A quinone-dependent dehydrogenase and two NADPH-dependent aldo/keto reductases detoxify deoxynivalenol in wheat via epimerization in a Devosia strain. (15th August 2020)

• Record Type: Journal Article
• Authors: He, Wei-Jie; Shi, Meng-Meng; Yang, Peng; Huang, Tao; Zhao, Yue; Wu, Ai-Bo; Dong, Wu-Bei; Li, He-Ping; Zhang, Jing-Bo; Liao, Yu-Cai
• Is Part Of: Food chemistry. Volume 321(2020)
• Publication Date: 2020-08-15
• Subjects: Deoxynivalenol (PubChem CID 40024) -- 3-epi-deoxynivalenol (PubChem CID 13456592) -- Pyrroloquinoline quinone (PubChem CID 1024) -- NADPH (PubChem CID 5884); 3-epi-DON 3-epi-deoxynivalenol -- 3-keto-DON 3-keto-deoxynivalenol -- AKR Aldo/keto reductase -- DH Dehydrogenases -- DI Deionized water -- DON Deoxynivalenol -- DW Dry weight -- FHB Fusarium head blight -- GC–MS Gas chromatography-mass spectrometry -- HPLC High performance liquid chromatography -- IPTG isopropyl-β-D-thiogalactopyranoside -- kb kilobase -- kD kilo-Dalton -- MM Minimum media -- NA Nutrient agar -- NADH Nicotinamide adenine dinucleotide -- NADPH Nicotinamide adenine dinucleotide phosphate -- PCR Polymerase chain reaction -- PQQ Pyrroloquinoline quinone -- QDDH Quinone-dependent DON dehydrogenase -- RPKM Reads per kilobase per million mapped reads; Deoxynivalenol epimerization -- Enzymatic detoxification -- Alcohol dehydrogenase -- Aldo/keto reductases -- Molecular docking; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2020.126703
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: The highly active DON-degrading bacterial strain Devosia sp. D6-9 was isolated. Strain D6-9 catabolized DON via epimerization to form 3-keto-DON and 3- epi -DON. A dehydrogenase and two reductases are responsible for DON detoxification in D6-9. Three recombinant enzymes efficiently degraded DON present in wheat grains. Residues S497, E499, and E535 in QDDH are essential for DON-oxidizing activity. Abstract: The Fusarium mycotoxin deoxynivalenol (DON) is typically controlled by fungicides. Here, we report DON detoxification using enzymes from the highly active Devosia strain D6-9 which degraded DON at 2.5 μg/min/10 8 cells. Strain D6-9 catabolized DON to 3-keto-DON and 3- epi -DON, completely removing DON in wheat. Genome analysis of three Devosia strains (D6-9, D17, and D13584), with strain D6-9 transcriptomes, identified three genes responsible for DON epimerization. One gene encodes a quinone-dependent DON dehydrogenase QDDH which oxidized DON into 3-keto-DON. Two genes encode the NADPH-dependent aldo/keto reductases AKR13B2 and AKR6D1 that convert 3-keto-DON into 3- epi -DON. Recombinant proteins expressed in E sch e richia coli efficiently degraded DON in wheat grains. Molecular docking and site-directed mutagenesis revealed that residues S497, E499, and E535 function in QDDH's DON-oxidizing activity. These results advance potential microbial and enzymatic elimination of DON in agricultural samples and lend insight into the underlying mechanisms and molecular evolution of DON detoxification.