scholarly journals Contamination by molds and inhibitory effect of hay cube on aflatoxin production by Aspergillus flavus

1986 ◽  
Vol 1986 (23) ◽  
pp. 15-22 ◽  
Author(s):  
T. TAKAHASHI ◽  
Y. ONOUE ◽  
M. MORI
Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 636 ◽  
Author(s):  
Zhao ◽  
Zhang ◽  
Folly ◽  
Chang ◽  
Wang ◽  
...  

Lactobacillus plantarum, as a natural bio-preservative, has attracted a great deal of attention in recent years. In this study, 22 L. plantarum strains were tested against the aflatoxin-producing fungus, Aspergillus flavus; strain IAMU80070 showed the highest antifungal activity. At a concentration of 5 × 105 colony-forming units (CFU) mL−1, it completely inhibited A. flavus growth and decreased aflatoxin production by 93%. Furthermore, ultrastructural examination showed that IAMU80070 destroyed the cellular structure of hyphae and spores. To explore the inhibitory effect of IAMU80070 on A. flavus at the transcriptional level, transcriptome data were obtained and subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The aflatoxin biosynthetic process was the most significantly downregulated functional category, while genes implicated in the synthesis and organization of cell wall polysaccharides were upregulated. Quantitative real-time PCR results verified the credibility and reliability of the RNA sequencing data. These results provided insight into the transcriptome of A. flavus in response to the antagonistic effects of L. plantarum IAMU80070.


2013 ◽  
Vol 136 (2) ◽  
pp. 789-793 ◽  
Author(s):  
Flavio Dias Ferreira ◽  
Carlos Kemmelmeier ◽  
Carla Cristina Arrotéia ◽  
Christiane Luciana da Costa ◽  
Carlos Augusto Mallmann ◽  
...  

1999 ◽  
Vol 89 (10) ◽  
pp. 902-907 ◽  
Author(s):  
Z.-Y. Chen ◽  
R. L. Brown ◽  
J. S. Russin ◽  
A. R. Lax ◽  
T. E. Cleveland

In this study, we found that the inhibition of fungal growth in potato dextrose broth (PDB) medium by the 14-kDa corn trypsin inhibitor (TI) protein, previously found to be associated with host resistance to aflatoxin production and active against various fungi, was relieved when exogenous α-amylase was added along with TI. No inhibitory effect of TI on fungal growth was observed when Aspergillus flavus was grown on a medium containing either 5% glucose or 1% gelatin as a carbon source. Further investigation found that TI not only inhibited fungal production of extracellular α-amylase when A. flavus was grown in PDB medium containing TI at 100 μg ml-1 but also reduced the enzymatic activity of A. flavus α-amylase by 27%. At a higher concentration, however, TI stimulated the production of α-amylase. The effect of TI on the production of amyloglucosidase, another enzyme involved in starch metabolism by the fungus, was quite different. It stimulated the production of this enzyme during the first 10 h at all concentrations studied. These studies suggest that the resistance of certain corn genotypes to A. flavus infection may be partially due to the ability of TI to reduce the production of extracellular fungal α-amylase and its activity, thereby limiting the availability of simple sugars for fungal growth. However, further investigation of the relationship between TI levels and fungal α-amylase expression in vivo is needed.


1981 ◽  
Vol 27 (9) ◽  
pp. 962-967 ◽  
Author(s):  
C. J. Rabie ◽  
C. J. Meyer ◽  
Laetitia van Heerden ◽  
Annelie Lübben

The effects of the elements zinc, manganese, iron, copper, molybdenum, and vanadium, added in various salt forms, on mycelial weights and aflatoxin B1 accumulation in the mycelium of Aspergillus flavus were investigated in liquid shake cultures. Ammonium heptamolybdate, when added to a complete medium at concentrations of 50–100 mg/L, appreciably reduced aflatoxin B1 accumulation without affecting growth of the fungus. Sodium molybdate and sodium monovanadate also reduced aflatoxin B1 yields without affecting mycelial growth, but to a lesser extent.The addition of zinc sulphate stimulated aflatoxin B1 production in all media used. The influence of the other trace elements on aflatoxin production depended on the level of trace elements present in the basal medium. In general, manganese chloride had a stimulatory effect, whereas copper sulphate depressed yields.Mycelial levels of aflatoxin had peaked and then declined before mycelial dry weights had reached maximum.High yields of aflatoxin B1 were obtained in media having a final pH as low as pH 2.8.


2020 ◽  
Vol 13 (2) ◽  
pp. 259-266 ◽  
Author(s):  
X. Dong ◽  
Q. Zhang ◽  
Z. Zhang ◽  
X. Yue ◽  
L. Zhang ◽  
...  

Aspergillus flavus can easily infect major agricultural products and produce aflatoxin. In this study, we investigated the effect of the biocontrol bacterium Enterobacter cloacae 3J1EC on the growth of A. flavus strain 3.4408. The biocontrol bacterium played a key role in preventing infection by A. flavus. E. cloacae 3J1EC was found to inhibit the growth of A. flavus 3.4408 mycelial pellets and reduce the production of aflatoxin by 96.9%. We found differential expression between the control and the treatment groups in the transcriptome of A. flavus 3.4408. Gene ontology (GO) analysis indicated that E. cloacae 3J1EC induced the down-regulated expression of cellular component and molecular function, while its effects on the up-regulated expression indicated the relationship of biological process and molecular function. Thus, these results suggest that E. cloacae 3J1EC decreased aflatoxin production via down-regulated gene expression in terms of aflatoxin biosynthesis. In summary, E. cloacae 3J1EC can be employed as an alternative for the biological control of A. flavus 3.4408.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Shiqi Xia ◽  
Hong Lin ◽  
Peilin Zhu ◽  
Peiling Wang ◽  
Shengliang Liao ◽  
...  

Aspergillus flavus (A. flavus) is a frequent harmful fungal pathogen. It can infect traditional Chinese medicine materials and release aflatoxin, to cause both economic and human health effects. By comparing the inhibitory potential of Litsea cubeba oil and its active components to A. flavus CGMCC 3.4408, citral was confirmed to be the main component that inhibits the growth of A. flavus CGMCC 3.4408, and the EC50 was 163.65 mg L−1. The inhibitory effect of citral on A. flavus CGMCC 3.4408 was studied for colony growth rate, mycelium biomass, aflatoxin production, and microstructure. Citral slowed down the growth rate of colonies and reduced mycelium biomass and toxin production. Moreover, citral altered the morphology of fungal spores and mycelium. In addition, citral also has the inhibitory effects on the isolates of A. flavus from moldy traditional Chinese medicinal materials. Thus, citral can be used as a potential agent to check the growth of A. flavus or related fungal strains.


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.


1999 ◽  
Vol 62 (4) ◽  
pp. 414-417 ◽  
Author(s):  
J. J. FAN ◽  
J. H. CHEN

Welsh onion ethanol extracts were tested for their inhibitory activity against the growth and aflatoxin production of Aspergillus flavus and A. parasiticus. The survival of spores of A. flavus and A. parasiticus depended on both the extract concentration and the exposure time of the spores to the Welsh onion extracts. The mycelial growth of two tested fungi cultured on yeast extract–sucrose broth was completely inhibited in the presence of the Welsh onion ethanol extract at a concentration of 10 mg/ml during 30 days of incubation at 25°C. The extracts added to the cultures also inhibited aflatoxin production at a concentration of 10 mg/ml or permitted only a small amount of aflatoxin production with extract concentration of 5 mg/ml after 2 weeks of incubation. Welsh onion ethanol extracts showed more pronounced inhibitory effects against the two tested aflatoxin-producing fungi than did the same added levels of the preservatives sorbate and propionate at pH values near 6.5.


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