Antifungal activity of the volatile organic compounds produced by Bacillus velezensis strains against postharvest fungal pathogens

The use of antagonistic microorganisms and their volatile organic compounds (VOCs) to control plant fungal pathogens is an eco-friendly and promising substitute for chemical fungicides. In this work, endophytic bacterium ETR-B22, isolated from the root of Sophora tonkinensis Gagnep., was found to exhibit strong antagonistic activity against 12 fungal pathogens found in agriculture. Strain ETR-B22 was identified as Burkholderia cenocepacia based on 16S rRNA and recA sequences. We evaluated the antifungal activity of VOCs emitted by ETR-B22. The VOCs from strain ETR-B22 also showed broad-spectrum antifungal activity against 12 fungal pathogens. The composition of the volatile profiles was analyzed based on headspace solid phase microextraction (HS-SPME) gas chromatography coupled to mass spectrometry (GC-MS). Different extraction strategies for the SPME process significantly affected the extraction efficiency of the VOCs. Thirty-two different VOCs were identified. Among the VOC of ETR-B22, dimethyl trisulfide, indole, methyl anthranilate, methyl salicylate, methyl benzoate, benzyl propionate, benzyl acetate, 3,5-di-tert-butylphenol, allyl benzyl ether and nonanoic acid showed broad-spectrum antifungal activity, and are key inhibitory compounds produced by strain ETR-B22 against various fungal pathogens. Our results suggest that the endophytic strain ETR-B22 and its VOCs have high potential for use as biological controls of plant fungal pathogens.

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Antifungal Effect of Volatile Organic Compounds from Bacillus velezensis CT32 against Verticillium dahliae and Fusarium oxysporum

Processes ◽

10.3390/pr8121674 ◽

2020 ◽

Vol 8 (12) ◽

pp. 1674

Author(s):

Xinxin Li ◽

Xiuhong Wang ◽

Xiangyuan Shi ◽

Baoping Wang ◽

Meiping Li ◽

...

Keyword(s):

Antifungal Activity ◽

Volatile Organic Compounds ◽

Fusarium Oxysporum ◽

Organic Compounds ◽

Verticillium Dahliae ◽

Inhibitory Effect ◽

Rrna Gene ◽

Vascular Wilt ◽

Bacillus Velezensis ◽

Volatile Organic

The present study focuses on the inhibitory effect of volatile metabolites released by Bacillus velezensis CT32 on Verticillium dahliae and Fusarium oxysporum, the causal agents of strawberry vascular wilt. The CT32 strain was isolated from maize straw compost tea and identified as B. velezensis based on 16S rRNA gene sequence analysis. Bioassays conducted in sealed plates revealed that the volatile organic compounds (VOCs) produced by the strain CT32 possessed broad-spectrum antifungal activity against eight phytopathogenic fungi. The volatile profile of strain CT32 was obtained by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). A total of 30 volatile compounds were identified, six of which have not previously been detected in bacteria or fungi: (Z)-5-undecene, decyl formate, 2,4-dimethyl-6-tert-butylphenol, dodecanenitrile, 2-methylpentadecane and 2,2’,5,5’-tetramethyl-1,1’-biphenyl. Pure compounds were tested in vitro for their inhibitory effect on the mycelial growth of V. dahliae and F. oxysporum. Decanal, benzothiazole, 3-undecanone, 2-undecanone, 2-undecanol, undecanal and 2,4-dimethyl-6-tert-butylphenol showed high antifungal activity, with benzothiazole and 2,4-dimethyl-6-tert-butylphenol being the most potent compounds. These results indicate that the VOCs produced by B. velezensis CT32 have the potential to be used as a biofumigant for management of vascular wilt pathogens.

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Effects of volatile organic compounds from Streptomyces albulus NJZJSA2 on growth of two fungal pathogens

Journal of Basic Microbiology ◽

10.1002/jobm.201400906 ◽

2015 ◽

Vol 55 (9) ◽

pp. 1104-1117 ◽

Cited By ~ 23

Author(s):

Yuncheng Wu ◽

Jun Yuan ◽

Yaoyao E ◽

Waseem Raza ◽

Qirong Shen ◽

...

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Fungal Pathogens ◽

Volatile Organic

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Control of Postharvest Fungal Pathogens by Antifungal Compounds from Penicillium expansum

Journal of Food Protection ◽

10.4315/0362-028x.jfp-13-072 ◽

2013 ◽

Vol 76 (11) ◽

pp. 1879-1886 ◽

Cited By ~ 20

Author(s):

WAFA ROUISSI ◽

LUISA UGOLINI ◽

CAMILLA MARTINI ◽

LUCA LAZZERI ◽

MARTA MARI

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Fungal Pathogens ◽

Solid Phase ◽

Petri Dish ◽

Pathogenic Fungi ◽

Penicillium Expansum ◽

Colletotrichum Acutatum ◽

Volatile Organic

The fungicidal effects of secondary metabolites produced by a strain of Penicillium expansum (R82) in culture filtrate and in a double petri dish assay were tested against one isolate each of Botrytis cinerea, Colletotrichum acutatum, and Monilinia laxa and six isolates of P. expansum, revealing inhibitory activity against every pathogen tested. The characterization of volatile organic compounds released by the R82 strain was performed by solid-phase microextraction–gas chromatographic techniques, and several compounds were detected, one of them identified as phenethyl alcohol (PEA). Synthetic PEA, tested in vitro on fungal pathogens, showed strong inhibition at a concentration of 1,230 μg/ml of airspace, and mycelium appeared more sensitive than conidia; nevertheless, at the concentration naturally emitted by the fungus (0.726 ± 0.16 μg/ml), commercial PEA did not show any antifungal activity. Therefore, a combined effect between different volatile organic compounds produced collectively by R82 can be hypothesized. This aspect suggests further investigation into the possibility of exploiting R82 as a nonchemical alternative in the control of some plant pathogenic fungi.

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Antifungal properties of volatile organic compounds produced by Daldinia eschscholtzii MFLUCC 19-0493 isolated from Barleria prionitis leaves against Colletotrichum acutatum and its post-harvest infections on strawberry fruits

PeerJ ◽

10.7717/peerj.11242 ◽

2021 ◽

Vol 9 ◽

pp. e11242

Author(s):

Sarunpron Khruengsai ◽

Patcharee Pripdeevech ◽

Chutima Tanapichatsakul ◽

Chanin Srisuwannapa ◽

Priya Esilda D’Souza ◽

...

Keyword(s):

Antifungal Activity ◽

Volatile Organic Compounds ◽

Organic Compounds ◽

Endophytic Fungi ◽

Colletotrichum Acutatum ◽

Anthracnose Disease ◽

Post Harvest ◽

Volatile Organic

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.

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