scholarly journals Mimosa tenuiflora Aqueous Extract: Role of Condensed Tannins in Anti-Aflatoxin B1 Activity in Aspergillus flavus

Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 391
Author(s):  
Christopher Hernandez ◽  
Laura Cadenillas ◽  
Anwar El Maghubi ◽  
Isaura Caceres ◽  
Vanessa Durrieu ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Aqueous Extract ◽  
Aflatoxin B1 ◽  
Condensed Tannins ◽  
Fungal Growth ◽  
Oxidation Reactions ◽  
Expression Of Genes ◽  
Dependent Inhibition ◽  
Interesting Candidate ◽  
Mimosa Tenuiflora

Aflatoxin B1 (AFB1) is a potent carcinogenic mycotoxin that contaminates numerous crops pre- and post-harvest. To protect foods and feeds from such toxins without resorting to pesticides, the use of plant extracts has been increasingly studied. The most interesting candidate plants are those with strong antioxidative activity because oxidation reactions may interfere with AFB1 production. The present study investigates how an aqueous extract of Mimosa tenuiflora bark affects both the growth of Aspergillus flavus and AFB1 production. The results reveal a dose-dependent inhibition of toxin synthesis with no impact on fungal growth. AFB1 inhibition is related to a down-modulation of the cluster genes of the biosynthetic pathway and especially to the two internal regulators aflR and aflS. Its strong anti-oxidative activity also allows the aqueous extract to modulate the expression of genes involved in fungal oxidative-stress response, such as msnA, mtfA, atfA, or sod1. Finally, a bio-guided fractionation of the aqueous extract demonstrates that condensed tannins play a major role in the anti-aflatoxin activity of Mimosa tenuiflora bark.

scholarly journals A Caleosin-Like Protein with Peroxygenase Activity Mediates Aspergillus flavus Development, Aflatoxin Accumulation, and Seed Infection

2015 ◽  
Vol 81 (18) ◽  
pp. 6129-6144 ◽  
Author(s):  
Abdulsamie Hanano ◽  
Ibrahem Almousally ◽  
Mouhnad Shaban ◽  
Elizabeth Blee
Keyword(s):  
Fatty Acid ◽  
Aspergillus Flavus ◽  
Polyunsaturated Fatty Acid ◽  
Calcium Binding ◽  
Antioxidant Activities ◽  
Fungal Growth ◽  
Oxidation Reactions ◽  
Content Type ◽  
Fatty Acid Hydroperoxides

ABSTRACTCaleosins are a small family of calcium-binding proteins endowed with peroxygenase activity in plants. Caleosin-like genes are present in fungi; however, their functions have not been reported yet. In this work, we identify a plant caleosin-like protein inAspergillus flavusthat is highly expressed during the early stages of spore germination. A recombinant purified 32-kDa caleosin-like protein supported peroxygenase activities, including co-oxidation reactions and reduction of polyunsaturated fatty acid hydroperoxides. Deletion of the caleosin gene prevented fungal development. Alternatively, silencing of the gene led to the increased accumulation of endogenous polyunsaturated fatty acid hydroperoxides and antioxidant activities but to a reduction of fungal growth and conidium formation. Two key genes of the aflatoxin biosynthesis pathway,aflRandaflD, were downregulated in the strains in whichA. flavusPXG(AfPXG) was silenced, leading to reduced aflatoxin B1 productionin vitro. Application of caleosin/peroxygenase-derived oxylipins restored the wild-type phenotype in the strains in whichAfPXGwas silenced.PXG-deficientA. flavusstrains were severely compromised in their capacity to infect maize seeds and to produce aflatoxin. Our results uncover a new branch of the fungal oxylipin pathway and may lead to the development of novel targets for controlling fungal disease.

scholarly journals Streptomyces roseolus, A Promising Biocontrol Agent Against Aspergillus flavus, the Main Aflatoxin B1 Producer

Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 442 ◽  
Author(s):  
Isaura Caceres ◽  
Selma Snini ◽  
Olivier Puel ◽  
Florence Mathieu
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Biocontrol Agent ◽  
Cyclopiazonic Acid ◽  
Over Expression ◽  
Expression Of Genes ◽  
B1 Gene ◽  
Genes Encoding ◽  
Molecular Mechanism Of Action ◽  
Potential Use

Crop contamination by aflatoxin B1 is a current problem in tropical and subtropical regions. In the future, this contamination risk may be expanded to European countries due to climate change. The development of alternative strategies to prevent mycotoxin contamination that further contribute to the substitution of phytopharmaceutical products are thus needed. For this, a promising method resides in the use of biocontrol agents. Several actinobacteria strains have demonstrated to effectively reduce the aflatoxin B1 concentration. Nevertheless, the molecular mechanism of action by which these biological agents reduce the mycotoxin concentration has not been determined. The aim of the present study was to test the potential use of Streptomyces roseolus as a biocontrol agent against aflatoxin B1 contamination. Co-cultures with Aspergillus flavus were conducted, and the molecular fungal response was investigated through analyzing the q-PCR expression of 65 genes encoding relevant fungal functions. Moreover, kojic and cyclopiazonic acid concentrations, as well as morphological fungal changes were also analyzed. The results demonstrated that reduced concentrations of aflatoxin B1 and kojic acid were respectively correlated with the down-regulation of the aflatoxin B1 gene cluster and kojR gene expression. Moreover, a fungal hypersporulated phenotype and a general over-expression of genes involved in fungal development were observed in the co-culture condition.

Analysis of Fungi on Coix (Coix lacryma-jobi) Seed and the Effect of Its Aqueous Extract on the Growth of Aspergillus flavus

2019 ◽  
Vol 82 (10) ◽  
pp. 1775-1782 ◽  
Author(s):  
XUEMEI LUO ◽  
HONGXIA LI ◽  
DAN JIANG ◽  
JIEQIN MENG ◽  
FAN ZHANG ◽  
...  
Keyword(s):  
Dna Barcoding ◽  
Aspergillus Flavus ◽  
Aqueous Extract ◽  
High Throughput Sequencing ◽  
Rhizopus Oryzae ◽  
Fungal Infections ◽  
Fungal Growth ◽  
Promoting Effect ◽  
Illumina Hiseq ◽  
Coix Seed

ABSTRACT Coix (Coix lacryma-jobi) seeds are susceptible to fungal infections, making their surface fungi complex and diverse. Some fungi can produce mycotoxins under suitable conditions, and fungal growth is closely related to the production of mycotoxins. In this study, the surface fungi of coix seed were identified by Illumina HiSeq high-throughput sequencing. Simultaneously, the fungi cultured by the plate method were identified by microscopy and DNA barcoding; finally, the species of fungi were identified accurately and reliably by combining three methods. The aqueous extract of coix seed was cocultured with Aspergillus flavus spores, and the relationship between the aqueous extract and the growth of A. flavus was studied with the dry weight of mycelium as an indicator. The results showed that there were 89 genera and 96 species of fungi on coix seed, which were mainly distributed in Ascomycota (81.48%) and Basidiomycota (4.08%), and Xeromyces (8.50%), Gibberella (7.25%), and Aspergillus (4.74%) were the predominant genera. Four fungi were isolated from coix seed by plate culture and identified as Aspergillus fumigatus, A. flavus, Aspergillus oryzae, and Rhizopus oryzae by microscopy and DNA barcoding. The aqueous extract of coix seed at low concentrations has a promoting effect on the growth of A. flavus. When the concentration is 3.125%, the promotion effect is the most pronounced, and the promotion rate is 29.17%. These results reveal the diversity of fungi on the coix seed, which can provide a reference for the prevention and control of harmful fungi on coix seed.

scholarly journals Activity of the aqueous extract from Polymnia sonchifolia leaves on growth and production of aflatoxin B1 by Aspergillus flavus

2001 ◽  
Vol 32 (2) ◽  
Author(s):  
Marina M. Pinto ◽  
Edlayne Gonçalez ◽  
Maria H. Rossi ◽  
Joana D. Felício ◽  
Cláudia S. Medina ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Aqueous Extract ◽  
Aflatoxin B1

Fungal Growth and Aflatoxin Production on Apiarian Substrates

1977 ◽  
Vol 60 (1) ◽  
pp. 96-99
Author(s):  
Jo Ann L Hilldrup ◽  
Thomas Eadie ◽  
Gerald C Llewellyn
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Brood Comb

Abstract Unprocessed honey, Lilium longiflorium pollen, brood comb, whole larvae, and whole bees were inoculated with Aspergillus flavus NRRL 3251, A. flavus ATCC 15548, and A. parasiticus NRRL 2999. The fungi grew, sporulated, and produced various amounts of aflatoxin on all substrates except the unprocessed honey. The largest quantity of aflatoxin B1 was produced on whole larvae supporting A. flavus NRRL 3251 growth. A. parasiticus NRRL 2999 growing on whole larvae produced the most aflatoxin G1. Aflatoxins B2 and G2 were seldom detected. Apiarian substrates with the exception of honey seem capable of supporting fungal growth and resultant aflatoxin production.

scholarly journals Chemical Composition and Antifungal Activity of Ocimum basilicum L. Essential Oil

2015 ◽  
Vol 3 (3) ◽  
pp. 374-379 ◽  
Author(s):  
Neveen Helmy Abou El-Soud ◽  
Mohamed Deabes ◽  
Lamia Abou El-Kassem ◽  
Mona Khalil
Keyword(s):  
Chemical Composition ◽  
Antifungal Activity ◽  
Essential Oil ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Fungal Growth ◽  
Ocimum Basilicum ◽  
Growth Media ◽  
Oil Concentration

BACKGROUND: The leaves of Ocimum basilicum L. (basil) are used in traditional cuisine as spices; its essential oil has found a wide application in perfumery, dental products as well as antifungal agents.AIM: To assess the chemical composition as well as the in vitro antifungal activity of O. basilicum L. essential oil against Aspergillus flavus fungal growth and aflatoxin B1 production.MATERIAL AND METHODS: The essential oil of O. basilicum was obtained by hydrodistillation and analysed using gas chromatography (GC) and GC coupled with mass spectrometry (GC/MS). The essential oil was tested for its effects on Aspergillus flavus (A. flavus) mycelial growth and aflatoxin B1 production in Yeast Extract Sucrose (YES) growth media. Aflatoxin B1 production was determined by high performance liquid chromatography (HPLC).RESULTS: Nineteen compounds, representing 96.7% of the total oil were identified. The main components were as follows: linalool (48.4%), 1,8-cineol (12.2%), eugenol (6.6%), methyl cinnamate (6.2%), α-cubebene (5.7%), caryophyllene (2.5%), β-ocimene (2.1%) and α-farnesene (2.0%).The tested oil showed significant antifungal activity that was dependent on the used oil concentration. The complete inhibition of A. flavus growth was observed at 1000 ppm oil concentration, while marked inhibition of aflatoxin B1 production was observed at all oil concentrations tested (500, 750 and 1000 ppm).CONCLUSION: These results confirm the antifungal activities of O. basilicum L. oil and its potential use to cure mycotic infections and act as pharmaceutical preservative against A. flavus growth and aflatoxin B1 production.

scholarly journals Maize Milling and Modifying Atmospheric Conditions Limit Formation of Aflatoxin B1 by Aspergillus Flavus

2021 ◽  
Vol 12 (2) ◽  
pp. 16
Author(s):  
Benigni Alfred Temba ◽  
Gaymary George Bakari
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Fungal Growth ◽  
Health Concern ◽  
Atmospheric Conditions ◽  
Physical Status ◽  
The World ◽  
Baseline Information ◽  
Petri Dishes ◽  
Maize Kernels

Occurrence of mycotoxins in foods poses a serious health concern all over the world. Aflatoxin B1 (AFB1) is the most toxic, with widest occurrence in various foods, but mainly in cereals and nuts and its accumulation depends on substrate and environmental factors. This study investigated the how physical status (milling) of maize kernels and atmospheric conditions (aeration, moisture and temperature) affect production of aflatoxin B1 by Aspergillus flavus (ATCC 28862). Intact kernels and flour were incubated for up to 20 days in open and partially sealed petri dishes under controlled temperatures of 25 ºC, 30 ºC and 37 ºC and initial moisture contents of 27%, 22%, 18%, 15% and 12%. It was found that on average, significantly higher (p < 0.05) aflatoxin B1 level was accumulated in intact kernels (145.7 µg/kg) as compared to milled kernels (2.2 µg/kg). Also, none of the samples incubated under partially sealed conditions, compared to up to 100% of the samples incubated in open atmosphere had detectable levels of aflatoxin B1 after 20 days. Fungal growth was not affected by milling or aeration, but sporulation was low at 37 ºC and high at 25 ºC and 30 ºC. The findings of this study provide baseline information on how conditions can be modified to control postharvest accumulation of aflatoxin B1 in cereals.

scholarly journals Licorice, Doum, and Banana Peel Extracts Inhibit Aspergillus flavus Growth and Suppress Metabolic Pathway of Aflatoxin B1 Production

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1587
Author(s):  
Nesrine H. Youssef ◽  
Sameer H. Qari ◽  
Saleh Matar ◽  
Najwa A. Hamad ◽  
Eldessoky S. Dessoky ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Diethyl Ether ◽  
Plant Extracts ◽  
Aflatoxin B1 ◽  
Fungal Growth ◽  
Dry Weight ◽  
Banana Peel ◽  
Total Phenolic ◽  
Dry Extract ◽  
Promising Source

Three different concentrations of four (ethanol, acetone, methanol, and diethyl ether) extracts of licorice, doum, and banana peel were evaluated for antifungal and antimycotoxigenic efficiency against a maize aflatoxigenic fungus, Aspergillus flavus. Among them, the licorice diethyl ether 75% extract was intensely active, showing the best wet and dry weight inhibition and exhibiting the highest efficacy ratio (91%). Regarding aflatoxin B1 (AFB1) production, all the plant extracts tested were effective against AFB1 production after one month of maize storage, with average efficacy ratios ranging from 74.1% to 97.5%. At the same time, Thiram fungicide exhibited an efficacy ratio of 20.14%. The relative expression levels of three structural genes (aflD, aflP, and aflQ) and two regulatory genes (aflR and aflS) were significantly downregulated when compared to untreated maize grains or Thiram-treated maize grains. The doum diethyl ether 75% peel extract showed the highest total phenolic content (60.48 mg GAE/g dry extract wt.) and antioxidant activity (84.71 μg/mL). GC–MS analysis revealed that dimethoxycinnamic acid, aspartic acid, valproic acid, and linoleic acid might imbue the extracts with antioxidant capacities in relation to fungal growth and aflatoxin biosynthesis. Finally, the results suggest that the three plant extracts can be considered a promising source for developing potentially effective and environmentally safer alternative ways to control aflatoxin formation, thus creating a potentially protective method for grain storage.

scholarly journals Antifungal and Antiaflatoxigenic Activities of 1,8-Cineole and t-Cinnamaldehyde on Aspergillus flavus

2018 ◽  
Vol 8 (9) ◽  
pp. 1655 ◽  
Author(s):  
Hyeong-Mi Kim ◽  
Hyunwoo Kwon ◽  
Kyeongsoon Kim ◽  
Sung-Eun Lee
Keyword(s):  
Propionic Acid ◽  
Aspergillus Flavus ◽  
Growth Medium ◽  
Aflatoxin B1 ◽  
Mode Of Action ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Inhibitory Effects ◽  
Aflatoxin B2

Aspergillus flavus and A. parsiticus produce aflatoxins that are highly toxic to mammals and birds. In this study, the inhibitory effects of 1,8-cineole and t-cinnamaldehyde were examined on the growth of Aspergillus flavus ATCC 22546 and aflatoxin production. 1,8-Cineole showed 50% inhibition of fungal growth at a concentration of 250 ppm, while t-cinnamaldehyde almost completely inhibited fungal growth at a concentration of 50 ppm. Furthermore, no fungal growth was observed when the growth medium was treated with 100 ppm t-cinnamaldehyde. 1,8-Cineole also exhibited 50% inhibition on the production of aflatoxin B1 and aflatoxin B2 at a concentration of 100 ppm, while the addition of 100 ppm t-cinnamaldehyde completely inhibited aflatoxin production. These antiaflatoxigenic activities were related to a dramatic downregulation of the expression of aflE and aflL by 1,8-cineole, but the mode of action for t-cinnamaldehyde was unclear. Collectively, our results suggest that both of the compounds are promising alternatives to the currently used disinfectant, propionic acid, for food and feedstuff preservation.

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