Behaviour of Aspergillus flavus in presence of Aspergillus niger during biosynthesis of aflatoxin B1

1990 ◽  
Vol 58 (2) ◽  
pp. 121-127 ◽  
Author(s):  
T. Shantha ◽  
E. R. Rati ◽  
T. N. Bhavani Shankar
Keyword(s):  
Aspergillus Niger ◽  
Aspergillus Flavus ◽  
Aflatoxin B1

scholarly journals Detection of aflatoxin producing Aspergillus flavus from animal feed in Karnataka, India.

2021 ◽  
Vol 36 (3) ◽  
pp. e2021017
Author(s):  
Pethannan Rajarajan ◽  
Katherin Sylvia ◽  
Malaiyarasa Pandian Periasamy ◽  
Maheswari Subramanian
Keyword(s):  
Aspergillus Niger ◽  
Secondary Metabolite ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Liquid Ammonia ◽  
Animal Feed ◽  
Average Concentration ◽  
Aflatoxin Contamination ◽  
Ammonia Vapor ◽  
Karnataka State

Aflatoxins are toxic carcinogenic secondary metabolite produced by Aspergillus flavus and are responsible for contamination in animal feed. The aim of the study was to determine the prevalence of aflatoxin contamination in animal feed in Karnataka state, India. The screening was performed by desiccated coconut agar and quantification of aflatoxin by liquid ammonia vapor test, TLC and ELISA. A total of 29 samples received from different places of Karnataka were analysed for aflatoxin B1. Out of 29 animal feed sample aflatoxin B1 detected in 12 samples representing 41.38% at average concentration of 288.50 μg/kg. Out of 42 isolates screened in animal feed, Aspergillus flavus was found to be in 86.2% and Aspergillus niger was 24.1%. It was observed that out of 42 isolates analyzed from animal feed, aflatoxin B1 was detected in 12 samples. Aflatoxin B1 is the most common contaminant and the method is more sensitive in screening and detection of aflatoxin B1 in the animal feed.

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 Impacts of Climate Change Interacting Abiotic Factors on Growth, aflD and aflR Gene Expression and Aflatoxin B1 Production by Aspergillus flavus Strains In Vitro and on Pistachio Nuts

Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 385
Author(s):  
Alaa Baazeem ◽  
Alicia Rodriguez ◽  
Angel Medina ◽  
Naresh Magan
Keyword(s):  
Climate Change ◽  
Gene Expression ◽  
Water Stress ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Abiotic Factors ◽  
Pistachio Nuts ◽  
Significant Difference ◽  
Spoilage Fungi

Pistachio nuts are an important economic tree nut crop which is used directly or processed for many food-related activities. They can become colonized by mycotoxigenic spoilage fungi, especially Aspergillus flavus, mainly resulting in contamination with aflatoxins (AFs), especially aflatoxin B1 (AFB1). The prevailing climate in which these crops are grown changes as temperature and atmospheric CO2 levels increase, and episodes of extreme wet/dry cycles occur due to human industrial activity. The objectives of this study were to evaluate the effect of interacting Climate Change (CC)-related abiotic factors of temperature (35 vs. 37 °C), CO2 (400 vs. 1000 ppm), and water stress (0.98–0.93 water activity, aw) on (a) growth (b) aflD and aflR biosynthetic gene expression and (c) AFB1 production by two strains A. flavus (AB3, AB10) in vitro on milled pistachio-based media and when colonizing layers of shelled raw pistachio nuts. The A. flavus strains were resilient in terms of growth on pistachio-based media and the colonisation of pistachio nuts with no significant difference when exposed to the interacting three-way climate-related abiotic factors. However, in vitro studies showed that AFB1 production was significantly stimulated (p < 0.05), especially when exposed to 1000 ppm CO2 at 0.98–0.95 aw and 35 °C, and sometimes in the 37 °C treatment group at 0.98 aw. The relative expression of the structural aflD gene involved in AFB1 biosynthesis was decreased or only slightly increased, relative to the control conditions at elevated CO, regardless of the aw level examined. For the regulatory aflR gene expression, there was a significant (p < 0.05) increase in 1000 ppm CO2 and 37 °C for both strains, especially at 0.95 aw. The in situ colonization of pistachio nuts resulted in a significant (p < 0.05) stimulation of AFB1 production at 35 °C and 1000 ppm CO2 for both strains, especially at 0.98 aw. At 37 °C, AFB1 production was either decreased, in strain AB3, or remained similar, as in strain AB10, when exposed to 1000 ppm CO2. This suggests that CC factors may have a differential effect, depending on the interacting conditions of temperature, exposure to CO2 and the level of water stress on AFB1 production.

scholarly journals Production of aflatoxins and aflatoxicols by Aspergillus flavus and Aspergillus parasiticus and metabolism of aflatoxin B1 by aflatoxin-non-producing Aspergillus flavus.

Eisei kagaku ◽  
1991 ◽  
Vol 37 (2) ◽  
pp. 107-116 ◽  
Author(s):  
MITSUO NAKAZATO ◽  
SATOSHI MOROZUMI ◽  
KAZUO SAITO ◽  
KENJI FUJINUMA ◽  
TAICHIRO NISHIMA ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Aspergillus Parasiticus

EVALUATION OF SUSCEPTIBILITY OF PISTACHIO CULTIVARS TO AFLATOXIGENIC ASPERGILLUS FLAVUS AND AFLATOXIN B1 PRODUCTION

2006 ◽  
pp. 655-658 ◽  
Author(s):  
M.M. Moghaddam ◽  
E.M. Goltapeh ◽  
H. Hokmabadi ◽  
M. Haghdel ◽  
A.M. Mortazavi
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin B1

Mycoflora in Commercial Pet Foods

2001 ◽  
Vol 64 (5) ◽  
pp. 741-743 ◽  
Author(s):  
DANTE J. BUENO ◽  
JULIO O. SILVA ◽  
GUILLERMO OLIVER
Keyword(s):  
Aspergillus Niger ◽  
Moisture Content ◽  
Aspergillus Flavus ◽  
Aspergillus Terreus ◽  
Animal Health ◽  
Mold Growth ◽  
Mucor Racemosus ◽  
Isolation Frequency ◽  
Mycelia Sterilia ◽  
Made In

This article reports on the identification of mycoflora of 21 dry pet foods (12 belonging to dogs and 9 to cats) that corresponded to 8 commercial brands made in Argentina and imported. The isolation frequency and relative density of the prevalent fungal genera are compared too. Ten genera and fungi classified as Mycelia sterilia were identified. The predominant genera were Aspergillus (62%), Rhizopus (48%), and Mucor (38%). The most prevalent among Aspergillus was Aspergillus flavus followed by Aspergillus niger and Aspergillus terreus. The predominant Mucor was Mucor racemosus followed by Mucor plumbeus and Mucor globosus. The moisture content of these foods ranged from 5.6 to 10.0% and from 7.2 to 9.9% for dog and cat foods, respectively. A greater moisture content in food for the senior category (9.5 ± 0.2) was observed only in comparison to adult and kitten/puppy. If the moisture content can be maintained at these levels, mold growth would be prevented or at least it would remain at an insignificant level. Some genera and species isolated and identified from the foods analyzed are potentially producing toxins, which are known as mycotoxins. This involves a risk for animal health.

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.

scholarly journals Fullerol C60(OH)24 nanoparticles modulate aflatoxin B1 biosynthesis in Aspergillus flavus

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Tihomir Kovač ◽  
Ivana Borišev ◽  
Biljana Crevar ◽  
Frane Čačić Kenjerić ◽  
Marija Kovač ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin B1
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