Bioautographic detection of T-2 and HT-2 toxins

Biological detoxification of fungal toxins and its use in plant breeding, feed and food production

Enzymatic inactivation of fungal toxins is an attractive strategy for the decontamination of agricultural commodities and for the protection of crops from phytotoxic effects of fungal metabolites. This review summarizes research on the biological detoxification of fungal toxins by microorganisms and plants and its practical applications. Some mycotoxins are detoxified during ensiling and other fermentation processes (aflatoxins, alternariol, mycophenolic acid, patulin, PR toxin) while others are transformed into toxic products or survive fermentation unchanged. Plants can detoxify fomannoxin, fusaric acid, HC-toxin, ochratoxin A and oxalate but the degradation of deoxynivalenol has yet to be proven. Microflora of the digestive tract of vertebrates and invertebrates exhibit detoxification activities towards aflatoxins, ochratoxin A, oxalate and trichothecenes. Some toxin-producing fungi are able to degrade or transform their own products under suitable conditions. Pure cultures of bacteria and fungi which detoxify mycotoxins have been isolated from complex microbial populations by screening and enrichment culture techniques. Genes responsible for some of the detoxification activities have been cloned and expressed in heterologous hosts. The detoxification of aflatoxins, cercosporin, fumonisins, fusaric acid, ochratoxin A, oxalic acid, patulin, trichothecenes and zearalenone by pure cultures is reviewed. Finally, current application of these results in food and feed production and plant breeding is summarized and expected future developments are outlined.

Detection of sub-nanogram quantities of Mojave toxin via enzyme immunoassay with light addressable potentiometric detector

Sensitive detection of Mojave toxin (MoTX), a potent neurotoxin isolated from the venom of Crotalus scutulatus scutulatus, was developed using an enzyme immunoassay (EIA) and light addressable potentiometric detection. This EIA utilizes both biotin- and fluorescein-labeled anti-MoTX antibodies to immobilize and detect sub-nanogram to nanogram quantities of toxin. Labeled mono- and polyclonal anti-MoTX antibodies were used alone and/or in combination to determine maximum assay sensitivity. Assays performed using a combination of biotinylated poly- and fluoresceinated monoclonal antibodies produced an assay with a lower detection limit near 2.5 ng. Assays performed using labeled polyclonals alone, or in combination with biotinylated mono- and fluoresceinated polyclonal antibodies, indicated increased sensitivity with a detection limit near 300 pg. In conclusion, we describe an enzyme immunoassay using different labeled antibody schemes which detects sub-nanogram quantities of MoTX via light addressable potentiometric detection.

Chromatographic methods as tools in the field of mycotoxins

Achievements in the applications of chromatographic techniques in mycotoxicology are reviewed. Historically, column chromatography (CC) and paper chromatography (PC) were applied first, followed by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and gas chromatography (GC). Although PC techniques are no longer used in the analysis of mycotoxins, selected applications of PC are included to underline historical continuity. The most important achievements published from 1980 onwards are described. They include clean-up methods, TLC, CC, HPLC and GC of mycotoxins in environmental samples, foods, feeds, body fluids and in studies on biosynthesis and biotransformations of mycotoxins. Advantages and disadvantages of chromatographic techniques used in mycotoxicology are also evaluated.