Fungal degradation of aflatoxin B1

Abstract

A number of fungal cultures were screened to select an organism suitable to be used in the detoxification of aflatoxin B1. They were co-cultured in Czapek-Dox-Casamino acid medium with aflatoxin B1 producing Aspergillus flavus. Several fungal cultures were found to prevent synthesis of aflatoxin B1 in liquid culture medium. Among these Phoma sp., Mucor sp., Trichoderma harzianum, Trichoderma sp. 639, Rhizopus sp. 663, Rhizopus sp. 710, Rhizopus sp. 668, Alternaria sp. and some strains belonging to the Sporotrichum group (ADA IV B14(a), ADA SF VI BF (9), strain 720) could inhibit aflatoxin synthesis by > or =90%. A few fungi, namely ADA IV B1, ADA F1, ADA F8, also belonging to the Sporotrichum group, were less efficient than the Phoma sp. The Cladosporium sp. and A. terreus sp. were by far the least efficient, registering <10% inhibition. The cultures which prevent aflatoxin biosynthesis are also capable of degrading the preformed toxin. Among these, Phoma sp. was the most efficient destroying about 99% of aflatoxin B1. The cell free extract of Phoma sp. destroyed nearly 50 microg aflatoxin B1 100 ml(-1) culture medium (90% of the added toxin), and this was more effective than its own culture filtrate over 5 days incubation at 28+/-2 degrees C. The degradation was gradual: 35% at 24 h, 58% at 48 h, 65% at 72 h, 85% at 96 h and 90% at 120 h. The possibility of a heat stable enzymatic activity in the cell free extract of Phoma is proposed.

Strategies to Prevent Mycotoxin Contamination of Food and Animal Feed: A Review

“…SF, and Alternaria sp. have been shown to degrade AFB 1 to levels between 65% and 99% in 5 days at 28 ± 2 • C. 119 Similarly, Varga et al 231 reported the ability of various Aspergillus strains such as A. fumigatus, A. japonicus, and A. niger to degrade OTA in liquid YES media, with A. niger degrading OTA to ochratoxin-α and phenylalanine in solid media and liquid cultures. Additionally, Acinetobacter calcoaceticus has been shown to degrade 100% of OTA in ethanol minimal salts medium at an initial OTA concentration of 10 µg ml −1 at 30 • C within 120 h. 232 Various fermentation processes have also been shown to result in reducing the toxic effects of mycotoxins.…”

Detoxification of aflatoxins by seed extracts of the medicinal plant, Trachyspermum ammi (L.) Sprague ex Turrill – Structural analysis and biological toxicity of degradation product of aflatoxin G1

“…(Cole & Kirksey, 1971), Corynebacterium rubrum (Mann & Rehm, 1976), Phoma sp. (Shantha, 1999), Rhodococcus erythropolis and Mycobacterium fluoranthenivorans sp. nov (Teniola et al, 2005) and nontoxigenic strains of A. flavus and A. parasiticus (Dorner et al, 2003) and physical detoxification of aflatoxins by hydrated sodium calcium aluminosilicate (Harvey et al, 1989;Phillips, Kubena, Harvey, Taylor, & Heidelbaugh, 1988).…”

Mycotoxins

“…and Aspergillus fl avus followed by A. chevalieri Thom & Church, A. fumigatus, Penicillium spp. Other factors affecting mycotoxin concentration include microbial genetics, minimum climatic conditions (moisture content, temperature), substrate, variations within species, the presence of other fungal species, 25 and the geographic distribution of mycotoxin -producing fungi. Link, and Basipetospora species.…”