scholarly journals Investigation of the Antifungal and Anti-Aflatoxigenic Potential of Plant-Based Essential Oils against Aspergillus flavus in Peanuts

2020 ◽  
Vol 6 (4) ◽  
pp. 383
Author(s):  
Premila Narayana Achar ◽  
Pham Quyen ◽  
Emmanuel C. Adukwu ◽  
Abhishek Sharma ◽  
Huggins Zephaniah Msimanga ◽  
...  

Aspergillus species are known to cause damage to food crops and are associated with opportunistic infections in humans. In the United States, significant losses have been reported in peanut production due to contamination caused by the Aspergillus species. This study evaluated the antifungal effect and anti-aflatoxin activity of selected plant-based essential oils (EOs) against Aspergillus flavus in contaminated peanuts, Tifguard, runner type variety. All fifteen essential oils, tested by the poisoned food technique, inhibited the growth of A. flavus at concentrations ranging between 125 and 4000 ppm. The most effective oils with total clearance of the A. flavus on agar were clove (500 ppm), thyme (1000 ppm), lemongrass, and cinnamon (2000 ppm) EOs. The gas chromatography-mass spectrometry (GC-MS) analysis of clove EO revealed eugenol (83.25%) as a major bioactive constituent. An electron microscopy study revealed that clove EO at 500 ppm caused noticeable morphological and ultrastructural alterations of the somatic and reproductive structures. Using both the ammonia vapor (AV) and coconut milk agar (CMA) methods, we not only detected the presence of an aflatoxigenic form of A. flavus in our contaminated peanuts, but we also observed that aflatoxin production was inhibited by clove EO at concentrations between 500 and 2000 ppm. In addition, we established a correlation between the concentration of clove EO and AFB1 production by reverse-phase high-performance liquid chromatography (HPLC). We demonstrate in our study that clove oil could be a promising natural fungicide for an effective bio-control, non-toxic bio-preservative, and an eco-friendly alternative to synthetic additives against A. flavus in Georgia peanuts.

2013 ◽  
Vol 6 (1) ◽  
pp. 43-50 ◽  
Author(s):  
V. Aiko ◽  
A. Mehta

Cinnamon, cardamom, star anise and clove were studied for their effect on growth of Aspergillus flavus and aflatoxin B1 (AFB1) synthesis. The experiments were carried out in yeast extract sucrose culture broth as well as in rice supplemented with spices. AFB1 produced was analysed qualitatively and quantitatively using thin layer chromatography and high performance liquid chromatography, respectively. At a concentration of 10 mg/ml, cardamom and star anise did not exhibit any antifungal or anti-aflatoxigenic activity in culture broth, whereas cinnamon and clove inhibited A. flavus growth completely. The minimum inhibitory concentrations of cinnamon and clove were 4 and 2 mg/ml, respectively. Concentrations of cinnamon and clove below their minimum inhibitory concentrations showed enhanced fungal growth, while AFB1 synthesis was reduced. Clove inhibited the synthesis of AFB1 significantly up to 99% at concentrations ≥1.0 mg/ml. The spices also inhibited AFB1 synthesis in rice at 5 mg/g, although fungal growth was not inhibited. Clove and cinnamon inhibited AFB1 synthesis significantly up to 99 and 92%, respectively, and star anise and cardamom by 41 and 23%, respectively. The results of this study suggest the use of whole spices rather than their essential oils for controlling fungal and mycotoxin contamination in food grains.


mBio ◽  
2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Milton T. Drott ◽  
Tatum R. Satterlee ◽  
Jeffrey M. Skerker ◽  
Brandon T. Pfannenstiel ◽  
N. Louise Glass ◽  
...  

ABSTRACT The apparent rarity of sex in many fungal species has raised questions about how much sex is needed to purge deleterious mutations and how differences in frequency of sex impact fungal evolution. We sought to determine how differences in the extent of recombination between populations of Aspergillus flavus impact the evolution of genes associated with the synthesis of aflatoxin, a notoriously potent carcinogen. We sequenced the genomes of, and quantified aflatoxin production in, 94 isolates of A. flavus sampled from seven states in eastern and central latitudinal transects of the United States. The overall population is subdivided into three genetically differentiated populations (A, B, and C) that differ greatly in their extent of recombination, diversity, and aflatoxin-producing ability. Estimates of the number of recombination events and linkage disequilibrium decay suggest relatively frequent sex only in population A. Population B is sympatric with population A but produces significantly less aflatoxin and is the only population where the inability of nonaflatoxigenic isolates to produce aflatoxin was explained by multiple gene deletions. Population expansion evident in population B suggests a recent introduction or range expansion. Population C is largely nonaflatoxigenic and restricted mainly to northern sampling locations through restricted migration and/or selection. Despite differences in the number and type of mutations in the aflatoxin gene cluster, codon optimization and site frequency differences in synonymous and nonsynonymous mutations suggest that low levels of recombination in some A. flavus populations are sufficient to purge deleterious mutations. IMPORTANCE Differences in the relative frequencies of sexual and asexual reproduction have profound implications for the accumulation of deleterious mutations (Muller’s ratchet), but little is known about how these differences impact the evolution of ecologically important phenotypes. Aspergillus flavus is the main producer of aflatoxin, a notoriously potent carcinogen that often contaminates food. We investigated if differences in the levels of production of aflatoxin by A. flavus could be explained by the accumulation of deleterious mutations due to a lack of recombination. Despite differences in the extent of recombination, variation in aflatoxin production is better explained by the demography and history of specific populations and may suggest important differences in the ecological roles of aflatoxin among populations. Furthermore, the association of aflatoxin production and populations provides a means of predicting the risk of aflatoxin contamination by determining the frequencies of isolates from low- and high-production populations.


2011 ◽  
Vol 35 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Rosane Tamara da Silva Medeiros ◽  
Edlayne Gonçalez ◽  
Roberto Carlos Felicio ◽  
Joana D'arc Felicio

The presence of mycotoxins as a result of fungal attack can occur before, after and during the harvest and storage operations on agricultural crops and food commodities. Considering the inhibitory property of essential plant oils on the mycelial development of fungi and the importance of Aspergillus flavus, the main producer of aflatoxins, this research was designed to evaluate the toxicity of essential oil from Pittosporum undulatum against A. flavus. The essential oils were obtained from P. undulatum leaves, collected in different months and analyzed by GC/MS. The oils were rich in hydrocarbon, monoterpenes and sesquiterpenes and it was observed a significant variation on the chemical composition of the essential oil of leaves at different months. Besides, the essential oils were tested against fungal growth and the results showed different spectrum of inhibition on A. flavus. However, the essential oils inhibited the aflatoxin B1 production.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 273-274
Author(s):  
Patricia M Oba ◽  
Nagait Hwisa ◽  
Xinhe Huang ◽  
Keith Cadwallader ◽  
Kelly S Swanson

Abstract Exposing ingredients to high temperatures may result in chemical reactions between amino acids and sugars, leading to the formation of Maillard reaction products (MRPs). These products may result in altered palatability, protein quality, and digestibility. This experiment quantified key MRPs in commercial pet foods, estimated daily intake of MRPs of pet animals, and correlated MRPs with macronutrient concentrations present in the foods. The analysis included 53 pet foods and treats commercially available in the United States: 11 dry dog foods, 29 wet dog foods, 2 dry dog treats, 3 wet dog treats, 2 dry cat foods, and 6 wet cat foods. Diets and treats were analyzed for dry matter, organic matter, crude protein (CP), acid-hydrolyzed fat, total dietary fiber, and gross energy using standard techniques. MRPs were analyzed using high-performance liquid chromatography and gas chromatography-mass spectrometry. All data were analyzed as a completely randomized design using the GLM procedure of SAS 9.4. On average, wet foods had higher (P < 0.001) fructoselysine (FRUC) and carboxymethyllysine (CML) than dry foods. Dry dog treats had the highest (P < 0.001) FRUC (29.64 µg/g) and CML (0.47 mg/g) concentrations of all products tested. Dry cat foods had the lowest (P < 0.001) CML (0.10 mg/g) concentrations of all commercial segments. Wet dog treats had the highest (P < 0.001) 5-hydroxymethyl-2-furfural (HMF) (10.92 µg/g) concentrations of all segments and wet cat foods had the lowest (P < 0.001) HMF (0.22 µg/g) content. Dogs and cats fed wet diets would be more likely to ingest higher amounts of CML and FRUC compared to animals fed dry diets. Dogs consuming dry treats would be more likely to ingest higher amounts of CML than wet treats. CP was negatively correlated to HMF (P = 0.0425; r = -0.27973), while TSF was positively correlated to CML (P = 0.0417; r = 0.28080).


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.


2014 ◽  
Vol 4 (1) ◽  
pp. 51 ◽  
Author(s):  
Vania Maria Moreira Valente ◽  
Gulab Newandram Jham ◽  
Carolina Marangon Jardim ◽  
Onkar Dev Dhingra ◽  
Ion Ghiviriga

<p>Aiming to substitute toxic synthetic fungicides, the activity of nutmeg (<em>Myristica fragrans</em>) essential oil (EO, obtained by hydrodistillation) was investigated against two important storage fungi-<em>Aspergillus flavus</em> <em>A. ochraceus</em>. The activity of crude nutmeg EO was investigated using poison food assay (PFA). At a concentration of 0.1%, the EO inhibited <em>A. flavus</em> and <em>A. ochraceus</em> growth by 43 and 65%, respectively. At a concentration of 0.3 %, <em>A. flavus</em> and <em>A. ochraceus</em> inhibitions were 84 and 79%, respectively. The crude nutmeg EO on fractionation by preparative TLC-bioautography presented one band from which two pure compounds were isolated by semi-preparative normal-phase high performance liquid chromatography. Myristicin and safrole were identified by nuclear magnetic resonance (<sup>1</sup>H and <sup>13</sup>C) and gas chromatography-mass spectrometry. The relative % of myristicin and safrol in the crude EO was 10.8 and 2.9, respectively, determined by gas chromatography with a flame ionization detector. The crude EO, the isolated active fraction, isolated myristicin and standard myristicin presented similar activities against the two fungi at concentrations of 0.1 and 0.3% by PFA. Based on these results it is concluded that myristicin is the major antifungal in nutmeg EO against <em>A. flavus</em> and <em>A. ochraceus</em>.</p>


2010 ◽  
Vol 170 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Priyanka Singh ◽  
Ravindra Shukla ◽  
Ashok Kumar ◽  
Bhanu Prakash ◽  
Shubhra Singh ◽  
...  

Toxins ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 142 ◽  
Author(s):  
Marta García-Díaz ◽  
Jessica Gil-Serna ◽  
Belén Patiño ◽  
Esther García-Cela ◽  
Naresh Magan ◽  
...  

Aflatoxin contamination of foodstuffs poses a serious risk to food security, and it is essential to search for new control methods to prevent these toxins entering the food chain. Several essential oils are able to reduce the growth and mycotoxin biosynthesis of toxigenic species, although their efficiency is strongly influenced by the environmental conditions. In this work, the effectiveness of Satureja montana and Origanum virens essential oils to control Aspergillus flavus growth was evaluated under three water activity levels (0.94, 0.96 and 0.98 aw) using a Bioscreen C, a rapid in vitro spectrophotometric technique. The aflatoxin concentrations at all conditions tested were determined by HPLC-FLD. Aspergillus flavus growth was delayed by both essential oil treatments. However, only S. montana essential oil was able to significantly affect aflatoxin production, although the inhibition percentages widely differed among water activities. The most significant reduction was observed at 0.96 aw, which is coincident with the conditions in which A. flavus reached the highest levels of aflatoxin production. On the contrary, the treatment with S. montana essential oil was not effective in significantly reducing aflatoxin production at 0.94 aw. Therefore, it is important to study the interaction of the new control compounds with environmental factors before their application in food matrices, and in vitro ecophysiological studies are a good option since they provide accurate and rapid results.


2014 ◽  
Vol 9 (6) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Cynthia R. Wright ◽  
Emanuel A. Waddell ◽  
William N. Setzer

Four different cactus species growing in the United States, Stenocereus thurberi growing in Organ Pipe Cactus National Monument, Arizona, Opuntia littoralis and Opuntia ficus-indica, growing on Santa Catalina Island, California, and Opuntia stricta, growing in northern Alabama, were examined for the presence of silica bodies (opaline phytoliths). Silica bodies were found in all four of these cactus species, parallelepiped-shaped crystals in S. thurberi, and starburst-shaped crystalline structures in the three Opuntia species. In addition, the essential oils of the four cactus species were obtained by hydrodistillation and analyzed by gas chromatography – mass spectrometry. To our surprise, S. thurberi, O. littoralis, and O. ficus-indica (but not O. stricta) essential oils contained cyclic oligosiloxanes. To our knowledge, cyclic oligosiloxanes have not been previously found as essential oil components.


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