Selected Publication:
Michlmayr, H; Varga, E; Malachova, A; Nguyen, NT; Lorenz, C; Haltrich, D; Berthiller, F; Adam, G; .
(2015):
A Versatile Family 3 Glycoside Hydrolase from Bifidobacterium adolescentis Hydrolyzes β-Glucosides of the Fusarium Mycotoxins Deoxynivalenol, Nivalenol, and HT-2 Toxin in Cereal Matrices.
Appl Environ Microbiol. 2015; 81(15):4885-4893
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- Abstract:
- Glycosylation plays a central role in plant defense against xenobiotics, including mycotoxins. Glucoconjugates of Fusarium toxins, such as deoxynivalenol-3-O-beta-D-glucoside (DON-3G), often cooccur with their parental toxins in cereal-based food and feed. To date, only limited information exists on the occurrence of glucosylated mycotoxins and their toxicological relevance. Due to a lack of analytical standards and the requirement of high-end analytical instrumentation for their direct determination, hydrolytic cleavage of beta-glucosides followed by analysis of the released parental toxins has been proposed as an indirect determination approach. This study compares the abilities of several fungal and recombinant bacterial beta-glucosidases to hydrolyze the model analyte DON-3G. Furthermore, substrate specificities of two fungal and two bacterial (Lactobacillus brevis and Bifidobacterium adolescentis) glycoside hydrolase family 3 beta-glucosidases were evaluated on a broader range of substrates. The purified recombinant enzyme from B. adolescentis (BaBgl) displayed high flexibility in substrate specificity and exerted the highest hydrolytic activity toward 3-O-beta-D-glucosides of the trichothecenes deoxynivalenol (DON), nivalenol, and HT-2 toxin. A K-m of 5.4 mM and a V-max of 16 mu mol min(-1) mg(-1) were determined with DON-3G. Due to low product inhibition (DON and glucose) and sufficient activity in several extracts of cereal matrices, this enzyme has the potential to be used for indirect analyses of trichothecene-beta-glucosides in cereal samples.
- Authors BOKU Wien:
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Adam Gerhard
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Berthiller Franz
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Haltrich Dietmar
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Lorenz Cindy
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Malachova Alexandra
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Michlmayr Herbert
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Varga Elisabeth
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