A NADPH-Dependent Aldo/Keto Reductase Is Responsible for Detoxifying 3-Keto-Deoxynivalenol to 3-<i>epi</i>-Deoxynivalenol in <i>Pelagibacterium halotolerans</i> ANSP101

Abstract

Deoxynivalenol (DON), primarily generated by Fusarium species, often exists in agricultural products. It can be transformed to 3-epi-deoxynivalenol (3-epi-DON), with a relatively low toxicity, via two steps. DDH in Pelagibacterium halotolerans ANSP101 was proved to convert DON to 3-keto-deoxynivalenol (3-keto-DON). In the present research, AKR4, a NADPH-dependent aldo/keto reductase from P. halotolerans ANSP101, was identified to be capable of converting 3-keto-DON into 3-epi-DON. Our results demonstrated that AKR4 is clearly a NADPH-dependent enzyme, for its utilization of NADPH is higher than that of NADH. AKR4 functions at a range of pH 5–10 and temperatures of 20–60 °C. AKR4 is able to degrade 89% of 3-keto-DON in 90 min at pH 7 and 50 °C with NADPH as the cofactor. The discovery of AKR4, serving as an enzyme involved in the final step in DON degradation, might provide an option for the final detoxification of DON in food and feed.

Keywords

• Deoxynivalenol (DON)
• 3-keto-DON
• 3-<i>epi</i>-DON
• aldo/keto reductase
• biodegradation