of their action. Altogether, pilosulin- and ponericin-like peptides from the giant ant D. quadriceps venom display a broad-spectrum of candicidal activity, what allows their inclusion in the row of the antifungal peptides and gives support for further studies on the development of strategies to fight candidiasis.


2016 ◽  
pp. AAC.01061-16 ◽  
Author(s):  
Kristy Koselny ◽  
Julianne Green ◽  
Louis DiDone ◽  
Justin P. Halterman ◽  
Annette W. Fothergill ◽  
...  

Only one new class of antifungal drugs has been introduced into clinical practice in the last thirty years and, thus, the identification of small molecules with novel mechanisms of action is an important goal of current anti-infective research. Here, we describe the characterization of the spectrum of in vitro activity and in vivo activity of AR-12, a celecoxib-derivative which has been tested in a Phase I clinical trial as an anti-cancer agent. AR-12 inhibits fungal acetyl CoA synthetase in vitro and is fungicidal at concentrations similar to those achieved in human plasma. AR-12 has a broad spectrum of activity including active against yeasts (e.g.,C. albicans, non-albicansCandidaspp.,C. neoformans); molds (e.g.,Fusarium,Mucor), and dimorphic fungi (Blastomyces,Histoplasma, andCoccidioides) with minimum inhibitory concentrations of 2-4 μg/mL. AR-12 is also active against azole- and echinocandin-resistantCandidaisolates and sub-inhibitory AR-12 concentrations increase susceptibility of fluconazole- and echinocandin-resistantCandidaisolates. Finally, AR-12 also increases the activity of fluconazole in a murine model of cryptococcosis. Taken together, these data indicate that AR-12 represents a promising class of small molecules with broad spectrum antifungal activity.


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