Inhibitory effect of molybdenum and vanadium salts on aflatoxin B1 synthesis by Aspergillus flavus

1981 ◽  
Vol 27 (9) ◽  
pp. 962-967 ◽  
Author(s):  
C. J. Rabie ◽  
C. J. Meyer ◽  
Laetitia van Heerden ◽  
Annelie Lübben
Keyword(s):  
Trace Elements ◽  
Aspergillus Flavus ◽  
Basal Medium ◽  
Sodium Molybdate ◽  
Aflatoxin Production ◽  
Inhibitory Effect ◽  
Complete Medium ◽  
Ammonium Heptamolybdate ◽  
Vanadium Salts ◽  
Aflatoxin B

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.

Control of Aspergillus flavus and aflatoxin production with spices in culture medium and rice

2013 ◽  
Vol 6 (1) ◽  
pp. 43-50 ◽  
Author(s):  
V. Aiko ◽  
A. Mehta
Keyword(s):  
Aspergillus Flavus ◽  
High Performance ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Culture Broth ◽  
Minimum Inhibitory Concentrations ◽  
Food Grains ◽  
Star Anise ◽  
Aflatoxin B ◽  
Layer Chromatography

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.

scholarly journals Morphological and Transcriptomic Analysis of the Inhibitory Effects of Lactobacillus plantarum on Aspergillus flavus Growth and Aflatoxin Production

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 636 ◽  
Author(s):  
Zhao ◽  
Zhang ◽  
Folly ◽  
Chang ◽  
Wang ◽  
...  
Keyword(s):  
Lactobacillus Plantarum ◽  
Aspergillus Flavus ◽  
Aflatoxin Production ◽  
Inhibitory Effect ◽  
Transcriptional Level ◽  
Sequencing Data ◽  
Inhibitory Effects ◽  
Cell Wall Polysaccharides ◽  
Colony Forming Units ◽  
Insight Into

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.

scholarly journals Effect of Lactic Acid Bacteria Strains on the Growth and Aflatoxin Production Potential of Aspergillus parasiticus, and Their Ability to Bind Aflatoxin B1, Ochratoxin A, and Zearalenone in vitro

2021 ◽  
Vol 12 ◽  
Author(s):  
Cleide Oliveira de Almeida Møller ◽  
Luisa Freire ◽  
Roice Eliana Rosim ◽  
Larissa Pereira Margalho ◽  
Celso Fasura Balthazar ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Ochratoxin A ◽  
Aspergillus Parasiticus ◽  
Potassium Phosphate ◽  
Aflatoxin Production ◽  
Inhibitory Effect ◽  
Binding Studies ◽  
Aflatoxin B

The increased consumption of plant-based foods has intensified the concern related to mycotoxin intoxication. This study aimed to investigate the effect of selected lactic acid bacteria (LAB) strains on the growth of Aspergillus parasiticus NRRL 2999 and its production of aflatoxin (AF). The ability of the heat-killed (100°C for 1 h) LAB strains to bind aflatoxin M1 (AFM1) in milk and aflatoxin B1 (AFB1), ochratoxin A (OTA), and zearalenone (ZEN) in potassium phosphate buffer (PPB) was also evaluated in vitro. Ten LAB strains were tested individually, by inoculating them simultaneously with the fungus or after incubation of the fungus for 24 or 48 h at 25°C. Double layer yeast extract sucrose (YES) agar, de Man Rogosa and Sharpe (MRS) agar, and YES broth were incubated for 7 days at 25°C to follow the development of the fungus. Levilactobacillus spp. 3QB398 and Levilactobacillus brevis 2QB422 strains were able to delay the growth of A. parasiticus in YES broth, even when these strains were inoculated 24 h after the fungus. The inhibitory effect of these LAB strains was confirmed by the reduction of fungus colony size, suggesting dominance of LAB by competition (a Lotka-Voltera effect). The production of AFB1 by A. parasiticus was inhibited when the fungus was inoculated simultaneously with Lactiplantibacillus plantarum 3QB361 or L. plantarum 3QB350. No AFB1 was found when Levilactobacillus spp. 2QB383 was present, even when the LAB was inoculated 48 h after the fungus. In binding studies, seven inactivated LAB strains were able to promote a reduction of at least 50% the level of AFB1, OTA, and ZEN. This reduction varied depending on the pH of the PPB. In milk, however, only two inactivated LAB strains were able to reduce AFM1, with a reduction of 33 and 45% for Levilactobacillus spp. 3QB398 (Levilactobacillus spp.) and L. brevis 2QB422, respectively. Nevertheless, these results clearly indicate the potential of using LAB for mycotoxin reduction.

scholarly journals Regulation of Morphology, Aflatoxin Production, and Virulence of Aspergillus flavus by the Major Nitrogen Regulatory Gene areA

Toxins ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 718 ◽  
Author(s):  
Opemipo Esther Fasoyin ◽  
Kunlong Yang ◽  
Mengguang Qiu ◽  
Bin Wang ◽  
Sen Wang ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Regulatory Gene ◽  
Nitrogen Sources ◽  
Aflatoxin Production ◽  
Fungal Species ◽  
Complete Medium ◽  
Over Expression ◽  
Oxidative Stresses ◽  
Gata Transcription Factor

Aspergillus flavus is a renowned plant, animal and human pathogen. areA is a global nitrogen regulatory gene of the GATA transcription factor family, shown to be the major nitrogen regulator. In this study, we identified areA in A. flavus and studied its function. The AreA protein contained a signatory zinc finger domain, which is extremely conserved across fungal species. Gene deletion (ΔareA) and over-expression (OE::areA) strains were constructed by homologous recombination to elucidate the role of areA in A. flavus. The ΔareA strain was unable to efficiently utilize secondary nitrogen sources for growth of A. flavus, and it had poorly developed conidiophores, when observed on complete medium, resulting in the production of significantly less conidia than the wild-type strain (WT). Aflatoxin B1 (AFB1) production was reduced in ΔareA compared with the WT strain in most conditions tested, and ΔareA had impaired virulence in peanut seeds. areA also played important roles in the sensitivity of A. flavus to osmotic, cell wall and oxidative stresses. Hence, areA was found to be important for the growth, aflatoxin production and pathogenicity of A. flavus. This work sheds light on the function of areA in the regulation of the nitrogen metabolism of A. flavus, and consequently aims at providing new ways for controlling the crossover pathogen, A. flavus.

scholarly journals Inhibitory effect of the essential oil of Curcuma longa L. and curcumin on aflatoxin production by Aspergillus flavus Link

2013 ◽  
Vol 136 (2) ◽  
pp. 789-793 ◽  
Author(s):  
Flavio Dias Ferreira ◽  
Carlos Kemmelmeier ◽  
Carla Cristina Arrotéia ◽  
Christiane Luciana da Costa ◽  
Carlos Augusto Mallmann ◽  
...  
Keyword(s):  
Essential Oil ◽  
Aspergillus Flavus ◽  
Curcuma Longa ◽  
Aflatoxin Production ◽  
Inhibitory Effect

scholarly journals A Corn Trypsin Inhibitor with Antifungal Activity Inhibits Aspergillus flavus α-Amylase

1999 ◽  
Vol 89 (10) ◽  
pp. 902-907 ◽  
Author(s):  
Z.-Y. Chen ◽  
R. L. Brown ◽  
J. S. Russin ◽  
A. R. Lax ◽  
T. E. Cleveland
Keyword(s):  
Aspergillus Flavus ◽  
Trypsin Inhibitor ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Inhibitory Effect ◽  
Starch Metabolism ◽  
Potato Dextrose Broth ◽  
The Relationship ◽  
Corn Trypsin Inhibitor

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.

scholarly journals Aspergillus flavus Infection and Aflatoxin Production in Corn: Influence of Trace Elements

1974 ◽  
Vol 28 (5) ◽  
pp. 763-767 ◽  
Author(s):  
E. B. Lillehoj ◽  
W. J. Garcia ◽  
M. Lambrow
Keyword(s):  
Trace Elements ◽  
Aspergillus Flavus ◽  
Aflatoxin Production

scholarly journals Aspergillus flavus and Aflatoxin Contamination of Leguminous Trees of the Sonoran Desert in Arizona

2001 ◽  
Vol 91 (9) ◽  
pp. 913-919 ◽  
Author(s):  
María L. Boyd ◽  
Peter J. Cotty
Keyword(s):  
Aspergillus Flavus ◽  
Sonoran Desert ◽  
Aflatoxin Production ◽  
Common Species ◽  
Aflatoxin Contamination ◽  
Leguminous Trees ◽  
Significant Growth ◽  
Tree Legumes ◽  
Aflatoxin B

Aspergillus spp. in section Flavi were frequently associated with desert tree legumes in uncultivated areas of the Sonoran Desert. Of 270 samples of debris and fruits of mesquite (Prosopis spp.), ironwood (Olneya tesota), acacia (Acacia spp.), and palo verde (Cercidium and Parkinsonia spp.), 87% were positive for A. flavus (S and L strains) and A. tamarii. A. flavus was the most common species (87%) among the 3,763 isolates examined. Mesquite pods were both the substrate from which A. flavus was recovered most frequently and the substrate from native habitats with the greatest aflatoxin content. In vitro, most desert legumes supported significant growth, reproduction, and aflatoxin production by A. flavus, with mesquite pods yielding 1 × 1010 propagules/g and 5,000 μg/kg of aflatoxin B1. Twenty percent of legume pods collected in the desert contained measurable quantities of aflatoxin, ranging from 1 to >2,500 μg/kg. Insect-damaged mesquite pods had significantly higher aflatoxin than intact pods. Legumes are apparently important reservoirs of aflatoxin-producing fungi and significant sources of aflatoxin contamination in the native Sonoran Desert habitats of Arizona.

Growth and aflatoxin production of an Italian strain of Aspergillus flavus: influence of ecological factors and nutritional substrates

2011 ◽  
Vol 4 (4) ◽  
pp. 425-432 ◽  
Author(s):  
P. Giorni ◽  
N. Magan ◽  
A. Pietri ◽  
P. Battilani
Keyword(s):  
Predictive Model ◽  
Aspergillus Flavus ◽  
Growth Rates ◽  
Fungal Growth ◽  
Ecological Factors ◽  
Quantitative Relationship ◽  
Aflatoxin Production ◽  
Optimum Temperature ◽  
Ripening Stages ◽  
Aflatoxin B

The aim of this study was to define quantitative relationships between temperature and water activity (aw), fungal growth and aflatoxin B1 (AFB1) production. A strain of Aspergillus flavus isolated from maize in north Italy, and previously tested and found positive for AFB1 production, was used for these experiments. The optimum temperature for AFB1 production was at 25 °C, slightly lower with respect to results obtained in other countries. 0.83 aw was the limit for growth of this strain of A. flavus after 60 days incubation at the optimum temperature. The solutes used to modify aw, glycerol and NaCl, influenced both growth and secondary metabolite production. Media modified with glycerol resulted in more AFB1 production when compared to the non-ionic solute NaCl added media. Maize based media, prepared with flour obtained from kernels at different ripening stages, only slightly influenced growth rates of A. flavus. The quantitative relationship obtained between fungal growth and AFB1 production in diverse temperature and aw levels were used to develop a valid predictive model for A. flavus presence and AFB1 production in the field.

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