Antimicrobial activity of aflatoxins.

Journal of Bacteriology (Impact Factor: 3.19). 02/1967; 93(1):59-64.
Source: PubMed

ABSTRACT Antimicrobial activity of a crude aflatoxin preparation and of aflatoxin B(1) was studied. They were found inactive against common gram-positive and gram-negative bacteria at a concentration of 100 mug/ml. Both samples of aflatoxin did, however, exhibit antimicrobial activity, though narrow and limited, against various strains of Streptomyces and Nocardia. The antibiotic action of aflatoxin B(1) was confirmed by bioautogram after thin-layer chromatography. Among seven strains of microorganisms, including aflatoxin-sensitive and -resistant strains, N. asteroides IFM 8 was found to reduce aflatoxin B(1), in addition to other minor fluorescent components in the crude preparation.

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    ABSTRACT: The degradation of aflatoxin B1 by various representatives of bacteria, yeasts and moulds in growing and resting cultures was investigated. We found that growing cultures of Corynebacterium rubrum degraded the added aflatoxin nearly quantitatively. -- Growing cultures of anascosporogenous yeasts degraded most of aflatoxin B1 while no degradation of this substance by ascosporogenous yeasts could be stated. Moulds degraded aflatoxin B1 to a high extent. -- With regard to the course of degradation three types can be distinguished. -- In the cultures of moulds two blue fluorescing compounds were found beside aflatoxin B1.
    Zeitschrift für Le0bensmittel-Untersuchung und -Forschung 02/1977; 163(1):39-43.
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    ABSTRACT: Aflatoxins are cancerogenic compounds produced predominantly by certain strains of the Aspergillus genus. The ideal solution for minimization of health risk that aflatoxins pose is the prevention of foods and feeds contamination. Unfortunately, these contaminants can never be completely removed, and on that account, many studies have been carried out to explore an effective process of their detoxification to a threshold level. Biological decontamination seems to be attractive because it works under mild, environmentally friendly conditions. This review is focused on the biological detoxification of aflatoxins, especially aflatoxin B1, by microorganisms. There are briefly mentioned aflatoxin metabolic pathways in the human and animal body. Microorganisms such as soil or water bacteria, fungi, and protozoa and specific enzymes isolated from microbial systems can degrade aflatoxin group members with varied efficiency to less- or nontoxic products. Some aflatoxin-producing fungi from Aspergillus species have the capability to degrade their own synthesized mycotoxins. Yeasts and lactic acid bacteria work as biological adsorbents that prevent aflatoxin's transfer to the intestinal tract of humans and animals. Aflatoxin B1 absorbed into the organism could be metabolized by significantly different pathways. They lead to the production of the relatively nontoxic compounds, on the one hand, or to highly toxic active forms on the other hand.
    Drug Metabolism Reviews 02/2009; 41(1):1-7. · 5.54 Impact Factor
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    ABSTRACT: Trichothecenes are a group of mycotoxins mainly produced by the fungi of Fusarium genus. Consumers are particularly concerned over the toxicity and food safety of trichothecenes and their metabolites from food-producing animals. The metabolism of T-2 toxin, deoxynivalenol (DON), nivalenol (NIV), fusarenon-X (FX), diacetoxyscirpenol (DAS), 3-acetyldeoxy-nivalenol (3-aDON), and 15-acetyldeoxynivalenol (15-aDON) in rodents, swine, ruminants, poultry, and humans are reviewed in this article. Metabolic pathways of these mycotoxins are very different. The major metabolic pathways of T-2 toxin in animals are hydrolysis, hydroxylation, de-epoxidation, and conjugation. After being transformed to HT-2 toxin, it undergoes further hydroxylation at C-3' to yield 3'-hydroxy-HT-2 toxin, which is considered as an activation pathway, whereas transformation from T-2 to T-2 tetraol is an inactivation pathway in animals. The typical metabolites of T-2 toxin in animals are HT-2 toxin, T-2 triol, T-2 tetraol, neosolaniol (NEO), 3'-hydroxy-HT-2, and 3'-hydroxy-T-2, whereas HT-2 toxin is the main metabolite in humans. De-epoxidation is an important pathway for detoxification in animals. De-epoxy products, DOM-1, and de-epoxy-NIV are the main metabolites of DON and NIV in most animals, respectively. However, the two metabolites are not found in humans. Deacetyl can occur rapidly on the acetyl derivatives, 3-aDON, 15-aDON, and FX. DAS is metabolized in animals to 15-monoacetoxyscirpenol (15-MAS) via C-4 deacetylation and then transformed to scirpentriol (SCP) via C-15 deacetylation. Finally, the epoxy is lost, yielding de-epoxy-SCP. De-epoxy-15-MAS is also the main metabolite of DAS. 15-MAS is the main metabolite in human skin. The review on the metabolism of trichothecenes will help one to well understand the fate of these toxins' future in animals and humans, as well as provide basic information for the risk assessment of them for food safety.
    Drug Metabolism Reviews 09/2009; 42(2):250-67. · 5.54 Impact Factor


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